N-CSRS

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM N-CSR

CERTIFIED SHAREHOLDER REPORT OF REGISTERED
MANAGEMENT INVESTMENT COMPANIES

Investment Company Act file number			811-01829
Columbia Acorn Trust
(Exact name of registrant as specified in charter)
225 Franklin Street, Boston, Massachusetts					02110
(Address of principal executive offices)					(Zip code)
Scott R. Plummer 5228 Ameriprise Financial Center Minneapolis, MN 55474
(Name and address of agent for service)
Registrant’s telephone number, including area code:				1-612-671-1947
Date of fiscal year end:	December 31
Date of reporting period:		June 30, 2012

Form N-CSR is to be used by management investment companies to file reports with the Commission not later than 10 days after the transmission to stockholders of any report that is required to be transmitted to stockholders under Rule 30e-1 under the Investment Company Act of 1940 (17 CFR 270.30e-1). The Commission may use the information provided on Form N-CSR in its regulatory, disclosure review, inspection, and policymaking roles.

A registrant is required to disclose the information specified by Form N-CSR, and the Commission will make this information public. A registrant is not required to respond to the collection of information contained in Form N-CSR unless the Form displays a currently valid Office of Management and Budget ("OMB") control number. Please direct comments concerning the accuracy of the information collection burden estimate and any suggestions for reducing the burden to Secretary, Securities and Exchange Commission, 450 Fifth Street, NW, Washington, DC 20549-0609. The OMB has reviewed this collection of information under the clearance requirements of 44 U.S.C. § 3507.

Item 1. Reports to Stockholders.

Q2 2012

Columbia Acorn Family of Funds

Class Z Shares

Managed by Columbia Wanger Asset Management, LLC

Semiannual Report

June 30, 2012

n  Columbia
Acorn® Fund

n  Columbia
Acorn International®

n  Columbia
Acorn USA®

n  Columbia
Acorn International Select^SM

n  Columbia
Acorn Select^SM

n  Columbia
Thermostat Fund^SM

n  Columbia
Acorn Emerging Markets Fund^SM

n  Columbia
Acorn European Fund^SM

Not FDIC insured • No bank guarantee • May lose value

Columbia Acorn Family of Funds

Descriptions of Indexes Included in this Report

•50/50 Blended Benchmark, established by the Fund's investment manager, is an equally weighted custom composite of Columbia Thermostat Fund's primary equity and primary debt benchmarks, the S&P 500 Index and the Barclays Capital U.S. Aggregate Bond Index, respectively. The percentage of the Fund's assets allocated to underlying stock and bond portfolio funds will vary, and accordingly the composition of the Fund's portfolio will not always reflect the composition of the 50/50 Blended Benchmark.

•Barclays U.S. Aggregate Bond Index is a market value-weighted index that tracks the daily price, coupon, pay-downs and total return performance of fixed-rate, publicly placed, dollar-denominated and non-convertible investment grade debt issues with at least $250 million par amount outstanding and with at least one year to final maturity.

•HSBC Smaller European Companies (inc UK) Index is a weighted combination of two indexes: the HSBC Smaller Europe (ex UK) Index and the HSBC Smaller UK Index. The index is rebalanced on a quarterly basis.

•Lipper Indexes include the largest funds tracked by Lipper, Inc. in the named category. Lipper Mid-Cap Growth Funds Index, 30 largest mid-cap growth funds, including Columbia Acorn Fund and Columbia Acorn Select; Lipper International Small/Mid Growth Funds Index, 10 largest non-U.S. small/mid growth funds, including Columbia Acorn International; Lipper Small-Cap Growth Funds Index, 30 largest small-cap growth funds, including Columbia Acorn USA; Lipper Flexible Portfolio Funds Index, an equal-weighted index of the 30 largest mutual funds within the Flexible Portfolio fund classification, as defined by Lipper. Lipper Emerging Markets Index, 30 largest emerging markets funds; Lipper European Region Index, 10 largest European funds.

•MSCI Europe, Australasia, Far East (EAFE) Index (Net) is a capitalization-weighted index that tracks the total return of common stocks in 22 developed-market countries within Europe, Australasia and the Far East. The returns of the MSCI EAFE Index (Net) are presented net of the withholding tax rate applicable to foreign non-resident institutional investors in the foreign companies included in the index who do not benefit from double taxation treaties.

•MSCI Emerging Markets Small Cap Index, a widely recognized international benchmark, is a free float-adjusted market capitalization index that is designed to measure small-cap emerging market equity performance. The MSCI Emerging Markets Small Cap Index currently consists of the following 21 emerging market country indexes: Brazil, Chile, China, Colombia, Czech Republic, Egypt, Hungary, India, Indonesia, Korea, Malaysia, Mexico, Morocco, Peru, Philippines, Poland, Russia, South Africa, Taiwan, Thailand and Turkey.

•Russell 2000 Index measures the performance of the 2,000 smallest companies in the Russell 3000 Index, which represents approximately 10% of the total market capitalization of the Russell 3000 Index.

•Russell 2500 Index measures the performance of the 2,500 smallest companies in the Russell 3000 Index, which represents approximately 17% of the total market capitalization of the Russell 3000 Index.

•Standard & Poor's (S&P) 500 Index tracks the performance of 500 widely held, large-capitalization U.S. stocks.

•Standard & Poor's (S&P) MidCap 400 Index is a market value-weighted index that tracks the performance of 400 mid-cap U.S. companies.

•S&P Developed Ex-U.S. Between $2B and $10B Index is a subset of the broad market selected by the index sponsor representing the mid-cap developed market, excluding the United States.

•S&P Emerging Markets Between $500M and $5B Index represents the institutionally investable capital of emerging market countries with market caps ranging between $500 million to $5 billion, as selected by S&P. The index currently consists of the following 21 emerging market country indexes: Brazil, Chile, China, Colombia, Czech Republic, Egypt, Hungary, India, Indonesia, Korea, Malaysia, Mexico, Morocco, Peru, Philippines, Poland, Russia, South Africa, Taiwan, Thailand and Turkey.

•S&P Europe Between $500M and $5B Index represents the institutionally investable capital of European countries with market caps ranging between $500 million to $5 billion, as selected by S&P. The index currently consists of the following 17 developed market country indexes: Austria, Belgium, Denmark, Finland, France, Germany, Greece, Ireland, Italy, Luxembourg, the Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and the United Kingdom.

•S&P Global Ex-U.S. SmallCap Index consists of the bottom 20% of institutionally investable capital of developed and emerging countries, excluding the United States.

•S&P Global Ex-U.S. Between $500M and $5B Index is a subset of the broad market selected by the index sponsor representing the mid- and small-cap developed and emerging markets, excluding the United States.

Unlike mutual funds, indexes are not managed and do not incur fees or expenses. It is not possible to invest directly in an index.

The views expressed in the "Chattering Squirrels" and "In a Nutshell" commentaries reflect the current views of the respective authors. These views are not guarantees of future performance and involve certain risks, uncertainties and assumptions that are difficult to predict so actual outcomes and results may differ significantly from the views expressed. These views are subject to change at any time based upon economic, market or other conditions and the respective authors disclaim any responsibility to update such views. These views may not be relied upon as investment advice and, because investment decisions for a Columbia Acorn Fund are based on numerous factors, may not be relied upon as an indication of trading intent on behalf of any particular Columbia Acorn Fund. References to specific company's securities should not be construed as a recommendation or investment advice and there can be no assurance that as of the date of publication of this report, the securities mentioned in each Fund's portfolio are still held or that the securities sold have not been repurchased.

Acorn®, Acorn USA® and Acorn International® are service marks owned and registered by Columbia Acorn Trust. Columbia^SM, Columbia Management®, and the Columbia Management Logo® are service marks owned and/or registered by Ameriprise Financial, Inc.

You are invited to the 2012 Columbia Acorn Funds Shareholder Information Meeting

Join us to hear presentations by Columbia Acorn Fund's lead portfolio manager Chuck McQuaid and other members of the Columbia Wanger Asset Management investment team.

Where: Drinker Biddle & Reath LLP
191 North Wacker Drive, Suite 3700
Chicago, IL

When: Wednesday, September 19, 2012
12 p.m. CSTA buffet lunch will be served beginning at 11:30.

RSVP: 800.922.6769 by September 14, 2012

Webcast Replay: Available at columbiamanagement.com in October.

Public Transportation

For directions using public transportation, call 312.836.7000 or visit the Chicago Transit Authority website at transitchicago.com. Metra information is also available by calling this number or can be found at metrarail.com.

Parking Information

Two parking options are located on Lake Street in the same block as the meeting location, which is between N. Wacker Drive and N. Franklin Street. Lake Street runs one way east after crossing N. Wacker Drive. Hourly parking rates apply at both locations. The first, with signage stating "Public Parking" (phone: 312.267.6867), provides direct access to the building in which the meeting will be held. The second option is a "Self Park" garage (phone: 312.201.1795) located next to the first but without direct access to the building.

Driving Directions

From the south:
Take 1-57 to the Dan Ryan Expressway. Follow the signs for the Kennedy Expressway West. Travel on the Kennedy and exit using the Washington exit (Exit 51C). Turn right onto W. Washington. Proceed east on Washington until you reach Canal Street. Turn left on Canal Street. Travel on Canal to Lake Street. Turn right on Lake Street. Take Lake Street across N. Wacker Drive to the southeast corner of Lake Street and N. Wacker Drive.

From the north:
Take the Kennedy Expressway (I-90/94) south to Chicago. Exit in the city using the W. Randolph Street exit (Exit 51B). Turn right onto W. Randolph Street. Proceed west on Randolph Street until you reach N. Halsted Street. Turn right onto N. Halsted Street. Travel on Halsted to W. Lake Street. Turn right on Lake Street. Take Lake Street across N. Wacker Drive to the southeast corner of Lake Street and N. Wacker Drive.

From the west:
Take the Eisenhower Expressway (I-290) from the west. Follow the signs for the Kennedy Expressway West. Travel on the Kennedy and exit using the Washington exit (Exit 51C). Turn right onto W. Washington. Proceed east on Washington until you reach Canal Street. Turn left on Canal Street. Travel on Canal to Lake Street. Turn right on Lake Street. Take Lake Street across N. Wacker Drive to the southeast corner of Lake Street and N. Wacker Drive.

From the southwest:
Take the Stevenson Expressway (I-55). Exit to the Kennedy Expressway (North-Wisconsin). Travel on the Kennedy and exit using the Washington exit (Exit 51C). Turn right onto W. Washington. Proceed east on Washington until you reach Canal Street. Turn left on Canal Street. Travel on Canal to Lake Street. Turn right on Lake Street. Take Lake Street across N. Wacker Drive to the southeast corner of Lake Street and N. Wacker Drive.

Wacker Drive Construction

Please keep Chicago's Wacker Drive construction project in mind when planning your route. Current information on the project can be found at wackerdrive.org.

Columbia Acorn Family of Funds

Table of Contents

Performance At A Glance	1
Chattering Squirrels: Columbia Thermostat Fund Turns 10	2
Understanding Your Expenses	6
Columbia Acorn Fund
In a Nutshell	8
At a Glance	9
Major Portfolio Changes	24
Statement of Investments	26
Columbia Acorn International
In a Nutshell	10
At a Glance	11
Major Portfolio Changes	39
Statement of Investments	41
Portfolio Diversification	50
Columbia Acorn USA
In a Nutshell	12
At a Glance	13
Major Portfolio Changes	51
Statement of Investments	52
Columbia Acorn International Select
In a Nutshell	14
At a Glance	15
Major Portfolio Changes	59
Statement of Investments	60
Portfolio Diversification	64

Columbia Acorn Select
In a Nutshell	16
At a Glance	17
Major Portfolio Changes	65
Statement of Investments	66
Columbia Thermostat Fund
In a Nutshell	18
At a Glance	19
Statement of Investments	72
Columbia Acorn Emerging Markets Fund
In a Nutshell	20
At a Glance	21
Major Portfolio Changes	73
Statement of Investments	75
Portfolio Diversification	79
Columbia Acorn European Fund
In a Nutshell	22
At a Glance	23
Major Portfolio Changes	80
Statement of Investments	81
Portfolio Diversification	85
Columbia Acorn Family of Funds
Statements of Assets and Liabilities	86
Statements of Operations	88
Statements of Changes in Net Assets	90
Financial Highlights	96
Notes to Financial Statements	100
Board Approval of the Advisory Agreement	109
Columbia Acorn Family of Funds Information	113

2012 Mid-Year Distributions

The following table lists the mid-year distributions for the Columbia Acorn Funds. The record date was June 5, 2012, and the ex-dividend date and the payable date was June 6, 2012.

	Short-term Capital Gains		Long-term Capital Gains		Ordinary Income		Reinvestment Price
Columbia Acorn Fund		None	$	0.35688		None	$	29.09
Columbia Acorn International		None		None	$	0.19568	$	35.88
Columbia Acorn USA		None	$	0.05114		None	$	28.96
Columbia Acorn International Select		None	$	0.11963		None	$	26.29
Columbia Acorn Select		None	$	0.53050		None	$	24.82
Columbia Thermostat Fund		None		None	$	0.01739	$	13.26
Columbia Acorn Emerging Markets Fund		None		None	$	0.00432	$	9.83
Columbia Acorn European Fund	$	0.00458		None	$	0.01203	$	10.15

Columbia Acorn Family of Funds

Performance At A Glance Class Z Average Annual Total Returns through 6/30/12

	NAV on 6/30/12		2nd quarter*			Year to date*			1 year			5 years			10 years			Life of Fund
Columbia Acorn Fund (ACRNX) (6/10/70)	$	29.74		-5.42	%		9.23	%		-2.78	%		1.70	%		9.59	%		14.55	%
Russell 2500 Index				-4.14	%		8.31	%		-2.29	%		1.18	%		8.01	%		NA
S&P 500 Index**				-2.75	%		9.49	%		5.45	%		0.22	%		5.33	%		10.54	%
Russell 2000 Index				-3.47	%		8.53	%		-2.08	%		0.54	%		7.00	%		NA
Lipper Mid-Cap Growth Funds Index				-6.32	%		7.72	%		-5.16	%		1.61	%		7.29	%		NA
Columbia Acorn International (ACINX) (9/23/92)	$	37.10		-5.52	%		8.72	%		-9.31	%		-0.84	%		11.07	%		10.81	%
S&P Global Ex-U.S. Between $500M and $5B Index				-8.03	%		4.82	%		-15.17	%		-2.48	%		10.95	%		7.95	%
S&P Global Ex-U.S. SmallCap Index				-8.62	%		4.96	%		-16.34	%		-3.88	%		10.06	%		7.18	%
MSCI EAFE Index				-7.13	%		2.96	%		-13.83	%		-6.10	%		5.14	%		5.22	%
Lipper International Small/Mid Growth Funds Index				-6.03	%		7.68	%		-10.22	%		-2.99	%		9.65	%		NA
Columbia Acorn USA (AUSAX) (9/4/96)	$	29.72		-5.18	%		10.35	%		-3.90	%		0.97	%		7.85	%		9.86	%
Russell 2000 Index				-3.47	%		8.53	%		-2.08	%		0.54	%		7.00	%		7.08	%
Lipper Small-Cap Growth Funds Index				-4.56	%		8.95	%		-3.50	%		0.76	%		6.23	%		5.61	%
Columbia Acorn Int'l Select (ACFFX) (11/23/98)	$	26.88		-0.87	%		10.39	%		-3.98	%		0.16	%		10.52	%		9.12	%
S&P Developed Ex-U.S. Between $2B and $10B Index				-7.60	%		3.47	%		-14.48	%		-4.59	%		8.19	%		6.49	%
MSCI EAFE Index				-7.13	%		2.96	%		-13.83	%		-6.10	%		5.14	%		2.76	%
Lipper International Small/Mid Growth Funds Index				-6.03	%		7.68	%		-10.22	%		-2.99	%		9.65	%		9.40	%
Columbia Acorn Select (ACTWX) (11/23/98)	$	24.92		-8.44	%		7.76	%		-9.90	%		-2.64	%		7.39	%		9.02	%
S&P MidCap 400 Index				-4.93	%		7.90	%		-2.33	%		2.55	%		8.21	%		8.85	%
S&P 500 Index**				-2.75	%		9.49	%		5.45	%		0.22	%		5.33	%		3.01	%
Lipper Mid-Cap Growth Funds Index				-6.32	%		7.72	%		-5.16	%		1.61	%		7.29	%		5.92	%
Columbia Thermostat Fund (COTZX) (9/25/02)†	$	13.51		-1.40	%		6.77	%		6.97	%		4.68	%		—			7.84	%
S&P 500 Index				-2.75	%		9.49	%		5.45	%		0.22	%		—			7.48	%
Barclays U.S. Aggregate Bond Index				2.06	%		2.37	%		7.47	%		6.79	%		—			5.31	%
Lipper Flexible Portfolio Funds Index				-2.89	%		5.75	%		-0.55	%		1.82	%		—			7.34	%
50/50 Blended Benchmark				-0.29	%		6.02	%		6.92	%		3.94	%		—			6.73	%
Columbia Acorn Emerging Markets Fund (CEFZX) (8/19/11)	$	10.19		-6.90	%		9.85	%		—			—			—			1.94	%*
S&P Emerging Markets Between $500M and $5B Index				-8.09	%		8.88	%		—			—			—			-5.77	%*
MSCI Emering Markets Small Cap Index				-8.02	%		7.27	%		—			—			—			-10.59	%*
Lipper Emerging Markets Index				-7.84	%		5.57	%		—			—			—			-1.62	%*
Columbia Acorn European Fund (CAEZX) (8/19/11)	$	10.52		-5.16	%		11.62	%		—			—			—			6.29	%*
S&P Europe Between $500M and $5B Index				-8.62	%		7.65	%		—			—			—			-0.07	%*
HSBC Smaller European Companies Index				-10.14	%		5.53	%		—			—			—			-4.53	%*
Lipper European Region Index				-7.82	%		5.05	%		—			—			—			3.75	%*

*Not annualized.

**Although the Fund typically invests in small- and mid-sized companies, the comparison to the S&P 500 Index is presented to show performance against a widely recognized market index over the life of the Fund.

Performance data shown represents past performance and is not a guarantee of future results. The investment return and principal value of an investment will fluctuate so that shares, when redeemed, may be worth more or less than their original cost. Performance results reflect any fee waivers or reimbursements of Fund expenses by the investment manager (Columbia Wanger Asset Management, LLC ("CWAM")) and/or any of its affiliates. Absent these fee waivers or expense reimbursement arrangements, performance results would have been lower. Current performance may be lower or higher than the performance data shown. Please visit columbiamanagement.com for daily and most recent month-end updates.

Net asset value (NAV) returns do not include sales charges or contingent deferred sales charges (CDSC). If they were included, returns would have been lower. Class Z shares are sold only at NAV with no distribution and service (Rule 12b-1) fees. Only eligible investors may purchase Class Z shares of the Funds, directly or by exchange. Please see each Fund's prospectus for eligibility and other details. Class Z shares have limited eligibility and the investment minimum requirement may vary.

Annual operating expense ratios are stated as of each Fund's prospectus dated May 1, 2012, and differences in expense ratios disclosed elsewhere in this report may result from including fee waivers and expense reimbursements as well as different time periods used in calculating the ratios for Class Z shares. Columbia Acorn Fund: 0.77%. Columbia Acorn International: 0.98%. Columbia Acorn USA: 1.05%. Columbia Acorn International Select: 1.25%. Columbia Acorn Select: 1.00%. Columbia Thermostat Fund has a contractual fee waiver and expense reimbursement agreement with CWAM that expires April 30, 2013; expense ratios without and with the contractual waiver/reimbursement, including fees and expenses associated with the Fund's investments in other investment companies (underlying funds), are 1.03% and 0.90%, respectively. Columbia Acorn Emerging Markets Fund has a contractual fee waiver and expense reimbursement agreement with CWAM that expires April 30, 2013; expense ratios without and with the contractual waiver/reimbursement are 13.35% and 1.60%, respectively. Columbia Acorn European Fund has a contractual fee waiver and expense reimbursement agreement with CWAM that expires April 30, 2013; expense ratios without and with the contractual waiver/reimbursement are 19.02% and 1.50%, respectively. See Page 113 for more information about the Funds' fees and expenses.

†A "fund of funds" bears its allocable share of the costs and expenses of the underlying funds in which it invests. Such funds are thus subject to two levels of fees and potentially higher expense ratios than would be associated with an investment in a fund that invests and trades directly in financial instruments under the direction of a single manager.

All results shown assume reinvestment of distributions and do not reflect the deduction of taxes that a shareholder would pay on fund distributions or on the redemption of fund shares. Unlike mutual funds, indexes are not actively managed and do not incur fees or expenses. It is not possible to invest directly in an index.

1

Chattering Squirrels: Columbia Thermostat Fund Turns 10

On September 25, 2002, Columbia Wanger Asset Management, LLC (CWAM) launched Columbia Thermostat Fund. To mark the Fund's 10-year anniversary, CWAM's founder, Ralph Wanger, who now serves as a trustee emeritus on the Columbia Acorn Funds board of trustees, and CWAM's chief investment officer and Columbia Thermostat Fund's current lead portfolio manager, Chuck McQuaid, got together to talk about the Fund. Ralph came up with the idea for the Columbia Thermostat Fund and was a portfolio manager of the Fund until 2005. Chuck has been a portfolio manager of the Fund since its inception.

Q: What drove you to launch the Columbia Thermostat Fund in 2002?

Ralph: In 2001, I started to give some thought to what the market was likely to do next. The bull market had died following the tech/media/telecom collapse. Could it be that the days of successfully investing using a buy-and-hold strategy were behind us? I studied the major tops in the stock market, especially 1929, 1968 and the Japanese market in 1989. All of these bull markets were followed by periods in which the market fluctuated wildly with no uptrend for an average of 25 years.

Dow Jones Industrial Average (1925 – 2012)

Source: Columbia Management Investment Advisers, LLC

While the Columbia Acorn Funds have always believed that good stock selection will do well in all market environments, if the market was going to be in a frustrating trading pattern for a long time, I figured a mutual fund that could take advantage of this pattern might be a worthwhile product.

I defined the bull market as the exponential state. A prime example of this type of market was the period from 1982 to 1999. I defined the second state as a sine wave market or a prolonged period during which the market moves up and down in a very quick and volatile fashion and equity investors make no forward progress. Previous periods of sine-wave movement occurred from 1930 to 1954 and from 1969 to 1981.

Exponential Market

Dow Jones Industrial Average 1982 – 1999

Source: Columbia Management Investment Advisers, LLC

Sine Wave Market

Dow Jones Industrial Average 1969 – 1981

Source: Columbia Management Investment Advisers, LLC

Chuck: I think it is fair to say that Columbia Thermostat Fund came about because Ralph is a student of market history. In a memo Ralph distributed within CWAM in May of 2002 titled, "How to Survive the Next Ten Years," he made the case for a Thermostat-type fund. He noted that the March 2000 peak was a three-way peak: a business cycle peak, a valuation peak and a psychological peak.

After such peaks a sine wave market can start. I believe this is because the stock market has a feedback loop into the economy itself and if the market goes up a lot companies raise a lot of capital and then put that capital to work. During the tech/media/telecom boom, companies raised enormous amounts of money that led to huge overcapacity. For example, loads of fiber optic cable was put in the ground and to this day the price just keeps going down for high-capacity internet connections. When you have a long capital cycle with too much capital invested, it increases competition and hurts profits. During sine wave periods, excess capital in the economy gets burned off and valuations in the

2

market drop from too high to too low. Sine wave markets also have the volatility we're experiencing now.

Q: So how does Columbia Thermostat Fund take advantage of these volatile conditions?

Ralph: The Fund is made up of a mix of stock and bond mutual funds. When the Standard & Poor's (S&P)® 500 Index goes up, the Fund sells a portion of its stock funds and invests more in its bond funds. When the S&P 500 Index goes down, the Fund increases its investment in stock funds and sells shares from the bond funds. It's as simple as that. I consider this rebalancing the real secret of the Fund. By doing this, we are essentially trying to use the market tides to pump energy into the Fund.

S&P Price Range & Columbia Thermostat's Equity Allocation

Source: Columbia Wanger Asset Management, LLC

There are other asset allocation funds that move assets from stocks to bonds based on market moves. Most asset allocation funds, however, are run by sophisticated investment professionals who make subjective decisions based on economic and financial data and complex graphs of market behavior. By contrast, the day-to-day investment decisions for the Columbia Thermostat Fund are made according to predetermined rules based on the current level of the S&P 500 Index. Because the Fund invests according to a pre-set program, there is no need for subjective day-to-day management.

Chuck: The Fund is designed for those who doubt the wisdom of trying to "time" the market. It simply buys stocks when they go down and sells them when they go up. The Fund takes psychology out of investing; it avoids the temptation to buy more stocks because the stock market is currently going up or to sell stocks because the market is declining. The Fund operates by investing its stock and bond assets according to a predetermined asset allocation table based on S&P 500 Index trading ranges described in the prospectus. For example, at June 30, 2012, the Fund had a 50% stock and 50% bond allocation because the S&P 500 Index fell into the 1350 to 1400 price level band. A 5% rebalance in one direction or the other will be triggered when the S&P 500 Index moves out of that range. The only exception is the result of our "31-day Rule." In order to reduce taxable events, after the Fund has increased its percentage allocation to either stock funds or bond funds, it will not decrease that allocation for at least 31 days. The 31-day Rule can also prevent the Fund from buying stock funds too soon during a sudden steep downward reversal in the market.

Stock/Bond Allocation Table

How the Fund will invest the stock/bond assets

Level of the S&P 500® Index	Stock Percentage			Bond Percentage
over 1750		10	%		90	%
over 1700-1750		15	%		85	%
over 1650-1700		20	%		80	%
over 1600-1650		25	%		75	%
over 1550-1600		30	%		70	%
over 1500-1550		35	%		65	%
over 1450-1500		40	%		60	%
over 1400-1450		45	%		55	%
over 1350-1400		50	%		50	%
over 1300-1350		55	%		45	%
over 1250-1300		60	%		40	%
over 1200-1250		65	%		35	%
over 1150-1200		70	%		30	%
over 1100-1150		75	%		25	%
over 1050-1100		80	%		20	%
over 1000-1050		85	%		15	%
1000 and under		90	%		10	%

Q: The name is a bit unusual. How did you come up with it?

Ralph: With this Fund, I wanted to create a very simple investment option, something that was easy to understand for investors at every level. I thought about my stepmother Elaine. She was very sweet and very sensible but she had no knowledge of finance. I wanted this fund to make sense to people like her. When thinking about what to name the Fund, I thought about familiar things, items we all have in our houses. The thermostat was an obvious choice: it keeps your house cool when it's hot and hot when it's cool. Columbia Thermostat Fund attempts to adjust the temperature of your investments in the same way.

Q: How has Columbia Thermostat Fund performed?

Chuck: Better than expected, actually. With this type of Fund, our hope was to provide Fund shareholders with returns that fell between the bond market and the S&P 500 Index, but to offer these returns with less volatility than the stock market. From inception through June 30, 2012, the Fund's Class Z shares, the oldest share class, had an annualized return of 7.84% and topped both the S&P 500 Index, which was up 7.48% for the period, and the Barclays U.S. Aggregate Bond Index, which was up 5.31%.¹ The Fund has a five-star overall Morningstar rating and is ranked in the top decile of the Morningstar aggressive allocation category for the one-, three- and five-year periods ended June 30, 2012.²

3

Q: What about the underlying investments? How do you choose the funds you use within this fund-of-funds?

Ralph: We want to have Columbia Thermostat Fund invested broadly across the stock and bond universes, while being biased toward segments and funds that we think are relatively attractive. We initially selected from among the Columbia Acorn Funds managed by CWAM, which provided fine opportunities in the small- and mid-cap equity segments. We also added mid-cap and large-cap stock funds and bond funds managed by Columbia Management Investment Advisers, LLC (CMIA). When the Fund launched in 2002, we had a bias toward small- and mid-caps in our weighting because they appeared relatively cheap.

Allocation of Stock/Bond Assets Within Asset Classes

As of June 30, 2012

Columbia Stock Funds	Type of Fund	Allocation
Acorn Fund	Small/Mid-cap growth		15	%
Acorn Select	Mid-cap growth		10	%
Acorn International	Small/Mid-cap international growth		20	%
Dividend Income Fund	Large-cap value		20	%
Large Cap Enhanced Core Fund	Large-cap blend		10	%
Contrarian Core Fund	Large-cap blend		15	%
Select Large Cap Growth Fund	Large-cap growth		10	%
Columbia Bond Funds	Type of Fund	Allocation
Intermediate Bond Fund	Intermediate-term bonds		50	%
Income Opportunities Fund	High-yield bonds		30	%
U.S. Treasury Index Fund	U.S. Treasury notes/bonds		20	%

Chuck: CMIA and CWAM combined manage 56 mutual funds rated four or five stars overall by Morningstar. As of June 30, 2012, Columbia Thermostat Fund was invested in 10 funds, nine of which had overall Morningstar ratings of four or five stars. We certainly have lots of highly rated funds to choose from.³

Q: Since Columbia Thermostat Fund was designed largely to buy stocks low and sell them high, why does the Fund own bond funds instead of money market funds?

Ralph: Bond funds usually yield more than money market funds, tend to have much lower volatility than stock funds, and their short-term returns are generally not correlated much with stock funds. I also thought that in a sine wave scenario, bond funds would have returns not far from stock funds. We choose bond funds with relatively short durations to reduce risk from rising interest rates, though interest rates have instead fallen for much of Columbia Thermostat Fund's history.

Q: How has the Fund changed over time?

Chuck: We do a review of the allocation table and underlying funds held in the portfolio at least annually. We take a long-term perspective on what the trading range of the stock market might be and, as Ralph mentioned, which market segments and funds appear relatively attractive.

Our first adjustments to the portfolio were made in September 2005. At that time, we changed the stock allocation table to allow for more equities within the new ranges. We also changed the equity fund line-up to reduce domestic small- and mid-cap exposure from 50% to 25% because smaller cap stock valuations seemed to be getting high. Equity large-cap exposure was increased from 50% to 60% and, with the addition of Columbia Acorn International, we invested in an international component for the first time. International stocks looked relatively attractive, international investing tends to provide excellent diversification and Columbia Acorn International's performance was gaining traction.

During the Fund's 10-year history, we've adjusted the allocation table three times to hike the stock weighting and one time to cut it, each time in response to what we perceived as changes in stock trading ranges. Additional adjustments have also been made to the underlying funds. Most recently, in December 2011, we rebalanced the Fund's bond exposure after looking at interest rate spreads. Treasury rates looked pretty low and corporate bond rates looked more attractive so we did some swapping. We also fine-tuned the investment mix of the Fund's large-cap equity portion.

One other thing we consider is expenses. When debating between similar investments, the lower-cost funds have an edge. In 2011 we exchanged from the Class Z shares of each underlying fund to the newly introduced Class I shares, which is a lower-cost Columbia share class available only to fund-of-funds, such as Columbia Thermostat Fund.

Q: Have there been any times during the past 10 years when the Fund didn't work as you'd expected?

Ralph: Well, there was one law of economics that we forgot about when we launched the Fund: Murphy's Law. In September 2002, the market was at a low and then in 2003, there was a roaring upswing, which dampened interest in an asset allocation fund. As it turned out, the mini bull market of 2003 was just the upside of the sine.

Chuck: Also, Columbia Thermostat Fund was never set up to be a doomsday fund for the ultra bears who thought the market was going to go to zero. It was always meant for a market that was trading within a range and so we set the allocation table based on our expectations for the market. The real estate collapse in 2008 and the subsequent market turmoil was not something we anticipated so we were 100% invested in stocks for nine months from October 2008 through June 2009. We had raised the allocation table in January of 2008 because we felt price-to-earnings ratios had compressed enough and because we didn't want to go to a zero percentage weight in stocks. Well, that didn't happen! In effect, we had over-estimated earnings but the important thing was not to compound the impact in a knee-jerk reaction and sell stocks at or near the bottom. As it turned out, we

4

rode out the storm and caught every bit of the initial upside when the wave turned, starting in March 2009.

Q: Do you dare speculate on how long you think this sine wave will last?

Ralph: That is the question, isn't it? Let's say it's July and it's 97 degrees. What do you wear to work? Likely very light-weight clothing. In February in Chicago when it's 10 below zero, we dress entirely differently with coats, hats and gloves on top of wool suits. If you dress for the weather, you ought to invest for the weather. Investing in a long-only fund is basically a summer idea, best followed when things are optimistic and warm and beautiful. Columbia Thermostat Fund is a winter-time fund that is designed to be variable and that seeks to help you weather stormy and cold days. I believe a long-only fund and an asset allocation fund ought to both be owned within a long-term investment strategy. The tricky part is knowing when to switch from one to the other. The good news is that the failure consequence is different. If you own a long-only fund and you hold it too long and the market goes down dramatically, you lose money and feel lousy. With Columbia Thermostat Fund, if the next exponential market starts, the Fund is designed to turn into more of a bond fund that seeks to preserve your capital and go up a little bit.

If we look to history for the answer, we see that the sine wave markets have lasted quite a while. As I mentioned earlier, after 1929 it took 25 years to reach the old high. After 1968, it also took 25 years, adjusted for inflation. In Japan, their market peaked in late 1989 at 38,000 and it's now about 9,000 after 22 years. It's certainly going to take more than 25 years for that country to get back to the old high. After more than 20 years of a sine wave market, you can be assured of one thing: almost everyone will be disgusted with stocks.

Japanese Great Recession

Source: Columbia Management Investment Advisers, LLC

Chuck: I can attest to that from my own experience. I began my career in the investment industry in 1976 and friends I had in my MBA program thought I was nuts for choosing this sector. They didn't think anyone could make money in stocks because stocks had been flat or down for a very long time. As it turned out, it was a great time to launch a career in this industry. The term I use is stocks were "in the wilderness." No one cared about stocks and no one wanted to talk about them. People weren't bragging about their portfolios but were taking cover in other investment options. While I still believe that investing in stocks with good fundamentals and growth potential can yield good results in the market, stocks generally seem to be somewhat in the wilderness now.

Ralph: Yes, I suppose we could get to the point where the word "stock" will first bring to mind cattle or a task assigned to supermarket employees. When that happens, go long!

Charles P. McQuaid

President and Chief Investment Officer
Columbia Wanger Asset Management, LLC
Trustee, Columbia Acorn Trust and Wanger Advisors Trust
Current Portfolio Manager, Columbia Thermostat Fund

Ralph Wanger

Retired Founder, Columbia Wanger Asset Management, LLC
Trustee Emeritus, Columbia Acorn Trust and Wanger Advisors Trust
Former Portfolio Manager, Columbia Thermostat Fund

The information and data provided in this analysis are derived from sources that we deem to be reliable and accurate. These views are not guarantees of future performance and involve certain risks, uncertainties and assumptions that are difficult to predict so actual outcomes and results may differ significantly from the views expressed. The views/opinions expressed in "Chattering Squirrels" are those of the authors and not of the Columbia Acorn Trust Board, are subject to change at any time based upon economic, market or other conditions, may differ from views expressed by other Columbia Management associates and the respective parties disclaim any responsibility to update such views. These views may not be relied on as investment advice and, because investment decisions for a Columbia Acorn Fund are based on numerous factors, may not be relied on as an indication of trading intent on behalf of any particular Columbia Acorn Fund.

¹  Please see Page 1 of this report for additional performance data for Columbia Thermostat Fund and its benchmarks.

²  Overall ratings among 371 Aggressive Allocation funds. The Fund received a Morningstar Rating of 5 stars among 371 funds and 5 stars among 345 funds for the 3- and 5-year periods, respectively.

³  All ratings are for Class Z shares as of 06/30/12. Other classes may have different performance characteristics and may have different ratings. Out of 118 Z-share Columbia funds rated by Morningstar, eight funds received a 5-star Overall Rating and 48 funds received a 4-star Overall Rating. The Overall Morningstar Rating^TM for a fund is derived from a weighted average of the performance figures associated with its 3-, 5- and 10-year Morningstar Rating metrics.

  For each fund with at least a 3-year history, Morningstar calculates a Morningstar Rating based on a Morningstar Risk-Adjusted Return measure that accounts for variation in a fund's monthly performance (including the effects of sales charges, loads and redemption fees), placing more emphasis on downward variations and rewarding consistent performance. The top 10% of funds in each category receive 5 stars, the next 22.5% receive 4 stars, the next 35% receive 3 stars, the next 22.5% receive 2 stars and the bottom 10% receive 1 star. (Each share class is counted as a fraction of one fund within this scale and rated separately, which may cause slight variations in the distribution percentages.)

  © 2012 Morningstar, Inc. All rights reserved. The Morningstar information contained herein: (1) is proprietary to Morningstar and/or its content providers; (2) may not be copied or distributed; and (3) is not warranted to be accurate, complete or timely. Neither Morningstar nor its content providers are responsible for any damages or losses arising from any use of this information.

5

Understanding Your Expenses

As a shareholder, you incur two types of costs. There are transaction costs, which generally include sales charges on purchases and may include redemption fees. There are also ongoing costs, which generally include management fees, distribution and service (Rule 12b-1) fees, and other Fund expenses. The following information is intended to help you understand your ongoing costs (in dollars) of investing in the Fund and to help you compare these costs with the ongoing costs of investing in other mutual funds.

Analyzing Your Fund's Expenses

To illustrate these ongoing costs, we have provided examples and calculated the expenses paid by investors in Class Z shares of the Funds during the period. The actual and hypothetical information in the tables is based on an initial investment of $1,000 at the beginning of the period indicated and held for the entire period. Expense information is calculated two ways and each method provides you with different information. The amount listed in the "Actual" column is calculated using the Funds' actual operating expenses and total return for the period. You may use the Actual information, together with the amount invested, to estimate the expenses that you paid over the period. Simply divide your account value by $1,000 (for example, an $8,600 account value divided by $1,000 = 8.6), then multiply the results by the expenses paid during the period under the Actual column. The amount listed in the "Hypothetical" column assumes a 5% annual rate of return before expenses (which is not the Funds' actual return) and then applies the Funds' actual expense ratio for the period to the hypothetical return. You should not use the hypothetical account values and expenses to estimate either your actual account balance at the end of the period or the expenses you paid during the period. See "Compare With Other Funds" below for details on how to use the hypothetical data.

In addition to the ongoing expenses which the Funds bear directly, Columbia Thermostat Fund's shareholders indirectly bear the Fund's allocable share of the costs and expenses of each underlying fund in which the Fund invests. You can also estimate the effective expenses paid during the period, which includes the indirect fees associated with investing in the underlying funds, by using the amounts listed in the effective expenses paid during the period column in the "Fund of Funds" table below.

Compare With Other Funds

Since all mutual funds are required to include the same hypothetical calculations about expenses in shareholder reports, you can use this information to compare the ongoing cost of investing in the Funds with other funds. To do so, compare the hypothetical example with the 5% hypothetical examples that appear in the shareholder reports of other funds. As you compare hypothetical examples of other funds, it is important to note that hypothetical examples are meant to highlight the ongoing costs of investing in a fund only and do not reflect any transaction costs, such as sales charges, or redemption or exchange fees. Therefore, the hypothetical calculations are useful in comparing ongoing costs only, and will not help you determine the relative total costs of owning different funds. If transaction costs were included in these calculations, your costs would be higher.

6

January 1, 2012 – June 30, 2012

	Account value at the beginning of the period ($)				Account value at the end of the period ($)				Expenses paid during period ($)				Fund's annualized expense ratio (%)
	Actual		Hypothetical		Actual		Hypothetical		Actual		Hypothetical		Actual
Class Z Shares
Columbia Acorn Fund		1,000.00		1,000.00		1,092.30		1,021.08		3.95		3.82		0.76
Columbia Acorn International		1,000.00		1,000.00		1,087.20		1,020.34		4.72		4.57		0.91
Columbia Acorn USA		1,000.00		1,000.00		1,103.50		1,019.69		5.44		5.22		1.04
Columbia Acorn International Select		1,000.00		1,000.00		1,103.90		1,019.00		6.17		5.92		1.18
Columbia Acorn Select		1,000.00		1,000.00		1,077.60		1,019.79		5.27		5.12		1.02
Columbia Acorn Emerging Markets Fund		1,000.00		1,000.00		1,098.50		1,017.70		7.51		7.22		1.44
Columbia Acorn European Fund		1,000.00		1,000.00		1,116.20		1,018.25		7.00		6.67		1.33

Fund of Funds—Columbia Thermostat Fund

January 1, 2012 – June 30, 2012

Account value at the beginning of the period ($)

Account value at the end of the period ($)

Expenses paid during period ($)

Fund's annualized expense ratio (%)

Effective expenses paid during the period

Fund's effective annualized expense ratio (%)

Actual

Hypothetical

Actual

Hypothetical

Actual

Hypothetical

Actual

Actual

Hypothetical

Actual

Class Z Shares

Columbia Thermostat Fund

1,000.00

1,000.00

1,067.70

1,023.62

1.29

1.26

0.25

4.42

4.33

0.25

Expenses paid during the period are equal to the annualized expense ratio, multiplied by the average account value over the period and then multiplied by the number of days in the Fund's most recent fiscal half year and divided by 366.

Expenses do not include fees and expenses incurred indirectly by the Fund from the underlying funds in which the Fund may invest (also referred to as "acquired funds"), including affiliated and non-affiliated pooled investments vehicles (including mutual funds and exchange traded funds).

In the case of Columbia Thermostat Fund, effective expenses paid during the period and the Fund's effective annualized expense ratio include expenses borne directly to the class plus the Fund's pro rata portion of the ongoing expenses charged by the underlying funds using the expense ratio of each class of the underlying funds as of the underlying fund's most recent shareholder report.

Had the investment manager and/or certain of its affiliates not waived/reimbursed certain fees and expenses, account value at the end of the period would have been reduced.

7

Columbia Acorn Fund

In a Nutshell

Charles P. McQuaid	Robert A. Mohn
Lead Portfolio Manager	Co-Portfolio Manager

Performance data shown represents past performance and is not a guarantee of future results. The investment return and principal value will fluctuate so that shares, when redeemed, may be worth more or less than the original cost. Current performance may be lower or higher than the performance data shown. Please visit columbiamanagement.com for daily and most recent month-end performance updates.

Fund Positions
in Mentioned Holdings

As a percentage of net assets, as of 6/30/12

lululemon athletica	1.6	%
Crown Castle International	1.5	%
tw telecom	1.4	%
FMC Technologies	1.2	%
SBA Communications	1.1	%
Biomarin Pharmaceuticals	1.0	%
Seattle Genetics	0.9	%
Alexion Pharmaceuticals	0.9	%
Coach	0.7	%
Auxilium Pharmaceuticals	0.5	%
Pacific Rubiales Energy	0.5	%
Onyx Pharmaceuticals	0.3	%
Fossil	0.2	%

Columbia Acorn Fund fell 5.42% in the second quarter, offsetting some of the first quarter gains to end up 9.23% for the first half of 2012. The Fund's primary benchmark, the Russell 2500 Index, dropped 4.14% in the quarter and rose 8.31% during the half year. In both periods, Columbia Acorn Fund beat the Lipper Mid-Cap Growth Index, which fell 6.32% in the quarter and gained 7.72% in the half.

Driven by explosive growth in data transmission, telecom stocks helped performance during both the quarter and the half. Cell tower companies Crown Castle International and SBA Communications rose 10% and 12%, respectively, in the quarter and 31% and 33%, respectively, in the half. tw telecom, which provides fiber optic connections to over 15,000 buildings, grew 16% in the second quarter and 32% in the half.

Pharmaceutical and biotech stocks bolstered performance in the second quarter. Onyx Pharmaceuticals, Auxilium Pharmaceuticals, Seattle Genetics and Biomarin Pharmaceuticals all reported good news about drugs either recently approved and/or in development pipelines. The stocks' gains in the quarter ranged from 16% to 77%. Alexion Pharmaceuticals rose 7% in the quarter, resulting in a 39% gain in the half and making it the Fund's second largest dollar winner year to date through June 30.

Consumer durable and apparel stocks helped performance in the first quarter but hurt in the second. The Fund's largest dollar loser in the second quarter was premium active apparel retailer lululemon athletica, down 20% on disappointing earnings guidance. Last year investors were wrongly concerned that inventories were too high but, in the second quarter of 2012, low inventories reduced near-term earnings upside. Due to fine first quarter performance, lululemon was still the Fund's largest dollar winner for the half, up 28%. Other consumer stocks fell in the second quarter due to concerns about sales overseas; handbag maker Coach dropped 24% and watch designer and retailer Fossil fell 42%.

Energy stocks were also disappointing in the second quarter, largely due to declining oil prices and low natural gas prices. In addition, offshore oil equipment maker FMC Technologies had problems ramping up production. Its stock fell 22% in the quarter and was down 25% in the half, making it the Fund's second largest dollar loser in the quarter and the largest loser in the half. Colombian oil producer Pacific Rubiales Energy continued to be volatile; after surging 59% in the first quarter, it fell 27% in the second. The company suffered from delays in receiving drilling permits and lacked new oil discoveries. We cut the Fund's weighting in energy stocks during the second quarter to 6.2%, about matching the benchmark.

Columbia Acorn Fund's international stocks were off 12.74% in the quarter and up just 2.31% in the half.* While we see lots of foreign companies with good business models and attractively valued stocks, we fear macroeconomic concerns could keep their stocks depressed. Foreign holdings accounted for 8.3% of assets at the end of the half, down from 9.2% at the end of the first quarter and 9.3% at the end of 2011. Investors that desire greater exposure to foreign stocks may wish to consider one or more of the Columbia Acorn international funds.

As of press time, a majority of companies in Columbia Acorn Fund seem to be achieving their earnings targets, though many are cutting their outlooks somewhat. Corporations and consumers have generally improved their balance sheets since the Great Recession. As a percentage of income, minimum required payments on consumer mortgages and consumer credit are near 20-year lows. However, federal government deficit, tax and regulatory issues appear to be hindering economic growth and causing uncertainty in the markets. We can't predict when uncertainty will lessen, but when it does, stock prices may be a lot higher. We continue to pursue investments in good businesses at reasonable prices.

*These returns are not comparable to mutual fund returns, as they are gross of fees and other expenses and do not portray the cash effects incurred by actual mutual funds. Columbia Acorn Fund's foreign stockholdings were not purchased as a balanced, stand-alone portfolio.

Stocks of small- and mid-cap companies pose special risks, including possible illiquidity and greater price volatility than stocks of larger, more established companies. International investing involves special risks, including foreign taxation, currency risks, risks associated with possible differences in financial standards and other risks associated with future political and economic developments.

Portfolio holdings are subject to change periodically and may not be representative of current holdings.

8

Columbia Acorn Fund (ACRNX)

At a Glance

Performance data shown represents past performance and is not a guarantee of future results. The investment return and principal value of an investment will fluctuate so that shares, when redeemed, may be worth more or less than their original cost. Current performance may be lower or higher than the performance data shown. Performance results reflect any fee waivers or reimbursements of Fund expenses by the investment manager and/or any of its affiliates. Absent these fee waivers and/or expense reimbursement arrangements, performance results would have been lower. Please visit columbiamanagement.com for daily and most recent month-end updates.

Pretax and After-tax Average Annual Total Returns (Class Z)

through June 30, 2012

Inception 6/10/70	Year to date*			1 year			5 years			10 years
Returns before taxes		9.23	%		-2.78	%		1.70	%		9.59	%
Returns after taxes on distributions		9.04			-3.40			1.15			8.99
Returns after taxes on distributions and sale of fund shares		6.26			-1.04			1.40			8.45
Russell 2500 Index (pretax)**		8.31			-2.29			1.18			8.01

All results shown assume reinvestment of distributions.

*Year to date data is not annualized.

**The Fund's primary benchmark.

After-tax returns are calculated using the highest historical individual federal marginal income tax rates, and do not reflect the impact of state and local taxes. Returns after taxes on distributions and sale of Fund shares reflect the additional tax impact of long-term gains or losses realized when Fund shares are sold. The returns are taxed at the maximum rate and assume shares were purchased at the beginning of the period. Actual after-tax returns depend on the investor's tax situation and may differ from those shown. After-tax returns are not relevant to investors who hold their Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts. After-tax returns are shown for Class Z shares only; after-tax returns for other share classes will vary. Indexes do not reflect any deduction for fees, expenses or taxes.

The Fund's Class Z annual operating expense ratio, as stated in the May 1, 2012, prospectus, is 0.77%.

Columbia Acorn Fund Portfolio Diversification

as a percentage of net assets, as of 6/30/12

Columbia Acorn Fund Top 10 Holdings

as a percentage of net assets, as of 6/30/12

1.	Ametek Aerospace/Industrial Instruments	2.0	%
2.	Donaldson Industrial Air Filtration	1.6	%
3.	lululemon athletica Premium Active Apparel Retailer	1.6	%
4.	Crown Castle International Communications Towers	1.5	%
5.	Mettler-Toledo International Laboratory Equipment	1.5	%
6.	tw telecom Fiber Optic Telephone/Data Services	1.4	%
7.	Informatica Enterprise Data Integration Software	1.2	%
8.	Cepheid Molecular Diagnostics	1.2	%
9.	FMC Technologies Oil & Gas Well Head Manufacturer	1.2	%
10.	SBA Communications Communications Towers	1.1	%

The Fund's top 10 holdings and portfolio diversification vary with changes in portfolio investments. See the Statement of Investments for a complete list of the Fund's holdings.

The Growth of a $10,000 Investment in Columbia Acorn Fund (Class Z)

June 10, 1970 through June 30, 2012

This graph compares the results of $10,000 invested in Columbia Acorn Fund at inception on June 10, 1970 to the S&P 500 Index and to an initial $31,777 investment in the Russell 2500 Index on the index's December 31, 1978 inception date. Although the indexes are provided for use in assessing the Fund's performance, the Fund's holdings may differ significantly from those in the indexes. The indexes are unmanaged and returns for both the indexes and the Fund include reinvested dividends and capital gains. It is not possible to invest directly in an index. The graph does not reflect taxes that a shareholder would pay on Fund distributions or on a sale of Fund shares.

Total Net Assets of the Fund: $17.2 billion

*  A $10,000 investment in Columbia Acorn Fund at inception appreciated to $31,777 on December 31, 1978, the inception date of the Russell 2500 Index. For comparison with the Russell 2500 Index, we assigned the index the same value as the Fund at index inception.

**Although the Fund typically invests in small- and mid-sized companies, the comparison to the S&P 500 Index is presented to show performance against a widely recognized market index over the life of the Fund.

9

Columbia Acorn International

In a Nutshell

P. Zachary Egan	Louis J. Mendes III
Co-Portfolio Manager	Co-Portfolio Manager

Performance data shown represents past performance and is not a guarantee of future results. The investment return and principal value will fluctuate so that shares, when redeemed, may be worth more or less than the original cost. Current performance may be lower or higher than the performance data shown. Please visit columbiamanagement.com for daily and most recent month-end performance updates.

Fund's Positions
in Mentioned Holdings

As a percentage of net assets, as of 6/30/12

Eurofins Scientific	1.1	%
Gemalto	0.9	%
Mongolian Mining	0.6	%
Nagacorp	0.4	%
Northam Platinum	0.4	%
Archipelago Resources	0.4	%
FMC Technologies	0.3	%
Celtic Exploration	0.1	%

Columbia Acorn International fell 5.52% in the second quarter of 2012, which was 2.51% better than its primary benchmark, the S&P Global Ex-U.S. between $500M and $5B Index. This comes on the heels of a strong first quarter, during which the Fund was up 15.07%. The Fund's return for the first half of the year was 8.72%, 3.90% ahead of the benchmark. For comparison, the large-cap, developed-market MSCI EAFE Index rose 2.96% during the six month period.

This reversal of fortune in the markets in the second quarter occurred in a context of high anxiety regarding the financial stability of peripheral eurozone states and the worsening outlook for Chinese growth. Markets do not like uncertainty and the lack of a resolution to European budget crises continues to rattle the confidence of long-term investors in the region. As confidence falls, sovereign borrowing costs rise, which further deteriorates the long-term financial outlook. Aside from this unhelpful, self-reinforcing mechanism, signs of a slowing Chinese economy further fueled market volatility. Despite the ebb and flow of sentiment, however, many of the Fund's holdings have continued to post a pleasing growth in earnings.

Most notable about the Fund's first-half results is the relatively strong performance of classic "Acorn-style" companies. By this we refer to companies that are taking advantage of structural changes within the market for their products or services—whether related to regulation, technology, energy efficiency, social change or otherwise. These can be contrasted with companies that primarily depend on macroeconomic factors to drive earnings. Top performers for the half year included Nagacorp (+85%), a Cambodian-based casino operator catering to the growing needs of Indochina's emerging middle class for quality entertainment facilities. Two French companies, Eurofins Scientific (+72%) and Gemalto (+47%) performed well despite eurozone concerns. Eurofins Scientific provides laboratory analysis of food, pharmaceuticals and cosmetics products globally and, after a long period of consolidation, looms as a one-stop solution for multinational companies and others increasingly concerned with the safety and purity of traded goods. Gemalto is a leader in developing smart-chip technology for use in credit cards and mobile handsets. These mobile devices are finding increasingly valuable applications in secure payment systems.

Macroeconomic worries did hurt the Fund in commodity-related holdings. Fears of slower global growth drove down a number of energy and basic material stocks. Indonesian gold miner Archipelago Resources (-26%), Mongolian coal miner Mongolian Mining (-24%) and South African platinum miner Northam Platinum (-23%) all fell during the half year on weakened outlook for demand. Similarly, oil exploration-related companies Celtic Exploration (-41%) and FMC Technologies (-25%) declined on expectations that oil prices would soften.

We expect continued volatility in the second half of the year. The euro debt crisis does not lend itself to a tidy resolution in the short- or even mid-term. The most likely outcome in our view is piecemeal structural reform within uncompetitive states, incented by explicit and tacit German support and the fact that the alternatives entail a lower standard of living for these states on a long-term basis. We believe that will be a political process fraught with complexity and made more complicated by the way Europe is organized. In the fall, the presidential election in the United States and the transition of leadership in China will also likely become a focus for continued sentiment shifts in the marketplace. As always, we will strive to work through the noise to identify companies where reasonable valuations are supported by good or improving fundamentals. Thank you for your continued investment in the Fund.

International investing involves special risks, including foreign taxation, currency risks, risks associated with possible differences in financial standards and other risks associated with future political and economic developments. Stocks of small- and mid-cap companies pose special risks, including possible illiquidity and greater price volatility than stocks of larger, more established companies. Investing in emerging markets may involve greater risks than investing in more developed countries. In addition, concentration of investments in a single region may result in greater volatility.

Portfolio holdings are subject to change periodically and may not be representative of current holdings.

10

Columbia Acorn International (ACINX)

At a Glance

Performance data shown represents past performance and is not a guarantee of future results. The investment return and principal value of an investment will fluctuate so that shares, when redeemed, may be worth more or less than their original cost. Current performance may be lower or higher than the performance data shown. Performance results reflect any fee waivers or reimbursements of Fund expenses by the investment manager and/or any of its affiliates. Absent these fee waivers and/or expense reimbursement arrangements, performance results would have been lower. Please visit columbiamanagement.com for daily and most recent month-end updates.

Pretax and After-tax Average Annual Total Returns (Class Z)

through June 30, 2012

Inception 9/23/92	Year to date*			1 year			5 years			10 years
Returns before taxes		8.72	%		-9.31	%		-0.84	%		11.07	%
Returns after taxes on distributions		8.52			-9.37			-1.38			10.51
Returns after taxes on distributions and sale of fund shares		5.66			-5.94			-0.76			9.89
S&P Global Ex-U.S. Between $500M and $5B Index**		4.82			-15.17			-2.48			10.95

All results shown assume reinvestment of distributions.

*Year to date data is not annualized.

**The Fund's primary benchmark.

After-tax returns are calculated using the highest historical individual federal marginal income tax rates, and do not reflect the impact of state and local taxes. Returns after taxes on distributions and sale of Fund shares reflect the additional tax impact of long-term gains or losses realized when Fund shares are sold. The returns are taxed at the maximum rate and assume shares were purchased at the beginning of the period. Actual after-tax returns depend on the investor's tax situation and may differ from those shown. After-tax returns are not relevant to investors who hold their Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts. After-tax returns are shown for Class Z shares only; after-tax returns for other share classes will vary. Indexes do not reflect any deduction for fees, expenses or taxes.

The Fund's Class Z shares annual operating expense ratio, as stated in the May 1, 2012, prospectus, is 0.98%.

Columbia Acorn International Portfolio Diversification

as a percentage of net assets, as of 6/30/12

Columbia Acorn International Top 10 Holdings

as a percentage of net assets, as of 6/30/12

1.	Far EasTone Telecom (Taiwan) Taiwan's Third Largest Mobile Operator	1.3	%
2.	Melco Crown Entertainment (Hong Kong) Macau Casino Operator	1.2	%
3.	Hexagon (Sweden) Design, Measurement & Visualization Software & Equipment	1.2	%
4.	Eurofins Scientific (France) Food, Pharmaceuticals & Materials Screening & Testing	1.1	%
5.	Naspers (South Africa) Media in Africa, China, Russia & Other Emerging Markets	1.0	%
6.	Kansai Paint (Japan) Paint Producer in Japan, India, China & Southeast Asia	1.0	%
7.	Localiza Rent A Car (Brazil) Car Rental	0.9	%
8.	Partners Group (Switzerland) Private Markets Asset Management	0.9	%
9.	Taiwan Mobile (Taiwan) Taiwan's Second Largest Mobile Operator	0.9	%
10.	Gemalto (France) Digital Security Solutions	0.9	%

The Fund's top 10 holdings and portfolio diversification vary with changes in portfolio investments. See the Statement of Investments for a complete list of the Fund's holdings.

The Growth of a $10,000 Investment in Columbia Acorn International (Class Z)

September 23, 1992 through June 30, 2012

This graph compares the results of $10,000 invested in Columbia Acorn International at inception on September 23, 1992 to the S&P Global Ex-U.S. Between $500M and $5B Index. Although the index is provided for use in assessing the Fund's performance, the Fund's holdings may differ significantly from those in the index. The index is unmanaged and returns for both the index and Fund include reinvested dividends and capital gains. It is not possible to invest directly in an index. The graph does not reflect taxes that a shareholder would pay on Fund distributions or on a sale of Fund shares.

Total Net Assets of the Fund: $6.0 billion

11

Columbia Acorn USA

In a Nutshell

Robert A. Mohn

Lead Portfolio Manager

Performance data shown represents past performance and is not a guarantee of future results. The investment return and principal value will fluctuate so that shares, when redeemed, may be worth more or less than the original cost. Current performance may be lower or higher than the performance data shown. Please visit columbiamanagement.com for daily and most recent month-end performance updates.

Fund's Positions
in Mentioned Holdings

As a percentage of net assets, as of 6/30/12

Informatica	2.4	%
tw telecom	2.4	%
lululemon athletica	2.2	%
Gaylord Entertainment	2.1	%
SBA Communications	1.9	%
Abercrombie & Fitch	1.0	%
Atmel	0.8	%
Auxilium Pharmaceuticals	0.7	%
Finisar	0.7	%
Akorn	0.6	%
Onyx Pharmaceuticals	0.4	%
SM Energy	0.4	%
Houston American Energy	0.0	%*

*Rounds to less than 0.1%.

Columbia Acorn USA ended the second quarter of 2012 down 5.18%, underperforming the 3.47% drop of its primary benchmark, the Russell 2000 Index. For the half year ended June 30, 2012, the Fund was up 10.35%, outpacing the 8.53% gain of its benchmark. It was a rough quarter for the markets in general, but lagging performance in Fund retail and technology stocks further dampened returns relative to the benchmark.

On the positive side, two deal announcements positively impacted results. Cost management software company Ariba is to be taken over by SAP. Ariba's stock rose 37% in the quarter on the news and ended the half year up 60%. Convention hotel operator Gaylord Entertainment announced it would convert to a real estate investment trust, news that sent its stock up 25% for the quarter and 60% for the half year.

The Fund's two large investments in the telecom sector, tw telecom, a provider of fiber optic telephone and data services, and SBA Communications, a mobile communications tower company, both benefited from a surge in data usage and reported solid growth in cash flow year-over-year. Their stocks responded favorably, with tw telecom ending the quarter up 16% and the half year up 32%. SBA Communications had a 12% gain in the quarter and was up 33% year-to-date through June.

Several Fund biopharmaceutical stocks were strong in the second quarter. Auxilium Pharmaceuticals gained 45% on news of a successful phase three drug trial. Onyx Pharmaceuticals gained 77% upon receiving approval from an FDA advisory panel for one of its medications. Generic drug manufacturer Akorn rose 34% in the quarter as sales of its generic injectable drugs tripled versus the prior year.

Laggards for the second quarter included several tech stocks. Informatica, an enterprise data integration software company, fell 20% in the quarter (but was up 15% year to date) on concerns over slowing sales activity. Those concerns were confirmed after quarter end as the company pre-announced a drop in software license revenue. The economic turmoil overseas is impacting Informatica's near-term results, as 25% of the company's revenues are generated in Europe. Semiconductor manufacturer Atmel fell 32% in the quarter and ended the half year down 17%. Atmel's revenues dropped 22% versus the prior year due to the loss of an anticipated touchscreen microcontroller contract. Optical components manufacturer Finisar fell 26% in the quarter and was down 11% for the half year as its business suffered from weakening global demand.

Several Fund retail stocks also struggled during the period ended June 30. Premium active apparel retailer lululemon athletica announced a fantastic first quarter, with same-store sales up 25% over the prior year, but company guidance of slower growth in the second quarter sent the stock down 21%. For the half year lululemon gained 27%. Teen apparel retailer Abercrombie & Fitch experienced a sales shortfall on woeful sales in woebegone Europe. Its stock was down roughly 30% for the quarter and for the half year.

Our energy investments were also weak. Oil and gas producer SM Energy fell more than 30% for both the second quarter and the half year as prices of natural gas liquids fell more than crude oil during the second quarter. Houston American Energy was down 79% for the quarter and 91% for the half year on disappointing drilling results in Colombia.

These days the financial press seems to enjoy obsessing over existential economic issues. Certainly, talk of euro woes and fiscal cliffs can be as riveting and entertaining as a good horror flick. "Experts" claim that investing is all about getting the macro right, given the current uncertain economic environment (truthfully, when has the economic outlook ever been certain?). But when the investment community is so overly focused on the big picture, we believe it pays to go small. We'll leave the macro anguish to others who can't see the trees for the forest, and instead dig for what we believe are well-run companies able to grow faster than their peers and that thrive in our current much-maligned, but still growing, economy.

Stocks of small- and mid-cap companies pose special risks, including possible illiquidity and greater price volatility than stocks of larger, more established companies.

Portfolio holdings are subject to change periodically and may not be representative of current holdings.

12

Columbia Acorn USA (AUSAX)

At a Glance

Performance data shown represents past performance and is not a guarantee of future results. The investment return and principal value of an investment will fluctuate so that shares, when redeemed, may be worth more or less than their original cost. Current performance may be lower or higher than the performance data shown. Performance results reflect any fee waivers or reimbursements of Fund expenses by the investment manager and/or any of its affiliates. Absent these fee waivers and/or expense reimbursement arrangements, performance results would have been lower. Please visit columbiamanagement.com for daily and most recent month-end updates.

Pretax and After-tax Average Annual Total Returns (Class Z)

through June 30, 2012

Inception 9/4/96	Year to date*			1 year			5 years			10 years
Returns before taxes		10.35	%		-3.90	%		0.97	%		7.85	%
Returns after taxes on distributions		10.32			-4.01			0.69			7.56
Returns after taxes on distributions and sale of fund shares		6.77			-2.40			0.80			6.92
Russell 2000 Index (pretax)**		8.53			-2.08			0.54			7.00

All results shown assume reinvestment of distributions.

*Year to date data is not annualized.

**The Fund's primary benchmark.

After-tax returns are calculated using the highest historical individual federal marginal income tax rates, and do not reflect the impact of state and local taxes. Returns after taxes on distributions and sale of Fund shares reflect the additional tax impact of long-term gains or losses realized when Fund shares are sold. The returns are taxed at the maximum rate and assume shares were purchased at the beginning of the period. Actual after-tax returns depend on the investor's tax situation and may differ from those shown. After-tax returns are not relevant to investors who hold their Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts. After-tax returns are shown for Class Z shares only; after-tax returns for other share classes will vary. Indexes do not reflect any deduction for fees, expenses or taxes.

The Fund's Class Z shares annual operating expense ratio, as stated in the May 1, 2012, prospectus, is 1.05%.

Columbia Acorn USA Portfolio Diversification

as a percentage of net assets, as of 6/30/12

Columbia Acorn USA Top 10 Holdings

as a percentage of net assets, as of 6/30/12

1.	Ametek Aerospace/Industrial Instruments	2.8	%
2.	Informatica Enterprise Data Integration Software	2.4	%
3.	Nordson Dispensing Systems for Adhesives & Coatings	2.4	%
4.	tw telecom Fiber Optic Telephone/Data Services	2.4	%
5.	Micros Systems Information Systems for Hotels, Restaurants & Retailers	2.3	%
6.	lululemon athletica Premium Active Apparel Retailer	2.2	%
7.	Gaylord Entertainment Convention Hotels	2.1	%
8.	Bally Technologies Slot Machines & Software	1.9	%
9.	ESCO Technologies Automatic Electric Meter Readers	1.9	%
10.	SBA Communications Communications Towers	1.9	%

The Fund's top 10 holdings and portfolio diversification vary with changes in portfolio investments. See the Statement of Investments for a complete list of the Fund's holdings.

The Growth of a $10,000 Investment in Columbia Acorn USA (Class Z)

September 4, 1996 through June 30, 2012

This graph compares the results of $10,000 invested in Columbia Acorn USA at inception on September 4, 1996 to the Russell 2000 Index. Although the index is provided for use in assessing the Fund's performance, the Fund's holdings may differ significantly from those in the index. The index is unmanaged and returns for both the index and the Fund include reinvested dividends and capital gains. It is not possible to invest directly in an index. The graph does not reflect taxes that a shareholder would pay on Fund distributions or on a sale of Fund shares.

Total Net Assets of the Fund: $1.6 billion

13

Columbia Acorn International Select

In a Nutshell

Christopher J. Olson

Lead Portfolio Manager

Performance data shown represents past performance and is not a guarantee of future results. The investment return and principal value will fluctuate so that shares, when redeemed, may be worth more or less than the original cost. Current performance may be lower or higher than the performance data shown. Please visit columbiamanagement.com for daily and most recent month-end performance updates.

Fund's Positions
in Mentioned Holdings

As a percentage of net assets, as of 6/30/12

Far EasTone Telecom	7.1	%
Ascendas REIT	6.6	%
Mapletree Industrial Trust	5.8	%
Seven Bank	4.4	%
Rand Merchant Insurance	4.1	%
Taiwan Mobile	3.1	%
Mapletree Logistics Trust	2.6	%
Archipelago Resources	2.2	%
Zhaojin Mining Industry	1.6	%

Columbia Acorn International Select ended the second quarter of 2012 down 0.87%, holding up much better than the 7.60% drop of its primary benchmark, the S&P Developed Ex-U.S. Between $2B and $10B Index. Year to date through June 30, 2012, the Fund was up 10.39%, strongly outperforming the 3.47% gain of its benchmark.

Financial stocks provided the biggest boost to Fund gains relative to the benchmark for both the second quarter and the half year. Singapore's Ascendas REIT, Mapletree Industrial Trust and Mapletree Logistics Trust had gains ranging from 4% to 12% in the quarter and each was up 20% or more year to date. These industrial property landlords continue to benefit from a resilient Singaporean economic outlook and investor interest in their strong dividend yields. Japan's Seven Bank, a provider of ATM processing services, rose 17% in the quarter and was up 34% for the half year as its ATM expansion within Japan continued to benefit the company's stock. Rand Merchant Insurance, a South African insurance company, led gains in the first quarter but cooled in the second quarter, falling 4.93%. Despite the drop in the second quarter, Rand Merchant was still up 31% for the half year.

Fund holdings in the telecom services sector also performed strongly for both the second quarter and half year. Far EasTone Telecom, Taiwan's third largest mobile operator, gained 6% in the second quarter and ended the half year up 16%. The company benefited from accelerated smartphone sales that are driving increased data usage. Taiwan Mobile, the second largest mobile operator in Taiwan, saw its stock rise 8% in the second quarter, leading to a 6% gain for the half year. Taiwan Mobile's stock fell in the first quarter, despite an improving earnings outlook, but investors returned in the second quarter after their brief flight to more cyclical names.

Mining companies did not fare well in the first half of 2012 as fears of slower global growth decreased demand. The biggest detractor to Fund performance in the second quarter was Indonesian gold miner Archipelago Resources, which fell 23% in the quarter and was down 26% for the half year. In China, Zhaojin Mining Industry fell 20% in the second quarter and ended the half year off 15%. Northam Platinum, a South African platinum miner, was off 26% in the quarter and down 22% year to date. We opted to sell the Fund's position in Northam Platinum and invested the proceeds elsewhere.

While fears of a global recession eased in the first quarter, the second quarter saw renewed uncertainty regarding the financial stability of Europe and signs of slowing economic growth in China. We are also concerned and have maintained a focus on defensive, secular growth companies with good dividend yields and strong balance sheets. As we mentioned last quarter, the Fund remains underweight in areas such as Europe, the United Kingdom and Japan, where the concerns about global debt are greatest, and is overweight in Asia ex-Japan and emerging markets.

International investing involves special risks, including foreign taxation, currency risks, risks associated with possible differences in financial standards and other risks associated with future political and economic developments. Stocks of small- and mid-cap companies pose special risks, including possible illiquidity and greater price volatility than stocks of larger, more established companies. Investing in emerging markets may involve greater risks than investing in more developed countries.

Portfolio holdings are subject to change periodically and may not be representative of current holdings.

14

Columbia Acorn International Select (ACFFX)

At a Glance

Performance data shown represents past performance and is not a guarantee of future results. The investment return and principal value of an investment will fluctuate so that shares, when redeemed, may be worth more or less than their original cost. Current performance may be lower or higher than the performance data shown. Performance results reflect any fee waivers or reimbursements of Fund expenses by the investment manager and/or any of its affiliates. Absent these fee waivers and/or expense reimbursement arrangements, performance results would have been lower. Please visit columbiamanagement.com for daily and most recent month-end updates.

Pretax and After-tax Average Annual Total Returns (Class Z)

through June 30, 2012

Inception 11/23/98	Year to date*			1 year			5 years			10 years
Returns before taxes		10.39	%		-3.98	%		0.16	%		10.52	%
Returns after taxes on distributions		10.32			-4.35			-0.24			10.30
Returns after taxes on distributions and sale of fund shares		6.85			-1.87			0.18			9.48
S&P Developed Ex-U.S. Between $2B and $10B Index (pretax)**		3.47			-14.48			-4.59			8.19

All results shown assume reinvestment of distributions.

*Year to date data is not annualized.

**The Fund's primary benchmark.

After-tax returns are calculated using the highest historical individual federal marginal income tax rates, and do not reflect the impact of state and local taxes. Returns after taxes on distributions and sale of Fund shares reflect the additional tax impact of long-term gains or losses realized when Fund shares are sold. The returns are taxed at the maximum rate and assume shares were purchased at the beginning of the period. Actual after-tax returns depend on the investor's tax situation and may differ from those shown. After-tax returns are not relevant to investors who hold their Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts. After-tax returns are shown for Class Z shares only; after-tax returns for other share classes will vary. Indexes do not reflect any deduction for fees, expenses or taxes.

The Fund's Class Z shares annual operating expense ratio, as stated in the May 1, 2012, prospectus, is 1.25%.

Columbia Acorn International Select Portfolio Diversification

as a percentage of net assets, as of 6/30/12

Columbia Acorn International Select
Top 10 Holdings

as a percentage of net assets, as of 6/30/12

1.	Far EasTone Telecom (Taiwan) Taiwan's Third Largest Mobile Operator	7.1	%
2.	Ascendas REIT (Singapore) Industrial Property Landlord	6.6	%
3.	Mapletree Industrial Trust (Singapore) Industrial Property Landlord	5.8	%
4.	Seven Bank (Japan) ATM Processing Services	4.4	%
5.	Rand Merchant Insurance (South Africa) Directly Sold Property & Casualty Insurance; Holdings in Other Insurers	4.1	%
6.	Fresnillo (Mexico) Silver & Metal Byproduct Mining in Mexico	4.0	%
7.	Goldcorp (Canada) Gold Mining	3.8	%
8.	UGL (Australia) Engineering & Facilities Management	3.8	%
9.	Wirecard (Germany) Online Payment Processing & Risk Management	3.6	%
10.	Commonwealth Property Office Fund (Australia) Australia Prime Office REIT	3.2	%

The Fund's top 10 holdings and portfolio diversification vary with changes in portfolio investments. See the Statement of Investments for a complete list of the Fund's holdings.

The Growth of a $10,000 Investment in Columbia Acorn International Select (Class Z)

November 23, 1998 through June 30, 2012

This graph compares the results of $10,000 invested in Columbia Acorn International Select at inception on November 23, 1998 to the S&P Developed Ex-U.S. Between $2B and $10B Index. Although the index is provided for use in assessing the Fund's performance, the Fund's holdings may differ significantly from those in the index. The index and Fund returns include reinvested dividends and capital gains. It is not possible to invest directly in an index. The graph does not reflect taxes that a shareholder would pay on Fund distributions or on a sale of Fund shares.

Total Net Assets of the Fund: $338.1 million

15

Columbia Acorn Select

In a Nutshell

Ben Andrews	Robert A. Chalupnik
Lead Portfolio Manager	Co-Portfolio Manager

Performance data shown represents past performance and is not a guarantee of future results. The investment return and principal value will fluctuate so that shares, when redeemed, may be worth more or less than the original cost. Current performance may be lower or higher than the performance data shown. Please visit columbiamanagement.com for daily and most recent month-end performance updates.

Fund's Positions
in Mentioned Holdings

As a percentage of net assets, as of 6/30/12

Discover Financial Services	6.1	%
Hertz	5.2	%
CNO Financial Group	5.1	%
SBA Communications	3.8	%
Gaylord Entertainment	3.3	%
Coach	3.0	%
Sanmina-SCI	2.3	%
Akorn	1.9	%
Abercrombie & Fitch	1.4	%
Canacol	1.2	%
Vail Resorts	1.1	%
Houston American Energy	0.1	%

Columbia Acorn Select fell 8.44% in the second quarter of 2012, but year to date through June 30, 2012 was up 7.76%. The Fund's primary benchmark, the S&P MidCap 400 Index was down 4.93% in the second quarter and was up 7.90% year to date. The S&P 500 Index, a general barometer of U.S. market large-cap performance, was down 2.75% in the quarter and year to date was up 9.49%.

In our first quarter report, we noted that we were seeing some strengthening in U.S. economic indicators and speculated that improvements might continue for a little while. Unfortunately, they didn't. U.S., European and Asian economic indicators turned down in the second quarter. Many of the stocks that added to the Fund's outperformance in the first quarter took it away this quarter.

On the downside, Sanmina-SCI, Hertz and Coach each cost the Fund close to one percent of portfolio performance in the second quarter. On the upside, we saw Gaylord Entertainment, Akorn and SBA Communications each add between 40 and 65 basis points to the Fund's performance in the quarter. For the first six months of the year, Discover Financial Services added two percent to the Fund's performance, while Gaylord Entertainment, CNO Financial Group and SBA Communications each added a little more than one percent. The larger detractors to the Fund's six-month performance were Houston American Energy, Abercrombie & Fitch and Canacol, which each cost the portfolio between 60 and 75 basis points.

When an economy is over leveraged, we believe a country has a choice to either grow, collapse, or inflate its way out of the problem. In our opinion, the western world has been doing a pretty good job of inflating but political leadership has done a poor job of providing a path to growth. The United States' path has been fraught with consistently changing regulation, controversial interpretations of legislation and court rulings, and concerns that new anti-business legislation will be passed. Each has helped cause businesses to sit back and wait. The western economies have been driven by huge government deficit spending and have bumped along with growth rates in the low single digits, prompting continuous investor concerns of possible recession.

We have struggled to outperform the Fund's primary benchmark. As we've mentioned in previous "Nutshells," we have been slowly changing the mix of the Fund's core growth holdings and the Fund's opportunistic holdings. In an environment in which the economy is struggling to deliver consecutive quarters of increasing growth, we believe core growth stocks should perform better than companies trying to turn around their operations in a weak economic environment (which is the case with many of the Fund's opportunistic holdings). Though the Fund's performance was disappointing this quarter, we feel strongly that we are on the right path as we near the end of this transition within the Fund's portfolio.

During the second quarter, we added one new stock to the portfolio and exited from one position. Our new position is Vail Resorts, a ski resort operator that we believe we picked up cheaply due to the warm winter. On the sell side, we exited from Safeway as we believe the supermarket industry's gross margin pressure is not going to subside.

As investors along with you in the Fund, we are anxious to see performance improve. We believe we are making adjustments to help our Fund seek to outperform its benchmark. Thank you for your investment in the Fund.

Risks include stock market fluctuations due to economic and business developments. The Fund also has potentially greater price volatility due to the Fund's concentration in a limited number of stocks of mid-size companies. International investments involve greater potential risks, including less regulation, currency fluctuations, economic instability and political developments.

Portfolio holdings are subject to change periodically and may not be representative of current holdings.

16

Columbia Acorn Select (ACTWX)

At a Glance

Performance data shown represents past performance and is not a guarantee of future results. The investment return and principal value of an investment will fluctuate so that shares, when redeemed, may be worth more or less than their original cost. Current performance may be lower or higher than the performance data shown. Performance results reflect any fee waivers or reimbursements of Fund expenses by the investment manager and/or any of its affiliates. Absent these fee waivers and/or expense reimbursement arrangements, performance results would have been lower. Please visit columbiamanagement.com for daily and most recent month-end updates.

Pretax and After-tax Average Annual Total Returns (Class Z)

through June 30, 2012

Inception 11/23/98	Year to date*			1 year			5 years			10 years
Returns before taxes		7.76	%		-9.90	%		-2.64	%		7.39	%
Returns after taxes on distributions		7.42			-10.18			-2.94			7.08
Returns after taxes on distributions and sale of fund shares		5.49			-6.06			-2.29			6.48
S&P MidCap 400 Index (pretax)**		7.90			-2.33			2.55			8.21

All results shown assume reinvestment of distributions.

*Year to date data is not annualized.

**The Fund's primary benchmark.

After-tax returns are calculated using the highest historical individual federal marginal income tax rates, and do not reflect the impact of state and local taxes. Returns after taxes on distributions and sale of Fund shares reflect the additional tax impact of long-term gains or losses realized when Fund shares are sold. The returns are taxed at the maximum rate and assume shares were purchased at the beginning of the period. Actual after-tax returns depend on the investor's tax situation and may differ from those shown. After-tax returns are not relevant to investors who hold their Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts. After-tax returns are shown for Class Z shares only; after-tax returns for other share classes will vary. Indexes do not reflect any deduction for fees, expenses or taxes.

The Fund's Class Z shares annual operating expense ratio, as stated in the May 1, 2012, prospectus, is 1.00%.

Columbia Acorn Select Portfolio Diversification

as a percentage of net assets, as of 6/30/12

Columbia Acorn Select Top 10 Holdings

as a percentage of net assets, as of 6/30/12

1.	Ametek Aerospace/Industrial Instruments	6.2	%
2.	Discover Financial Services Credit Card Company	6.1	%
3.	Hertz Largest U.S. Rental Car Operator	5.2	%
4.	CNO Financial Group Life, Long-term Care & Medical Supplement Insurance	5.1	%
5.	SBA Communications Communications Towers	3.8	%
6.	Crown Castle International Communications Towers	3.7	%
7.	Donaldson Industrial Air Filtration	3.5	%
8.	Gaylord Entertainment Convention Hotels	3.3	%
9.	Pall Filtration & Fluids Clarification	3.1	%
10.	WNS (India) Offshore BPO (Business Process Outsourcing) Services	3.0	%

The Fund's top 10 holdings and portfolio diversification vary with changes in portfolio investments. See the Statement of Investments for a complete list of the Fund's holdings.

The Growth of a $10,000 Investment in Columbia Acorn Select (Class Z)

November 23, 1998 through June 30, 2012

This graph compares the results of $10,000 invested in Columbia Acorn Select at inception on November 23, 1998 to the S&P MidCap 400 Index. Although the index is provided for use in assessing the Fund's performance, the Fund's holdings differ significantly from those in the index. The index is unmanaged and returns for both the index and the Fund include reinvested dividends and capital gains. It is not possible to invest directly in an index. The graph does not reflect taxes that a shareholder would pay on Fund distributions or on a sale of Fund shares.

Total Net Assets of the Fund: $1.1 billion

17

Columbia Thermostat Fund

In a Nutshell

Charles P. McQuaid

Lead Portfolio Manager

Performance data shown represents past performance and is not a guarantee of future results. The investment return and principal value will fluctuate so that shares, when redeemed, may be worth more or less than the original cost. Current performance may be lower or higher than the performance data shown. Please visit columbiamanagement.com for daily and most recent month-end performance updates.

A "fund of fund" bears its allocable share of the costs and expenses of the underlying funds in which it invests. Such funds are thus subject to two levels of fees and potentially higher expense ratios than would be associated with a fund that invests and trades directly in financial instruments under the direction of a single manager.

Columbia Thermostat Fund ended the second quarter of 2012 off 1.40%, above the 2.75% drop of its primary equity benchmark, the S&P 500 Index, and below the 2.06% gain of its primary debt benchmark, the Barclays U.S. Aggregate Bond Index. Year to date through June 30, 2012, the Fund was up 6.77%, falling below the 9.49% S&P 500 Index return and above the 2.37% gain of the Barclays U.S. Aggregate Bond Index.

The Fund hit four reallocation triggers in the second quarter, increasing stock exposure in April and twice in May as the markets cooled, then reducing stocks in June as the equity markets turned. At quarter end, the Fund had an even weighting in its underlying stock and bond investments.

For the quarter, the equity portion of the Fund had a weighted average loss of 4.96%, while the bond portion provided a 2.11% gain. Columbia U.S. Treasury Index Fund led performance among both groups with a 2.76% return for the three months.

Year to date through the end of June, the equity portion of the Fund had an 8.66% return, while the income portion posted a 4.01% gain. Top contributors for the half year were Columbia LargeCap Enhanced Core Fund, up 10.05%, and Columbia Contrarian Core Fund, up 9.67%.

On September 25, Columbia Thermostat Fund will reach its 10-year anniversary. The "Chattering Squirrels" essay at the front of this report looks back at how a fund called "Thermostat" came to be and how it is managed. As always, we thank you for your investment in the Fund. We are pleased to report that, since inception through the end of June, the Fund has, once again, exceeded our expectations by besting both its stock and bond benchmarks.

Results of the Funds Owned in Columbia Thermostat Fund as of June 30, 2012

Stock Funds	Weightings			2nd			Year to
Fund	in category			quarter			date
Columbia Acorn International, Class I		20	%		-5.49	%		8.79	%
Columbia Dividend Income Fund, Class I		20	%		-0.45	%		7.79	%
Columbia Acorn Fund, Class I		15	%		-5.42	%		9.27	%
Columbia Contrarian Core Fund, Class I		15	%		-4.37	%		9.67	%
Columbia Select Large Cap Growth Fund, Class I		10	%		-11.47	%		6.22	%
Columbia Acorn Select, Class I		10	%		-8.46	%		7.79	%
Columbia Large Cap Enhanced Core Fund, Class I		10	%		-2.98	%		10.05	%
Weighted Average Equity Gain/Loss		100	%		-4.96	%		8.66	%
Bond Funds	Weightings			2nd			Year to
Fund	in category			quarter			date
Columbia Intermediate Bond Fund, Class I		50	%		1.87	%		3.62	%
Columbia Income Opportunities Fund, Class I		30	%		2.02	%		6.33	%
Columbia U.S. Treasury Index Fund, Class I		20	%		2.76	%		1.41	%
Weighted Average Income Gain		100	%		2.11	%		4.01	%

Columbia Thermostat Fund
Rebalancing in the Second Quarter

April 16, 2012	50% stocks, 50% bonds
May 15, 2012	55% stocks, 45% bonds
May 21, 2012	60% stocks, 40% bonds
June 21, 2012	50% stocks, 50% bonds

The value of an investment in the Fund is based primarily on the performance of the underlying portfolio funds and the allocation of the Fund's assets among them. An investment in the underlying portfolio funds may present certain risks, including stock market fluctuations that occur in response to economic and business developments; and a greater degree of social, political and economic volatility associated with international investing. Stocks of small- and mid-cap companies pose special risks, including possible illiquidity and greater price volatility than stocks of larger, more established companies. Value stocks may also be subject to specific business risks that have caused the stocks to be out of favor. Lower-rated and medium quality debt securities are more speculative and incur more risk. International investing involves special risks, including foreign taxation, currency risks, risks associated with possible differences in financial standards and other risks associated with future political and economic developments. Changes in interest rates and changes in the financial strength of issuers of lower-rated bonds may also affect underlying fund performance. The Fund is also subject to the risk that the investment advisor's decisions regarding asset classes and underlying portfolio funds will not anticipate market trends successfully, resulting in a failure to preserve capital or lower total return. In addition, the Fund may buy and sell shares of the portfolio funds frequently. This may result in higher transaction costs and additional tax liability. This is not an offer of the shares of any other mutual fund mentioned herein.

18

Columbia Thermostat Fund (COTZX)

At a Glance

Performance data shown represents past performance and is not a guarantee of future results. The investment return and principal value of an investment will fluctuate so that shares, when redeemed, may be worth more or less than their original cost. Current performance may be lower or higher than the performance data shown. Performance results reflect any fee waivers or reimbursements of Fund expenses by the investment manager and/or any of its affiliates. Absent these fee waivers and/or expense reimbursement arrangements, performance results would have been lower. Please visit columbiamanagement.com for daily and most recent month-end updates.

Pretax and After-tax Average Annual Total Returns (Class Z)

through June 30, 2012

Inception 9/25/02	Year to date*			1 year			5 years			Life of fund
Returns before taxes		6.77	%		6.97	%		4.68	%		7.84	%
Returns after taxes on distributions		6.72			6.46			3.73			6.67
Returns after taxes on distributions and sale of fund shares		4.40			4.66			3.52			6.31
S&P 500 Index (pretax)**		9.49			5.45			0.22			7.48
Barclays U.S. Aggregate Bond Index (pretax)**		2.37			7.47			6.79			5.31
Lipper Flexible Portfolio Funds Index (pretax)		5.75			-0.55			1.82			7.34

All results shown assume reinvestment of distributions.

*Year to date data is not annualized.

**The Fund's primary stock and bond benchmarks, respectively.

After-tax returns are calculated using the highest historical individual federal marginal income tax rates, and do not reflect the impact of state and local taxes. Returns after taxes on distributions and sale of Fund shares reflect the additional tax impact of long-term gains or losses realized when Fund shares are sold. The returns are taxed at the maximum rate and assume shares were purchased at the beginning of the period. Actual after-tax returns depend on the investor's tax situation and may differ from those shown. After-tax returns are not relevant to investors who hold their Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts. After-tax returns are shown for Class Z shares only; after-tax returns for other share classes will vary. Indexes do not reflect any deduction for fees, expenses or taxes.

The Fund's Class Z annual operating expense ratio, as stated in the May 1, 2012, prospectus, is 0.90%. Columbia Thermostat Fund has a contractual fee waiver and expense reimbursement with CWAM that expires April 30, 2013; expense ratios without and with the contractual waiver/reimbursement, including fees and expenses associated with the Fund's investment in other investment companies (underlying funds), are 1.03% and 0.90%, respectively. Absent the waiver or reimbursement, performance results would have been lower.

Columbia Thermostat Fund Asset Allocation

as a percentage of net assets, as of 6/30/12

Columbia Thermostat Fund Portfolio Weightings

as a percentage of assets in each investment category, as of 6/30/12

Stock Mutual Funds

Columbia Acorn International, Class I	20	%
Columbia Dividend Income Fund, Class I	20	%
Columbia Acorn Fund, Class I	15	%
Columbia Contrarian Core Fund, Class I	15	%
Columbia Select Large Cap Growth Fund, Class I	10	%
Columbia Acorn Select, Class I	10	%
Columbia Large Cap Enhanced Core Fund, Class I	10	%

Bond Mutual Funds

Columbia Intermediate Bond Fund, Class I	50	%
Columbia Income Opportunities Fund, Class I	30	%
Columbia U.S. Treasury Index Fund, Class I	20	%

The Growth of a $10,000 Investment in Columbia Thermostat Fund (Class Z)

September 25, 2002 through June 30, 2012

This graph compares the results of $10,000 invested in Columbia Thermostat Fund at inception on September 25, 2002 to the S&P 500 Index, the Barclays U.S. Aggregate Bond Index and the Lipper Flexible Portfolio Funds Index. Although the indexes are provided for use in assessing the Fund's performance, the Fund's holdings differ significantly from those in the indexes. The Indexes are unmanaged and returns for the indexes and the Fund include reinvested dividends and capital gains. It is not possible to invest directly in an index. The graph does not reflect taxes that a shareholder would pay on Fund distributions or on a sale of Fund shares.

Total Net Assets of the Fund: $440.1 million

19

Columbia Acorn Emerging Markets Fund

In a Nutshell

Fritz Kaegi	Stephen Kusmierczak
Lead Portfolio Manager	Lead Portfolio Manager
P. Zachary Egan	Louis J. Mendes
Co-Portfolio Manager	Co-Portfolio Manager

Performance data shown represents past performance and is not a guarantee of future results. The investment return and principal value will fluctuate so that shares, when redeemed, may be worth more or less than the original cost. Current performance may be lower or higher than the performance data shown. Please visit columbiamanagement.com for daily and most recent month-end performance updates.

Fund's Positions
in Mentioned Holdings

As a percentage of net assets, as of 6/30/12

Grupo Aeroportuario del Sureste	2.4	%
Surya Citra Media	1.8	%
Multiplus	1.4	%
Mongolian Mining	1.4	%
Mayora Indah	0.6	%
Americas Petrogas	0.6	%
Northam Platinum	0.5	%
Madalena Ventures	0.2	%

Columbia Acorn Emerging Markets Fund fell 6.90% in the second quarter of 2012 versus the 8.09% decline in the Fund's primary benchmark, the S&P Emerging Markets Between $500M and $5B Index. The Fund's more conservative positioning in very volatile markets has helped it outperform the benchmark since inception. Since the Fund's launch on August 19, 2011, it has returned a positive 1.94%, outperforming the benchmark's 5.77% decline. For the half year ended June 30, the Fund was up 9.85%, outpacing the 8.88% gain of its benchmark.

In the second quarter, the Fund benefited from its continued overweight in companies that we believe should benefit from rising incomes in emerging markets. Mayora Indah, an Indonesian maker of biscuits and chocolates, was added to the Fund during the quarter and gained nearly 29%. Grupo Aeroportuario del Sureste operates airports in Mexico, where air travel for tourism is growing strongly. Its stock gained over 18% following positive news about possible expansion into Puerto Rico. Surya Citra Media is Indonesia's most profitable private free-to-air broadcaster and gained 17% to reach a new record since its listing in 2002. Multiplus is Brazil's largest operator of loyalty programs and is a beneficiary of secular growth in credit and travel. Despite somewhat disappointing results due to higher airline ticket prices used in rewards, Multiplus gained over 15%.

The largest performance detractors in the second quarter were the Fund's energy and basic materials stocks. Two Canadian-listed oil and gas exploration companies with substantial assets in Argentina dropped sharply in the quarter following government moves to nationalize a large energy company. While we see no evidence of specific government action against our holdings, Madalena Ventures dropped nearly 63% and Americas Petrogas declined 48% as the risk premium for Argentina jumped substantially. Mongolian Mining is a world-class coking coal deposit in Southern Mongolia near the Chinese border. The stock fell 40% to a record low on concerns about tightening investment rules following recent elections. Northam Platinum owns one of the world's best undeveloped deposits of platinum, a precious metal used in important industrial applications like catalytic converters. Northam fell 35% in the wake of weak platinum prices and a leak at its smelter.

An important element of the Fund's relatively conservative positioning is its focus on investing in companies that pay dividends. We believe that a meaningful and growing dividend is the ultimate proof that a company is generating free cash flow, and that reinvested dividends represent the largest component of total shareholder returns over time. The current dividend yield of the Fund's portfolio is slightly below the benchmark's, yet the Fund's more concentrated portfolio is a higher quality one as measured by return on shareholder equity. We think companies that earn higher returns on capital should grow faster than their peers. We do not believe we have to sacrifice growth for higher dividends, and we have tried to identify companies with defensible business models and above-average returns that are exposed to durable growth trends in the emerging markets.

International investing involves special risks, including foreign taxation, currency risks, risks associated with possible differences in financial standards and other risks associated with future political and economic developments. Stocks of small- and mid-cap companies pose special risks, including possible illiquidity and greater price volatility than stocks of larger, more established companies. Investing in emerging markets may involve greater risks than investing in more developed countries.

Portfolio holdings are subject to change periodically and may not be representative of current holdings.

20

Columbia Acorn Emerging
Markets Fund(CEFZX)

At a Glance

Performance data shown represents past performance and is not a guarantee of future results. The investment return and principal value of an investment will fluctuate so that shares, when redeemed, may be worth more or less than their original cost. Current performance may be lower or higher than the performance data shown. Performance results reflect any fee waivers or reimbursements of Fund expenses by the investment manager and/or any of its affiliates. Absent these fee waivers and/or expense reimbursement arrangements, performance results would have been lower. Please visit columbiamanagement.com for daily and most recent month-end updates.

Pretax and After-tax Total Returns (Class Z)

through June 30, 2012

Inception 8/19/11	Year to date*			Life of fund*†
Returns before taxes		9.85	%		1.94	%
Returns after taxes on distributions		9.84			1.94
Returns after taxes on distributions and sale of fund shares		6.40			1.27
S&P Emerging Markets Between $500M and $5B Index (pretax)***		8.88			-5.77

All results shown assume reinvestment of distributions.

*Year to date and life of fund data is not annualized.

†Reflects performance from Fund inception on 8/19/11 through 6/30/12.

***The Fund's primary benchmark.

After-tax returns are calculated using the highest historical individual federal marginal income tax rates, and do not reflect the impact of state and local taxes. Returns after taxes on distributions and sale of Fund shares reflect the additional tax impact of long-term gains or losses realized when Fund shares are sold. The returns are taxed at the maximum rate and assume shares were purchased at the beginning of the period. Actual after-tax returns depend on the investor's tax situation and may differ from those shown. After-tax returns are not relevant to investors who hold their Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts. After-tax returns are shown for Class Z shares only; after-tax returns for other share classes will vary. Indexes do not reflect any deduction for fees, expenses or taxes.

The Fund's Class Z annual operating expense ratio, as stated in the May 1, 2012 prospectus, is 1.60%. Columbia Acorn Emerging Markets Fund has a contractual fee waiver and expense reimbursement agreement with CWAM that expires April 30, 2013; expense ratios without and with the contractual waiver/reimbursement are 13.35% and 1.60%, respectively. Absent the waiver or reimbursement, performance results would have been lower.

Columbia Acorn Emerging Markets Fund Portfolio Diversification

as a percentage of net assets, as of 6/30/12

Columbia Acorn Emerging Markets Fund
Top 10 Holdings

as a percentage of net assets, as of 6/30/12

1.	Ace Indonesia (Indonesia) Home Improvement Retailer	3.5	%
2.	Tower Bersama Infrastructure (Indonesia) Communications Towers	3.3	%
3.	Nagacorp (Cambodia) Casino/Entertainment Complex in Cambodia	3.3	%
4.	Far EasTone Telecom (Taiwan) Taiwan's Third Largest Mobile Operator	2.8	%
5.	Rand Merchant Insurance (South Africa) Directly Sold Property & Casualty Insurance; Holdings in Other Insurers	2.8	%
6.	Coronation Fund Managers (South Africa) South African Fund Manager	2.7	%
7.	Dufry Group (Switzerland) Operators Airport Duty Free & Duty Paid Shops	2.5	%
8.	CTCI Corp (Taiwan) International Engineering Firm	2.4	%
9.	Grupo Aeroportuario del Sureste (Mexico) Mexican Airport Operator	2.4	%
10.	Hexagon (Sweden) Design, Measurement & Visualization Software & Equipment	2.1	%

The Fund's top 10 holdings and portfolio diversification vary with changes in portfolio investments. See the Statement of Investments for a complete list of the Fund's holdings.

The Growth of a $10,000 Investment in Columbia Acorn Emerging Markets Fund (Class Z)

August 19, 2011 through June 30, 2012

This graph compares the results of $10,000 invested in Columbia Acorn Emerging Markets Fund at inception on August 19, 2011 to the S&P Emerging Markets Between $500M and $5B Index. Although the index is provided for use in assessing the Fund's performance, the Fund's holdings may differ significantly from those in the index. The index and Fund returns include reinvested dividends and capital gains. It is not possible to invest directly in an index. The graph does not reflect taxes that a shareholder would pay on Fund distributions or on a sale of Fund shares.

Total Net Assets of the Fund:
$5.8 million

21

Columbia Acorn European Fund

In a Nutshell

Andreas Waldburg-Wolfegg	Stephen Kusmierczak
Lead Portfolio Manager	Co-Portfolio Manager

Performance data shown represents past performance and is not a guarantee of future results. The investment return and principal value will fluctuate so that shares, when redeemed, may be worth more or less than the original cost. Current performance may be lower or higher than the performance data shown. Please visit columbiamanagement.com for daily and most recent month-end performance updates.

Fund's Positions
in Mentioned Holdings

As a percentage of net assets, as of 6/30/12

Eurofins Scientific	3.6	%
Gemalto	3.4	%
Aalberts Industries	2.0	%
Domino's Pizza UK & Ireland	1.9	%
Geox	1.1	%

Columbia Acorn European Fund was up 11.62% for the six months ended June 30, 2012, outperforming the 7.65% return of its primary benchmark, the S&P Europe Between $500M and $5B Index. In absolute numbers, the Fund had a very strong first quarter, up 17.69%, followed by a lackluster second quarter, in which the Fund was down 5.16%. But the real story was in the relative numbers. Whereas the Fund closely matched the 17.80% gain in the first quarter of its benchmark, it contained the losses from the general downdraft in the second quarter better than the benchmark, which fell 8.62%.

French Fund holdings continued to perform strongly in the second quarter. Smart card products and solutions company Gemalto was up 9%, and food, drug and materials testing provider Eurofins Scientific gained 15%. Gemalto released a very positive first quarter sales report that showed sales in the mobile phone division up 11%, the first such growth in a few quarters. This turn confirmed our thesis that the change to fourth-generation wireless technology should increasingly feed through the company's top line. Eurofins Scientific announced a near doubling of its net profit in the first quarter of 2012, which, in itself, is not very significant because the bulk of the business's sales happen in the second half. What we were more interested to see was that Eurofins Scientific's business grew 10% organically in Europe, proof that when you're in the right business, macro issues can take second place. We shaved some off our position in Gemalto and added some in Eurofins Scientific to reflect short-term performance. Both continue to be in the Fund's top-five stocks by size.

Retailers like to complain about the weather: it's never right. Not so for Domino's Pizza UK & Ireland, the U.S. pizza maker's British, Irish and German franchise. The rainiest April on record in the United Kingdom caused people to stay home and order in. Domino's was only too happy to deliver, and so did the stock, up 17% in the quarter and 29% for the half year.

There were few strong detractors in the portfolio, largely because the largest slides came from small positions. Geox, the Italian maker of casual shoes, saw its stock decline 26% in the second quarter following a profit warning that accompanied the release of first quarter figures. Start-up costs related to expansion in Asia, Russia and Eastern Europe have negatively impacted Geox's margins. We believe that the strength of the company's patents, brand and balance sheet will help it gain market share over competitors, especially now that franchisees will be willing to ally themselves closer to a strong operator.

Another detractor to performance in the second quarter was Aalberts Industries, a manufacturer of flow control and heat treatment equipment based in the Netherlands, down almost 23%. An update on quarterly sales and management's outlook at the beginning of May were cautious, which hurt the stock. This diversified industrial company has strong market positions in most European countries and is suffering from lower capacity utilization in its industrial services division. For 2012, we believe the company is likely to show flat growth. On the other hand, we believe Aalberts's strong market positions, outstanding margins and excellent management are unlikely to go away, even during this time of weak demand. We believe its competitive position is bound to improve.

International investing involves special risks, including foreign taxation, currency risks, risks associated with possible differences in financial standards and other risks associated with future political and economic developments. Stocks of small- and mid-cap companies pose special risks, including possible illiquidity and greater price volatility than stocks of larger, more established companies. Investing in emerging markets may involve greater risks than investing in more developed countries.

Portfolio holdings are subject to change periodically and may not be representative of current holdings.

22

Columbia Acorn
European Fund(CAEZX)

At a Glance

Performance data shown represents past performance and is not a guarantee of future results. The investment return and principal value of an investment will fluctuate so that shares, when redeemed, may be worth more or less than their original cost. Current performance may be lower or higher than the performance data shown. Performance results reflect any fee waivers or reimbursements of Fund expenses by the investment manager and/or any of its affiliates. Absent these fee waivers and/or expense reimbursement arrangements, performance results would have been lower. Please visit columbiamanagement.com for daily and most recent month-end updates.

Pretax and After-tax Total Returns (Class Z)

through June 30, 2012

Inception 8/19/11	Year to date*			Life of fund*†
Returns before taxes		11.62	%		6.29	%
Returns after taxes on distributions		11.56			5.99
Returns after taxes on distributions and sale of fund shares		7.55			4.15
S&P Europe Between $500M and $5B Index (pretax)***		7.65			-0.07

All results shown assume reinvestment of distributions.

*Year to date and life of fund data is not annualized.

†Reflects performance from Fund inception on 8/19/11 through 6/30/12.

***The Fund's primary benchmark.

After-tax returns are calculated using the highest historical individual federal marginal income tax rates, and do not reflect the impact of state and local taxes. Returns after taxes on distributions and sale of Fund shares reflect the additional tax impact of long-term gains or losses realized when Fund shares are sold. The returns are taxed at the maximum rate and assume shares were purchased at the beginning of the period. Actual after-tax returns depend on the investor's tax situation and may differ from those shown. After-tax returns are not relevant to investors who hold their Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts. After-tax returns are shown for Class Z shares only; after-tax returns for other share classes will vary. Indexes do not reflect any deduction for fees, expenses or taxes.

The Fund's Class Z annual operating expense ratio, as stated in the May 1, 2012 prospectus, is 1.50%. Columbia Acorn European Fund has a contractual fee waiver and expense reimbursement agreement with CWAM that expires April 30, 2013; expense ratios without and with the contractual waiver/reimbursement are 19.02% and 1.50%, respectively. Absent the waiver or reimbursement, performance results would have been lower.

Columbia Acorn European Fund Portfolio Diversification

as a percentage of net assets, as of 6/30/12

Columbia Acorn European Fund Top 10 Holdings

as a percentage of net assets, as of 6/30/12

1.	Eurofins Scientific (France) Food, Pharmaceuticals & Materials Screening & Testing	3.6	%
2.	Gemalto (France) Digital Security Solutions	3.4	%
3.	Wirecard (Germany) Online Payment Processing & Risk Management	3.0	%
4.	Geberit (Switzerland) Plumbing Supplies	2.8	%
5.	Charles Taylor (United Kingdom) Insurance Services	2.7	%
6.	1000 mercis (France) Interactive Advertising and Marketing	2.6	%
7.	Marel (Iceland) Largest Manufacturer of Poultry & Fish Processing Equipment	2.5	%
8.	Hexagon (Sweden) Design, Measurement & Visualization Software & Equipment	2.5	%
9.	Partners Group (Switzerland) Private Markets Asset Management	2.5	%
10.	Sweco (Sweden) Engineering Consultants	2.3	%

The Fund's top 10 holdings and portfolio diversification vary with changes in portfolio investments. See the Statement of Investments for a complete list of the Fund's holdings.

The Growth of a $10,000 Investment in Columbia Acorn European Fund (Class Z)

August 19, 2011 through June 30, 2012

This graph compares the results of $10,000 invested in Columbia Acorn European Fund at inception on August 19, 2011 to the S&P Europe Between $500M and $5B Index. Although the index is provided for use in assessing the Fund's performance, the Fund's holdings may differ significantly from those in the index. The index and Fund returns include reinvested dividends and capital gains. It is not possible to invest directly in an index. The graph does not reflect taxes that a shareholder would pay on Fund distributions or on a sale of Fund shares.

Total Net Assets of the Fund:
$2.1 million

23

Columbia Acorn Fund

Major Portfolio Changes in the Second Quarter (Unaudited)

	Number of Shares
	3/31/12		6/30/12
Purchases
Information
Angies list		0		231,700
Cree		380,000		560,000
Genpact		1,575,000		1,705,000
Hexagon (Sweden)		5,164,999		5,450,000
Lamar Advertising		0		1,725,000
SABA		0		2,000,000
Velti		2,500,000		2,700,000
Yandex (Russia)		0		700,100
Industrial Goods & Services
Aalberts Industries (Netherlands)		2,263,654		2,324,833
Ashland		0		800,000
Chicago Bridge & Iron		1,725,000		2,850,000
Forward Air		1,300,000		1,400,000
Generac		1,776,000		2,350,000
Moog		2,775,000		3,000,000
Neopost (France)		210,000		350,000
Polypore International		900,000		1,325,000
Consumer Goods & Services
American Eagle Outfitters		300,000		1,075,000
Arcos Dorados (Brazil)		0		1,800,000
Avis Budget Group		3,800,000		4,400,000
Deckers Outdoor		1,140,000		1,310,000
Fossil		392,500		527,845
GNC Holdings		1,528,500		2,305,000
Interface		1,750,000		2,038,555
Lifestyle International (Hong Kong)		13,500,000		16,857,500
Pier 1 Imports		5,600,000		6,600,000
Finance
Associated Banc-Corp		6,287,800		6,956,800
City National		1,175,000		1,348,000
Eaton Vance		3,700,000		4,036,000
First Commonwealth		1,000,000		2,500,000
FX Alliance		0		300,000
Onex Capital (Canada)		0		450,000
SEI Investments		6,198,000		6,654,000
SVB Financial Group		810,000		985,000
Health Care
ARIAD Pharmaceuticals		0		2,568,248
Cepheid		3,900,000		4,600,000
DENTSPLY International		1,136,500		1,550,000
InterMune		2,950,000		3,850,000
Synageva Biopharma		180,167		569,898

	Number of Shares
	3/31/12		6/30/12
Energy & Minerals
Gulf United (Colombia)		0		50,000,000
Kirkland Lake Gold (Canada)		920,000		1,400,000
Laredo Petroleum		0		1,159,000
Mongolian Mining (Mongolia)		12,000,000		16,000,000
Other Industries
Rush Enterprises, Class A		2,800,000		2,937,175

See accompanying notes to financial statements.

24

	Number of Shares
	3/31/12		6/30/12
Sales
Information
Akamai		250,000		0
Amphenol		3,495,000		3,415,000
Ariba		2,850,000		900,000
Atmel		12,300,000		11,562,000
Blackbaud		1,650,000		960,329
Concur Technologies		1,830,000		1,400,000
Constant Contact		2,350,000		2,000,000
Discovery Series C		1,595,000		900,000
Equinix		585,000		450,000
F5 Networks		685,000		640,000
Finisar		1,695,000		1,345,000
FTI Consulting		868,516		234,615
Global Payments		2,299,000		1,700,000
Ixia		2,330,000		1,730,000
Kenexa		1,700,000		1,173,100
Liberty Global Series A		1,250,000		900,000
Littelfuse		500,000		420,000
Mail.ru - GDR (Russia)		400,000		234,168
NetSuite		1,150,000		800,000
Plexus		1,100,000		960,000
Red Hat		750,000		700,000
Saga Communications		164,991		145,271
SBA Communications		3,700,000		3,400,000
TIBCO		2,150,000		1,450,000
Tyler Technologies		1,700,000		900,000
Zebra Technologies		1,605,000		1,365,000
Industrial Goods & Services
Albany International		900,000		600,000
GrafTech International		3,750,000		2,800,000
Imtech (Netherlands)		1,601,465		1,491,313
Interline Brands		2,399,751		1,400,000
Jain Irrigation Systems (India)		3,450,000		0
Jain Irrigation Systems - DVR (India)		172,500		0
Kaydon		501,000		0
Mersen (France)		260,000		92,046
Pentair		3,100,000		1,890,000
Waste Connections		2,400,000		2,050,000
Consumer Goods & Services
Abercrombie & Fitch		3,460,000		3,040,000
GLG Life Tech (Canada)		1,678,125		1,665,270
lululemon athletica		4,922,800		4,505,000
Monster Beverage		2,340,000		1,700,000
Saks		5,225,000		4,425,000
Snyder's-Lance		240,000		0
True Religion Apparel		393,452		231,452
Universal Technical Institute		612,205		0
Warnaco Group		2,190,000		1,460,000

	Number of Shares
	3/31/12		6/30/12
Finance
Assured Guaranty		500,000		0
BOK Financial		2,691,414		2,638,000
CVB Financial		3,400,000		3,000,000
Green Bankshares		152,569		79,800
Oriental Financial Group		500,000		0
World Acceptance		1,459,555		1,425,202
Health Care
Alexion Pharmaceuticals		2,290,000		1,476,000
Allscripts Healthcare Solutions		1,200,000		0
Gen-Probe		760,000		0
Hill-Rom Holdings		1,873,800		1,275,000
Onyx Pharmaceuticals		1,000,000		750,000
Pacific Biosciences of California		2,525,000		0
Raptor Pharmaceutical		4,200,000		3,609,594
Energy & Minerals
Alexco Resource		2,800,000		2,050,000
Athabasca Oil Sands (Canada)		2,160,000		750,000
Baytex (Canada)		650,000		361,000
Black Diamond Group (Canada)		1,056,600		893,600
Canacol (Colombia)		5,917,100		5,116,000
Celtic Exploration (Canada)		1,140,000		718,000
Core Laboratories (Netherlands)		442,000		387,000
Crew Energy (Canada)		1,547,000		493,000
FMC Technologies		5,298,000		5,150,000
Fugro (Netherlands)		1,988,054		1,289,106
Oil States International		743,000		513,000
Pacific Rubiales Energy (Colombia)		4,250,000		3,700,000
Silver Wheaton (Canada)		1,600,000		550,000
SM Energy		900,000		703,000
Tullow Oil (United Kingdom)		1,697,000		1,050,000
Tuscany International Drilling (Colombia)		4,435,000		4,415,000
Vopak (Netherlands)		300,000		218,000
Other Industries
Genesee & Wyoming		400,000		300,000

See accompanying notes to financial statements.

25

Columbia Acorn Fund

Statement of Investments (Unaudited), June 30, 2012

Number of Shares			Value (000)
			Equities: 95.8%
Information 27.2%
		> Business Software 6.9%
	5,000,000	Informatica (a)	$	211,800
		Enterprise Data Integration Software
	2,550,000	Ansys (a)		160,930
		Simulation Software for Engineers & Designers
	2,700,000	Micros Systems (a)		138,240
		Information Systems for Hotels, Restaurants & Retailers
	1,400,000	Concur Technologies (a)		95,340
		Web Enabled Cost & Expense Management Software
	5,450,000	Hexagon (Sweden)		93,549
		Design, Measurement & Visualization Software & Equipment
	2,350,000	Quality Systems		64,649
		IT Systems for Medical Groups & Ambulatory Care Centers
	800,000	NetSuite (a)		43,816
		End-to-end IT Systems Solutions Delivered Over the Web
	1,450,000	TIBCO (a)		43,384
		Datacenter Software
	900,000	Ariba (a)		40,284
		Cost Management Software
	700,000	Red Hat (a)		39,536
		Maintenance & Support for Opensource Operating Systems & Middleware
	900,000	Tyler Technologies (a)		36,315
		Financial, Tax, Court & Document Management Systems for Local Governments
	2,000,000	Constant Contact (a)(b)(c)		35,760
		Email & Other Marketing Campaign Management Systems Delivered Over the Web
	1,173,100	Kenexa (a)		34,055
		Recruiting & Workforce Management Solutions
	900,000	SPS Commerce (a)(b)		27,342
		Supply Chain Management Software Delivered via the Web
	750,000	Jack Henry & Associates		25,890
		IT Systems & Outsourced IT Solutions for Financial Institutions
	960,329	Blackbaud		24,652
		Software & Services for Non-profits
	690,000	Advent Software (a)		18,706
		Asset Management & Trading Systems
	2,000,000	SABA (a)(b)		18,560
		Learning Management Systems
	2,700,000	Velti (a)(c)		17,550
		Mobile Marketing Software Platform
	900,000	Active Network (a)		13,851
		Web Delivered Software Solution for Managing Events & Activities
	1,000,000	InContact (a)		5,010
		Call Center Systems Delivered Via the Web & Telco Services
	55,000	Solera Holdings		2,298
		Software for Automotive Insurance Claims Processing
				1,191,517

Number of Shares			Value (000)
		> Instrumentation 2.7%
	1,600,000	Mettler-Toledo International (a)(b)	$	249,360
		Laboratory Equipment
	2,780,000	IPG Photonics (a)(b)		121,180
		Fiber Lasers
	2,035,000	Trimble Navigation (a)		93,631
		GPS-based Instruments
				464,171
		> Mobile Communications 2.7%
	4,465,000	Crown Castle International (a)		261,917
		Communications Towers
	3,400,000	SBA Communications (a)		193,970
		Communications Towers
	1,500,000	Globalstar (a)		480
		Satellite Mobile Voice & Data Carrier
				456,367
		> Telephone & Data Services 2.6%
	9,500,000	tw telecom (a)(b)		243,770
		Fiber Optic Telephone/Data Services
	1,400,000	AboveNet (b)		117,600
		Metropolitan Fiber Communications Services
	2,200,000	Cogent Communications (a)		42,350
		Internet Data Pipelines
	1,650,000	Boingo Wireless (a)		19,173
		Wholesale & Retail WiFi Networks
	2,000,000	General Communications (a)(b)		16,620
		Commercial Communication & Consumer CATV, Web & Phone in Alaska
				439,513
		> Computer Hardware & Related Equipment 2.4%
	3,415,000	Amphenol		187,552
		Electronic Connectors
	4,550,000	II-VI (a)(b)		75,849
		Laser Optics & Specialty Materials
	1,365,000	Zebra Technologies (a)		46,901
		Bar Code Printers
	900,000	Netgear (a)		31,059
		Networking Products for Small Business & Home
	605,000	Stratasys (a)(c)		29,978
		Rapid Prototyping Systems
	800,000	Nice Systems - ADR (Israel) (a)		29,280
		Audio & Video Recording Solutions
	207,000	Gemalto (France)		14,867
		Digital Security Solutions
				415,486
		> Semiconductors & Related Equipment 2.1%
	11,562,000	Atmel (a)		77,465
		Microcontrollers, Radio Frequency & Memory Semiconductors
	7,932,000	ON Semiconductor (a)		56,317
		Mixed Signal & Power Management Semiconductors
	5,000,000	Entegris (a)		42,700
		Semiconductor Materials Management Products
	2,160,000	Microsemi (a)		39,938
		Analog/Mixed Signal Semiconductors

See accompanying notes to financial statements.

26

Number of Shares			Value (000)
		> Semiconductors & Related Equipment—continued
	420,000	Littelfuse	$	23,894
		Little Fuses
	1,165,000	Monolithic Power Systems (a)		23,149
		High Performance Analog & Mixed Signal Integrated Circuits
	1,900,000	IXYS (a)(b)		21,223
		Power Semiconductors
	400,000	Hittite Microwave (a)		20,448
		Radio Frequency, Microwave & Millimeterwave Semiconductors
	615,000	Ultratech (a)		19,373
		Semiconductor Equipment
	1,765,000	Pericom Semiconductor (a)(b)		15,885
		Interface Integrated Circuits & Frequency Control Products
	560,000	Cree (a)(c)		14,375
		LED Lighting, Components & Chips
	2,290,000	TriQuint Semiconductor (a)		12,595
		Radio Frequency Semiconductors
				367,362
		> Computer Services 1.3%
	3,400,000	iGATE (a)(b)		57,868
		IT & Business Process Outsourcing Services
	680,000	Syntel		41,275
		Offshore IT Services
	1,618,000	ExlService Holdings (a)(b)		39,868
		Business Process Outsourcing
	2,125,000	Virtusa (a)(b)		28,369
		Offshore IT Outsourcing
	1,705,000	Genpact (a)		28,354
		Business Process Outsourcing
	3,849,207	Hackett Group (a)(b)		21,440
		IT Integration & Best Practice Research
	1,091,353	WNS - ADR (India) (a)		10,619
		Offshore BPO (Business Process Outsourcing) Services
				227,793
		> Gaming Equipment & Services 1.2%
	3,725,000	Bally Technologies (a)(b)		173,809
		Slot Machines & Software
	1,530,000	WMS Industries (a)		30,523
		Slot Machine Provider
				204,332
		> Internet Related 1.1%
	450,000	Equinix (a)		79,042
		Network Neutral Data Centers
	1,450,000	TripAdvisor		64,801
		Online Travel Research
	304,000	NetEase.com - ADR (China) (a)		17,890
		Chinese Online Gaming Services
	700,100	Yandex (Russia) (a)		13,337
		Search Engine for Russian & Turkish Languages
	234,168	Mail.ru - GDR (Russia) (a)(d)		7,975
		Internet Social Networking & Games for Russian Speakers
	231,700	Angies list (a)		3,670
		Consumer Subscription & Internet Advertising
				186,715

Number of Shares			Value (000)
		> Business Information & Marketing Services 0.9%
	1,900,000	Verisk Analytics (a)	$	93,594
		Risk & Decision Analytics
	3,027,016	Navigant Consulting (a)(b)		38,261
		Financial Consulting Firm
	505,000	RPX (a)		7,247
		Patent Aggregation & Defensive Patent Consulting
	234,615	FTI Consulting (a)		6,745
		Financial Consulting Firm
				145,847
		> Telecommunications Equipment 0.7%
	640,000	F5 Networks (a)		63,718
		Internet Traffic Management Equipment
	1,730,000	Ixia (a)		20,795
		Telecom Network Test Equipment
	1,345,000	Finisar (a)		20,121
		Optical Subsystems & Components
	1,925,000	Infinera (a)		13,167
		Optical Networking Equipment
				117,801
		> CATV 0.6%
	900,000	Discovery Series C (a)		45,081
		Cable TV Programming
	900,000	Liberty Global Series A (a)		44,667
		Cable TV Franchises Outside the USA
	15,770	Jupiter Telecommunications (Japan)		16,079
		Largest Cable Service Provider in Japan
				105,827
		> Financial Processors 0.6%
	1,700,000	Global Payments		73,491
		Credit Card Processor
	5,000,000	Singapore Exchange (Singapore)		25,119
		Singapore Equity & Derivatives Market Operator
				98,610
		> Electronics Distribution 0.6%
	3,125,000	Avnet (a)		96,438
		Electronic Components Distribution
				96,438
		> Contract Manufacturing 0.3%
	3,800,000	Sanmina-SCI (a)		31,122
		Electronic Manufacturing Services
	960,000	Plexus (a)		27,072
		Electronic Manufacturing Services
				58,194
		> Advertising 0.3%
	1,725,000	Lamar Advertising (a)		49,335
		Outdoor Advertising
	1,500,000	VisionChina Media - ADR (China) (a)		1,395
		Advertising on Digital Screens in China's Mass Transit System
				50,730

See accompanying notes to financial statements.

27

Columbia Acorn Fund

Statement of Investments (Unaudited), continued

Number of Shares			Value (000)
		> Entertainment Programming 0.2%
	1,100,000	IMAX (Canada) (a)(c)	$	26,433
		IMAX Movies, Theatre Equipment & Theatre Joint Ventures
				26,433
		> TV Broadcasting —%
	2,500,000	Entravision Communications		3,025
		Spanish Language TV & Radio Stations
	1,750,000	Gray Television (a)(c)		2,573
		Mid-market Affiliated TV Stations
				5,598
		> Radio —%
	145,271	Saga Communications (a)		5,391
		Radio Stations in Small & Mid-sized Cities
				5,391
		> Consumer Software —%
	273,500	Carbonite (a)(c)		2,445
		Online Data Storage
				2,445
Information: Total				4,666,570
Industrial Goods & Services 19.0%
		> Machinery 11.1%
	6,750,000	Ametek		336,893
		Aerospace/Industrial Instruments
	8,400,000	Donaldson (b)		280,308
		Industrial Air Filtration
	3,125,000	Nordson		160,281
		Dispensing Systems for Adhesives & Coatings
	3,000,000	Moog (a)(b)		124,050
		Motion Control Products for Aerospace, Defense & Industrial Markets
	3,725,000	Kennametal		123,484
		Consumable Cutting Tools
	2,325,000	Clarcor		111,972
		Mobile & Industrial Filters
	3,063,000	HEICO (b)		98,812
		FAA Approved Aircraft Replacement Parts
	1,800,000	Pall		98,658
		Filtration & Fluids Clarification
	2,200,000	ESCO Technologies (b)		80,168
		Automatic Electric Meter Readers
	1,890,000	Pentair		72,349
		Pumps & Water Treatment
	805,000	Toro		58,998
		Turf Maintenance Equipment
	2,350,000	Generac		56,541
		Standby Power Generators
	2,675,000	Oshkosh Corporation (a)		56,041
		Specialty Truck Manufacturer
	1,325,000	Polypore International (a)(c)		53,517
		Battery Separators & Filtration Media
	435,000	Valmont Industries		52,622
		Center Pivot Irrigation Systems & Utility Poles
	950,000	WABCO Holdings (a)		50,284
		Truck & Bus Component Supplier

Number of Shares			Value (000)
	600,000	Wabtec	$	46,806
		Freight & Transit Component Supplier
	350,000	Neopost (France)		18,678
		Postage Meter Machines
	170,000	Middleby Corp (a)		16,934
		Manufacturer of Cooking Equipment
	10,000,000	Marel (Iceland)		12,162
		Largest Manufacturer of Poultry & Fish Processing Equipment
	1,000,000	Spartan Motors		5,240
		Specialty Truck & Chassis Manufacturer
				1,914,798
		> Industrial Materials & Specialty Chemicals 2.4%
	1,750,000	Albemarle		104,370
		Refinery Catalysts & Other Specialty Chemicals
	1,520,000	FMC Corporation		81,290
		Niche Specialty Chemicals
	800,000	Ashland		55,448
		Diversified Chemicals Company
	1,880,000	Drew Industries (a)(b)		52,358
		RV & Manufactured Home Components
	1,525,000	Novozymes (Denmark)		39,545
		Industrial Enzymes
	673,000	Sociedad Quimica y Minera de Chile - ADR (Chile) (c)		37,466
		Producer of Specialty Fertilizers, Lithium & Iodine
	2,218,700	Kansai Paint (Japan)		23,775
		Paint Producer in Japan, India, China & Southeast Asia
	600,000	Albany International		11,226
		Paper Machine Clothing & Composites for Aerospace
	200,000	Silgan Holdings		8,538
		Metal & Plastic Packaging
	92,046	Mersen (France)		2,306
		Advanced Industrial Materials
				416,322
		> Other Industrial Services 1.7%
	3,050,000	Expeditors International of Washington		118,187
		International Freight Forwarder
	1,400,000	Forward Air		45,178
		Freight Transportation Between Airports
	1,350,000	LKQ (a)		45,090
		Alternative Auto Parts Distribution
	1,491,313	Imtech (Netherlands)		35,610
		Electromechanical & Information & Communications Technology Installation & Maintenance
	1,600,000	Mobile Mini (a)		23,040
		Portable Storage Units Leasing
	1,500,000	Acorn Energy (b)(c)		12,480
		Frac Well Exploration/Monitoring Device, Sonar Security, Electric Grid Monitoring
	750,000	UTI Worldwide		10,958
		Freight Forwarding & Logistics
				290,543

See accompanying notes to financial statements.

28

Number of Shares			Value (000)
		> Construction 1.3%
	2,850,000	Chicago Bridge & Iron	$	108,186
		Engineering & Construction for Liquefied Natural Gas & Petrochemicals
	66,000	NVR (a)		56,100
		DC Homebuilder
	1,350,000	Fortune Brands Home & Security (a)		30,065
		Home Building Supplies & Small Locks
	1,800,000	Mills Estruturas e Servicos de Engenharia (Brazil)		24,197
		Civil Engineering & Construction
				218,548
		> Electrical Components 0.7%
	1,765,000	Acuity Brands		89,856
		Commercial Lighting Fixtures
	1,500,000	Ushio (Japan)		18,592
		Industrial Light Sources
	351,000	Saft (France)		8,421
		Niche Battery Manufacturer
				116,869
		> Outsourcing Services 0.7%
	2,800,000	Quanta Services (a)		67,396
		Electrical & Telecom Construction Services
	1,359,200	Insperity (b)		36,766
		Professional Employer Organization
	600,000	GP Strategies (a)		11,082
		Training Programs
				115,244
		> Waste Management 0.5%
	2,050,000	Waste Connections		61,336
		Solid Waste Management
	560,000	Clean Harbors (a)		31,595
		Hazardous Waste Services & Disposal
				92,931
		> Conglomerates 0.2%
	2,324,833	Aalberts Industries (Netherlands)		36,200
		Flow Control & Heat Treatment
				36,200
		> Industrial Distribution 0.2%
	1,400,000	Interline Brands (a)		35,098
		Industrial Distribution
				35,098
		> Steel 0.2%
	2,800,000	GrafTech International (a)		27,020
		Industrial Graphite Materials Producer
				27,020
Industrial Goods & Services: Total				3,263,573
Consumer Goods & Services 15.9%
		> Retail 4.3%
	4,505,000	lululemon athletica (a)		268,633
		Premium Active Apparel Retailer
	6,600,000	Pier 1 Imports (b)		108,438
		Home Furnishing Retailer
	3,040,000	Abercrombie & Fitch		103,786
		Teen Apparel Retailer

Number of Shares			Value (000)
	3,370,000	Shutterfly (a)(b)	$	103,425
		Internet Photo-centric Retailer
	4,425,000	Saks (a)(c)		47,126
		Luxury Department Store Retailer
	527,845	Fossil (a)		40,401
		Watch Designer & Retailer
	525,000	DSW		28,560
		Branded Footwear Retailer
	1,075,000	American Eagle Outfitters		21,210
		Teen Apparel Retailer
	971,500	Teavana (a)(c)		13,145
		Specialty Tea Retailer
	1,371,366	Gaiam (a)(b)		5,348
		Healthy Living Catalogs & E-Commerce
	66,000	The Fresh Market (a)		3,540
		Specialty Food Retailer
				743,612
		> Travel 3.0%
	3,850,000	Gaylord Entertainment (a)(b)		148,456
		Convention Hotels
	1,430,000	Vail Resorts		71,614
		Ski Resort Operator & Developer
	1,450,000	Expedia		69,702
		Online Travel Services Company
	4,400,000	Avis Budget Group (a)		66,880
		Second Largest Car Rental Company
	3,750,000	Hertz (a)		48,000
		Largest U.S. Rental Car Operator
	970,000	Choice Hotels		38,732
		Franchisor of Budget Hotel Brands
	1,600,000	HomeAway (a)(c)		34,784
		Vacation Rental Online Marketplace
	2,000,000	Localiza Rent A Car (Brazil)		30,082
		Car Rental
				508,250
		> Apparel 2.3%
	1,660,000	PVH		129,131
		Apparel Wholesaler & Retailer
	2,100,000	Coach		122,808
		Designer & Retailer of Branded Leather Accessories
	1,460,000	Warnaco Group (a)		62,167
		Global Branded Apparel Manufacturer
	1,310,000	Deckers Outdoor (a)(c)		57,653
		Fashion Footwear Wholesaler
	600,000	Steven Madden (a)		19,050
		Wholesaler/Retailer of Fashion Footwear
	231,452	True Religion Apparel		6,708
		Premium Denim
				397,517
		> Food & Beverage 1.1%
	1,700,000	Monster Beverage (a)		121,040
		Alternative Beverages
	32,000,000	Olam International (Singapore)		46,347
		Agriculture Supply Chain Manager
	1,800,000	Arcos Dorados (Brazil)		26,604
		McDonald's Master Franchise for Latin America

See accompanying notes to financial statements.

29

Columbia Acorn Fund

Statement of Investments (Unaudited), continued

Number of Shares			Value (000)
		> Food & Beverage—continued
	45,500	Annie's (a)(c)	$	1,905
		Developer & Marketer of Natural & Organic Food
	1,665,270	GLG Life Tech (Canada) (a)(b)(e)		689
		All-natural Sweetener Extracted from the Stevia Plant
				196,585
		> Consumer Goods Distribution 1.1%
	2,305,000	GNC Holdings		90,356
		Specialty Retailer of Health & Wellness Products
	2,015,000	Pool		81,527
		Distributor of Swimming Pool Supplies & Equipment
	625,000	United Stationers		16,844
		Wholesale Distributor of Business Products
				188,727
		> Other Consumer Services 0.9%
	2,190,000	Lifetime Fitness (a)(b)		101,857
		Sport & Fitness Club Operator
	16,857,500	Lifestyle International (Hong Kong)		37,146
		Mid to High-end Department Store Operator in Hong Kong & China
	1,062,500	Move (a)		9,679
		Real Estate Internet Websites
	441,666	IFM Investments (Century 21 China RE) - ADR (China) (a)		481
		Provide Real Estate Services in China
				149,163
		> Casinos & Gaming 0.8%
	3,950,000	Pinnacle Entertainment (a)(b)		37,999
		Regional Casino Operator
	850,000	Penn National Gaming (a)		37,902
		Regional Casino Operator
	3,000,000	Melco Crown Entertainment - ADR (Hong Kong) (a)		34,560
		Macau Casino Operator
	12,000,000	MGM China Holdings (Hong Kong)		18,400
		Macau Casino Operator
				128,861
		> Furniture & Textiles 0.8%
	4,200,000	Knoll (b)		56,364
		Office Furniture
	2,250,000	Herman Miller		41,670
		Office Furniture
	2,038,555	Interface		27,785
		Modular & Broadloom Carpet
	215,000	Caesarstone (Israel) (a)		2,604
		Quartz Countertops
				128,423
		> Other Durable Goods 0.6%
	1,500,000	Jarden		63,030
		Branded Household Products
	460,000	Cavco Industries (a)(b)		23,589
		Manufactured Homes
	400,000	Tesla Motors (a)(c)		12,516
		Design, Manufacture & Sell High Performance Electric Vehicles
				99,135

Number of Shares			Value (000)
		> Restaurants 0.4%
	2,000,000	AFC Enterprises (a)(b)	$	46,280
		Popeye's Restaurants
	450,000	Cheesecake Factory (a)		14,382
		Casual Dining Restaurants
	675,000	Bravo Brio Restaurant Group (a)		12,035
		Upscale Casual Italian Restaurants
				72,697
		> Nondurables 0.3%
	1,600,000	Helen of Troy (a)(b)		54,224
		Personal Care, Housewares, Healthcare & Home Environment Products
				54,224
		> Educational Services 0.2%
	800,000	New Oriental Education & Technology - ADR (China) (a)		19,600
		Education Service Provider
	300,000	ITT Educational Services (a)(c)		18,225
		Postsecondary Degree Services
	2,000,000	Voyager Learning - Contingent Value Rights (e)(f)		220
		Education Services for the K-12 Market
				38,045
		> Leisure Products 0.1%
	1,290,000	Skullcandy (a)(c)		18,253
		Lifestyle Branded Headphones
				18,253
		> Other Entertainment —%
	265,000	CTS Eventim (Germany)		7,974
		Event Ticket Sales
				7,974
Consumer Goods & Services: Total				2,731,466
Finance 11.0%
		> Banks 4.4%
	2,638,000	BOK Financial		153,532
		Tulsa-based Southwest Bank
	6,956,800	Associated Banc-Corp		91,760
		Midwest Bank
	2,337,313	Hancock Holding		71,148
		Gulf Coast Bank
	1,348,000	City National		65,486
		Bank & Asset Manager
	2,860,000	MB Financial (b)		61,604
		Chicago Bank
	985,000	SVB Financial Group (a)		57,839
		Bank to Venture Capitalists
	5,323,500	Valley National Bancorp		56,429
		New Jersey/New York Bank
	3,000,000	CVB Financial		34,950
		Inland Empire Business Bank
	2,200,000	TCF Financial		25,256
		Great Lakes Bank
	700,000	Wintrust Financial		24,850
		Chicago & Milwaukee Full Service Bank
	1,350,000	TriCo Bancshares (b)		20,790
		California Central Valley Bank

See accompanying notes to financial statements.

30

Number of Shares			Value (000)
		> Banks—continued
	4,299,507	First Busey	$	20,767
		Illinois Bank
	1,121,188	Sandy Spring Bancorp		20,181
		Baltimore, D.C. Bank
	2,500,000	First Commonwealth		16,825
		Western Pennsylvania Bank
	811,295	Hudson Valley		14,685
		Metro New York City Bank
	2,136,500	TrustCo Bank		11,665
		New York State Bank
	706,559	Eagle Bancorp (a)		11,128
		Metro D.C. Bank
	241,405	Pacific Continental Bank		2,141
		Pacific Northwest Bank
	79,800	Green Bankshares (a)		133
		Tennessee Bank
				761,169
		> Insurance 2.4%
	8,900,000	CNO Financial Group		69,420
		Life, Long-term Care & Medical Supplement Insurance
	833,000	Allied World Holdings		66,198
		Commerical Lines Insurance/Reinsurance
	2,764,000	Tower Group (b)		57,685
		Commercial & Personal Lines Insurance
	1,120,000	The Hanover Insurance Group		43,826
		Commercial & Personal Lines Insurance
	2,050,000	Selective Insurance Group		35,690
		Commercial & Personal Lines Insurance
	1,100,000	HCC Insurance Holdings		34,540
		Specialty Insurance
	832,000	Willis Group (Ireland)		30,360
		Insurance Broker
	925,000	Kemper		28,444
		Multi-line Insurance
	250,000	Enstar Group (a)		24,735
		Insurance/Reinsurance & Related Services
	900,000	Brown & Brown		24,543
		Insurance Broker
				415,441
		> Finance Companies 1.6%
	1,425,202	World Acceptance (a)(b)		93,778
		Personal Loans
	2,150,000	McGrath Rentcorp (b)		56,975
		Temporary Space & IT Rentals
	3,400,000	H & E Equipment Services (a)(b)		51,102
		Heavy Equipment Leasing
	1,123,400	CAI International (a)(b)		22,333
		International Container Leasing
	1,091,000	Marlin Business Services (b)		17,882
		Small Equipment Leasing
	450,000	Onex Capital (Canada)		17,472
		Private Equity
	422,500	Regional Management (a)		6,950
		Consumer Loans
	78,500	Textainer Group Holdings		2,897
		Top International Container Leasor
				269,389

Number of Shares			Value (000)
		> Brokerage & Money Management 1.5%
	6,654,000	SEI Investments	$	132,348
		Mutual Fund Administration & Investment Management
	4,036,000	Eaton Vance		108,770
		Specialty Mutual Funds
	300,000	FX Alliance (a)		4,713
		FX Trading Software & Services
	1,000,000	Artio Global Investors (c)		3,500
		International Asset Manager
				249,331
		> Credit Cards 0.5%
	550,000	Alliance Data Systems (a)		74,250
		Diversified Credit Card Provider
	275,000	Wright Express (a)		16,973
		Pay Card Processor
				91,223
		> Diversified Financial Companies 0.4%
	2,820,000	Leucadia National		59,981
		Holding Company
				59,981
		> Savings & Loans 0.2%
	400,000	Financial Engines (a)		8,580
		Asset Management for 401k Plans
	1,010,000	Provident New York Bancorp		7,666
		New York State Thrift
	470,000	ViewPoint Financial		7,351
		Texas Thrift
	452,146	Kaiser Federal		6,682
		Los Angeles Savings & Loan
	65,991	Berkshire Hills Bancorp		1,452
		Northeast Thrift
				31,731
Finance: Total				1,878,265
Health Care 9.7%
		> Biotechnology & Drug Delivery 4.9%
	4,315,000	BioMarin Pharmaceutical (a)		170,787
		Biotech Focused on Orphan Diseases
	6,153,000	Seattle Genetics (a)(b)(c)		156,225
		Antibody-based Therapies for Cancer
	1,476,000	Alexion Pharmaceuticals (a)		146,567
		Biotech Focused on Orphan Diseases
	3,250,000	Auxilium Pharmaceuticals (a)(b)		87,393
		Biotech Focused on Niche Disease Areas
	6,000,000	NPS Pharmaceuticals (a)(b)		51,660
		Orphan Drugs & Healthy Royalties
	750,000	Onyx Pharmaceuticals (a)		49,837
		Commercial-stage Biotech Focused on Cancer
	3,850,000	InterMune (a)(b)		46,007
		Drugs for Pulmonary Fibrosis & Hepatitis C
	2,568,248	ARIAD Pharmaceuticals (a)		44,200
		Biotech Focused on Cancer
	3,430,000	Isis Pharmaceuticals (a)		41,160
		Biotech Pioneer in Antisense Drugs
	569,898	Synageva Biopharma (a)(c)		23,115
		Biotech Focused on Orphan Diseases

See accompanying notes to financial statements.

31

Columbia Acorn Fund

Statement of Investments (Unaudited), continued

Number of Shares			Value (000)
		> Biotechnology & Drug Delivery—continued
	3,609,594	Raptor Pharmaceutical (a)(b)(c)	$	20,178
		Orphan Drug Company
	5,750,000	Chelsea Therapeutics International (a)(b)(c)		8,510
		Biotech Focused on Rare Diseases
	2,990,000	Anthera Pharmaceuticals (a)(b)		2,022
		Biotech Focused on Cardiovascular, Cancer & Immunology
	359,944	MicroDose Therapeutx (e)(f)		252
		Drug Inhaler Development
				847,913
		> Medical Supplies 2.6%
	4,600,000	Cepheid (a)(b)		205,850
		Molecular Diagnostics
	950,000	Henry Schein (a)		74,565
		Largest Distributor of Healthcare Products
	2,126,000	Patterson Companies		73,283
		Dental/Vet/Med Distributor
	1,550,000	DENTSPLY International		58,606
		Leading Dental Supplies Manufacturer
	375,000	Techne		27,825
		Cytokines, Antibodies & Other Reagents for Life Science
				440,129
		> Medical Equipment & Devices 0.9%
	550,000	Haemonetics (a)		40,760
		Blood & Plasma Collection Equipment
	1,275,000	Hill-Rom Holdings		39,334
		Hospital Beds/Patient Handling
	675,000	Sirona Dental Systems (a)		30,382
		Manufacturer of Dental Equipment
	950,000	PerkinElmer Inc.		24,510
		Analytical Instruments for Life Sciences
	570,000	Orthofix International (a)		23,513
		Bone Fixation & Stimulation Devices
				158,499
		> Health Care Services 0.7%
	665,000	Mednax (a)		45,579
		Physician Management for Pediatric & Anesthesia Practices
	4,900,000	eResearch Technology (a)(b)		39,151
		Clinical Research Services
	825,000	HealthSouth (a)		19,189
		Inpatient Rehabalitation Facilities
	1,875,000	Health Management Associates (a)		14,719
		Non-urban Hospitals
				118,638
		> Pharmaceuticals 0.6%
	4,000,000	Akorn (a)		63,080
		Develops, Manufactures & Sells Specialty Generic Drugs
	3,388,000	Adcock Ingram Holdings (South Africa)		24,904
		Manufacturer of Pharmaceuticals & Medical Supplies
	1,095,000	Horizon Pharma (a)(c)		7,807
		Specialty Pharma Company

Number of Shares			Value (000)
	2,040,000	Alimera Sciences (a)(b)(c)	$	6,100
		Ophthalmology-focused Pharmaceutical Company
				101,891
Health Care: Total				1,667,070
Energy & Minerals 6.7%
		> Oil Services 3.2%
	5,150,000	FMC Technologies (a)		202,034
		Oil & Gas Well Head Manufacturer
	2,114,000	Atwood Oceanics (a)		79,994
		Offshore Drilling Contractor
	1,289,106	Fugro (Netherlands)		78,196
		Subsea Oilfield Services
	1,670,000	ShawCor (Canada)		60,445
		Oil & Gas Pipeline Products
	1,000,000	Hornbeck Offshore (a)		38,780
		Supply Vessel Operator in U.S. Gulf of Mexico
	513,000	Oil States International (a)		33,961
		Diversified North American Oil Service Provider
	893,600	Black Diamond Group (Canada)		20,021
		Provides Accommodations/Equipment for Oil Sands Development
	585,000	Rowan (a)		18,913
		Contract Offshore Driller
	2,890,900	Horizon North Logistics (Canada)		16,497
		Provides Diversified Oil Service Offering in Northern Canada
	4,415,000	Tuscany International Drilling (Colombia) (a)		1,713
		South America-based Drilling Rig Contractor
				550,554
		> Oil & Gas Producers 2.4%
	3,700,000	Pacific Rubiales Energy (Colombia)		78,354
		Oil Production & Exploration in Colombia
	695,000	Range Resources		43,000
		Oil & Gas Producer
	2,700,000	Denbury Resources (a)		40,797
		Oil Producer Using CO2 Injection
	974,000	Rosetta Resources (a)		35,687
		Oil & Gas Producer Exploring in South Texas & Montana
	703,000	SM Energy		34,524
		Oil & Gas Producer
	1,050,000	Tullow Oil (United Kingdom)		24,268
		Oil & Gas Producer
	1,159,000	Laredo Petroleum (a)		24,107
		Permian Basin Oil Producer
	500,000	Cabot Oil and Gas		19,700
		Large Natural Gas Producer in Appalachia & Gulf Coast
	361,000	Baytex (Canada) (c)		15,208
		Oil & Gas Producer in Canada
	7,582,928	PetroMagdalena Energy (Colombia) (a)(b)		11,768
		Oil & Gas Exploration/Production in Colombia
	550,000	Swift Energy (a)		10,236
		Oil & Gas Exploration & Production
	718,000	Celtic Exploration (Canada) (a)		9,711
		Canadian Oil & Gas Producer

See accompanying notes to financial statements.

32

Number of Shares			Value (000)
		> Oil & Gas Producers—continued
	1,100,000	Kodiak Oil and Gas (a)	$	9,031
		Bakken Oil & Gas Producer
	340,000	Petroleum Development Corporation (a)		8,337
		Oil & Gas Producer in U.S.
	750,000	Athabasca Oil Sands (Canada) (a)		8,251
		Oil Sands & Unconventional Oil Development
	37,500,000	Petromanas (Canada) (a)(b)		7,919
		Exploring for Oil in Albania
	200,000	Approach Resource (a)		5,108
		Oil & Gas Producer in West Texas Permian
	27,000,000	Shamaran Petroleum (Iraq) (a)		4,509
		Oil Exploration in Kurdistan
	26,000,000	Petrodorado (Colombia) (a)(b)		4,086
	24,000,000	Petrodorado - Warrants (Colombia) (a)(f)		340
		Oil & Gas Exploration & Production in Colombia, Peru & Paraguay
	1,198,100	Pan Orient (Canada) (a)		4,413
		Asian Oil & Gas Explorer
	25,000,000	Petroamerica (Colombia) (a)(c)		3,192
		Oil Exploration & Production in Colombia
	493,000	Crew Energy (Canada) (a)		2,784
		Canadian Oil & Gas Producer
	50,000,000	Gulf United (Colombia) (a)(e)(f)		2,640
		Prospecting for Oil Alongside Large Producers in Colombia
	5,116,000	Canacol (Colombia) (a)		2,286
		Oil Producer in South America
	8,400,000	Canadian Overseas Petroleum (United Kingdom) (a)(f)		1,465
	4,200,000	Canadian Overseas Petroleum - Warrants (United Kingdom) (a)(e)(f)		81
		Oil & Gas Exploration/Production in the North Sea
	4,110,000	Santa Maria Petroleum (Colombia) (a)(f)		1,240
	890,000	Santa Maria Petroleum (Colombia) (a)		280
		Explores for Oil & Gas in Latin America
	393,600	Houston American Energy (a)		441
		Oil & Gas Exploration/Production in Colombia
				413,763
		> Mining 0.8%
	387,000	Core Laboratories (Netherlands)		44,853
		Oil & Gas Reservoir Consulting
	15,000,000	Zhaojin Mining Industry (China)		19,723
		Gold Mining & Refining in China
	1,400,000	Kirkland Lake Gold (Canada) (a)		15,071
		Gold Mining
	550,000	Silver Wheaton (Canada)		14,762
		Silver Mining Royalty Company
	4,432,000	Northam Platinum (South Africa)		12,677
		Platinum Mining in South Africa
	1,150,000	Ivanhoe Mines (Mongolia) (a)(c)		11,341
		Copper Mine Project in Mongolia
	7,500,000	Duluth Metals (Canada) (a)(b)		10,976

Number of Shares			Value (000)
	500,000	Duluth Exploration - Special Warrants (Canada) (a)(e)(f)	$	39
		Copper & Nickel Miner
	16,000,000	Mongolian Mining (Mongolia) (a)		9,079
		Coking Coal Mining in Mongolia
	2,050,000	Alexco Resource (a)		9,041
		Mining, Exploration & Environmental Services
	800,000	Augusta Resource (a)		1,328
		US Copper/Moly Mine
	4,000,000	Wolverine Minerals (Canada) (a)(b)(f)		377
	2,000,000	Wolverine Minerals - Warrants (Canada) (a)(e)(f)		3
		Gold Mining
				149,270
		> Oil Refining, Marketing & Distribution 0.1%
	218,000	Vopak (Netherlands)		13,983
		World's Largest Operator of Petroleum & Chemical Storage Terminals
				13,983
		> Agricultural Commodities 0.1%
	1,306,818	Union Agriculture Group (Uruguay) (a)(e)(f)		12,794
		Farmland Operator in Uruguay
				12,794
		> Alternative Energy 0.1%
	2,000,000	GT Advanced Technologies (a)		10,560
		Largest Manufacturer of Furnaces & Reactors to Produce & Cast Polysilicon
	1,210,300	Synthesis Energy Systems (China) (a)		1,477
		Owner/Operator of Gasification Plants
				12,037
Energy & Minerals: Total				1,152,401
Other Industries 6.3%
		> Real Estate 4.0%
	3,700,000	DuPont Fabros Technology (b)		105,672
		Technology-focused Office Buildings
	750,000	Federal Realty Investment Trust		78,068
		Shopping Centers
	1,850,000	Extra Space Storage		56,610
		Self Storage Facilities
	3,700,000	Associated Estates Realty (b)		55,315
		Multi-family Properties
	720,000	Digital Realty Trust		54,051
		Technology-focused Office Buildings
	975,000	Post Properties		47,726
		Multi-family Properties
	2,450,000	Biomed Realty Trust		45,766
		Life Science-focused Office Buildings
	770,000	Kilroy Realty		37,276
		West Coast Office & Industrial Properties
	43,000,000	Mapletree Logistics Trust (Singapore)		33,434
		Industrial Property Landlord
	3,000,000	Education Realty Trust		33,240
		Student Housing
	15,000,000	Ascendas REIT (Singapore)		25,589
		Industrial Property Landlord

See accompanying notes to financial statements.

33

Columbia Acorn Fund

Statement of Investments (Unaudited), continued

Number of Shares			Value (000)
		> Real Estate—continued
	3,750,000	DCT Industrial Trust	$	23,625
		Industrial Properties
	325,000	Jones Lang LaSalle		22,870
		Real Estate Services
	1,300,000	St. Joe (a)(c)		20,553
		Florida Panhandle Landowner
	3,500,000	Kite Realty Group (b)		17,465
		Community Shopping Centers
	2,000,031	Summit Hotel Properties (b)		16,740
		Owner of Select Service Hotels
	2,800	Orix JREIT (Japan)		12,586
		Diversified REIT
				686,586
		> Transportation 1.3%
	1,155,000	JB Hunt Transport Services		68,838
		Truck & Intermodal Carrier
	2,937,175	Rush Enterprises, Class A (a)(b)		48,023
	550,000	Rush Enterprises, Class B (a)(b)		7,381
		Truck Sales & Service
	1,260,000	World Fuel Services		47,918
		Global Fuel Broker
	2,400,000	Heartland Express		34,344
		Regional Trucker
	300,000	Genesee & Wyoming (a)		15,852
		Short-line Operator
				222,356
		> Regulated Utilities 1.0%
	2,000,000	Northeast Utilities		77,620
		Regulated Electric Utility
	1,660,000	Wisconsin Energy		65,686
		Wisconsin Utility
	500,000	Allete		20,900
		Regulated Electric Utility in Minnesota
	200,000	Red Eléctrica de España (Spain)		8,729
		Spanish Power Transmission
				172,935
Other Industries: Total				1,081,877
Total Equities: 95.8% (Cost: $10,608,838)				16,441,222

Number of Shares			Value (000)
Securities Lending Collateral 1.8%
	303,633,050	Dreyfus Government Cash Management Fund (7 day yield of 0.01%) (g)	$	303,633
Total Securities Lending Collateral: (Cost: $303,633)				303,633
Total Investments: 97.6% (Cost: $10,912,471)(h)(i)				16,744,855
Obligation to Return Collateral for Securities Loaned: (1.8)%				(303,633	)
Cash and Other Assets Less Liabilities: 4.2%				723,250
Total Net Assets: 100.0%			$	17,164,472

ADR - American Depositary Receipts

GDR - Global Depositary Receipts

REIT - Real Estate Investment Trust

See accompanying notes to financial statements.

34

> Notes to Statement of Investments (dollar values in thousands)

(a)  Non-income producing security.

(b)  An affiliated person of the Fund may include any company in which the Fund owns five percent or more of its outstanding voting shares. Holdings and transactions in these affiliated companies during the six months ended June 30, 2012, are as follows:

Security	Balance of Shares Held 12/31/11		Purchases/ Additions		Sales/ Reductions		Balance of Shares Held 6/30/12		Value		Dividend
AboveNet		1,400,000		-		-		1,400,000	$	117,600	$	-
Acorn Energy		1,500,000		-		-		1,500,000		12,480		180
AFC Enterprises		2,000,000		-		-		2,000,000		46,280		-
Alimera Sciences		2,040,000		-		-		2,040,000		6,100		-
Anthera Pharmaceuticals		1,740,000		1,250,000		-		2,990,000		2,022		-
Associated Estates Realty		3,700,000		-		-		3,700,000		55,315		-
Auxilium Pharmaceuticals		3,033,715		216,285		-		3,250,000		87,393		1,295
Bally Technologies		3,725,000		-		-		3,725,000		173,809		-
CAI International		1,123,400		-		-		1,123,400		22,333		-
Cavco Industries		460,000		-		-		460,000		23,589		-
Cepheid		3,200,000		1,400,000		-		4,600,000		205,850		-
Chelsea Therapeutics International		4,550,000		1,200,000		-		5,750,000		8,510		-
Cogent Communications*		2,520,000		-		320,000		2,200,000		42,350		-
Constant Contact		2,350,000		-		350,000		2,000,000		35,760		-
Donaldson**		4,200,000		4,200,000		-		8,400,000		280,308		1,428
Drew Industries		1,500,000		380,000		-		1,880,000		52,358		-
Duluth Metals		7,500,000		-		-		7,500,000		10,976		-
DuPont Fabros Technology		3,350,000		350,000		-		3,700,000		105,672		822
eResearch Technology		4,900,000		-		-		4,900,000		39,151		-
ESCO Technologies		2,200,000		-		-		2,200,000		80,168		352
ExlService Holdings		1,145,000		473,000		-		1,618,000		39,868		-
Gaiam		1,371,366		-		-		1,371,366		5,348		-
Gaylord Entertainment		3,850,000		-		-		3,850,000		148,456		-
General Communications		2,000,000		-		-		2,000,000		16,620		-
GLG Life Tech		1,750,000		-		84,730		1,665,270		689		-
H & E Equipment Services		3,400,000		-		-		3,400,000		51,102		-
Hackett Group+		4,500,000		-		650,793		3,849,207		21,440		-
HEICO***		2,250,000		813,000		-		3,063,000		98,812		135
Helen of Troy		1,600,000		-		-		1,600,000		54,224		-
Horizon Pharma*		1,095,000		-		-		1,095,000		7,807		-
iGATE		3,400,000		-		-		3,400,000		57,868		-
II-VI		4,550,000		-		-		4,550,000		75,849		-
Insperity		1,210,000		149,200		-		1,359,200		36,766		387
Interline Brands*		2,600,000		-		1,200,000		1,400,000		35,098		-
InterMune		2,950,000		900,000		-		3,850,000		46,007		-
IPG Photonics		2,780,000		-		-		2,780,000		121,180		-
IXYS		1,900,000		-		-		1,900,000		21,223		-
Kenexa*		1,700,000		-		526,900		1,173,100		34,055		-
Kite Realty Group		3,500,000		-		-		3,500,000		17,465		420
Knoll		4,200,000		-		-		4,200,000		56,364		1,260
Lifetime Fitness		2,190,000		-		-		2,190,000		101,857		-
lululemon athletica*		5,740,000		-		1,235,000		4,505,000		268,633		-
Marlin Business Services		1,091,000		-		-		1,091,000		17,882		131
MB Financial		2,360,000		500,000		-		2,860,000		61,604		55
McGrath Rentcorp		2,150,000		-		-		2,150,000		56,975		1,000
Mettler-Toledo International		1,600,000		-		-		1,600,000		249,360		-
Micromet*		6,702,347		137,138		6,766,894		72,591		-		-
Moog		2,775,000		225,000		-		3,000,000		124,050		-
Navigant Consulting		2,800,000		227,016		-		3,027,016		38,261		-
NPS Pharmaceuticals		6,000,000		-		-		6,000,000		51,660		-
Pericom Semiconductor		1,765,000		-		-		1,765,000		15,885		-
Petroamerica*		30,275,000		-		5,275,000		25,000,000		3,192		-
Petrodorado		26,000,000		-		-		26,000,000		4,086		-
PetroMagdalena Energy		7,582,928		-		-		7,582,928		11,768		-
Petromanas		37,500,000		-		-		37,500,000		7,919		-
Pier 1 Imports		5,600,000		1,000,000		-		6,600,000		108,438		224
Pinnacle Entertainment		3,950,000		-		-		3,950,000		37,999		-
Raptor Pharmaceutical		3,455,000		745,000		590,406		3,609,594		20,178		-

See accompanying notes to financial statements.

35

Columbia Acorn Fund

Statement of Investments (Unaudited), continued

> Notes to Statement of Investments (dollar values in thousands)

Security	Balance of Shares Held 12/31/11		Purchases/ Additions		Sales/ Reductions		Balance of Shares Held 6/30/12		Value		Dividend
Rush Enterprises		3,350,000		137,175		-		3,487,175	$	55,404	$	-
SABA		-		2,000,000		-		2,000,000		18,560		-
Salem Communications*		1,527,700		-		1,527,700		-		-		-
Santa Maria Petroleum*,****		50,000,000		-		45,000,000		5,000,000		1,520		-
Seattle Genetics		6,153,000		-		-		6,153,000		156,225		-
Shutterfly		3,070,000		300,000		-		3,370,000		103,425		-
SPS Commerce		900,000		-		-		900,000		27,342		-
Summit Hotel Properties		1,500,000		500,031		-		2,000,031		16,740		413
Tower Group		1,675,000		1,089,000		-		2,764,000		57,685		1,038
TriCo Bancshares		1,350,000		-		-		1,350,000		20,790		364
True Religion Apparel*		1,507,000		-		1,275,548		231,452		6,708		46
tw telecom		9,500,000		-		-		9,500,000		243,770		-
Tyler Technologies*		1,700,000		-		800,000		900,000		36,315		-
Virtusa		2,125,000		-		-		2,125,000		28,369		-
Warnaco Group*		2,190,000		-		730,000		1,460,000		62,167		-
Wolverine Minerals		4,000,000		-		-		4,000,000		377		-
World Acceptance		1,505,202		-		80,000		1,425,202		93,778		-
Total of Affiliated Transactions		350,332,658		18,191,845		66,412,971		302,111,532	$	4,463,187	$	9,550

*  At June 30, 2012, the Fund owned less than five percent of the company's outstanding voting shares.

**  Includes the effects of a 2:1 stock split.

***  Includes the effects of a 5:4 stock split.

****  Includes the effects of a 1:10 reverse stock split.

+  Includes the effects of a corporate action.

The aggregate cost and value of these companies at June 30, 2012, were $2,717,367 and $3,965,342, respectively. Investments in affiliated companies represented 23.10% of the Fund's total net assets at June 30, 2012.

(c)  All or a portion of this security was on loan at June 30, 2012. The total market value of securities on loan at June 30, 2012 was $302,684.

(d)  Security exempt from registration under Section 4(2) of the Securities Act of 1933. This security may only be resold in exempt transactions to qualified buyers. Private resales of this security to qualified institutional buyers are also exempt from registration pursuant to Rule 144A under the Securities Act of 1933. At June 30, 2012, this security had an aggregate value of $7,975, which represented 0.05% of total net assets.

(e)  Illiquid security.

(f)  Denotes a restricted security, which is subject to restrictions on resale under federal securities laws. These securities are valued at fair value determined in good faith under consistently applied procedures established by the Board of Trustees. At June 30, 2012, the market value of these securities amounted to $19,451, which represented 0.11% of total net assets.

  Additional information on these securities is as follows:

Security	Acquisition Dates	Shares		Cost		Value
Union Agriculture Group	12/8/10-6/27/12		1,306,818	$	15,000	$	12,794
Gulf United	4/18/12		50,000,000		4,000		2,640
Canadian Overseas Petroleum	11/24/10		8,400,000		3,591		1,465
Santa Maria Petroleum	1/14/11		4,110,000		5,193		1,240
Wolverine Minerals	6/3/11		4,000,000		2,005		377
Petrodorado - Warrants	11/20/09		24,000,000		2,965		340
MicroDose Therapeutx	11/24/00		359,944		2,005		252
Voyager Learning - Contingent Value Rights	12/24/09		2,000,000		-		220
Canadian Overseas Petroleum - Warrants	11/24/10		4,200,000		526		81
Duluth Exploration - Special Warrants	8/19/11		500,000		-		39
Wolverine Minerals - Warrants	6/3/11		2,000,000		243		3
				$	35,528	$	19,451

(g)  Investment made with cash collateral received from securities lending activity.

(h)  At June 30, 2012 for federal income tax purposes, the cost of investments was $10,912,471 and net unrealized appreciation was $5,832,384 consisting of gross unrealized appreciation of $6,608,143 and gross unrealized depreciation of $775,759.

See accompanying notes to financial statements.

36

> Notes to Statement of Investments (dollar values in thousands)

(i)  On June 30, 2012, the market value of foreign securities represented 8.26% of total net assets. The Fund's foreign portfolio was diversified as follows:

Country	Value		Percentage of Net Assets
Canada	$	231,071		1.34
Netherlands		208,842		1.22
Singapore		130,489		0.76
Colombia		105,899		0.62
Sweden		93,549		0.55
Hong Kong		90,106		0.52
Brazil		80,883		0.47
Japan		71,032		0.41
China		60,566		0.35
France		44,272		0.26
Denmark		39,545		0.23
South Africa		37,581		0.22
Chile		37,466		0.22
Country	Value		Percentage of Net Assets
Israel	$	31,884		0.19
Ireland		30,360		0.18
United Kingdom		25,814		0.15
Russia		21,312		0.12
Mongolia		20,420		0.12
Uruguay		12,794		0.07
Iceland		12,162		0.07
India		10,619		0.06
Spain		8,729		0.05
Germany		7,974		0.05
Iraq		4,509		0.03
Total Foreign Portfolio	$	1,417,878		8.26

Fair Value Measurements

  Various inputs are used in determining the value of the Fund's investments, following the input prioritization hierarchy established by GAAP. These inputs are summarized in the three broad levels listed below:

•  Level 1 – quoted prices in active markets for identical securities

•  Level 2 – prices determined using other significant observable inputs (including quoted prices for similar securities, interest rates, prepayment speeds, credit risk and others)

•  Level 3 – prices determined using significant unobservable inputs where quoted prices or observable inputs are unavailable or less reliable (including management's own assumptions about the factors market participants would use in pricing an investment)

  The inputs or methodology used for valuing securities are not necessarily an indication of the risk associated with investing in those securities.

  Examples of the types of securities in which the Fund would typically invest and how they are classified within this hierarchy are as follows. Typical Level 1 securities include exchange traded domestic equities, mutual funds whose NAVs are published each day and exchange traded foreign equities that are not statistically fair valued. Typical Level 2 securities include exchange traded foreign equities that are statistically fair valued and short-term investments valued at amortized cost. Additionally, securities fair valued by the Valuation Committee (the Committee) of the Fund's Board of Trustees (the Board) that rely on significant observable inputs are also included in Level 2. Typical Level 3 securities include any security fair valued by the Committee that relies on significant unobservable inputs.

  Under the direction of the Board, the Committee is responsible for carrying out the valuation procedures approved by the Board.

  The Committee meets as necessary, and no less frequently than quarterly, to determine fair values for securities for which market quotations are not readily available or for which the investment manager believes that available market quotations are unreliable, and to review the continuing appropriateness of the current value of any security subject to the Trust's Portfolio Pricing Policy and the pricing procedures of the investment manager (the Policies). The Policies address, among other things: circumstances under which market quotations will be deemed readily available; selection of third party pricing vendors; appropriate pricing methodologies; events that require fair valuation and fair value techniques; and circumstances under which securities will be deemed to pose a potential for stale pricing, including when securities are illiquid, restricted, or in default. The Committee may also meet to discuss additional valuation matters, which may include review of back-testing results, review of time-sensitive information or approval of other valuation related actions, and to review the appropriateness of the Policies.

  For investments categorized as Level 3, the significant unobservable inputs used in the fair value measurement of the Funds' securities may include: (i) data specific to the issuer or comparable issuers, (ii) general market or specific sector news and (iii) quoted prices and specific or similar security transactions. The Committee considers this data and any changes from prior periods in order to assess the reasonableness of observable and unobservable inputs, any assumptions or internal models used to value those securities and changes in fair value. Significant changes in any of these factors could result in lower or higher fair value measurements. Various factors impact the frequency of monitoring (which may occur as often as daily), however the Committee may determine that changes to inputs, assumptions and models are not required with the same frequency.

See accompanying notes to financial statements.

37

Columbia Acorn Fund

Statement of Investments (Unaudited), continued

> Notes to Statement of Investments (dollar values in thousands)

The following table summarizes the inputs used, as of June 30, 2012, in valuing the Fund's assets:

Investment Type	Quoted Prices (Level 1)		Other Significant Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)		Total
Equities
Information	$	4,508,981	$	157,589	$	-	$	4,666,570
Industrial Goods & Services		3,068,284		195,289		-		3,263,573
Consumer Goods & Services		2,620,690		110,556		220		2,731,466
Finance		1,878,265		-		-		1,878,265
Health Care		1,641,914		24,904		252		1,667,070
Energy & Minerals		975,496		164,072		12,833		1,152,401
Other Industries		1,001,539		80,338		-		1,081,877
Total Equities		15,695,169		732,748		13,305		16,441,222
Total Securities Lending Collateral		303,633		-		-		303,633
Total Investments	$	15,998,802	$	732,748	$	13,305	$	16,744,855

  The Fund's assets assigned to the Level 2 input category are generally valued using a market approach, in which a security's value is determined through its correlation to prices and information from observable market transactions for similar or identical assets. Foreign equities are generally valued at the last sale price on the foreign exchange or market on which they trade. The Fund may use a statistical fair valuation model, in accordance with the policy adopted by the Board, provided by an independent third party to value securities principally traded in foreign markets in order to adjust for possible stale pricing that may occur between the close of the foreign exchanges and the time for valuation. These models take into account available market data including intraday index, ADR, and ETF movements. Securities acquired via private placement that have a holding period or an extended settlement period are valued at a discount to the same shares that are trading freely on the market. These discounts are determined by the investment manager's experience with similar securities or situations. Factors may include, but are not limited to, trade volume, shares outstanding and stock price. Warrants which do not trade are valued as a percentage of the actively trading common stock using a model, based on Black Scholes. Securities which have halted or temporarily stopped trading are valued at the last sale and adjusted by a premium or a discount to account for the anticipated re-opening price. These adjustments are determined by the investment manager's experience with similar securities or situations.

  The following table shows transfers between Level 1 and Level 2 of the fair value hierarchy:

Transfers In				Transfers Out
Level 1		Level 2		Level 1		Level 2
$	-	$	1,575	$	1,575	$	-

  Financial assets were transferred from Level 1 to Level 2 as trading halted during the period.

The following table reconciles asset balances for the period ending June 30, 2012, in which significant observable and/or unobservable inputs (Level 3) were used in determining value:

Investments in Securities	Balance as of December 31, 2011		Realized Gain/(Loss)		Change in Unrealized Appreciation (Depreciation)			Purchases		Sales		Transfers into Level 3		Transfers out of Level 3		Balance as of June 30, 2012
Equities
Consumer Goods & Services	$	180	$	-	$	40		$	-	$	-	$	-	$	-	$	220
Health Care		270		-		(18	)		-		-		-		-		252
Energy & Minerals		12,507		-		326			-		-		-		-		12,833
	$	12,957	$	-	$	348		$	-	$	-	$	-	$	-	$	13,305

  The information in the above reconciliation table represents fiscal year to date activity for any securities identified as using Level 3 inputs at either the beginning or the end of the current fiscal period.

  The change in unrealized appreciation attributed to securities owned at June 30, 2012, which were valued using significant unobservable inputs (Level 3), amounted to $348.

  The Fund does not hold any significant investments categorized as Level 3.

  Certain common stock classified as Level 3 are valued at fair value, using a market approach, as determined in good faith under consistently applied procedures established by and under the general supervision of the Board. To determine fair value for these securities, for which no market exists, the Committee utilizes the valuation technique it deems most appropriate in the circumstances, using some unobservable inputs, which may include but are not limited to trades of similar securities, estimated earnings of the company, market multiples derived from a set of comparable companies, and the position of the security within the company's capital structure. Significant increases or decreases to any of these inputs could result in a significantly lower or higher fair value measurement. Generally, a change in estimated earnings of a company may result in a change to the comparable companies and market multiples utilized.

See accompanying notes to financial statements.

38

Columbia Acorn International

Major Portfolio Changes in the Second Quarter (Unaudited)

	Number of Shares
	3/31/12		6/30/12
Purchases
Asia
> Japan
Daiseki		1,427,129		1,613,429
Doshisha		750,600		828,000
Horiba		257,800		424,000
Miraca Holdings		0		659,500
NGK Insulators		2,400,000		2,552,000
Nihon Parkerizing		145,700		756,900
Sanrio		500,000		865,800
Start Today		1,718,724		2,572,724
> Taiwan
Chroma Ate		10,277,000		10,677,000
CTCI Corp		18,571,200		20,120,000
MStar Semiconductor		2,930,000		3,661,100
Taiwan Mobile		10,329,000		16,405,300
> Hong Kong
Lifestyle International		18,000,000		21,845,000
Vitasoy International		0		4,495,200
> Singapore
Petra Foods		0		3,071,300
> China
AMVIG Holdings		28,763,700		30,000,000
Digital China		13,570,200		18,000,300
> India
Colgate-Palmolive India		0		545,000
Redington India		1,477,269		13,195,000
Titan Industries		791,352		1,600,000
> Korea
Hyundai Home Shopping		10,090		55,000
Kepco Plant Service & Engineering		0		244,530
> Indonesia
Ace Indonesia		10,000,000		15,000,000
Mayora Indah		0		2,176,600
Mitra Adiperkasa		0		12,488,000
MNC Skyvision		0		32,766,000
Tower Bersama Infrastructure		48,560,000		51,767,300
> Mongolia
Mongolian Mining		42,636,400		60,037,500
> Cambodia
Nagacorp		50,000,000		60,000,000
Europe
> United Kingdom
Aggreko		0		596,100
BBA Aviation		3,167,139		8,785,000
Domino's Pizza United Kingdom & Ireland		2,497,000		3,107,000

	Number of Shares
	3/31/12		6/30/12
Greggs		1,060,885		2,300,000
Rightmove		548,000		822,000
Spirax Sarco		0		256,202
WH Smith		0		1,555,000
> Netherlands
TKH Group		403,800		850,468
> France
Compagnie Française de l'Afrique Occidentale		0		134,254
Eurofins Scientific		418,000		553,000
Neopost		430,000		675,000
> Germany
NORMA Group		0		690,000
> Denmark
Solar A/S		130,651		166,013
> Italy
Geox		5,800,000		7,000,000
> Russia
Yandex		0		1,123,695
> Portugal
Redes Energéticas Nacionais		8,531,175		8,635,000
Other Countries
> Australia
Challenger Financial		4,546,885		11,936,400
Commonwealth Property Office Fund		17,451,906		48,533,075
Domino's Pizza Enterprises		0		1,576,290
IAG		0		7,595,003
UGL		2,653,389		3,973,200
> United States
Rowan		0		548,900
> Israel
Caesarstone		125,000		625,000
Latin America
> Brazil
Arcos Dorados		0		1,300,000
MRV Engenharia		2,917,000		3,577,000
> Chile
Viña Concha y Toro		4,016,878		5,640,000

See accompanying notes to financial statements.

39

Columbia Acorn International

Major Portfolio Changes in the Second Quarter (Unaudited), continued

	Number of Shares
	3/31/12		6/30/12
Sales
Asia
> Japan
Aeon Delight		1,860,438		1,417,438
Ain Pharmaciez		589,792		349,792
Gree		246,300		0
Miura		511,450		407,050
Seven Bank		22,694,000		20,227,000
Shinsei Bank		18,673,649		15,024,649
Tsumura		855,604		0
> Taiwan
Simplo Technology		5,614,530		5,058,830
> Hong Kong
Melco Crown Entertainment - ADR		7,000,000		6,500,000
MGM China Holdings		12,500,000		10,000,000
Sasa International		38,000,000		30,000,000
> Singapore
Olam International		27,000,000		25,000,000
> China
NetEase.com - ADR		644,000		381,300
> Indonesia
Jasa Marga		6,937,300		0
> Thailand
Home Product Center		118,000,000		110,000,000
Europe
> United Kingdom
Abcam		2,950,000		2,855,000
Chemring		5,654,735		2,303,000
Intertek Group		1,460,000		1,004,500
JLT Group		3,000,000		2,579,333
Premier Oil		2,636,932		2,027,932
Rotork		730,000		517,000
Tullow Oil		740,581		382,581
Workspace Group		7,500,000		0
> Netherlands
Core Laboratories		177,395		143,395
Fugro		687,967		460,000
Imtech		1,763,611		1,680,623
> Switzerland
Dufry Group		360,000		330,000
Kuehne & Nagel		245,000		170,000
> France
Gemalto		1,073,700		729,700
Mersen		460,000		162,844
Rubis		353,648		0

	Number of Shares
	3/31/12		6/30/12
> Germany
Elringklinger		555,700		333,000
Rheinmetall		679,600		405,000
Rhoen-Klinikum		1,600,000		0
> Sweden
East Capital Explorer		905,452		419,877
> Italy
Ansaldo STS		2,621,149		0
CIR		12,503,754		8,951,757
> Russia
Mail.ru - GDR		629,642		368,493
> Ireland
Paddy Power		289,400		263,400
United Drug		6,750,000		4,237,000
> Greece
Intralot		6,954,400		4,384,185
Other Countries
> Canada
Athabasca Oil Sands		731,000		450,000
Baytex		615,857		263,857
Black Diamond Group		1,049,576		770,576
Celtic Exploration		721,000		454,000
Crew Energy		1,043,000		332,700
Horizon North Logistics		2,411,514		2,096,514
> United States
Alexion Pharmaceuticals		627,431		0
FMC Technologies		461,213		407,213
Oil States International		270,000		0
World Fuel Services		987,228		763,228
Latin America
> Colombia
Canacol		8,353,169		7,850,769

See accompanying notes to financial statements.

40

Columbia Acorn International

Statement of Investments (Unaudited), June 30, 2012

Number of Shares			Value (000)
			Equities: 94.6%
Asia 43.8%
		> Japan 17.6%
	5,582,600	Kansai Paint	$	59,822
		Paint Producer in Japan, India, China & Southeast Asia
	20,227,000	Seven Bank		51,943
		ATM Processing Services
	20,096	Wacom		45,009
		Computer Graphic Illustration Devices
	3,029,900	Park24		44,746
		Parking Lot Operator
	1,582,200	Hoshizaki Electric		40,047
		Commercial Kitchen Equipment
	2,981,100	Kuraray		38,633
		Special Resin, Fine Chemical, Fibers & Textures
	2,572,724	Start Today (a)		35,952
		Online Japanese Apparel Retailer
	1,694,562	Glory		35,351
		Currency Handling Systems & Related Equipment
	7,780	Orix JREIT		34,971
		Diversified REIT
	1,417,438	Aeon Delight		32,546
		Facility Maintenance & Management
	865,800	Sanrio (a)		31,566
		Character Goods & Licensing
	295,762	Nakanishi		30,061
		Dental Tools & Machinery
	937,651	Kintetsu World Express		30,011
		Airfreight Logistics
	15,116	Advance Residence Investment		29,385
		Residential REIT
	2,552,000	NGK Insulators		28,260
		Ceramic Products for Auto, Power & Electronics
	1,613,429	Daiseki		28,052
		Waste Disposal & Recycling
	659,500	Miraca Holdings		27,381
		Outsourced Lab Testing, Diagnostic Equipment & Reagents
	480,000	Disco		27,184
		Semiconductor Dicing & Grinding Equipment
	25,979	Jupiter Telecommunications		26,488
		Largest Cable Service Provider in Japan
	2,137,272	Japan Airport Terminal		26,068
		Airport Terminal Operator at Haneda
	5,540	Mori Hills REIT Investment		23,942
		Tokyo-centric Diversified REIT
	828,000	Doshisha		22,937
		Wholesaler
	2,600,000	Shimadzu		22,498
		Analytical Instrument, Medical & Industrial Equipment
	1,885,600	Asahi Diamond Industrial		21,652
		Consumable Diamond Tools
	349,792	Ain Pharmaciez		21,101
		Dispensing Pharmacy/Drugstore Operator
	339,000	FP Corporation		21,028
		Disposable Food Trays & Containers
	6,140	Kenedix Realty Investment		19,852
		Tokyo Mid-size Office REIT

Number of Shares			Value (000)
	1,940,200	Sintokogio	$	19,450
		Automated Casting Machines, Surface Treatment System & Consumables
	880,474	Aeon Mall		18,762
		Suburban Shopping Mall Developer, Owner & Operator
	15,024,649	Shinsei Bank		18,279
		Commercial Bank
	772,000	Misumi Group		18,192
		Industrial Components Distributor
	732,108	Icom		17,976
		Two Way Radio Communication Equipment
	1,405,739	Ushio		17,424
		Industrial Light Sources
	857,144	Ibiden		15,527
		Electronic Parts & Ceramics
	424,000	Horiba		14,891
		Measuring Instruments & Analyzers
	1,346,963	Torishima Pump Manufacturing		13,541
		Industrial Pump for Power Generation & Water Supply Systems
	1,400	Japan Real Estate Investment		12,836
		Office REIT in Tokyo
	1,821	Fukuoka REIT		12,539
		Diversified REIT in Fukuoka
	756,900	Nihon Parkerizing		11,723
		Metal Surface Treatment Agents & Processing
	407,050	Miura		10,838
		Industrial Boiler
				1,058,464
		> Taiwan 7.2%
	36,606,000	Far EasTone Telecom		79,642
		Taiwan's Third Largest Mobile Operator
	16,405,300	Taiwan Mobile		54,252
		Taiwan's Second Largest Mobile Operator
	20,120,000	CTCI Corp		37,671
		International Engineering Firm
	5,058,830	Simplo Technology		34,938
		Battery Packs for Notebook & Tablet PCs
	12,218,270	Tripod Technologies		34,730
		Printed Circuit Boards (PCB)
	5,910,000	Radiant Opto-Electronics (b)		30,036
		LCD Back Light Units & Modules
	2,492,300	St. Shine Optical		27,893
		World's Leading Disposable Contact Lens OEM
	11,200,000	Taiwan Hon Chuan		25,229
		Beverage Packaging (Bottles, Caps, Labels) Manufacturer
	3,661,100	MStar Semiconductor		24,695
		Integrated Circuits for TV, Digital Set-top-box & Handset
	10,677,000	Chroma Ate		24,374
		Automatic Test Systems, Testing & Measurement Instruments
	6,603,000	Advantech		21,959
		Industrial PC & Components
	3,181,000	President Chain Store		16,973
		Taiwan's Number One Convenience Chain Store Operator
	2,595,000	PC Home		14,711
		Taiwanese Internet Retail Company
	2,469,000	Lung Yen		7,138
		Funeral Services & Columbaria
				434,241

See accompanying notes to financial statements.

41

Columbia Acorn International

Statement of Investments (Unaudited), continued

Number of Shares			Value (000)
		> Hong Kong 3.9%
	6,500,000	Melco Crown Entertainment - ADR (b)	$	74,880
		Macau Casino Operator
	21,845,000	Lifestyle International		48,136
		Mid to High-end Department Store Operator in Hong Kong & China
	15,625,000	L'Occitane International		43,364
		Skin Care & Cosmetics Producer
	8,475,000	AAC Technologies		24,664
		Miniature Acoustic Components
	30,000,000	Sasa International		19,007
		Cosmetics Retailer
	10,000,000	MGM China Holdings		15,333
		Macau Casino Operator
	8,000,000	Melco International		6,472
		Macau Casino Operator
	4,495,200	Vitasoy International		3,778
		Hong Kong Soy Food Brand
				235,634
		> Singapore 3.8%
	25,000,000	Olam International		36,209
		Agriculture Supply Chain Manager
	20,000,000	Ascendas REIT		34,119
		Industrial Property Landlord
	20,000,000	CDL Hospitality Trust		30,934
		Hotel Owner/Operator
	35,000,000	Mapletree Logistics Trust		27,214
		Industrial Property Landlord
	35,000,000	Mapletree Commercial Trust		27,176
		Retail & Office Property Landlord
	28,000,000	Mapletree Industrial Trust		26,822
		Industrial Property Landlord
	15,000,000	Goodpack Limited		20,546
		International Bulk Container Leasing
	3,500,000	Singapore Exchange		17,584
		Singapore Equity & Derivatives Market Operator
	3,071,300	Petra Foods		6,061
		Cocoa Processor & Chocolate Manufacturer
				226,665
		> China 3.1%
	26,565,000	Want Want		32,851
		Chinese Branded Consumer Food Company
	18,000,300	Digital China		31,721
		IT Distribution & Systems Integration Services
	1,100,000	New Oriental Education & Technology - ADR (b)		26,950
		Education Service Provider
	18,920,554	Zhaojin Mining Industry		24,878
		Gold Mining & Refining in China
	381,300	NetEase.com - ADR (b)		22,440
		Chinese Online Gaming Services
	260,000,000	RexLot Holdings		18,625
		Lottery Equipment Supplier in China
	326,700	51job - ADR (a)(b)		14,881
		Integrated Human Resource Services
	30,000,000	AMVIG Holdings		13,284
		Chinese Tobacco Packaging Material Supplier
				185,630

Number of Shares			Value (000)
		> India 2.4%
	341,652	Asian Paints	$	23,850
		India's Largest Paint Company
	2,262,300	United Breweries		22,126
		India's Largest Brewer
	13,195,000	Redington India		18,222
		Supply Chain Solutions for IT & Mobile Handsets in Emerging Markets
	8,052,053	Adani Ports & Special Economic Zone		17,581
		Indian West Coast Shipping Port
	11,163,303	Jain Irrigation Systems		16,751
	558,165	Jain Irrigation Systems - DVR (b)		395
		Agricultural Micro-irrigation Systems & Food Processing
	1,550,000	Shriram Transport Finance		14,786
		Used Truck Finance
	545,000	Colgate-Palmolive India		11,762
		Consumer Products in Oral Care
	1,600,000	Titan Industries		6,443
		Jewlery, Watches & Eyeglasses
	10,249,300	S. Kumars Nationwide		6,361
		Textiles, Clothing & Retail
	32,642,905	REI Agro		5,466
		Basmati Rice Processing
	1,650,000	SKIL Ports and Logistics (b)		2,920
		Indian Container Port Project
				146,663
		> Korea 1.8%
	1,134,000	Grand Korea Leisure		23,541
		Largest 'Foreigner Only' Casino Group in Korea
	101,150	NHN		22,186
		Korean Online Search Services
	623,120	Woongjin Coway		19,457
		Korean Household Appliance Rental Service Provider
	580,000	iMarketKorea		10,751
		Procurement, Distribution of MRO (Maintenance, Repair, Operations) Goods
	474,441	Handsome		10,683
		Korea's Leading High-end Apparel Company
	244,530	Kepco Plant Service & Engineering		10,314
		Power Plant & Grid Maintenance
	182,000	Hana Tour Service		7,146
		Korea's Largest Wholesale Tour Provider
	55,000	Hyundai Home Shopping		5,382
		TV Home Shopping Company
				109,460
		> Indonesia 1.2%
	29,063,787	Archipelago Resources (b)(c)		23,214
		Gold Mining Projects in Indonesia, Vietnam & the Philippines
	51,767,300	Tower Bersama Infrastructure (b)		18,135
		Communications Towers
	12,488,000	Mitra Adiperkasa		9,588
		Operator of Department Store & Specialty Retail Stores
	15,000,000	Ace Indonesia		8,128
		Home Improvement Retailer
	2,176,600	Mayora Indah		5,907
		Consumer Branded Food Manufacturer

See accompanying notes to financial statements.

42

Number of Shares			Value (000)
		> Indonesia—continued
	32,766,000	MNC Skyvision (b)	$	5,486
		Largest Satellite Pay TV Operator in Indonesia
	6,217,500	Southern Arc Minerals (b)(c)		1,710
		Gold & Copper Exploration in Indonesia
				72,168
		> Mongolia 0.9%
	60,037,500	Mongolian Mining (b)		34,069
		Coking Coal Mining in Mongolia
	1,049,943	Ivanhoe Mines (a)(b)		10,354
	914,678	Ivanhoe Mines (a)(b)(d)		8,854
		Copper Mine Project in Mongolia
				53,277
		> Philippines 0.8%
	73,221,250	SM Prime Holdings		22,696
		Shopping Mall Operator
	7,931,700	Int'l Container Terminal		13,923
		Container Handling Terminals & Port Management
	19,454,700	Manila Water Company		11,331
		Water Utility Company in the Philippines
				47,950
		> Thailand 0.7%
	110,000,000	Home Product Center		43,930
		Home Improvement Retailer
				43,930
		> Cambodia 0.4%
	60,000,000	Nagacorp		26,831
		Casino/Entertainment Complex in Cambodia
				26,831
Asia: Total				2,640,913
Europe 29.9%
		> United Kingdom 5.9%
	1,004,500	Intertek Group		42,084
		Testing, Inspection, Certification Services
	3,375,000	Serco		28,343
		Facilities Management
	2,579,333	JLT Group		28,341
		International Business Insurance Broker
	8,785,000	BBA Aviation		28,124
		Aviation Support Services
	3,107,000	Domino's Pizza United Kingdom & Ireland		25,053
		Pizza Delivery in the UK, Ireland & Germany
	822,000	Rightmove		20,540
		Internet Real Estate Listings
	596,100	Aggreko		19,386
		Temporary Power & Temperature Control Services
	2,855,000	Abcam		18,643
		Online Sales of Antibodies
	2,300,000	Greggs		18,169
		Bakery
	1,761,742	Smith and Nephew		17,622
		Medical Equipment & Supplies
	517,000	Rotork		15,990
		Valve Actuators for Oil & Water Pipelines
	1,773,408	Shaftesbury		14,317
		London Prime Retail REIT

Number of Shares			Value (000)
	1,555,000	WH Smith	$	13,276
		Newsprint, Book & General Stationery Retailer
	262,300	Next		13,171
		Clothes & Home Retailer in the UK
	2,027,932	Premier Oil (b)		10,775
		Oil & Gas Producer in Europe, Pakistan & Asia
	2,303,000	Chemring		9,915
		Defense Manufacturer of Countermeasures & Energetics
	4,163,948	PureCircle (a)(b)		9,360
		Natural Sweeteners
	382,581	Tullow Oil		8,842
		Oil & Gas Producer
	256,202	Spirax Sarco		7,985
		Steam Systems for Manufacturing & Process Industries
	2,840,000	Sterling Resources (a)(b)		2,845
		Oil & Gas Exploration - Europe
				352,781
		> Netherlands 4.4%
	1,591,702	UNIT4 (c)		40,567
		Business Software Development
	1,680,623	Imtech		40,130
		Electromechanical & Information & Communications Technology Installation & Maintenance
	2,546,126	Aalberts Industries		39,645
		Flow Control & Heat Treatment
	1,234,758	Koninklijke TenCate		32,962
		Advanced Textiles & Industrial Fabrics
	460,000	Fugro		27,903
		Subsea Oilfield Services
	1,252,514	Arcadis (a)		27,394
		Engineering Consultants
	317,424	Vopak		20,360
		World's Largest Operator of Petroleum & Chemical Storage Terminals
	850,468	TKH Group		18,269
		Dutch Industrial Conglomerate
	143,395	Core Laboratories		16,620
		Oil & Gas Reservoir Consulting
				263,850
		> Switzerland 3.8%
	310,000	Partners Group		55,134
		Private Markets Asset Management
	255,000	Geberit		50,306
		Plumbing Supplies
	330,000	Dufry Group (b)		39,999
		Operates Airport Duty Free & Duty Paid Shops
	15,500	Sika		29,931
		Chemicals for Construction & Industrial Applications
	170,000	Kuehne & Nagel		18,010
		Freight Forwarding/Logistics
	280,000	Zehnder		16,736
		Radiators & Ventilation Systems
	580,000	Bank Sarasin & Cie (b)		16,342
		Private Banking
				226,458
		> France 3.5%
	553,000	Eurofins Scientific		68,673
		Food, Pharmaceuticals & Materials Screening & Testing

See accompanying notes to financial statements.

43

Columbia Acorn International

Statement of Investments (Unaudited), continued

Number of Shares			Value (000)
		> France—continued
	729,700	Gemalto	$	52,410
		Digital Security Solutions
	675,000	Neopost		36,023
		Postage Meter Machines
	971,800	Saft		23,315
		Niche Battery Manufacturer
	232,400	Norbert Dentressangle		14,744
		Leading European Logistics & Transport Group
	134,254	Compagnie Française de l'Afrique Occidentale		6,355
		African Wholesaler & Distributor
	1,831,204	Hi-Media (a)(b)		4,668
		Online Advertiser in Europe
	162,844	Mersen		4,080
		Advanced Industrial Materials
				210,268
		> Germany 3.2%
	2,500,000	Wirecard		48,476
		Online Payment Processing & Risk Management
	148,295	Rational		35,347
		Commercial Ovens
	500,000	Dürr		30,851
		Automotive Plant Engineering & Associated Capital Equipment
	405,000	Rheinmetall		19,909
		Defense & Automotive
	625,000	CTS Eventim		18,808
		Event Ticket Sales
	690,000	NORMA Group		15,161
		Clamps for Automotive & Industrial Applications
	165,400	Bertrandt		12,390
		Outsourced Engineering
	333,000	Elringklinger		7,946
		Automobile Components
	338,886	Deutsche Beteiligungs		6,691
		Private Equity Investment Management
				195,579
		> Sweden 2.2%
	4,056,007	Hexagon		69,621
		Design, Measurement & Visualization Software & Equipment
	4,150,024	Sweco (c)		43,732
		Engineering Consultants
	658,700	Unibet		16,700
		European Online Gaming Operator
	419,877	East Capital Explorer		2,892
		Sweden-based Russia & Central Eastern Europe Investment Fund
				132,945
		> Denmark 1.3%
	1,648,800	Novozymes		42,755
		Industrial Enzymes
	168,042	SimCorp		28,969
		Software for Investment Managers
	166,013	Solar A/S		9,002
		Technical Wholesaler of Electrical, Plumbing & HVAC Equipment
				80,726

Number of Shares			Value (000)
		> Italy 1.1%
	2,661,000	Pirelli (a)	$	28,065
		Global Tire Supplier
	166,200	Tod's (a)		16,671
		Leather Shoes & Bags
	7,000,000	Geox (a)		15,486
		Apparel & Shoe Maker
	8,951,757	CIR		8,829
		Italian Holding Company
				69,051
		> Russia 0.8%
	1,123,695	Yandex (b)		21,406
		Search Engine for Russian & Turkish Languages
	2,109,700	Petropavlovsk		15,114
		Gold & Iron Ore Mining in Russia
	368,493	Mail.ru - GDR (b)(e)		12,550
		Internet Social Networking & Games for Russian Speakers
				49,070
		> Iceland 0.6%
	35,982,499	Marel		36,188
		Largest Manufacturer of Poultry & Fish Processing Equipment
				36,188
		> Ireland 0.5%
	263,400	Paddy Power		17,195
		Irish Betting Services
	4,237,000	United Drug		11,118
		Irish Pharmaceutical Wholesaler & Outsourcer
				28,313
		> Spain 0.4%
	618,320	Red Eléctrica de España		26,987
		Spanish Power Transmission
				26,987
		> Portugal 0.4%
	8,635,000	Redes Energéticas Nacionais		22,858
		Portuguese Power Transmission & Gas Transportation
				22,858
		> Czech Republic 0.4%
	130,682	Komercni Banka		22,798
		Leading Czech Universal Bank
				22,798
		> Norway 0.4%
	2,403,664	Atea		21,165
		Leading Nordic IT Hardware/Software Reseller & Installation Company
				21,165
		> Finland 0.3%
	1,039,429	Stockmann (a)		21,015
		Department Store & Fashion Retailer in Scandinavia & Russia
				21,015
		> Belgium 0.3%
	438,880	EVS Broadcast Equipment		20,704
		Digital Live Mobile Production Software & Systems
				20,704

See accompanying notes to financial statements.

44

Number of Shares			Value (000)
		> Kazakhstan 0.3%
	3,319,000	Halyk Savings Bank of Kazakhstan - GDR (b)	$	16,554
		Largest Retail Bank & Insurer in Kazakhstan
				16,554
		> Greece 0.1%
	4,384,185	Intralot		4,949
		Lottery & Gaming Systems & Services
				4,949
Europe: Total				1,802,259
Other Countries 16.5%
		> South Africa 4.5%
	1,170,188	Naspers		62,503
		Media in Africa, China, Russia & Other Emerging Markets
	3,175,083	Mr. Price		43,531
		South African Retailer of Apparel, Household & Sporting Goods
	19,098,300	Rand Merchant Insurance		40,676
		Directly Sold Property & Casualty Insurance; Holdings in Other Insurers
	11,763,907	Coronation Fund Managers		39,830
		South African Fund Manager
	4,992,200	Adcock Ingram Holdings		36,696
		Manufacturer of Pharmaceuticals & Medical Supplies
	8,679,940	Northam Platinum		24,827
		Platinum Mining in South Africa
	1,025,504	Massmart Holdings		21,233
		General Merchandise, Food & Home Improvement Stores; Wal-Mart Subsidiary
				269,296
		> Canada 3.8%
	1,403,772	CCL Industries		51,499
		Leading Global Label Manufacturer
	1,212,597	ShawCor		43,890
		Oil & Gas Pipeline Products
	653,200	Onex Capital		25,362
		Private Equity
	582,942	AG Growth (a)		21,008
		Leading Manufacturer of Augers & Grain Handling Equipment
	770,576	Black Diamond Group		17,264
		Provides Accommodations/Equipment for Oil Sands Development
	984,500	Alliance Grain Traders		13,209
		Global Leader in Pulse Processing & Distribution
	2,919,000	DeeThree Exploration (b)(c)(f)		9,272
	1,142,377	DeeThree Exploration (b)(c)		3,703
		Canadian Oil & Gas Producer
	2,096,514	Horizon North Logistics		11,964
		Provides Diversified Oil Service Offering in Northern Canada
	263,857	Baytex (a)		11,116
		Oil & Gas Producer in Canada
	454,000	Celtic Exploration (b)		6,141
		Canadian Oil & Gas Producer
	1,607,306	Pan Orient (b)		5,920
		Asian Oil & Gas Explorer

Number of Shares			Value (000)
	450,000	Athabasca Oil Sands (b)	$	4,950
		Oil Sands & Unconventional Oil Development
	1,611,000	Americas Petrogas (a)(b)		2,991
		Oil & Gas Exploration in Argentina, Potash in Peru
	332,700	Crew Energy (b)		1,879
		Canadian Oil & Gas Producer
				230,168
		> Australia 3.6%
	3,973,200	UGL (a)		50,875
		Engineering & Facilities Management
	48,533,075	Commonwealth Property Office Fund		50,591
		Australia Prime Office REIT
	11,936,400	Challenger Financial		40,091
		Largest Annuity Provider
	498,560	Cochlear		33,859
		Cochlear Implants
	7,595,003	IAG		27,240
		General Insurance Provider
	1,576,290	Domino's Pizza Enterprises		16,294
		Domino's Pizza Operator in Australia/New Zealand & France/Benelux
				218,950
		> United States 3.4%
	1,229,871	BioMarin Pharmaceutical (b)		48,678
		Biotech Focused on Orphan Diseases
	952,080	Atwood Oceanics (b)		36,027
		Offshore Drilling Contractor
	965,297	Textainer Group Holdings (a)		35,619
		Top International Container Leasor
	763,228	World Fuel Services		29,026
		Global Fuel Broker
	555,500	Hornbeck Offshore (b)		21,542
		Supply Vessel Operator in U.S. Gulf of Mexico
	548,900	Rowan (b)		17,746
		Contract Offshore Driller
	407,213	FMC Technologies (b)		15,975
		Oil & Gas Well Head Manufacturer
				204,613
		> Israel 1.0%
	4,706,527	Israel Chemicals		52,074
		Producer of Potash, Phosphates, Bromine & Specialty Chemicals
	625,000	Caesarstone (b)		7,569
		Quartz Countertops
				59,643
		> Senegal 0.2%
	42,360	Sonatel		9,316
		Leading Telecoms Operator in Western Africa
				9,316
Other Countries: Total				991,986
Latin America 4.4%
		> Brazil 2.8%
	3,700,000	Localiza Rent A Car		55,652
		Car Rental
	1,200,000	Multiplus		28,618
		Loyalty Program Operator in Brazil

See accompanying notes to financial statements.

45

Columbia Acorn International

Statement of Investments (Unaudited), continued

Number of Shares			Value (000)
		> Brazil—continued
	1,880,200	Mills Estruturas e Servicos de Engenharia	$	25,275
		Civil Engineering & Construction
	4,500,000	Odontoprev		22,696
		Dental Insurance
	1,300,000	Arcos Dorados (a)		19,214
		McDonald's Master Franchise for Latin America
	3,577,000	MRV Engenharia		16,474
		Brazilan Property Developer
				167,929
		> Mexico 0.8%
	600,000	Grupo Aeroportuario del Sureste - ADR		46,842
		Mexican Airport Operator
				46,842
		> Guatemala 0.3%
	1,403,049	Tahoe Resources (b)		19,390
		Silver Project in Guatemala
				19,390
		> Uruguay 0.2%
	1,306,818	Union Agriculture Group (b)(f)(g)		12,794
		Farmland Operator in Uruguay
				12,794
		> Chile 0.2%
	5,640,000	Viña Concha y Toro		11,038
		Global Branded Wine Manufacturer
				11,038
		> Colombia 0.1%
	7,850,769	Canacol (b)		3,509
		Oil Producer in South America
	22,525,000	Gulf United (b)		1,351
		Prospecting for Oil Alongside Large Producers in Colombia
				4,860
		> Argentina —%
	4,950,000	Madalena Ventures (b)(f)		1,634
	2,475,000	Madalena Ventures (b)		851
		Oil & Gas Exploration in Argentina
				2,485
Latin America: Total				265,338
Total Equities: 94.6% (Cost: $4,751,710)				5,700,496

Number of Shares			Value (000)
Securities Lending Collateral 1.8%
	111,196,657	Dreyfus Government Cash Management Fund (7 day yield of 0.01%) (h)	$	111,197
Total Securities Lending Collateral: (Cost: $111,197)				111,197
Total Investments: 96.4% (Cost: $4,862,907)(i)(j)				5,811,693
Obligation to Return Collateral for Securities Loaned: (1.8)%				(111,197	)
Cash and Other Assets Less Liabilities: 5.4%				326,071
Total Net Assets: 100.0%			$	6,026,567

ADR - American Depositary Receipts

DVR - Differential Voting Right Equity Shares

GDR - Global Depositary Receipts

REIT - Real Estate Investment Trust

See accompanying notes to financial statements.

46

> Notes to Statement of Investments (dollar values in thousands)

(a)  All or a portion of this security was on loan at June 30, 2012. The total market value of securities on loan at June 30, 2012 was $110,353.

(b)  Non-income producing security.

(c)  An affiliated person of the Fund may include any company in which the Fund owns five percent or more of its outstanding voting shares. Holdings and transactions in these affiliated companies during the period ended June 30, 2012, are as follows:

Security	Balance of Shares Held 12/31/11		Purchases/ Additions		Sales/ Reductions		Balance of Shares Held 6/30/12		Value		Dividend
Archipelago Resources		29,063,787		-		-		29,063,787	$	23,214	$	-
DeeThree Exploration		4,061,377		-		-		4,061,377		12,975		-
Koninklijke TenCate*		1,371,573		53,685		190,500		1,234,758		32,962		-	**
Southern Arc Minerals		6,217,500		-		-		6,217,500		1,710		-
Sweco		4,150,024		-		-		4,150,024		43,732		1,574
UNIT4		1,591,702		-		-		1,591,702		40,567		677
Wacom*		23,790		-		3,694		20,096		45,009		794
Workspace Group*		8,000,000		-		8,000,000		-		-		298
Total of Affiliated Transactions		54,479,753		53,685		8,194,194		46,339,244	$	200,169	$	3,343

*  At June 30, 2012, the Fund owned less than five percent of the company's outstanding voting shares.

**  Rounds to less than $500.

  The aggregate cost and value of these companies at June 30, 2012 were $93,271 and $122,198 respectively. Investments in affiliated companies represented 2.03% of the Fund's total net assets at June 30, 2012.

(d)  Security is traded on a U.S. exchange.

(e)  Security exempt from registration under Section 4(2) of the Securities Act of 1933. This security may only be resold in exempt transactions to qualified buyers. Private resales of this security to qualified institutional buyers are also exempt from registration pursuant to Rule 144A under the Securities Act of 1933. At June 30, 2012, this security had an aggregate value of $12,550, which represented 0.21% of total net assets.

(f)  Denotes a restricted security, which is subject to restrictions on resale under federal securities laws. These securities are valued at fair value determined in good faith under consistently applied procedures established by the Board of Trustees. At June 30, 2012, the market value of these securities amounted to $23,700, which represented 0.39% of total net assets.

  Additional information on these securities is as follows:

Security	Acquisition Dates	Shares		Cost		Value
Union Agriculture Group	12/8/10-6/27/12		1,306,818	$	15,000	$	12,794
DeeThree Exploration	9/7/10-3/8/11		2,919,000		10,228		9,272
Madalena Ventures	10/21/10		4,950,000		3,136		1,634
				$	28,364	$	23,700

(g)  Illiquid security.

(h)  Investment made with cash collateral received from securities lending activity.

(i)  At June 30, 2012, for federal income tax purposes, the cost of investments was $4,862,907 and net unrealized appreciation was $948,786 consisting of gross unrealized appreciation of $1,372,957 and gross unrealized depreciation of $424,171.

(j)  On June 30, 2012, the Fund's total investments were denominated in currencies as follows:

Currency	Value		Percentage of Net Assets
Japanese Yen	$	1,058,464		17.5
Euro		846,954		14.1
United States Dollar		507,517		8.4
Taiwan Dollar		434,241		7.2
British Pound		391,184		6.5
Hong Kong Dollar		343,012		5.7
Australian Dollar		330,146		5.5
Other currencies less than 5% of total net assets		1,900,175		31.5
Total Portfolio	$	5,811,693		96.4

See accompanying notes to financial statements.

47

Columbia Acorn International

Statement of Investments (Unaudited), continued

> Notes to Statement of Investments (dollar values in thousands)

Fair Value Measurements

  Various inputs are used in determining the value of the Fund's investments, following the input prioritization hierarchy established by GAAP. These inputs are summarized in the three broad levels listed below:

•  Level 1 – quoted prices in active markets for identical securities

•  Level 2 – prices determined using other significant observable inputs (including quoted prices for similar securities, interest rates, prepayment speeds, credit risk and others)

•  Level 3 – prices determined using significant unobservable inputs where quoted prices or observable inputs are unavailable or less reliable (including management's own assumptions about the factors market participants would use in pricing an investment)

  The inputs or methodology used for valuing securities are not necessarily an indication of the risk associated with investing in those securities.

  Examples of the types of securities in which the Fund would typically invest and how they are classified within this hierarchy are as follows. Typical Level 1 securities include exchange traded domestic equities, mutual funds whose NAVs are published each day and exchange traded foreign equities that are not statistically fair valued. Typical Level 2 securities include exchange traded foreign equities that are statistically fair valued, forward foreign currency exchange contracts and short-term investments valued at amortized cost. Additionally, securities fair valued by the Valuation Committee (the Committee) of the Fund's Board of Trustees (the Board) that rely on significant observable inputs are also included in Level 2. Typical Level 3 securities include any security fair valued by the Committee that relies on significant unobservable inputs.

  Under the direction of the Board, the Committee is responsible for carrying out the valuation procedures approved by the Board.

  The Committee meets as necessary, and no less frequently than quarterly, to determine fair values for securities for which market quotations are not readily available or for which the investment manager believes that available market quotations are unreliable, and to review the continuing appropriateness of the current value of any security subject to the Trust's Portfolio Pricing Policy and the pricing procedures of the investment manager (the Policies). The Policies address, among other things: circumstances under which market quotations will be deemed readily available; selection of third party pricing vendors; appropriate pricing methodologies; events that require fair valuation and fair value techniques; and circumstances under which securities will be deemed to pose a potential for stale pricing, including when securities are illiquid, restricted, or in default. The Committee may also meet to discuss additional valuation matters, which may include review of back-testing results, review of time-sensitive information or approval of other valuation related actions, and to review the appropriateness of the Policies.

  For investments categorized as Level 3, the significant unobservable inputs used in the fair value measurement of the Funds' securities may include: (i) data specific to the issuer or comparable issuers, (ii) general market or specific sector news and (iii) quoted prices and specific or similar security transactions. The Committee considers this data and any changes from prior periods in order to assess the reasonableness of observable and unobservable inputs, any assumptions or internal models used to value those securities and changes in fair value. Significant changes in any of these factors could result in lower or higher fair value measurements. Various factors impact the frequency of monitoring (which may occur as often as daily), however the Committee may determine that changes to inputs, assumptions and models are not required with the same frequency.

The following table summarizes the inputs used, as of June 30, 2012, in valuing the Fund's assets:

Investment Type	Quoted Prices (Level 1)		Other Significant Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)		Total
Equities
Asia	$	160,069	$	2,480,844	$	-	$	2,640,913
Europe		40,871		1,761,388		-		1,802,259
Other Countries		433,078		558,908		-		991,986
Latin America		250,910		1,634		12,794		265,338
Total Equities		884,928		4,802,774		12,794		5,700,496
Total Securities Lending Collateral		111,197		-		-		111,197
Total Investments	$	996,125	$	4,802,774	$	12,794	$	5,811,693

  The Fund's assets assigned to the Level 2 input category are generally valued using a market approach, in which a security's value is determined through its correlation to prices and information from observable market transactions for similar or identical assets. Foreign equities are generally valued at the last sale price on the foreign exchange or market on which they trade. The Fund may use a statistical fair valuation model, in accordance with the policy adopted by the Board, provided by an independent third party to value securities principally traded in foreign markets in order to adjust for possible stale pricing that may occur between the close of the foreign exchanges and the time for valuation. These models take into account available market data including intraday index, ADR, and ETF movements. Securities acquired via private placement that have a holding period or an extended settlement period are valued at a discount to the same shares that are trading freely on the market. These discounts are determined by the investment manager's experience with similar securities or situations. Factors may include, but are not limited to, trade volume, shares outstanding and stock price.

  The following table shows transfers between Level 1 and Level 2 of the fair value hierarchy:

Transfers In				Transfers Out
Level 1		Level 2		Level 1		Level 2
$	10,584	$	-	$	-	$	10,584

  Financial assets were transferred from Level 2 to Level 1 as resale restrictions no longer apply.

See accompanying notes to financial statements.

48

> Notes to Statement of Investments (dollar values in thousands)

  The following table reconciles asset balances for the period ending June 30, 2012, in which significant observable and/or unobservable inputs (Level 3) were used in determining value:

Investments in Securities	Balance as of December 31, 2011		Realized Gain/(Loss)		Change in Unrealized Appreciation (Depreciation)		Purchases		Sales		Transfers into Level 3		Transfers out of Level 3		Balance as of June 30, 2012
Equities
Latin America	$	12,462	$	-	$	332	$	-	$	-	$	-	$	-	$	12,794
	$	12,462	$	-	$	332	$	-	$	-	$	-	$	-	$	12,794

  The information in the above reconciliation table represents fiscal year to date activity for any securities identified as using Level 3 inputs at either the beginning or the end of the current fiscal period.

  The change in unrealized appreciation attributed to securities owned at June 30, 2012, which were valued using significant unobservable inputs (Level 3), amounted to $332.

  The Fund does not hold any significant investments categorized as Level 3.

  Certain common stock classified as Level 3 are valued at fair value, using a market approach, as determined in good faith under consistently applied procedures established by and under the general supervision of the Board. To determine fair value for these securities, for which no market exists, the Committee utilizes the valuation technique it deems most appropriate in the circumstances, using some unobservable inputs, which may include but are not limited to trades of similar securities, estimated earnings of the company, market multiples derived from a set of comparable companies, and the position of the security within the company's capital structure. Significant increases or decreases to any of these inputs could result in a significantly lower or higher fair value measurement. Generally, a change in estimated earnings of a company may result in a change to the comparable companies and market multiples utilized.

See accompanying notes to financial statements.

49

Columbia Acorn International

Portfolio Diversification (Unaudited)

At June 30, 2012, the Fund's portfolio investments as a percentage of net assets were diversified as follows:

	Value (000)		Percentage of Net Assets
> Industrial Goods & Services
Other Industrial Services	$	498,256		8.3
Machinery		376,487		6.2
Industrial Materials & Specialty Chemicals		363,320		6.0
Construction		113,252		1.9
Conglomerates		82,269		1.4
Outsourcing Services		79,172		1.3
Electrical Components		78,914		1.3
Industrial Distribution		40,299		0.7
		1,631,969		27.1
> Consumer Goods & Services
Retail		362,751		6.0
Food & Beverage		205,154		3.4
Casinos & Gaming		204,526		3.4
Nondurables		111,534		1.9
Other Consumer Services		89,612		1.5
Travel		62,798		1.0
Apparel		53,546		0.9
Consumer Goods Distribution		52,921		0.9
Other Durable Goods		44,802		0.7
Restaurants		41,347		0.7
Educational Services		26,950		0.5
Other Entertainment		18,807		0.3
Furniture & Textiles		7,569		0.1
		1,282,317		21.3
> Information
Computer Hardware & Related Equipment		264,450		4.4
Mobile Communications		170,006		2.8
Internet Related		161,623		2.7
Business Software		139,157		2.3
Financial Processors		66,059		1.1
Instrumentation		61,762		1.0
Semiconductors & Related Equipment		51,879		0.9
Electronics Distribution		31,721		0.5
CATV		26,488		0.4
Computer Services		21,165		0.3
Telephone & Data Services		9,316		0.2
Satellite Broadcasting & Services		5,486		0.1
Advertising		4,669		0.1
		1,013,781		16.8
> Other Industries
Real Estate		383,867		6.4
Transportation		116,680		1.9
Regulated Utilities		61,175		1.0
		561,722		9.3

	Value (000)			Percentage of Net Assets
> Energy & Minerals
Oil Services	$	192,311			3.2
Mining		179,030			3.0
Oil & Gas Producers		75,778			1.3
Agricultural Commodities		26,003			0.4
Oil Refining, Marketing & Distribution		20,360			0.3
		493,482			8.2
> Finance
Insurance		159,044			2.6
Brokerage & Money Management		120,890			2.0
Banks		109,573			1.8
Finance Companies		75,767			1.3
		465,274			7.7
> Health Care
Medical Equipment & Devices		81,542			1.3
Biotechnology & Drug Delivery		48,678			0.8
Pharmaceuticals		47,814			0.8
Medical Supplies		46,536			0.8
Health Care Services		27,381			0.5
		251,951			4.2
Total Equities:		5,700,496			94.6
Security Lending Collateral:		111,197			1.8
Total Investments:		5,811,693			96.4
Obligation to Return Collateral for Securities Loaned:		(111,197	)		(1.8	)
Cash and Other Assets Less Liabilities:		326,071			5.4
Net Assets:	$	6,026,567			100.0

See accompanying notes to financial statements.

50

Columbia Acorn USA

Major Portfolio Changes in the Second Quarter (Unaudited)

	Number of Shares
	3/31/12		6/30/12
Purchases
Information
SABA		0		337,000
Industrial Goods & Services
Moog		355,000		436,000
Polypore International		100,000		200,000
Consumer Goods & Services
Caesarstone (Israel)		20,000		200,000
Helen of Troy		106,000		262,000
Finance
CAI International		330,000		376,000
First Commonwealth		556,000		834,000
Health Care
ARIAD Pharmaceuticals		0		379,040
Cepheid		488,600		551,600
NPS Pharmaceuticals		1,055,000		1,163,600
Synageva Biopharma		29,671		129,002
Other Industries
DuPont Fabros Technology		519,000		625,000
Energy & Minerals
Approach Resource		100,000		244,000
Hornbeck Offshore		83,000		125,000

	Number of Shares
	3/31/12		6/30/12
Sales
Information
AboveNet		148,000		0
Ariba		408,000		0
Blackbaud		300,000		67,869
Global Payments		170,000		153,000
Ixia		903,000		813,000
NetSuite		281,000		211,000
Nice Systems - ADR (Israel)		177,000		160,000
ON Semiconductor		1,061,750		961,000
Polycom		165,000		0
SBA Communications		560,000		529,000
Trimble Navigation		168,000		151,000
Industrial Goods & Services
GrafTech International		686,000		616,000
Interline Brands		233,400		0
Kennametal		226,000		204,000
Pentair		585,000		0
Waste Connections		176,000		90,000
Consumer Goods & Services
Hertz		750,000		675,000
Lifetime Fitness		259,000		233,000
lululemon athletica		730,000		583,000
Pinnacle Entertainment		775,000		698,000
Saks		790,000		715,000
True Religion Apparel		82,300		0
Finance
Eaton Vance		340,500		306,500
Hancock Holding		278,678		251,000
Valley National Bancorp		675,000		641,750
Health Care
Akorn		733,000		642,000
Alexion Pharmaceuticals		251,000		83,000
Gen-Probe		72,000		0
Pacific Biosciences of California		385,000		0
Seattle Genetics		682,000		614,000
Sirona Dental Systems		224,000		202,000
Other Industries
Associated Estates Realty		600,000		540,000
World Fuel Services		256,000		230,000
Energy & Minerals
FMC Technologies		167,000		0
Rosetta Resources		143,000		129,000

See accompanying notes to financial statements.

51

Columbia Acorn USA

Statement of Investments (Unaudited), June 30, 2012

Number of Shares			Value (000)
			Equities: 99.6%
Information 30.7%
		> Business Software 9.3%
	910,000	Informatica (a)	$	38,548
		Enterprise Data Integration Software
	698,000	Micros Systems (a)		35,738
		Information Systems for Hotels, Restaurants & Retailers
	375,000	Ansys (a)		23,666
		Simulation Software for Engineers & Designers
	243,000	Concur Technologies (a)		16,548
		Web Enabled Cost & Expense Management Software
	211,000	NetSuite (a)		11,557
		End-to-end IT Systems Solutions Delivered Over the Web
	290,000	SPS Commerce (a)		8,810
		Supply Chain Management Software Delivered via the Web
	198,000	Advent Software (a)		5,368
		Asset Management & Trading Systems
	337,000	SABA (a)		3,127
		Learning Management Systems
	400,000	Velti (a)(b)		2,600
		Mobile Marketing Software Platform
	67,869	Blackbaud		1,742
		Software & Services for Non-profits
				147,704
		> Semiconductors & Related Equipment 3.9%
	1,958,000	Atmel (a)		13,119
		Microcontrollers, Radio Frequency & Memory Semiconductors
	690,000	Microsemi (a)		12,758
		Analog/Mixed Signal Semiconductors
	426,000	Monolithic Power Systems (a)		8,465
		High Performance Analog & Mixed Signal Integrated Circuits
	262,000	Ultratech (a)		8,253
		Semiconductor Equipment
	961,000	ON Semiconductor (a)		6,823
		Mixed Signal & Power Management Semiconductors
	1,075,000	TriQuint Semiconductor (a)		5,912
		Radio Frequency Semiconductors
	390,000	Pericom Semiconductor (a)		3,510
		Interface Integrated Circuits & Frequency Control Products
	50,000	Hittite Microwave (a)		2,556
		Radio Frequency, Microwave & Millimeterwave Semiconductors
				61,396
		> Instrumentation 3.6%
	180,000	Mettler-Toledo International (a)		28,053
		Laboratory Equipment
	525,000	IPG Photonics (a)		22,885
		Fiber Lasers
	151,000	Trimble Navigation (a)		6,947
		GPS-based Instruments
				57,885

Number of Shares			Value (000)
		> Telephone & Data Services 2.7%
	1,457,000	tw telecom (a)	$	37,387
		Fiber Optic Telephone/Data Services
	400,000	Boingo Wireless (a)(b)		4,648
		Wholesale & Retail WiFi Networks
				42,035
		> Computer Hardware & Related Equipment 2.6%
	1,317,000	II-VI (a)		21,954
		Laser Optics & Specialty Materials
	292,000	Zebra Technologies (a)		10,033
		Bar Code Printers
	160,000	Nice Systems - ADR (Israel) (a)		5,856
		Audio & Video Recording Solutions
	97,000	Netgear (a)		3,348
		Networking Products for Small Business & Home
				41,191
		> Gaming Equipment & Services 2.2%
	660,000	Bally Technologies (a)		30,796
		Slot Machines & Software
	235,000	WMS Industries (a)		4,688
		Slot Machine Provider
				35,484
		> Computer Services 2.0%
	556,000	ExlService Holdings (a)		13,700
		Business Process Outsourcing
	97,000	Syntel		5,888
		Offshore IT Services
	776,766	Hackett Group (a)		4,326
		IT Integration & Best Practice Research
	640,000	RCM Technologies (a)(c)		3,546
		Technology & Engineering Services
	359,000	WNS - ADR (India) (a)		3,493
		Offshore BPO (Business Process Outsourcing) Services
				30,953
		> Mobile Communications 1.9%
	529,000	SBA Communications (a)		30,179
		Communications Towers
				30,179
		> Telecommunications Equipment 1.6%
	732,000	Finisar (a)		10,951
		Optical Subsystems & Components
	813,000	Ixia (a)		9,772
		Telecom Network Test Equipment
	752,000	Infinera (a)		5,144
		Optical Networking Equipment
				25,867
		> Contract Manufacturing 0.4%
	236,000	Plexus (a)		6,655
		Electronic Manufacturing Services
				6,655
		> Financial Processors 0.4%
	153,000	Global Payments		6,614
		Credit Card Processor
				6,614

See accompanying notes to financial statements.

52

Number of Shares			Value (000)
		> TV Broadcasting 0.1%
	875,000	Entravision Communications	$	1,059
		Spanish Language TV & Radio Stations
				1,059
Information: Total				487,022
Industrial Goods & Services 17.2%
		> Machinery 13.3%
	876,300	Ametek		43,736
		Aerospace/Industrial Instruments
	747,200	Nordson		38,324
		Dispensing Systems for Adhesives & Coatings
	835,000	ESCO Technologies		30,427
		Automatic Electric Meter Readers
	890,000	Donaldson		29,699
		Industrial Air Filtration
	631,000	HEICO		20,356
		FAA Approved Aircraft Replacement Parts
	436,000	Moog (a)		18,029
		Motion Control Products for Aerospace, Defense & Industrial Markets
	150,000	Toro		10,993
		Turf Maintenance Equipment
	200,000	Polypore International (a)(b)		8,078
		Battery Separators & Filtration Media
	204,000	Kennametal		6,763
		Consumable Cutting Tools
	146,000	Oshkosh Corporation (a)		3,059
		Specialty Truck Manufacturer
	26,000	Middleby Corp (a)		2,590
		Manufacturer of Cooking Equipment
				212,054
		> Industrial Materials & Specialty Chemicals 1.1%
	496,000	Drew Industries (a)		13,813
		RV & Manufactured Home Components
	170,000	Albany International		3,181
		Paper Machine Clothing & Composites for Aerospace
				16,994
		> Electrical Components 0.9%
	280,000	Acuity Brands		14,255
		Commercial Lighting Fixtures
				14,255
		> Other Industrial Services 0.8%
	600,000	Acorn Energy (b)		4,992
		Frac Well Exploration/Monitoring Device, Sonar Security, Electric Grid Monitoring
	240,000	TrueBlue (a)		3,715
		Temporary Manual Labor
	109,000	Forward Air		3,518
		Freight Transportation Between Airports
				12,225
		> Waste Management 0.4%
	65,000	Clean Harbors (a)		3,667
		Hazardous Waste Services & Disposal

Number of Shares			Value (000)
	90,000	Waste Connections	$	2,693
		Solid Waste Management
				6,360
		> Steel 0.4%
	616,000	GrafTech International (a)		5,944
		Industrial Graphite Materials Producer
				5,944
		> Construction 0.3%
	200,000	Fortune Brands Home & Security (a)		4,454
		Home Building Supplies & Small Locks
				4,454
Industrial Goods & Services: Total				272,286
Consumer Goods & Services 16.2%
		> Retail 5.4%
	583,000	lululemon athletica (a)		34,764
		Premium Active Apparel Retailer
	468,500	Abercrombie & Fitch		15,994
		Teen Apparel Retailer
	805,000	Pier 1 Imports		13,226
		Home Furnishing Retailer
	356,000	Shutterfly (b)		10,926
		Internet Photo-centric Retailer
	715,000	Saks (a)(b)		7,615
		Luxury Department Store Retailer
	161,500	Teavana (a)(b)		2,185
		Specialty Tea Retailer
	9,000	The Fresh Market (a)		483
		Specialty Food Retailer
				85,193
		> Travel 4.2%
	849,700	Gaylord Entertainment (a)		32,764
		Convention Hotels
	1,300,950	Avis Budget Group (a)		19,775
		Second Largest Car Rental Company
	675,000	Hertz (a)		8,640
		Largest U.S. Rental Car Operator
	64,000	Vail Resorts		3,205
		Ski Resort Operator & Developer
	140,000	HomeAway (a)(b)		3,044
		Vacation Rental Online Marketplace
				67,428
		> Furniture & Textiles 1.6%
	880,000	Knoll		11,810
		Office Furniture
	621,500	Interface		8,471
		Modular & Broadloom Carpet
	148,000	Herman Miller		2,741
		Office Furniture
	200,000	Caesarstone (Israel) (a)		2,422
		Quartz Countertops
				25,444
		> Consumer Goods Distribution 1.2%
	472,000	Pool		19,097
		Distributor of Swimming Pool Supplies & Equipment
				19,097

See accompanying notes to financial statements.

53

Columbia Acorn USA

Statement of Investments (Unaudited), continued

Number of Shares			Value (000)
		> Other Durable Goods 1.0%
	206,000	Cavco Industries (a)	$	10,564
		Manufactured Homes
	126,000	Jarden		5,294
		Branded Household Products
				15,858
		> Apparel 0.8%
	222,000	Warnaco Group (a)		9,453
		Global Branded Apparel Manufacturer
	73,000	Deckers Outdoor (a)(b)		3,212
		Fashion Footwear Wholesaler
				12,665
		> Other Consumer Services 0.7%
	233,000	Lifetime Fitness (a)		10,837
		Sport & Fitness Club Operator
				10,837
		> Nondurables 0.6%
	262,000	Helen of Troy (a)		8,879
		Personal Care, Housewares, Healthcare & Home Environment Products
				8,879
		> Casinos & Gaming 0.4%
	698,000	Pinnacle Entertainment (a)		6,715
		Regional Casino Operator
				6,715
		> Leisure Products 0.2%
	230,000	Skullcandy (a)(b)		3,255
		Lifestyle Branded Headphones
				3,255
		> Educational Services 0.1%
	37,350	ITT Educational Services (a)(b)		2,269
		Postsecondary Degree Services
				2,269
		> Food & Beverage —%
	4,900	Annie's (a)(b)		205
		Developer & Marketer of Natural & Organic Food
				205
Consumer Goods & Services: Total				257,845
Finance 13.4%
		> Banks 7.6%
	833,000	MB Financial		17,943
		Chicago Bank
	1,053,000	Associated Banc-Corp		13,889
		Midwest Bank
	431,597	Lakeland Financial		11,580
		Indiana Bank
	211,000	City National		10,250
		Bank & Asset Manager
	170,000	SVB Financial Group (a)		9,982
		Bank to Venture Capitalists
	251,000	Hancock Holding		7,640
		Gulf Coast Bank
	1,478,200	First Busey		7,140
		Illinois Bank

Number of Shares			Value (000)
	641,750	Valley National Bancorp	$	6,803
		New Jersey/New York Bank
	535,000	TCF Financial		6,142
		Great Lakes Bank
	834,000	First Commonwealth		5,613
		Western Pennsylvania Bank
	844,000	TrustCo Bank		4,608
		New York State Bank
	503,426	Pacific Continental Bank		4,465
		Pacific Northwest Bank
	269,600	Eagle Bancorp (a)		4,246
		Metro D.C. Bank
	178,826	Sandy Spring Bancorp		3,219
		Baltimore, D.C. Bank
	210,000	CVB Financial		2,447
		Inland Empire Business Bank
	105,700	Hudson Valley		1,913
		Metro New York City Bank
	851,247	Guaranty Bancorp (a)		1,796
		Colorado Bank
	90,000	TriCo Bancshares		1,386
		California Central Valley Bank
				121,062
		> Finance Companies 3.8%
	345,000	World Acceptance (a)		22,701
		Personal Loans
	310,000	Textainer Group Holdings (b)		11,439
		Top International Container Leasor
	346,000	McGrath Rentcorp		9,169
		Temporary Space & IT Rentals
	376,000	CAI International (a)		7,475
		International Container Leasing
	397,172	H & E Equipment Services (a)		5,970
		Heavy Equipment Leasing
	100,000	Marlin Business Services		1,639
		Small Equipment Leasing
	45,500	Regional Management (a)		748
		Consumer Loans
				59,141
		> Savings & Loans 1.0%
	602,487	ViewPoint Financial		9,423
		Texas Thrift
	194,000	Berkshire Hills Bancorp		4,268
		Northeast Thrift
	173,073	Kaiser Federal		2,558
		Los Angeles Savings & Loan
				16,249
		> Brokerage & Money Management 0.5%
	306,500	Eaton Vance (b)		8,260
		Specialty Mutual Funds
				8,260
		> Insurance 0.5%
	55,000	Allied World Holdings		4,371
		Commerical Lines Insurance/Reinsurance

See accompanying notes to financial statements.

54

Number of Shares			Value (000)
		> Insurance—continued
	39,000	Enstar Group (a)	$	3,859
		Insurance/Reinsurance & Related Services
				8,230
Finance: Total				212,942
Health Care 10.3%
		> Biotechnology & Drug Delivery 6.3%
	520,000	BioMarin Pharmaceutical (a)		20,582
		Biotech Focused on Orphan Diseases
	614,000	Seattle Genetics (a)(b)		15,589
		Antibody-based Therapies for Cancer
	421,000	Auxilium Pharmaceuticals (a)		11,321
		Biotech Focused on Niche Disease Areas
	1,163,600	NPS Pharmaceuticals (a)		10,019
		Orphan Drugs & Healthy Royalties
	83,000	Alexion Pharmaceuticals (a)		8,242
		Biotech Focused on Orphan Diseases
	643,000	Isis Pharmaceuticals (a)		7,716
		Biotech Pioneer in Antisense Drugs
	100,000	Onyx Pharmaceuticals (a)		6,645
		Commercial-stage Biotech Focused on Cancer
	379,040	ARIAD Pharmaceuticals (a)		6,523
		Biotech Focused on Cancer
	129,002	Synageva Biopharma (a)(b)		5,232
		Biotech Focused on Orphan Diseases
	400,000	InterMune (a)		4,780
		Drugs for Pulmonary Fibrosis & Hepatitis C
	317,506	Raptor Pharmaceutical (a)(b)		1,775
		Orphan Drug Company
	948,000	Chelsea Therapeutics International (a)(b)		1,403
		Biotech Focused on Rare Diseases
	530,000	Anthera Pharmaceuticals (a)		358
		Biotech Focused on Cardiovascular, Cancer & Immunology
	18,181	Metabolex, Series A-1 (d)(e)		10
		Diabetes Drug Development
				100,195
		> Medical Supplies 1.8%
	551,600	Cepheid (a)		24,684
		Molecular Diagnostics
	53,000	Techne		3,933
		Cytokines, Antibodies & Other Reagents for Life Science
				28,617
		> Medical Equipment & Devices 1.1%
	202,000	Sirona Dental Systems (a)		9,092
		Manufacturer of Dental Equipment
	268,000	Hill-Rom Holdings		8,268
		Hospital Beds/Patient Handling
				17,360
		> Pharmaceuticals 0.8%
	642,000	Akorn (a)		10,124
		Develops, Manufactures & Sells Specialty Generic Drugs
	150,000	Horizon Pharma (a)(b)		1,070
		Specialty Pharma Company

Number of Shares			Value (000)
	133,180	Alimera Sciences (a)(b)	$	398
		Ophthalmology-focused Pharmaceutical Company
				11,592
		> Health Care Services 0.3%
	664,900	Health Management Associates (a)		5,219
		Non-urban Hospitals
				5,219
Health Care: Total				162,983
Other Industries 7.3%
		> Real Estate 6.1%
	915,000	Extra Space Storage		27,999
		Self Storage Facilities
	625,000	DuPont Fabros Technology		17,850
		Technology-focused Office Buildings
	561,200	Biomed Realty Trust		10,483
		Life Science-focused Office Buildings
	783,000	Education Realty Trust		8,676
		Student Housing
	540,000	Associated Estates Realty		8,073
		Multi-family Properties
	1,380,000	Kite Realty Group		6,886
		Community Shopping Centers
	958,000	DCT Industrial Trust		6,035
		Industrial Properties
	100,000	Post Properties		4,895
		Multi-family Properties
	77,000	Kilroy Realty		3,728
		West Coast Office & Industrial Properties
	200,000	St. Joe (a)(b)		3,162
		Florida Panhandle Landowner
				97,787
		> Transportation 1.2%
	230,000	World Fuel Services		8,747
		Global Fuel Broker
	515,091	Rush Enterprises, Class A (a)		8,422
	115,000	Rush Enterprises, Class B (a)		1,543
		Truck Sales & Service
				18,712
Other Industries: Total				116,499
Energy & Minerals 4.5%
		> Oil Services 2.0%
	725,000	Atwood Oceanics (a)		27,434
		Offshore Drilling Contractor
	125,000	Hornbeck Offshore (a)		4,847
		Supply Vessel Operator in U.S. Gulf of Mexico
				32,281
		> Oil & Gas Producers 1.8%
	133,000	SM Energy		6,532
		Oil & Gas Producer
	244,000	Approach Resource (a)		6,232
		Oil & Gas Producer in West Texas Permian
	129,000	Rosetta Resources (a)		4,727
		Oil & Gas Producer Exploring in South Texas & Montana

See accompanying notes to financial statements.

55

Columbia Acorn USA

Statement of Investments (Unaudited), continued

Number of Shares			Value (000)
		> Oil & Gas Producers—continued
	170,000	Petroleum Development Corporation (a)	$	4,168
		Oil & Gas Producer in U.S.
	168,000	Swift Energy (a)		3,126
		Oil & Gas Exploration & Production
	510,000	Quicksilver Resources (a)(b)		2,764
		Natural Gas & Coal Seam Gas Producer
	262,200	Houston American Energy (a)(b)		294
		Oil & Gas Exploration/Production in Colombia
				27,843
		> Mining 0.7%
	77,000	Core Laboratories (Netherlands)		8,924
		Oil & Gas Reservoir Consulting
	600,000	Alexco Resource (a)		2,646
		Mining, Exploration & Environmental Services
	180,000	Augusta Resource (a)		299
		US Copper/Moly Mine
				11,869
Energy & Minerals: Total				71,993
Total Equities: 99.6% (Cost: $1,126,154)				1,581,570

Number of Shares			Value (000)
Securities Lending Collateral 3.4%
	53,351,300	Dreyfus Government Cash Management Fund (7 day yield of 0.01%) (f)	$	53,351
Total Securities Lending Collateral: (Cost: $53,351)				53,351
Total Investments: 103.0% (Cost: $1,179,505)(g)(h)				1,634,921
Obligation to Return Collateral for Securities Loaned: (3.4)%				(53,351	)
Cash and Other Assets Less Liabilities: 0.4%				6,291
Total Net Assets: 100.0%			$	1,587,861

ADR - American Depositary Receipts

> Notes to Statement of Investments (dollar values in thousands)

(a)  Non-income producing security.

(b)  All or a portion of this security was on loan at June 30, 2012. The total market value of securities on loan at June 30, 2012 was $52,943.

(c)  An affiliated person of the Fund may include any company in which the Fund owns five percent or more of its outstanding voting shares. Holdings and transactions in these affiliated companies during the period ended June 30, 2012, are as follows:

Security	Balance of Shares Held 12/31/11		Purchases/ Additions		Sales/ Reductions		Balance of Shares Held 6/30/12		Value		Dividend
RCM Technologies		640,000		-		-		640,000	$	3,546	$	-
Total of Affiliated Transactions		640,000		-		-		640,000	$	3,546	$	-

  The aggregate cost and value of this company at June 30, 2012, were $3,624 and $3,546, respectively. Investments in affiliated companies represented 0.22% of the Fund's total net assets at June 30, 2012.

(d)  Denotes a restricted security, which is subject to restrictions on resale under federal securities laws. These securities are valued at fair value determined in good faith under consistently applied procedures established by the Board of Trustees. At June 30, 2012, the market value of these securities amounted to $10, which represented less than 0.01% of total net assets.

  Additional information on these securities is as follows:

Security	Acquisition Dates	Shares		Cost		Value
Metabolex, Series A-1	2/11/00		18,181	$	2,000	$	10
				$	2,000	$	10

(e)  Illiquid security.

(f)  Investment made with cash collateral received from securities lending activity.

(g)  At June 30, 2012, for federal income tax purposes, the cost of investments was $1,179,505 and net unrealized appreciation was $455,416 consisting of gross unrealized appreciation of $563,241 and gross unrealized depreciation of $107,825.

See accompanying notes to financial statements.

56

> Notes to Statement of Investments (dollar values in thousands)

(h)  On June 30, 2012, the market value of foreign securities represented 1.30% of total net assets. The Fund's foreign portfolio was diversified as follows:

Country	Value		Percentage of Net Assets
Netherlands	$	8,924		0.56
Israel		8,278		0.52
India		3,493		0.22
Total Foreign Portfolio	$	20,695		1.30

Fair Value Measurements

  Various inputs are used in determining the value of the Fund's investments, following the input prioritization hierarchy established by GAAP. These inputs are summarized in the three broad levels listed below:

•  Level 1 – quoted prices in active markets for identical securities

•  Level 2 – prices determined using other significant observable inputs (including quoted prices for similar securities, interest rates, prepayment speeds, credit risk and others)

•  Level 3 – prices determined using significant unobservable inputs where quoted prices or observable inputs are unavailable or less reliable (including management's own assumptions about the factors market participants would use in pricing an investment)

  The inputs or methodology used for valuing securities are not necessarily an indication of the risk associated with investing in those securities.

  Examples of the types of securities in which the Fund would typically invest and how they are classified within this hierarchy are as follows. Typical Level 1 securities include exchange traded domestic equities, mutual funds whose NAVs are published each day and exchange traded foreign equities that are not statistically fair valued. Typical Level 2 securities include exchange traded foreign equities that are statistically fair valued and short-term investments valued at amortized cost. Additionally, securities fair valued by the Valuation Committee (the Committee) of the Fund's Board of Trustees (the Board) that rely on significant observable inputs are also included in Level 2. Typical Level 3 securities include any security fair valued by the Committee that relies on significant unobservable inputs.

  Under the direction of the Board, the Committee is responsible for carrying out the valuation procedures approved by the Board.

The Committee meets as necessary, and no less frequently than quarterly, to determine fair values for securities for which market quotations are not readily available or for which the investment manager believes that available market quotations are unreliable, and to review the continuing appropriateness of the current value of any security subject to the Trust's Portfolio Pricing Policy and the pricing procedures of the investment manager (the Policies). The Policies address, among other things: circumstances under which market quotations will be deemed readily available; selection of third party pricing vendors; appropriate pricing methodologies; events that require fair valuation and fair value techniques; and circumstances under which securities will be deemed to pose a potential for stale pricing, including when securities are illiquid, restricted, or in default. The Committee may also meet to discuss additional valuation matters, which may include review of back-testing results, review of time-sensitive information or approval of other valuation related actions, and to review the appropriateness of the Policies.

  For investments categorized as Level 3, the significant unobservable inputs used in the fair value measurement of the Funds' securities may include: (i) data specific to the issuer or comparable issuers, (ii) general market or specific sector news and (iii) quoted prices and specific or similar security transactions. The Committee considers this data and any changes from prior periods in order to assess the reasonableness of observable and unobservable inputs, any assumptions or internal models used to value those securities and changes in fair value. Significant changes in any of these factors could result in lower or higher fair value measurements. Various factors impact the frequency of monitoring (which may occur as often as daily), however the Committee may determine that changes to inputs, assumptions and models are not required with the same frequency.

The following table summarizes the inputs used, as of June 30, 2012, in valuing the Fund's assets:

Investment Type	Quoted Prices (Level 1)		Other Significant Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)		Total
Equities
Information	$	487,022	$	-	$	-	$	487,022
Industrial Goods & Services		272,286		-		-		272,286
Consumer Goods & Services		257,845		-		-		257,845
Finance		212,942		-		-		212,942
Health Care		162,973		-		10		162,983
Other Industries		116,499		-		-		116,499
Energy & Minerals		71,993		-		-		71,993
Total Equities		1,581,560		-		10		1,581,570
Total Securities Lending Collateral		53,351		-		-		53,351
Total Investments	$	1,634,911	$	-	$	10	$	1,634,921

See accompanying notes to financial statements.

57

Columbia Acorn USA

Statement of Investments (Unaudited), continued

> Notes to Statement of Investments (dollar values in thousands)

  There were no transfers of financial assets between levels 1 and 2 during the period.

The following table reconciles asset balances for the period ending June 30, 2012, in which significant observable and/or unobservable inputs (Level 3) were used in determining value:

Investments in Securities	Balance as of December 31, 2011		Realized Gain/(Loss)		Change in Unrealized Appreciation (Depreciation)			Purchases		Sales		Transfers into Level 3		Transfers out of Level 3		Balance as of June 30, 2012
Equities
Health Care	$	27	$	-	$	(17	)	$	-	$	-	$	-	$	-	$	10
	$	27	$	-	$	(17	)	$	-	$	-	$	-	$	-	$	10

  The information in the above reconciliation table represents fiscal year to date activity for any securities identified as using Level 3 inputs at either the beginning or the end of the current fiscal period.

  The change in unrealized depreciation attributed to securities owned at June 30, 2012, which were valued using significant unobservable inputs (Level 3), amounted to $17.

  The Fund does not hold any significant investments categorized as Level 3.

  Certain common stock classified as Level 3 are valued at fair value, using a market approach, as determined in good faith under consistently applied procedures established by and under the general supervision of the Board. To determine fair value for these securities, for which no market exists, the Committee utilizes the valuation technique it deems most appropriate in the circumstances, using some unobservable inputs, which may include but are not limited to trades of similar securities, estimated earnings of the company, market multiples derived from a set of comparable companies, and the position of the security within the company's capital structure. Significant increases or decreases to any of these inputs could result in a significantly lower or higher fair value measurement. Generally, a change in estimated earnings of a company may result in a change to the comparable companies and market multiples utilized.

See accompanying notes to financial statements.

58

Columbia Acorn International Select

Major Portfolio Changes in the Second Quarter (Unaudited)

	Number of Shares
	3/31/12		6/30/12
Purchases
Asia
> Taiwan
CTCI Corp		2,789,400		3,508,400
Taiwan Mobile		1,179,000		3,133,800
> Japan
Start Today		0		496,000
Other Countries
> Australia
Challenger Financial		826,355		2,809,800
Commonwealth Property Office Fund		3,170,358		10,466,968
IAG		0		1,652,046
UGL		0		1,000,050
> Canada
Goldcorp		0		344,400
Latin America
> Mexico
Fresnillo		0		597,400
> Guatemala
Tahoe Resources		0		196,800

	Number of Shares
	3/31/12		6/30/12
Sales
Asia
> Japan
Ain Pharmaciez		74,000		0
Asahi Diamond Industrial		528,000		1,000
Gree		59,400		0
Kansai Paint		1,911,000		319,000
> China
NetEase.com - ADR		84,000		1,000
> Korea
NHN		49,830		32,830
Other Countries
> South Africa
Northam Platinum		1,146,000		0
Rand Merchant Insurance		7,601,015		6,483,015
> Canada
AG Growth		89,000		0
Europe
> Germany
Rheinmetall		109,500		0
Rhoen-Klinikum		175,000		0
> United Kingdom
Chemring		772,800		0
Intertek Group		178,000		79,000
JLT Group		314,000		296,400
Serco		659,000		583,000
> Netherlands
Core Laboratories		28,100		0
Imtech		239,919		190,916
> Switzerland
Kuehne & Nagel		28,000		0
> Denmark
Novozymes		145,000		125,000

See accompanying notes to financial statements.

59

Columbia Acorn International Select

Statement of Investments (Unaudited), June 30, 2012

Number of Shares			Value (000)
			Equities: 94.9%
Asia 44.4%
		> Singapore 15.0%
	13,130,000	Ascendas REIT	$	22,399
		Industrial Property Landlord
	20,395,000	Mapletree Industrial Trust		19,537
		Industrial Property Landlord
	11,142,000	Mapletree Logistics Trust		8,664
		Industrial Property Landlord
				50,600
		> Taiwan 12.2%
	11,103,000	Far EasTone Telecom		24,156
		Taiwan's Third Largest Mobile Operator
	3,133,800	Taiwan Mobile		10,363
		Taiwan's Second Largest Mobile Operator
	3,508,400	CTCI Corp		6,569
		International Engineering Firm
				41,088
		> Japan 10.1%
	5,753,734	Seven Bank		14,776
		ATM Processing Services
	8,970	Jupiter Telecommunications		9,146
		Largest Cable Service Provider in Japan
	496,000	Start Today		6,931
		Online Japanese Apparel Retailer
	319,000	Kansai Paint		3,418
		Paint Producer in Japan, India, China & Southeast Asia
	1,000	Asahi Diamond Industrial		11
		Consumable Diamond Tools
				34,282
		> China 2.7%
	4,146,000	Zhaojin Mining Industry		5,452
		Gold Mining & Refining in China
	3,044,000	Want Want		3,764
		Chinese Branded Consumer Food Company
	1,000	NetEase.com - ADR (a)		59
		Chinese Online Gaming Services
				9,275
		> Indonesia 2.3%
	9,272,000	Archipelago Resources (a)		7,406
		Gold Mining Projects in Indonesia, Vietnam & the Philippines
	1,404,000	MNC Skyvision (a)		235
		Largest Satellite Pay TV Operator in Indonesia
				7,641
		> Korea 2.1%
	32,830	NHN		7,201
		Korean Online Search Services
				7,201
Asia: Total				150,087
Other Countries 28.6%
		> Australia 11.6%
	1,000,050	UGL		12,805
		Engineering & Facilities Management

Number of Shares			Value (000)
	10,466,968	Commonwealth Property Office Fund	$	10,911
		Australia Prime Office REIT
	2,809,800	Challenger Financial		9,437
		Largest Annuity Provider
	1,652,046	IAG		5,925
		General Insurance Provider
				39,078
		> South Africa 8.7%
	6,483,015	Rand Merchant Insurance		13,808
		Directly Sold Property & Casualty Insurance; Holdings in Other Insurers
	1,317,200	Adcock Ingram Holdings		9,682
		Manufacturer of Pharmaceuticals & Medical Supplies
	112,700	Naspers		6,020
		Media in Africa, China, Russia & Other Emerging Markets
				29,510
		> Canada 5.0%
	344,400	Goldcorp		12,943
		Gold Mining
	106,400	CCL Industries		3,903
		Leading Global Label Manufacturer
				16,846
		> United States 1.8%
	94,000	Atwood Oceanics (a)		3,557
		Offshore Drilling Contractor
	52,000	SM Energy		2,554
		Oil & Gas Producer
				6,111
		> Israel 1.5%
	460,000	Israel Chemicals		5,090
		Producer of Potash, Phosphates, Bromine & Specialty Chemicals
				5,090
Other Countries: Total				96,635
Europe 16.4%
		> Germany 3.6%
	630,000	Wirecard		12,216
		Online Payment Processing & Risk Management
				12,216
		> United Kingdom 3.4%
	583,000	Serco		4,896
		Facilities Management
	79,000	Intertek Group		3,310
		Testing, Inspection, Certification Services
	296,400	JLT Group		3,256
		International Business Insurance Broker
				11,462
		> Sweden 3.0%
	595,666	Hexagon		10,225
		Design, Measurement & Visualization Software & Equipment
				10,225

See accompanying notes to financial statements.

60

Number of Shares			Value (000)
		> Iceland 1.7%
	4,800,000	Marel	$	5,838
		Largest Manufacturer of Poultry & Fish Processing Equipment
				5,838
		> Netherlands 1.4%
	190,916	Imtech		4,559
		Electromechanical & Information & Communications Technology Installation & Maintenance
				4,559
		> Switzerland 1.3%
	24,000	Partners Group		4,268
		Private Markets Asset Management
				4,268
		> Belgium 1.0%
	74,000	EVS Broadcast Equipment		3,491
		Digital Live Mobile Production Software & Systems
				3,491
		> Denmark 1.0%
	125,000	Novozymes		3,241
		Industrial Enzymes
				3,241
Europe: Total				55,300
Latin America 5.5%
		> Mexico 4.0%
	597,400	Fresnillo		13,684
		Silver & Metal Byproduct Mining in Mexico
				13,684

Number of Shares			Value (000)
		> Guatemala 0.8%
	196,800	Tahoe Resources (a)	$	2,720
		Silver Project in Guatemala
				2,720
		> Uruguay 0.5%
	191,666	Union Agriculture Group (a)(b)(c)		1,876
		Farmland Operator in Uruguay
				1,876
		> Colombia 0.2%
	1,880,000	Santa Maria Petroleum (a)(b)		567
		Explores for Oil & Gas in Latin America
				567
Latin America: Total				18,847
Total Equities: 94.9% (Cost: $273,433)				320,869
Total Investments: 94.9% (Cost: $273,433)(d)(e)				320,869
Cash and Other Assets Less Liabilities: 5.1%				17,265
Total Net Assets: 100.0%			$	338,134

ADR - American Depositary Receipts

REIT - Real Estate Investment Trust

> Notes to Statement of Investments (dollar values in thousands)

(a)  Non-income producing security.

(b)  Denotes a restricted security, which is subject to restrictions on resale under federal securities laws. These securities are valued at fair value determined in good faith under consistently applied procedures established by the Board of Trustees. At June 30, 2012, the market value of these securities amounted to $2,443, which represented 0.72% of total net assets.

  Additional information on these securities is as follows:

Security	Acquisition Dates	Shares		Cost		Value
Union Agriculture Group	12/8/10-6/27/12		191,666	$	2,200	$	1,876
Santa Maria Petroleum	1/14/11		1,880,000		2,376		567
				$	4,576	$	2,443

(c)  Illiquid security.

(d)  At June 30, 2012, for federal income tax purposes, the cost of investments was $273,433 and net unrealized appreciation was $47,436 consisting of gross unrealized appreciation of $56,811 and gross unrealized depreciation of $9,375.

See accompanying notes to financial statements.

61

Columbia Acorn International Select

Statement of Investments (Unaudited), continued

> Notes to Statement of Investments (dollar values in thousands)

(e)  On June 30, 2012, the Fund's total investments were denominated in currencies as follows:

Currency	Value		Percentage of Net Assets
Singapore Dollar	$	50,600		15.0
Taiwan Dollar		41,089		12.2
Austrailian Dollar		39,078		11.6
Japanese Yen		34,282		10.1
British Pound		32,552		9.6
South African Rand		29,510		8.7
United States Dollar		20,988		6.2
Euro		20,266		6.0
Other currencies less than 5% of total net assets		52,504		15.5
Total Portfolio	$	320,869		94.9

  At June 30, 2012, the Fund had entered into the following forward foreign currency exchange contracts:

Forward Foreign Currency Exchange Contracts to Buy	Forward Foreign Currency Exchange Contracts to Sell	Principal Amount in Foreign Currency		Principal Amount in U.S. Dollar		Settlement Date	Unrealized Appreciation/ (Depreciation)
USD	ZAR		236,888	$	28,000	7/13/12	$	(932	)

The counterparty for all forward foreign currency exchange contracts is State Street Bank and Trust Company.

USD = United States Dollar

ZAR = South African Rand

Fair Value Measurements

  Various inputs are used in determining the value of the Fund's investments, following the input prioritization hierarchy established by GAAP. These inputs are summarized in the three broad levels listed below:

•  Level 1 – quoted prices in active markets for identical securities

•  Level 2 – prices determined using other significant observable inputs (including quoted prices for similar securities, interest rates, prepayment speeds, credit risk and others)

•  Level 3 – prices determined using significant unobservable inputs where quoted prices or observable inputs are unavailable or less reliable (including management's own assumptions about the factors market participants would use in pricing an investment)

  The inputs or methodology used for valuing securities are not necessarily an indication of the risk associated with investing in those securities.

  Examples of the types of securities in which the Fund would typically invest and how they are classified within this hierarchy are as follows. Typical Level 1 securities include exchange traded domestic equities, mutual funds whose NAVs are published each day and exchange traded foreign equities that are not statistically fair valued. Typical Level 2 securities include exchange traded foreign equities that are statistically fair valued, forward foreign currency exchange contracts and short-term investments valued at amortized cost. Additionally, securities fair valued by the Valuation Committee (the Committee) of the Fund's Board of Trustees (the Board) that rely on significant observable inputs are also included in Level 2. Typical Level 3 securities include any security fair valued by the Committee that relies on significant unobservable inputs.

  Under the direction of the Board, the Committee is responsible for carrying out the valuation procedures approved by the Board.

The Committee meets as necessary, and no less frequently than quarterly, to determine fair values for securities for which market quotations are not readily available or for which the investment manager believes that available market quotations are unreliable, and to review the continuing appropriateness of the current value of any security subject to the Trust's Portfolio Pricing Policy and the pricing procedures of the investment manager (the Policies). The Policies address, among other things: circumstances under which market quotations will be deemed readily available; selection of third party pricing vendors; appropriate pricing methodologies; events that require fair valuation and fair value techniques; and circumstances under which securities will be deemed to pose a potential for stale pricing, including when securities are illiquid, restricted, or in default. The Committee may also meet to discuss additional valuation matters, which may include review of back-testing results, review of time-sensitive information or approval of other valuation related actions, and to review the appropriateness of the Policies.

  For investments categorized as Level 3, the significant unobservable inputs used in the fair value measurement of the Funds' securities may include: (i) data specific to the issuer or comparable issuers, (ii) general market or specific sector news and (iii) quoted prices and specific or similar security transactions. The Committee considers this data and any changes from prior periods in order to assess the reasonableness of observable and unobservable inputs, any assumptions or internal models used to value those securities and changes in fair value. Significant changes in any of these factors could result in lower or higher fair value measurements. Various factors impact the frequency of monitoring (which may occur as often as daily), however the Committee may determine that changes to inputs, assumptions and models are not required with the same frequency.

See accompanying notes to financial statements.

62

> Notes to Statement of Investments (dollar values in thousands)

The following table summarizes the inputs used, as of June 30, 2012, in valuing the Fund's assets:

Investment Type	Quoted Prices (Level 1)		Other Significant Observable Inputs (Level 2)			Significant Unobservable Inputs (Level 3)		Total
Equities
Asia	$	59	$	150,028		$	-	$	150,087
Other Countries		22,957		73,678			-		96,635
Europe		-		55,300			-		55,300
Latin America		2,720		14,251			1,876		18,847
Total Equities		25,736		293,257			1,876		320,869
Total Investments	$	25,736	$	293,257		$	1,876	$	320,869
Unrealized Depreciation on Forward Foreign Currency Exchange Contracts		-		(932	)		-		(932	)
Total Investments	$	25,736	$	292,325		$	1,876	$	319,937

  The Fund's assets assigned to the Level 2 input category are generally valued using a market approach, in which a security's value is determined through its correlation to prices and information from observable market transactions for similar or identical assets. Foreign equities are generally valued at the last sale price on the foreign exchange or market on which they trade. The Fund may use a statistical fair valuation model, in accordance with the policy adopted by the Board, provided by an independent third party to value securities principally traded in foreign markets in order to adjust for possible stale pricing that may occur between the close of the foreign exchanges and the time for valuation. These models take into account available market data including intraday index, ADR, and ETF movements. Forward foreign currency exchange contracts are valued at the prevailing forward exchange rate of the underlying currencies. Securities acquired via private placement that have a holding period or an extended settlement period are valued at a discount to the same shares that are trading freely on the market. These discounts are determined by the Investment manager's experience with similar securities or situations. Factors may include, but are not limited to, trade volume, shares outstanding and stock price.

  There were no transfers of financial assets between levels 1 and 2 during the period.

The following table reconciles asset balances for the period ending June 30, 2012, in which significant observable and/or unobservable inputs (Level 3) were used in determining value:

Investments in Securities	Balance as of December 31, 2011		Realized Gain/(Loss)		Change in Unrealized Appreciation (Depreciation)		Purchases		Sales		Transfers into Level 3		Transfers out of Level 3		Balance as of June 30, 2012
Equities
Latin America	$	1,828	$	-	$	48	$	-	$	-	$	-	$	-	$	1,876
	$	1,828	$	-	$	48	$	-	$	-	$	-	$	-	$	1,876

  The information in the above reconciliation table represents fiscal year to date activity for any securities identified as using Level 3 inputs at either the beginning or the end of the current fiscal period.

  The change in unrealized appreciation attributed to securities owned at June 30, 2012, which were valued using significant unobservable inputs (Level 3), amounted to $48.

  The Fund does not hold any significant investments categorized as Level 3.

  Certain common stock classified as Level 3 are valued at fair value, using a market approach, as determined in good faith under consistently applied procedures established by and under the general supervision of the Board. To determine fair value for these securities, for which no market exists, the Committee utilizes the valuation technique it deems most appropriate in the circumstances, using some unobservable inputs, which may include but are not limited to trades of similar securities, estimated earnings of the company, market multiples derived from a set of comparable companies, and the position of the security within the company's capital structure. Significant increases or decreases to any of these inputs could result in a significantly lower or higher fair value measurement. Generally, a change in estimated earnings of a company may result in a change to the comparable companies and market multiples utilized.

See accompanying notes to financial statements.

63

Columbia Acorn International Select

Portfolio Diversification (Unaudited)

At June 30, 2012, the Fund's portfolio investments as a percentage of net assets were diversified as follows:

	Value (000)		Percentage of Net Assets
> Information
Mobile Communications	$	34,520		10.2
Internet Related		13,279		4.0
Financial Processors		12,216		3.6
Business Software		10,224		3.0
CATV		9,146		2.7
Computer Hardware & Related Equipment		3,491		1.0
Satellite Broadcasting & Services		235		0.1
		83,111		24.6
> Other Industries
Real Estate		61,511		18.2
> Finance
Insurance		32,427		9.6
Banks		14,776		4.4
Brokerage & Money Management		4,268		1.2
		51,471		15.2
> Energy & Minerals
Mining		42,204		12.5
Oil Services		3,557		1.0
Oil & Gas Producers		3,121		0.9
Agricultural Commodities		1,876		0.6
		50,758		15.0
> Industrial Goods & Services
Other Industrial Services		20,674		6.1
Industrial Materials & Specialty Chemicals		11,749		3.5
Construction		6,569		1.9
Machinery		5,849		1.7
Outsourcing Services		4,896		1.5
		49,737		14.7

	Value (000)		Percentage of Net Assets
> Consumer Goods & Services
Retail	$	6,931		2.0
Nondurables		3,904		1.2
Food & Beverage		3,764		1.1
		14,599		4.3
> Health Care
Pharmaceuticals		9,682		2.9
Total Equities:		320,869		94.9
Total Investments:		320,869		94.9
Cash and Other Assets Less Liabilities:		17,265		5.1
Net Assets:	$	338,134		100.0

See accompanying notes to financial statements.

64

Columbia Acorn Select

Major Portfolio Changes in the Second Quarter (Unaudited)

	Number of Shares
	3/31/12		6/30/12
Purchases
Industrial Goods & Services
Nordson		160,000		220,000
Information
Globalstar		15,000,000		16,721,800
Consumer Goods & Services
Vail Resorts		0		235,000
Energy & Minerals
Canadian Solar (China)		2,700,000		3,301,200
Houston American Energy		826,400		1,455,000
Tuscany International Drilling (Colombia)		12,700,000		13,613,200

	Number of Shares
	3/31/12		6/30/12
Sales
Industrial Goods & Services
Ametek		1,490,000		1,358,000
Donaldson		1,260,000		1,140,000
Expeditors International of Washington		600,000		475,000
Kennametal		975,000		865,000
Pall		690,000		625,000
Quanta Services		1,420,000		1,000,000
Information
Amphenol		645,000		560,000
Atmel		1,175,000		1,140,000
Sanmina-SCI		4,375,000		3,026,600
SBA Communications		1,010,000		735,000
VisionChina Media - ADR (China)		6,108,437		5,427,200
WNS - ADR (India)		3,940,000		3,405,000
Consumer Goods & Services
Abercrombie & Fitch		555,000		455,000
Coach		615,000		555,000
Gaylord Entertainment		1,020,000		930,000
Hertz		5,225,000		4,495,000
IFM Investments (Century 21 China RE) - ADR (China)		1,143,333		998,000
ITT Educational Services		270,000		223,000
lululemon athletica		390,000		305,000
RexLot Holdings (China)		260,000,000		208,000,000
Safeway		1,100,000		0
Tiffany & Co.		200,000		184,000
Finance
City National		630,000		540,000
CNO Financial Group		8,325,000		7,140,000
Discover Financial Services		2,115,000		1,935,000
Regional Management		84,500		0
SEI Investments		965,000		775,000
Energy & Minerals
Canacol (Colombia)		30,872,300		29,187,400
Eacom Timber (Canada)		33,572,000		8,440,000
Kirkland Lake Gold (Canada)		870,000		835,000
Pacific Rubiales Energy (Colombia)		1,480,000		1,170,000
Petrodorado (Colombia)		34,700,000		33,700,000
Shamaran Petroleum (Iraq)		36,500,000		30,473,500
Health Care
Akorn		1,400,000		1,310,000
NPS Pharmaceuticals		2,510,000		2,340,000
Seattle Genetics		395,000		383,000
Other Industries
Biomed Realty Trust		1,660,000		1,435,000

See accompanying notes to financial statements.

65

Columbia Acorn Select

Statement of Investments (Unaudited), June 30, 2012

Number of Shares			Value (000)
			Equities: 98.0%
Industrial Goods & Services 21.7%
		> Machinery 16.4%
	1,358,000	Ametek	$	67,778
		Aerospace/Industrial Instruments
	1,140,000	Donaldson		38,042
		Industrial Air Filtration
	625,000	Pall		34,256
		Filtration & Fluids Clarification
	865,000	Kennametal		28,675
		Consumable Cutting Tools
	220,000	Nordson		11,284
		Dispensing Systems for Adhesives & Coatings
				180,035
		> Outsourcing Services 2.2%
	1,000,000	Quanta Services (a)		24,070
		Electrical & Telecom Construction Services
				24,070
		> Other Industrial Services 1.7%
	475,000	Expeditors International of Washington		18,406
		International Freight Forwarder
				18,406
		> Industrial Materials & Specialty Chemicals 1.4%
	300,000	FMC Corporation		16,044
		Niche Specialty Chemicals
				16,044
Industrial Goods & Services: Total				238,555
Information 20.1%
		> Mobile Communications 8.0%
	735,000	SBA Communications (a)		41,932
		Communications Towers
	700,000	Crown Castle International (a)		41,062
		Communications Towers
	16,721,800	Globalstar (a)(b)(c)		5,351
		Satellite Mobile Voice & Data Carrier
				88,345
		> Computer Services 3.0%
	3,405,000	WNS - ADR (India) (a)(b)		33,131
		Offshore BPO (Business Process Outsourcing) Services
				33,131
		> Computer Hardware & Related Equipment 2.8%
	560,000	Amphenol		30,755
		Electronic Connectors
				30,755
		> Contract Manufacturing 2.3%
	3,026,600	Sanmina-SCI (a)		24,788
		Electronic Manufacturing Services
				24,788
		> Instrumentation 1.8%
	126,000	Mettler-Toledo International (a)		19,637
		Laboratory Equipment
				19,637

Number of Shares			Value (000)
		> Business Software 1.0%
	167,000	Concur Technologies (a)	$	11,373
		Web Enabled Cost & Expense Management Software
				11,373
		> Semiconductors & Related Equipment 0.7%
	1,140,000	Atmel (a)		7,638
		Microcontrollers, Radio Frequency & Memory Semiconductors
				7,638
		> Advertising 0.5%
	5,427,200	VisionChina Media - ADR (China) (a)(b)(c)		5,047
		Advertising on Digital Screens in China's Mass Transit System
				5,047
Information: Total				220,714
Consumer Goods & Services 19.2%
		> Travel 9.6%
	4,495,000	Hertz (a)		57,536
		Largest U.S. Rental Car Operator
	930,000	Gaylord Entertainment (a)		35,861
		Convention Hotels
	235,000	Vail Resorts		11,769
		Ski Resort Operator & Developer
				105,166
		> Retail 3.9%
	305,000	lululemon athletica (a)		18,187
		Premium Active Apparel Retailer
	455,000	Abercrombie & Fitch		15,534
		Teen Apparel Retailer
	184,000	Tiffany & Co.		9,743
		Luxury Good Retailer
				43,464
		> Apparel 2.9%
	555,000	Coach		32,456
		Designer & Retailer of Branded Leather Accessories
				32,456
		> Casinos & Gaming 1.4%
	208,000,000	RexLot Holdings (China)		14,900
		Lottery Equipment Supplier in China
				14,900
		> Educational Services 1.2%
	223,000	ITT Educational Services (a)(c)		13,547
		Postsecondary Degree Services
				13,547
		> Other Consumer Services 0.1%
	998,000	IFM Investments (Century 21 China RE) - ADR (China) (a)(b)		1,088
		Provide Real Estate Services in China
				1,088

See accompanying notes to financial statements.

66

Number of Shares			Value (000)
		> Food & Beverage 0.1%
	1,500,000	GLG Life Tech (Canada) (a)(c)(d)	$	621
		All-natural Sweetener Extracted from the Stevia Plant
				621
Consumer Goods & Services: Total				211,242
Finance 16.2%
		> Credit Cards 6.1%
	1,935,000	Discover Financial Services		66,912
		Credit Card Company
				66,912
		> Insurance 5.0%
	7,140,000	CNO Financial Group		55,692
		Life, Long-term Care & Medical Supplement Insurance
				55,692
		> Banks 3.7%
	540,000	City National		26,233
		Bank & Asset Manager
	1,075,000	Associated Banc-Corp		14,179
		Midwest Bank
				40,412
		> Brokerage & Money Management 1.4%
	775,000	SEI Investments		15,415
		Mutual Fund Administration & Investment Management
				15,415
Finance: Total				178,431
Energy & Minerals 9.7%
		> Oil & Gas Producers 5.3%
	1,170,000	Pacific Rubiales Energy (Colombia)		24,777
		Oil Production & Exploration in Colombia
	29,187,400	Canacol (Colombia) (a)		13,044
		Oil Producer in South America
	33,700,000	Petrodorado (Colombia) (a)(b)		5,296
	17,144,000	Petrodorado - Warrants (Colombia) (a)(e)		243
		Oil & Gas Exploration & Production in Colombia, Peru & Paraguay
	30,473,500	Shamaran Petroleum (Iraq) (a)		5,088
		Oil Exploration in Kurdistan
	24,000,000	Canadian Overseas Petroleum (United Kingdom) (a)(b)(e)		4,187
	12,000,000	Canadian Overseas Petroleum - Warrants (United Kingdom) (a)(d)(e)		232
		Oil & Gas Exploration/Production in the North Sea
	17,575,000	Petromanas (Canada) (a)		3,711
		Exploring for Oil in Albania
	1,455,000	Houston American Energy (a)(c)		1,630
		Oil & Gas Exploration/Production in Colombia
				58,208

Number of Shares			Value (000)
		> Agricultural Commodities 1.6%
	1,742,424	Union Agriculture Group (Uruguay) (a)(d)(e)	$	17,058
		Farmland Operator in Uruguay
	8,440,000	Eacom Timber (Canada) (a)		829
		Canadian Lumber Producer
				17,887
		> Alternative Energy 1.5%
	3,301,200	Canadian Solar (China) (a)(b)(c)		11,884
		Solar Cell & Module Manufacturer
	2,425,000	Synthesis Energy Systems (China) (a)		2,959
		Owner/Operator of Gasification Plants
	1,165,000	Real Goods Solar (a)		1,316
		Residential Solar Energy Installer
				16,159
		> Mining 0.8%
	835,000	Kirkland Lake Gold (Canada) (a)		8,989
		Gold Mining
				8,989
		> Oil Services 0.5%
	13,613,200	Tuscany International Drilling (Colombia) (a)		5,282
		South America-based Drilling Rig Contractor
				5,282
Energy & Minerals: Total				106,525
Health Care 6.0%
		> Biotechnology & Drug Delivery 2.7%
	2,340,000	NPS Pharmaceuticals (a)		20,148
		Orphan Drugs & Healthy Royalties
	383,000	Seattle Genetics (a)(c)		9,724
		Antibody-based Therapies for Cancer
				29,872
		> Pharmaceuticals 1.9%
	1,310,000	Akorn (a)		20,659
		Develops, Manufactures & Sells Specialty Generic Drugs
				20,659
		> Medical Supplies 1.4%
	190,000	Henry Schein (a)		14,913
		Largest Distributor of Healthcare Products
				14,913
Health Care: Total				65,444
Other Industries 5.1%
		> Real Estate 3.7%
	1,435,000	Biomed Realty Trust		26,806
		Life Science-focused Office Buildings
	475,000	DuPont Fabros Technology		13,566
		Technology-focused Office Buildings
				40,372

See accompanying notes to financial statements.

67

Columbia Acorn Select

Statement of Investments (Unaudited), continued

Number of Shares			Value (000)
		> Regulated Utilities 1.4%
	403,000	Wisconsin Energy	$	15,946
		Wisconsin Utility
				15,946
Other Industries: Total				56,318
Total Equities: 98.0% (Cost: $835,953)				1,077,229
Securities Lending Collateral 2.4%
	26,067,257	Dreyfus Government Cash Management Fund (7 day yield of 0.01%) (f)		26,067
Total Securities Lending Collateral: (Cost: $26,067)				26,067
Total Investments: 100.4% (Cost: $862,020)(g)(h)				1,103,296
Obligation to Return Collateral for Securities Loaned: (2.4)%				(26,067	)
Cash and Other Assets Less Liabilities: 2.0%				21,891
Total Net Assets: 100.0%			$	1,099,120

ADR - American Depositary Receipts

> Notes to Statement of Investments (dollar values in thousands)

(a)  Non-income producing security.

(b)  An affiliated person of the Fund may include any company in which the Fund owns five percent or more of its outstanding voting shares. Holdings and transactions in these affiliated companies during the period ended June 30, 2012, are as follows:

Security	Balance of Shares Held 12/31/11		Purchases/ Additions		Sales/ Reductions		Balance of Shares Held 6/30/12		Value		Dividend
Canacol*		31,372,300		-		2,184,900		29,187,400	$	13,044	$	-
Canadian Overseas Petroleum		24,000,000		-		-		24,000,000		4,187		-
Canadian Solar		2,700,000		601,200		-		3,301,200		11,884		-
Eacom Timber*		36,000,000		-		27,560,000		8,440,000		829		-
GLG Life Tech*		1,850,000		-		350,000		1,500,000		621		-
Globalstar		13,184,322		3,815,678		278,200		16,721,800		5,351		-
IFM Investments (Century 21 China RE) - ADR**		3,430,000		-		2,432,000		998,000		1,088		-
Petrodorado		34,700,000		-		1,000,000		33,700,000		5,296		-
Real Goods Solar*		1,500,000		-		335,000		1,165,000		1,316		-
Sanmina-SCI*		6,100,000		-		3,073,400		3,026,600		24,788		-
Synthesis Energy Systems*		2,950,372		-		525,372		2,425,000		2,959		-
VisionChina Media - ADR		7,000,000		-		1,572,800		5,427,200		5,047		-
WNS - ADR		4,254,230		-		849,230		3,405,000		33,131		-
Total of Affiliated Transactions		169,041,224		4,416,878		40,160,902		133,297,200	$	109,541	$	-

*  At June 30, 2012, the Fund owned less than five percent of the company's outstanding voting shares.

**  Includes the effects of a 1:3 stock split.

See accompanying notes to financial statements.

68

> Notes to Statement of Investments (dollar values in thousands)

  The aggregate cost and value of these companies at June 30, 2012, were $152,247 and $65,984, respectively. Investments in affiliated companies represented 6.00% of the Fund's total net assets at June 30, 2012.

(c)  All or a portion of this security was on loan at June 30, 2012. The total market value of securities on loan at June 30, 2012 was $25,542.

(d)  Illiquid security.

(e)  Denotes a restricted security, which is subject to restrictions on resale under federal securities laws. These securities are valued at fair value determined in good faith under consistently applied procedures established by the Board of Trustees. At June 30, 2012, the market value of these securities amounted to $21,720, which represented 1.98% of total net assets.

  Additional information on these securities is as follows:

Security	Acquisition Dates	Shares		Cost		Value
Union Agriculuture Group	12/8/10-6/27/12		1,742,424	$	20,000	$	17,058
Canadian Overseas Petroleum	11/24/10		24,000,000		10,260		4,187
Petrodorado - Warrants	11/20/09		17,144,000		2,118		243
Canadian Overseas Petroleum - Warrants	11/24/10		12,000,000		1,502		232
				$	33,880	$	21,720

(f)  Investment made with cash collateral received from securities lending activity.

(g)  At June 30, 2012, for federal income tax purposes, the cost of investments was $862,020 and net unrealized appreciation was $241,276 consisting of gross unrealized appreciation of $390,213 and gross unrealized depreciation of $148,937.

(h)  On June 30, 2012, the market value of foreign securities represented 14.41% of total net assets. The Fund's foreign portfolio was diversified as follows:

Country	Value		Percentage of Net Assets
Colombia	$	48,642		4.43
China		35,878		3.27
India		33,131		3.01
Uruguay		17,058		1.55
Canada		14,150		1.29
Iraq		5,088		0.46
United Kingdom		4,419		0.40
Total Foreign Portfolio	$	158,366		14.41

Fair Value Measurements

  Various inputs are used in determining the value of the Fund's investments, following the input prioritization hierarchy established by GAAP. These inputs are summarized in the three broad levels listed below:

•  Level 1 – quoted prices in active markets for identical securities

•  Level 2 – prices determined using other significant observable inputs (including quoted prices for similar securities, interest rates, prepayment speeds, credit risk and others)

•  Level 3 – prices determined using significant unobservable inputs where quoted prices or observable inputs are unavailable or less reliable (including management's own assumptions about the factors market participants would use in pricing an investment)

  The inputs or methodology used for valuing securities are not necessarily an indication of the risk associated with investing in those securities.

  Examples of the types of securities in which the Fund would typically invest and how they are classified within this hierarchy are as follows. Typical Level 1 securities include exchange traded domestic equities, mutual funds whose NAVs are published each day and exchange traded foreign equities that are not statistically fair valued. Typical Level 2 securities include exchange traded foreign equities that are statistically fair valued and short-term investments valued at amortized cost. Additionally, securities fair valued by the Valuation Committee (the Committee) of the Fund's Board of Trustees (the Board) that rely on significant observable inputs are also included in Level 2. Typical Level 3 securities include any security fair valued by the Committee that relies on significant unobservable inputs.

  Under the direction of the Board, the Committee is responsible for carrying out the valuation procedures approved by the Board.

The Committee meets as necessary, and no less frequently than quarterly, to determine fair values for securities for which market quotations are not readily available or for which the investment manager believes that available market quotations are unreliable, and to review the continuing appropriateness of the current value of any security subject to the Trust's Portfolio Pricing Policy and the pricing procedures of the investment manager (the Policies). The Policies address, among other things: circumstances under which market quotations will be deemed readily available; selection of third party pricing vendors; appropriate pricing methodologies; events that require fair valuation and fair value techniques; and circumstances under which securities will be deemed to pose a potential for stale pricing, including when securities are illiquid, restricted, or in default. The Committee may also meet to discuss additional valuation matters, which may include review of back-testing results, review of time-sensitive information or approval of other valuation related actions, and to review the appropriateness of the Policies.

See accompanying notes to financial statements.

69

Columbia Acorn Select

Statement of Investments (Unaudited), continued

> Notes to Statement of Investments (dollar values in thousands)

  For investments categorized as Level 3, the significant unobservable inputs used in the fair value measurement of the Funds' securities may include: (i) data specific to the issuer or comparable issuers, (ii) general market or specific sector news and (iii) quoted prices and specific or similar security transactions. The Committee considers this data and any changes from prior periods in order to assess the reasonableness of observable and unobservable inputs, any assumptions or internal models used to value those securities and changes in fair value. Significant changes in any of these factors could result in lower or higher fair value measurements. Various factors impact the frequency of monitoring (which may occur as often as daily), however the Committee may determine that changes to inputs, assumptions and models are not required with the same frequency.

The following table summarizes the inputs used, as of June 30, 2012, in valuing the Fund's assets:

Investment Type	Quoted Prices (Level 1)		Other Significant Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)		Total
Equities
Industrial Goods & Services	$	238,555	$	-	$	-	$	238,555
Information		220,714		-		-		220,714
Consumer Goods & Services		195,721		15,521		-		211,242
Finance		178,431		-		-		178,431
Energy & Minerals		84,805		4,662		17,058		106,525
Health Care		65,444		-		-		65,444
Other Industries		56,318		-		-		56,318
Total Equities		1,039,988		20,183		17,058		1,077,229
Total Securities Lending Collateral		26,067		-		-		26,067
Total Investments	$	1,066,055	$	20,183	$	17,058	$	1,103,296

  The Fund's assets assigned to the Level 2 input category are generally valued using a market approach, in which a security's value is determined through its correlation to prices and information from observable market transactions for similar or identical assets. Foreign equities are generally valued at the last sale price on the foreign exchange or market on which they trade. The Fund may use a statistical fair valuation model, in accordance with the policy adopted by the Board, provided by an independent third party to value securities principally traded in foreign markets in order to adjust for possible stale pricing that may occur between the close of the foreign exchanges and the time for valuation. These models take into account available market data including intraday index, ADR, and ETF movements. Securities acquired via private placement that have a holding period or an extended settlement period are valued at a discount to the same shares that are trading freely on the market. These discounts are determined by the investment manager's experience with similar securities or situations. Factors may include, but are not limited to, trade volume, shares outstanding and stock price. Warrants which do not trade are valued as a percentage of the actively trading common stock using a model, based on Black Scholes. Securities which have halted or temporarily stopped trading are valued at the last sale and adjusted by a premium or a discount to account for the anticipated re-opening price. These adjustments are determined by the investment manager's experience with similar securities or situations.

  The following table shows transfers between Level 1 and Level 2 of the fair value hierarchy:

Transfers In				Transfers Out
Level 1		Level 2		Level 1		Level 2
$	-	$	1,665	$	1,665	$	-

  Financial assets were transferred from Level 1 to Level 2 as trading halted during the period.

  The following table reconciles asset balances for the period ending June 30, 2012, in which significant observable and/or unobservable inputs (Level 3) were used in determining value:

Investments in Securities	Balance as of December 31, 2011		Realized Gain/(Loss)		Change in Unrealized Appreciation (Depreciation)		Purchases		Sales		Transfers into Level 3		Transfers out of Level 3		Balance as of June 30, 2012
Equities
Energy & Minerals	$	16,617	$	-	$	441	$	-	$	-	$	-	$	-	$	17,058
	$	16,617	$	-	$	441	$	-	$	-	$	-	$	-	$	17,058

  The information in the above reconciliation table represents fiscal year to date activity for any securities identified as using Level 3 inputs at either the beginning or the end of the current fiscal period.

  The change in unrealized appreciation attributed to securities owned at June 30, 2012, which were valued using significant unobservable inputs (Level 3), amounted to $441.

  Quantitative information pertaining to Level 3 unobservable fair value measurements

	Fair Value at 6/30/12		Valuation Technique(s)	Unobservable Input (s)	Range (Weighted Average)
Equities		17,058	Market comparable companies	Discount for lack of marketability	-2% to -28% (-12%)

See accompanying notes to financial statements.

70

> Notes to Statement of Investments (dollar values in thousands)

  Certain common stock classified as Level 3 are valued at fair value, using a market approach, as determined in good faith under consistently applied procedures established by and under the general supervision of the Board. To determine fair value for these securities, for which no market exists, the Committee utilizes the valuation technique it deems most appropriate in the circumstances, using some unobservable inputs which may include, but not limited to trades of similar securities, estimated earnings of the company, market multiples derived from a set of comparable companies, and the position of the security within the company's capital structure. Significant increases or decreases to any of these inputs could result in a significantly lower or higher fair value measurement. Generally, a change in estimated earnings of a company may result in a change to the comparable companies and market multiples utilized.

See accompanying notes to financial statements.

71

Columbia Thermostat Fund

Statement of Investments (Unaudited), June 30, 2012

Number of Shares			Value (000)
		> Affiliated Stock Funds: 49.4%
	1,176,526	Columbia Acorn International Fund, Class I	$	43,684
	2,984,136	Columbia Dividend Income Fund, Class I		43,240
	1,097,965	Columbia Acorn Fund, Class I		32,675
	2,152,889	Columbia Contrarian Core Fund, Class I		32,487
	1,706,619	Columbia Select Large Cap Growth Fund, Class I (a)		21,862
	872,274	Columbia Acorn Select Fund, Class I		21,772
	1,599,099	Columbia Large Cap Enhanced Core Fund, Class I		21,684
Total Stock Funds: (Cost: $196,004)				217,404

Number of Shares			Value (000)
		> Affiliated Bond Funds: 48.2%
	11,245,529	Columbia Intermediate Bond Fund, Class I	$	105,933
	6,646,182	Columbia Income Opportunities Fund, Class I		63,936
	3,616,501	Columbia U.S. Treasury Index Fund, Class I		42,205
Total Bond Funds: (Cost: $208,564)				212,074
Total Investments: 97.6% (Cost: $404,568)(b)				429,478
Cash and Other Assets Less Liabilities: 2.4%				10,573
Total Net Assets: 100.0%			$	440,051

> Notes to Statement of Investments (dollar values in thousands)

(a)  Non-income producing security.

(b)  At June 30, 2012 for federal income tax purposes, the cost of investments was $404,568 and net unrealized gain was $24,910 consisting of gross unrealized appreciation of $24,910 and gross unrealized depreciation of $0.

Fair Value Measurements

  Various inputs are used in determining the value of the Fund's investments, following the input prioritization hierarchy established by GAAP. These inputs are summarized in the three broad levels listed below:

•  Level 1 – quoted prices in active markets for identical securities

•  Level 2 – prices determined using other significant observable inputs (including quoted prices for similar securities, interest rates, prepayment speeds, credit risk and others)

•  Level 3 – prices determined using significant unobservable inputs where quoted prices or observable inputs are unavailable or less reliable (including management's own assumptions about the factors market participants would use in pricing an investment)

  The inputs or methodology used for valuing securities are not necessarily an indication of the risk associated with investing in those securities.

  Examples of the types of securities in which the Fund would typically invest and how they are classified within this hierarchy are as follows. Typical Level 1 securities include mutual funds whose NAVs are published each day. Typical Level 2 securities include short-term investments valued at amortized cost.

  Under the direction of the Board of Trustees (the Board), the Valuation Committee (the Committee) is responsible for carrying out the valuation procedures approved by the Board.

The Committee meets as necessary, and no less frequently than quarterly, to determine fair values for securities for which market quotations are not readily available or for which the investment manager believes that available market quotations are unreliable, and to review the continuing appropriateness of the current value of any security subject to the Trust's Portfolio Pricing Policy and the pricing procedures of the investment manager (the Policies). The Policies address, among other things: circumstances under which market quotations will be deemed readily available; selection of third party pricing vendors; appropriate pricing methodologies; events that require fair valuation and fair value techniques; and circumstances under which securities will be deemed to pose a potential for stale pricing, including when securities are illiquid, restricted, or in default. The Committee may also meet to discuss additional valuation matters, which may include review of back-testing results, review of time-sensitive information or approval of other valuation related actions, and to review the appropriateness of the Policies.

  For investments categorized as Level 3, the significant unobservable inputs used in the fair value measurement of the Funds' securities may include: (i) data specific to the issuer or comparable issuers, (ii) general market or specific sector news and (iii) quoted prices and specific or similar security transactions. The Committee considers this data and any changes from prior periods in order to assess the reasonableness of observable and unobservable inputs, any assumptions or internal models used to value those securities and changes in fair value. Significant changes in any of these factors could result in lower or higher fair value measurements. Various factors impact the frequency of monitoring (which may occur as often as daily), however the Committee may determine that changes to inputs, assumptions and models are not required with the same frequency.

The following table summarizes the inputs used, as of June 30, 2012, in valuing the Fund's assets:

Investment Type	Quoted Prices (Level 1)		Other Significant Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)		Total
Total Stock Funds	$	217,404	$	-	$	-	$	217,404
Total Bond Funds		212,074		-		-		212,074
Total Investments	$	429,478	$	-	$	-	$	429,478

  There were no transfers of financial assets between levels 1 and 2 during the period.

See accompanying notes to financial statements.

72

Columbia Acorn Emerging Markets Fund

Major Portfolio Changes in the Second Quarter (Unaudited)

	Number of Shares
	3/31/12		6/30/12
Purchases
Asia
> Taiwan
CTCI Corp		64,762		73,762
Far EasTone Telecom		58,126		74,126
MStar Semiconductor		9,800		13,500
PC Home		13,700		15,700
> Indonesia
Archipelago Resources		137,500		150,100
Mayora Indah		0		13,600
Surya Citra Media		93,264		102,764
Tower Bersama Infrastructure		535,709		537,609
> Hong Kong
AAC Technologies		18,027		21,027
Lifestyle International		28,089		52,089
Sasa International		89,999		99,799
> China
RexLot Holdings		823,246		1,196,000
> India
Redington India		7,562		37,794
> Philippines
Int'l Container Terminal		40,787		44,487
> Cambodia
Nagacorp		340,000		420,000
> Mongolia
Mongolian Mining		98,500		140,500
> Singapore
Petra Foods		0		19,900
Other Countries
> South Africa
Mr. Price		6,597		6,797
> United States
Textainer Group Holdings		2,204		2,404
> Canada
Americas Petrogas		17,500		19,000
Europe
> Kazakhstan
Halyk Savings Bank of Kazakhstan - GDR		17,800		19,400
> France
Compagnie Française de l'Afrique Occidentale		0		325

	Number of Shares
	3/31/12		6/30/12
Latin America
> Brazil
Arcos Dorados		0		4,000
MRV Engenharia		11,325		12,425
Multiplus		3,144		3,444
> Mexico
Grupo Aeroportuario del Sureste - ADR		1,647		1,747

See accompanying notes to financial statements.

73

Columbia Acorn Emerging Markets Fund

Major Portfolio Changes in the Second Quarter (Unaudited), continued

	Number of Shares
	3/31/12		6/30/12
Sales
Asia
> Indonesia
Jasa Marga		109,911		0
> China
NetEase.com - ADR		1,277		977
Other Countries
> South Africa
Northam Platinum		15,354		10,854
> Canada
Alliance Grain Traders		10,801		8,801
Crew Energy		4,172		0
Europe
> Sweden
East Capital Explorer		8,806		4,006
> Germany
Dürr		1,229		1,060
> France
Rubis		965		0
Latin America
> Brazil
Mills Estruturas e Servicos de Engenharia		3,361		0

See accompanying notes to financial statements.

74

Columbia Acorn Emerging Markets Fund

Statement of Investments (Unaudited), June 30, 2012

Number of Shares			Value (000)
			Equities: 96.9%
Asia 60.7%
		> Taiwan 19.3%
	74,126	Far EasTone Telecom	$	161
		Taiwan's Third Largest Mobile Operator
	73,762	CTCI Corp		138
		International Engineering Firm
	9,200	St. Shine Optical		103
		World's Leading Disposable Contact Lens OEM
	42,990	Chroma Ate		98
		Automatic Test Systems, Testing & Measurement Instruments
	33,000	Tripod Technologies		94
		Printed Circuit Boards (PCB)
	13,500	MStar Semiconductor		91
		Integrated Circuits for TV, Digital Set-top-box & Handset
	15,700	PC Home		89
		Taiwanese Internet Retail Company
	12,342	Simplo Technology		85
		Battery Packs for Notebook & Tablet PCs
	15,277	Radiant Opto-Electronics (a)		78
		LCD Back Light Units & Modules
	21,169	Advantech		70
		Industrial PC & Components
	18,500	Lung Yen		54
		Funeral Services & Columbaria
	23,689	Taiwan Hon Chuan		53
		Beverage Packaging (Bottles, Caps, Labels) Manufacturer
				1,114
		> Indonesia 11.2%
	369,019	Ace Indonesia		200
		Home Improvement Retailer
	537,609	Tower Bersama Infrastructure (a)		188
		Communications Towers
	150,100	Archipelago Resources (a)		120
		Gold Mining Projects in Indonesia, Vietnam & the Philippines
	102,764	Surya Citra Media		105
		Free to Air TV in Indonesia
	13,600	Mayora Indah		37
		Consumer Branded Food Manufacturer
				650
		> Hong Kong 7.1%
	52,089	Lifestyle International		115
		Mid to High-end Department Store Operator in Hong Kong & China
	128,862	Melco International		105
		Macau Casino Operator
	5,650	Melco Crown Entertainment - ADR (a)		65
		Macau Casino Operator
	99,799	Sasa International		63
		Cosmetics Retailer
	21,027	AAC Technologies		61
		Miniature Acoustic Components
				409

Number of Shares			Value (000)
		> China 6.0%
	54,951	Digital China	$	97
		IT Distribution & Systems Integration Services
	1,196,000	RexLot Holdings		86
		Lottery Equipment Supplier in China
	977	NetEase.com - ADR (a)		57
		Chinese Online Gaming Services
	1,254	51job - ADR (a)(b)		57
		Integrated Human Resource Services
	111,475	AMVIG Holdings		49
		Chinese Tobacco Packaging Material Supplier
				346
		> India 5.2%
	8,635	United Breweries		85
		India's Largest Brewer
	14,240	Titan Industries		57
		Jewlery, Watches & Eyeglasses
	24,700	Adani Ports & Special Economic Zone		54
		Indian West Coast Shipping Port
	37,794	Redington India		52
		Supply Chain Solutions for IT & Mobile Handsets in Emerging Markets
	33,749	Jain Irrigation Systems		51
		Agricultural Micro-irrigation Systems & Food Processing
				299
		> Philippines 3.4%
	44,487	Int'l Container Terminal		78
		Container Handling Terminals & Port Management
	109,465	Manila Water Company		64
		Water Utility Company in the Philippines
	176,818	SM Prime Holdings		55
		Shopping Mall Operator
				197
		> Cambodia 3.3%
	420,000	Nagacorp		188
		Casino/Entertainment Complex in Cambodia
				188
		> Thailand 1.9%
	272,518	Home Product Center		109
		Home Improvement Retailer
				109
		> Mongolia 1.4%
	140,500	Mongolian Mining (a)		80
		Coking Coal Mining in Mongolia
				80
		> Japan 1.2%
	6,760	Kansai Paint		72
		Paint Producer in Japan, India, China & Southeast Asia
				72
		> Singapore 0.7%
	19,900	Petra Foods		39
		Cocoa Processor & Chocolate Manufacturer
				39
Asia: Total				3,503

See accompanying notes to financial statements.

75

Columbia Acorn Emerging Markets Fund

Statement of Investments (Unaudited), continued

Number of Shares			Value (000)
Other Countries 16.9%
		> South Africa 10.9%
	75,000	Rand Merchant Insurance	$	160
		Directly Sold Property & Casualty Insurance; Holdings in Other Insurers
	45,226	Coronation Fund Managers		153
		South African Fund Manager
	16,350	Adcock Ingram Holdings		120
		Manufacturer of Pharmaceuticals & Medical Supplies
	6,797	Mr. Price		93
		South African Retailer of Apparel, Household & Sporting Goods
	3,497	Massmart Holdings		73
		General Merchandise, Food & Home Improvement Stores; Wal-Mart Subsidiary
	10,854	Northam Platinum		31
		Platinum Mining in South Africa
				630
		> United States 3.3%
	2,404	Textainer Group Holdings (b)		89
		Top International Container Leasor
	1,709	Hornbeck Offshore (a)		66
		Supply Vessel Operator in U.S. Gulf of Mexico
	952	Atwood Oceanics (a)		36
		Offshore Drilling Contractor
				191
		> Canada 2.7%
	8,801	Alliance Grain Traders		118
		Global Leader in Pulse Processing & Distribution
	19,000	Americas Petrogas (a)		35
		Oil & Gas Exploration in Argentina, Potash in Peru
				153
Other Countries: Total				974
Europe 11.0%
		> Sweden 2.6%
	7,231	Hexagon		124
		Design, Measurement & Visualization Software & Equipment
	4,006	East Capital Explorer		28
		Sweden-based Russia & Central Eastern Europe Investment Fund
				152
		> Switzerland 2.5%
	1,178	Dufry Group (a)		143
		Operates Airport Duty Free & Duty Paid Shops
				143
		> Kazakhstan 1.7%
	19,400	Halyk Savings Bank of Kazakhstan - GDR (a)		97
		Largest Retail Bank & Insurer in Kazakhstan
				97

Number of Shares			Value (000)
		> Czech Republic 1.4%
	474	Komercni Banka	$	83
		Leading Czech Universal Bank
				83
		> Italy 1.4%
	7,631	Pirelli		80
		Global Tire Supplier
				80
		> Germany 1.1%
	1,060	Dürr		65
		Automotive Plant Engineering & Associated Capital Equipment
				65
		> France 0.3%
	325	Compagnie Française de l'Afrique Occidentale		15
		African Wholesaler & Distributor
				15
Europe: Total				635
Latin America 8.3%
		> Brazil 5.0%
	6,090	Localiza Rent A Car		92
		Car Rental
	3,444	Multiplus		82
		Loyalty Program Operator in Brazil
	4,000	Arcos Dorados (b)		59
		McDonald's Master Franchise for Latin America
	12,425	MRV Engenharia		57
		Brazilan Property Developer
				290
		> Mexico 2.4%
	1,747	Grupo Aeroportuario del Sureste - ADR		136
		Mexican Airport Operator
				136
		> Chile 0.7%
	18,900	Viña Concha y Toro		37
		Global Branded Wine Manufacturer
				37
		> Argentina 0.2%
	40,200	Madalena Ventures (a)		14
		Oil & Gas Exploration in Argentina
				14
Latin America: Total				477
Total Equities: 96.9% (Cost: $5,503)				5,589

See accompanying notes to financial statements.

76

Number of Shares			Value (000)
Securities Lending Collateral 1.8%
	104,775	Dreyfus Government Cash Management Fund (7 day yield of 0.01%) (c)	$	105
Total Securities Lending Collateral: (Cost: $105)				105
Total Investments: 98.7% (Cost: $5,608)(d)(e)				5,694
Obligation to Return Collateral for Securities Loaned: (1.8)%				(105	)
Cash and Other Assets Less Liabilities: 3.1%				183
Total Net Assets: 100.0%			$	5,772

ADR - American Depositary Receipts

GDR - Global Depositary Receipts

> Notes to Statement of Investments (dollar values in thousands)

(a)  Non-income producing security.

(b)  All or a portion of this security was on loan at June 30, 2012. The total market value of securities on loan at June 30, 2012 was $105.

(c)  Investment made with cash collateral received from securities lending activity.

(d)  At June 30, 2012, for federal income tax purposes, the cost of investments was $5,608 and net unrealized appreciation was $86 consisting of gross unrealized appreciation of $549 and gross unrealized depreciation of $463.

(e)  On June 30, 2012, the Fund's total investments were denominated in currencies as follows:

Currency	Value		Percentage of Net Assets
Taiwan Dollar	$	1,114		19.3
Hong Kong Dollar		843		14.6
United States Dollar		663		11.5
South African Rand		630		10.9
Indonesian Rupiah		530		9.2
Indian Rupee		298		5.2
Other currencies less than 5% of total net assets		1,511		26.2
Total Portfolio	$	5,589		96.9

Fair Value Measurements

  Various inputs are used in determining the value of the Fund's investments, following the input prioritization hierarchy established by GAAP. These inputs are summarized in the three broad levels listed below:

•  Level 1 – quoted prices in active markets for identical securities

•  Level 2 – prices determined using other significant observable inputs (including quoted prices for similar securities, interest rates, prepayment speeds, credit risk and others)

•  Level 3 – prices determined using significant unobservable inputs where quoted prices or observable inputs are unavailable or less reliable (including management's own assumptions about the factors market participants would use in pricing an investment)

  The inputs or methodology used for valuing securities are not necessarily an indication of the risk associated with investing in those securities.

  Examples of the types of securities in which the Fund would typically invest and how they are classified within this hierarchy are as follows. Typical Level 1 securities include exchange traded domestic equities, mutual funds whose NAVs are published each day and exchange traded foreign equities that are not statistically fair valued. Typical Level 2 securities include exchange traded foreign equities that are statistically fair valued and short-term investments valued at amortized cost. Additionally, securities fair valued by the Valuation Committee (the Committee) of the Fund's Board of Trustees (the Board) that rely on significant observable inputs are also included in Level 2. Typical Level 3 securities include any security fair valued by the Committee that relies on significant unobservable inputs.

See accompanying notes to financial statements.

77

Columbia Acorn Emerging Markets Fund

Statement of Investments (Unaudited), continued

> Notes to Statement of Investments (dollar values in thousands)

  Under the direction of the Board, the Committee is responsible for carrying out the valuation procedures approved by the Board.

The Committee meets as necessary, and no less frequently than quarterly, to determine fair values for securities for which market quotations are not readily available or for which the investment manager believes that available market quotations are unreliable, and to review the continuing appropriateness of the current value of any security subject to the Trust's Portfolio Pricing Policy and the pricing procedures of the investment manager (the Policies). The Policies address, among other things: circumstances under which market quotations will be deemed readily available; selection of third party pricing vendors; appropriate pricing methodologies; events that require fair valuation and fair value techniques; and circumstances under which securities will be deemed to pose a potential for stale pricing, including when securities are illiquid, restricted, or in default. The Committee may also meet to discuss additional valuation matters, which may include review of back-testing results, review of time-sensitive information or approval of other valuation related actions, and to review the appropriateness of the Policies.

  For investments categorized as Level 3, the significant unobservable inputs used in the fair value measurement of the Funds' securities may include: (i) data specific to the issuer or comparable issuers, (ii) general market or specific sector news and (iii) quoted prices and specific or similar security transactions. The Committee considers this data and any changes from prior periods in order to assess the reasonableness of observable and unobservable inputs, any assumptions or internal models used to value those securities and changes in fair value. Significant changes in any of these factors could result in lower or higher fair value measurements. Various factors impact the frequency of monitoring (which may occur as often as daily), however the Committee may determine that changes to inputs, assumptions and models are not required with the same frequency.

The following table summarizes the inputs used, as of June 30, 2012, in valuing the Fund's assets:

Investment Type	Quoted Prices (Level 1)		Other Significant Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)		Total
Equities
Asia	$	179	$	3,324	$	-	$	3,503
Other Countries		344		630		-		974
Europe		-		635		-		635
Latin America		477		-		-		477
Total Equities		1,000		4,589		-		5,589
Total Securities Lending Collateral		105		-		-		105
Total Investments	$	1,105	$	4,589	$	-	$	5,694

  The Fund's assets assigned to the Level 2 input category are generally valued using a market approach, in which a security's value is determined through its correlation to prices and information from observable market transactions for similar or identical assets. Foreign equities are generally valued at the last sale price on the foreign exchange or market on which they trade. The Fund may use a statistical fair valuation model, in accordance with the policy adopted by the Board, provided by an independent third party to value securities principally traded in foreign markets in order to adjust for possible stale pricing that may occur between the close of the foreign exchanges and the time for valuation. These models take into account available market data including intraday index, ADR, and ETF movements.

  There were no transfers of financial assets between levels 1 and 2 during the period.

See accompanying notes to financial statements.

78

Columbia Acorn Emerging Markets Fund

Portfolio Diversification (Unaudited)

At June 30, 2012, the Fund's portfolio investments as a percentage of net assets were diversified as follows:

	Value (000)		Percentage of Net Assets
> Consumer Goods & Services
Retail	$	827		14.4
Casinos & Gaming		443		7.7
Food & Beverage		354		6.1
Other Consumer Services		225		3.9
Travel		92		1.6
Other Durable Goods		80		1.4
Consumer Goods Distribution		52		0.9
		2,073		36.0
> Information
Computer Hardware & Related Equipment		388		6.7
Mobile Communications		350		6.1
Business Software		124		2.1
TV Broadcasting		104		1.8
Instrumentation		98		1.7
Electronics Distribution		97		1.7
Semiconductors & Related Equipment		91		1.6
Internet Related		58		1.0
		1,310		22.7
> Finance
Brokerage & Money Management		181		3.2
Banks		180		3.1
Insurance		160		2.8
Finance Companies		89		1.5
		610		10.6
> Industrial Goods & Services
Industrial Materials & Specialty Chemicals		175		3.0
Construction		138		2.4
Other Industrial Services		132		2.3
Machinery		116		2.0
		561		9.7
> Energy & Minerals
Mining		231		4.0
Agricultural Commodities		118		2.0
Oil Services		102		1.8
Oil & Gas Producers		49		0.8
		500		8.6
> Other Industries
Transportation		136		2.4
Real Estate		112		1.9
Regulated Utilities		64		1.1
		312		5.4

	Value (000)			Percentage of Net Assets
> Health Care
Pharmaceuticals	$	120			2.1
Medical Supplies		103			1.8
		223			3.9
Total Equities:		5,589			96.9
Security Lending Collateral:		105			1.8
Total Investments:		5,694			98.7
Obligation to Return Collateral for Securities Loaned:		(105	)		(1.8	)
Cash and Other Assets Less Liabilities:		183			3.1
Net Assets:	$	5,772			100.0

See accompanying notes to financial statements.

79

Columbia Acorn European Fund

Major Portfolio Changes in the Second Quarter (Unaudited)

	Number of Shares
	3/31/12		6/30/12
Purchases
Europe
> United Kingdom
Aggreko		0		700
BBA Aviation		0		7,480
Charles Taylor		15,220		22,220
Domino's Pizza United Kingdom & Ireland		3,610		5,090
Greggs		999		3,200
Rightmove		1,000		1,400
WH Smith		0		2,000
> Netherlands
Vopak		0		300
> Switzerland
Dufry Group		170		310
Partners Group		160		295
> Russia
Yandex		0		1,900

	Number of Shares
	3/31/12		6/30/12
Sales
Europe
> United Kingdom
Chemring		4,900		0
Intertek Group		1,100		500
Workspace Group		5,800		0
> France
Mersen		600		213
Rubis		310		0
> Netherlands
Core Laboratories		330		230
Fugro		410		0
> Germany
Rheinmetall		560		360
> Russia
Mail.ru - GDR		1,000		600

See accompanying notes to financial statements.

80

Columbia Acorn European Fund

Statement of Investments (Unaudited), June 30, 2012

Number of Shares			Value (000)
			Equities: 92.9%
Europe 89.8%
		> United Kingdom 18.3%
	22,220	Charles Taylor	$	56
		Insurance Services
	5,090	Domino's Pizza United Kingdom & Ireland		41
		Pizza Delivery in the UK, Ireland & Germany
	1,400	Rightmove		35
		Internet Real Estate Listings
	2,827	JLT Group		31
		International Business Insurance Broker
	3,480	Serco		29
		Facilities Management
	3,180	Shaftesbury		26
		London Prime Retail REIT
	3,200	Greggs		25
		Bakery
	7,480	BBA Aviation		24
		Aviation Support Services
	700	Aggreko		23
		Temporary Power & Temperature Control Services
	500	Intertek Group		21
		Testing, Inspection, Certification Services
	3,190	Abcam		21
		Online Sales of Antibodies
	660	Rotork		20
		Valve Actuators for Oil & Water Pipelines
	2,000	WH Smith		17
		Newsprint, Book & General Stationery Retailer
	2,870	Premier Oil (a)		15
		Oil & Gas Producer in Europe, Pakistan & Asia
	71	Spirax Sarco		2
		Steam Systems for Manufacturing & Process Industries
				386
		> France 14.2%
	600	Eurofins Scientific		75
		Food, Pharmaceuticals & Materials Screening & Testing
	1,000	Gemalto		72
		Digital Security Solutions
	1,200	1000 mercis		55
		Interactive Advertising & Marketing
	1,300	Saft		31
		Niche Battery Manufacturer
	360	Norbert Dentressangle		23
		Leading European Logistics & Transport Group
	400	Neopost		21
		Postage Meter Machines
	7,100	Hi-Media (a)		18
		Online Advertiser in Europe
	213	Mersen		5
		Advanced Industrial Materials
				300
		> Netherlands 12.3%
	1,730	UNIT4		44
		Business Software Development

Number of Shares			Value (000)
	2,785	Aalberts Industries	$	43
		Flow Control & Heat Treatment
	1,412	Koninklijke TenCate		38
		Advanced Textiles & Industrial Fabrics
	1,499	Imtech		36
		Electromechanical & Information & Communications Technology Installation & Maintenance
	1,480	Arcadis		32
		Engineering Consultants
	230	Core Laboratories		27
		Oil & Gas Reservoir Consulting
	917	TKH Group		20
		Dutch Industrial Conglomerate
	300	Vopak		19
		World's Largest Operator of Petroleum & Chemical Storage Terminals
				259
		> Germany 10.1%
	3,250	Wirecard		63
		Online Payment Processing & Risk Management
	520	Dürr		32
		Automotive Plant Engineering & Associated Capital Equipment
	130	Rational		31
		Commercial Ovens
	375	Bertrandt		28
		Outsourced Engineering
	500	Stratec Biomedical Systems		22
		Diagnostic Instrumentation
	590	CTS Eventim		18
		Event Ticket Sales
	360	Rheinmetall		18
		Defense & Automotive
				212
		> Switzerland 9.9%
	300	Geberit		59
		Plumbing Supplies
	295	Partners Group		52
		Private Markets Asset Management
	21	Sika		41
		Chemicals for Construction & Industrial Applications
	310	Dufry Group (a)		38
		Operates Airport Duty Free & Duty Paid Shops
	320	Zehnder		19
		Radiators & Ventilation Systems
				209
		> Sweden 6.0%
	3,070	Hexagon		53
		Design, Measurement & Visualization Software & Equipment
	4,570	Sweco		48
		Engineering Consultants
	1,000	Unibet		25
		European Online Gaming Operator
				126
		> Italy 3.7%
	11,000	Geox		24
		Apparel & Shoe Maker

See accompanying notes to financial statements.

81

Columbia Acorn European Fund

Statement of Investments (Unaudited), continued

Number of Shares			Value (000)
		> Italy—continued
	230	Tod's	$	23
		Leather Shoes & Bags
	2,000	Pirelli		21
		Global Tire Supplier
	9,960	CIR		10
		Italian Holding Company
				78
		> Russia 2.7%
	1,900	Yandex (a)		36
		Search Engine for Russian & Turkish Languages
	600	Mail.ru - GDR (a)(b)		21
		Internet Social Networking & Games for Russian Speakers
				57
		> Iceland 2.5%
	43,750	Marel		53
		Largest Manufacturer of Poultry & Fish Processing Equipment
				53
		> Ireland 1.9%
	300	Paddy Power		20
		Irish Betting Services
	7,300	United Drug		19
		Irish Pharmaceutical Wholesaler & Outsourcer
				39
		> Portugal 1.7%
	13,480	Redes Energéticas Nacionais		36
		Portuguese Power Transmission & Gas Transportation
				36
		> Norway 1.6%
	3,710	Atea		33
		Leading Nordic IT Hardware/Software Reseller & Installation Company
				33
		> Belgium 1.2%
	530	EVS Broadcast Equipment		25
		Digital Live Mobile Production Software & Systems
				25
		> Czech Republic 1.1%
	140	Komercni Banka		24
		Leading Czech Universal Bank
				24
		> Poland 1.1%
	4,000	FX Energy (a)		24
		Oil & Gas Producer in Poland
				24
		> Denmark 0.8%
	300	Solar A/S		16
		Technical Wholesaler of Electrical, Plumbing & HVAC Equipment
				16

Number of Shares			Value (000)
		> Greece 0.7%
	13,330	Intralot	$	15
		Lottery & Gaming Systems & Services
				15
Europe: Total				1,892
Other Countries 1.7%
		> Canada 1.3%
	1,970	Alliance Grain Traders		26
		Global Leader in Pulse Processing & Distribution
				26
		> United States 0.4%
	1,300	Velti (a)(c)		9
		Mobile Marketing Software Platform
				9
Other Countries: Total				35
Asia 1.4%
		> Hong Kong 1.4%
	11,000	L'Occitane International		30
		Skin Care & Cosmetics Producer
				30
Asia: Total				30
Total Equities: 92.9% (Cost: $1,874)				1,957
Securities Lending Collateral 0.3%
	5,850	Dreyfus Government Cash Management Fund (7 day yield of 0.01%) (d)		6
Total Securities Lending Collateral: (Cost: $6)				6
Total Investments: 93.2% (Cost: $1,880)(e)(f)				1,963
Obligation to Return Collateral for Securities Loaned: (0.3)%				(6	)
Cash and Other Assets Less Liabilities: 7.1%				149
Total Net Assets: 100.0%			$	2,106

GDR - Global Depositary Receipts

REIT - Real Estate Investment Trust

See accompanying notes to financial statements.

82

> Notes to Statement of Investments (dollar values in thousands)

(a)  Non-income producing security.

(b)  Security exempt from registration under Section 4(2) of the Securities Act of 1933. This security may only be resold in exempt transactions to qualified buyers. Private resales of this security to qualified institutional buyers are also exempt from registration pursuant to Rule 144A under the Securities Act of 1933. At June 30, 2012, this security had an aggregate value of $21, which represented 1.00% of total net assets.

(c)  All or a portion of this security was on loan at June 30, 2012. The total market value of securities on loan at June 30, 2012 was $6.

(d)  Investment made with cash collateral received from securities lending activity.

(e)  At June 30, 2012, for federal income tax purposes, the cost of investments was $1,880 and net unrealized appreciation was $83 consisting of gross unrealized appreciation of $191 and gross unrealized depreciation of $108.

(f)  On June 30, 2012, the Fund's total investments were denominated in currencies as follows:

Currency	Value		Percentage of Net Assets
Euro	$	937		44.5
British Pound		386		18.3
Swiss Franc		209		9.9
Swedish Krona		126		6.0
United States Dollar		116		5.5
Other currencies less than 5% of total net assets		183		8.7
Total Portfolio	$	1,957		92.9

Fair Value Measurements

  Various inputs are used in determining the value of the Fund's investments, following the input prioritization hierarchy established by GAAP. These inputs are summarized in the three broad levels listed below:

•  Level 1 – quoted prices in active markets for identical securities

•  Level 2 – prices determined using other significant observable inputs (including quoted prices for similar securities, interest rates, prepayment speeds, credit risk and others)

•  Level 3 – prices determined using significant unobservable inputs where quoted prices or observable inputs are unavailable or less reliable (including management's own assumptions about the factors market participants would use in pricing an investment)

  The inputs or methodology used for valuing securities are not necessarily an indication of the risk associated with investing in those securities.

  Examples of the types of securities in which the Fund would typically invest and how they are classified within this hierarchy are as follows. Typical Level 1 securities include exchange traded domestic equities, mutual funds whose NAVs are published each day and exchange traded foreign equities that are not statistically fair valued. Typical Level 2 securities include exchange traded foreign equities that are statistically fair valued and short-term investments valued at amortized cost. Additionally, securities fair valued by the Valuation Committee (the Committee) of the Fund's Board of Trustees (the Board) that rely on significant observable inputs are also included in Level 2. Typical Level 3 securities include any security fair valued by the Committee that relies on significant unobservable inputs.

  Under the direction of the Board, the Committee is responsible for carrying out the valuation procedures approved by the Board.

The Committee meets as necessary, and no less frequently than quarterly, to determine fair values for securities for which market quotations are not readily available or for which the investment manager believes that available market quotations are unreliable, and to review the continuing appropriateness of the current value of any security subject to the Trust's Portfolio Pricing Policy and the pricing procedures of the investment manager (the Policies). The Policies address, among other things: circumstances under which market quotations will be deemed readily available; selection of third party pricing vendors; appropriate pricing methodologies; events that require fair valuation and fair value techniques; and circumstances under which securities will be deemed to pose a potential for stale pricing, including when securities are illiquid, restricted, or in default. The Committee may also meet to discuss additional valuation matters, which may include review of back-testing results, review of time-sensitive information or approval of other valuation related actions, and to review the appropriateness of the Policies.

  For investments categorized as Level 3, the significant unobservable inputs used in the fair value measurement of the Funds' securities may include: (i) data specific to the issuer or comparable issuers, (ii) general market or specific sector news and (iii) quoted prices and specific or similar security transactions. The Committee considers this data and any changes from prior periods in order to assess the reasonableness of observable and unobservable inputs, any assumptions or internal models used to value those securities and changes in fair value. Significant changes in any of these factors could result in lower or higher fair value measurements. Various factors impact the frequency of monitoring (which may occur as often as daily), however the Committee may determine that changes to inputs, assumptions and models are not required with the same frequency.

See accompanying notes to financial statements.

83

Columbia Acorn European Fund

Statement of Investments (Unaudited), continued

> Notes to Statement of Investments (dollar values in thousands)

The following table summarizes the inputs used, as of June 30, 2012, in valuing the Fund's assets:

Investment Type	Quoted Prices (Level 1)		Other Significant Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)		Total
Equities
Europe	$	87	$	1,805	$	-	$	1,892
Other Countries		35		-		-		35
Asia		-		30		-		30
Total Equities		122		1,835		-		1,957
Total Securities Lending Collateral		6		-		-		6
Total Investments	$	128	$	1,835	$	-	$	1,963

  The Fund's assets assigned to the Level 2 input category are generally valued using a market approach, in which a security's value is determined through its correlation to prices and information from observable market transactions for similar or identical assets. Foreign equities are generally valued at the last sale price on the foreign exchange or market on which they trade. The Fund may use a statistical fair valuation model, in accordance with the policy adopted by the Board, provided by an independent third party to value securities principally traded in foreign markets in order to adjust for possible stale pricing that may occur between the close of the foreign exchanges and the time for valuation. These models take into account available market data including intraday index, ADR, and ETF movements.

  There were no transfers of financial assets between levels 1 and 2 during the period.

See accompanying notes to financial statements.

84

Columbia Acorn European Fund

Portfolio Diversification (Unaudited)

At June 30, 2012, the Fund's portfolio investments as a percentage of net assets were diversified as follows:

	Value (000)		Percentage of Net Assets
> Industrial Goods & Services
Other Industrial Services	$	235		11.2
Machinery		178		8.4
Industrial Materials & Specialty Chemicals		84		4.0
Outsourcing Services		81		3.8
Conglomerates		73		3.4
Construction		59		2.8
Electrical Components		31		1.5
Industrial Distribution		16		0.8
		757		35.9
> Information
Business Software		105		5.0
Computer Hardware & Related Equipment		97		4.6
Internet Related		92		4.4
Financial Processors		63		3.0
Business Information & Marketing Services		55		2.6
Computer Services		32		1.5
Advertising		18		0.8
		462		21.9
> Consumer Goods & Services
Casinos & Gaming		60		2.9
Retail		55		2.6
Nondurables		54		2.6
Restaurants		41		1.9
Other Durable Goods		40		1.9
Food & Beverage		25		1.2
Apparel		24		1.1
Other Entertainment		18		0.9
		317		15.1
> Finance
Insurance		87		4.1
Brokerage & Money Management		53		2.5
Banks		24		1.2
		164		7.8
> Energy & Minerals
Oil & Gas Producers		39		1.9
Mining		27		1.3
Agricultural Commodities		26		1.2
Oil Refining, Marketing & Distribution		19		0.9
		111		5.3
> Other Industries
Regulated Utilities		36		1.7
Real Estate		25		1.2
Transportation		23		1.1
		84		4.0

	Value (000)			Percentage of Net Assets
> Health Care
Medical Equipment & Devices	$	22			1.0
Medical Supplies		21			1.0
Pharmaceuticals		19			0.9
		62			2.9
Total Equities:		1,957			92.9
Security Lending Collateral:		6			0.3
Total Investments:		1,963			93.2
Obligation to Return Collateral for Securities Loaned:		(6	)		(0.3	)
Cash and Other Assets Less Liabilities:		149			7.1
Net Assets:	$	2,106			100.0

See accompanying notes to financial statements.

85

Columbia Acorn Family of Funds

Statements of Assets and Liabilities (Unaudited)

June 30, 2012	Columbia Acorn Fund			Columbia Acorn International			Columbia Acorn USA			Columbia Acorn International Select
(in thousands)
Assets:
Unaffiliated investments, at cost	$	8,195,104		$	4,769,636		$	1,175,881		$	273,433
Affiliated investments, at cost (See Note 4)		2,717,367			93,271			3,624			—
Unaffiliated investments, at value (including securities on loan: Columbia Acorn Fund $302,684; Columbia Acorn International $110,353; Columbia Acorn USA $52,943; Columbia Acorn International Select $—; Columbia Acorn Select $25,542; Columbia Thermostat Fund $—; Columbia Acorn Emerging Markets Fund $105; Columbia Acorn European Fund $6)	$	12,779,513		$	5,689,495		$	1,631,375		$	320,869
Affiliated investments, at value (See Note 4)		3,965,342			122,198			3,546			—
Cash		723,080			234,386			5,316			17,891
Foreign currency (cost: Columbia Acorn Fund $—; Columbia Acorn International $978; Columbia Acorn USA $—; Columbia Acorn International Select $183; Columbia Acorn Select $—; Columbia Thermostat Fund $—; Columbia Acorn Emerging Markets Fund $1; Columbia Acorn European Fund $—)		1,468			980			—			184
Receivable for:
Investments sold		14,479			26,099			1,960			4,811
Fund shares sold		13,853			101,107			1,798			719
Dividends and interest		6,953			5,681			386			387
Securities lending income		764			147			111			3
Foreign tax reclaims		309			4,004			—			211
Expense reimbursement due from Advisor		—			1			—			—
Trustees' Deferred Compensation Investments		2,374			659			195			—
Other assets		228			20			10			1
Total Assets		17,508,363			6,184,777			1,644,697			345,076
Liabilities:
Collateral on securities loaned		303,633			111,197			53,351			—
Unrealized depreciation on forward foreign currency exchange contracts		—			—			—			933
Payable to advisor		—			—			—			—
Payable for:
Investments purchased		9,292			35,885			871			5,304
Fund shares redeemed		26,065			5,369			2,043			540
Management fee		292			120			36			8
Administration fee		18			6			2			—	(a)
12b-1 Service and Distribution fees		43			9			2			1
Reports to shareholders		565			263			50			39
Deferred Trustees' fees		2,374			659			195			—
Transfer agent fees		1,403			374			241			25
Trustees' fees		—			1			—			40
Custody fees		75			185			2			16
Professional fee		88			48			39			25
Chief compliance officer expenses		43			13			4			2
Deferred foreign capital gains tax payable		—			4,024			—			—
Other liabilities		—			57			—			9
Total Liabilities		343,891			158,210			56,836			6,942
Net Assets	$	17,164,472		$	6,026,567		$	1,587,861		$	338,134
Composition of Net Assets:
Paid-in capital	$	10,721,070		$	5,301,264		$	1,029,599		$	279,482
Undistributed (overdistributed) net investment income		(28,080	)		(36,596	)		(3,403	)		(2,516	)
Accumulated net realized gain (loss)		639,075			(182,854	)		106,249			14,670
Net unrealized appreciation (depreciation) on:
Unaffiliated investments		4,584,409			919,859			455,494			47,436
Affiliated investments		1,247,975			28,927			(78	)		—
Foreign currency translations		23			(9	)		—			(6	)
Forward foreign currency exchange contracts		—			—			—			(932	)
Foreign capital gains tax		—			(4,024	)		—			—
Net Assets	$	17,164,472		$	6,026,567		$	1,587,861		$	338,134
Net asset value per share – Class A (b)	$	28.69		$	37.01		$	28.52		$	26.62
(Net assets/shares)		($3,289,689/114,676)			($926,998/25,045)			($157,525/5,523)			($57,282/2,152)
Maximum offering price per share – Class A (c)	$	30.44		$	39.27		$	30.26		$	28.24
(Net asset value per share/front-end sales charge)		($28.69/0.9425)			($37.01/0.9425)			($28.52/0.9425)			($26.62/0.9425)
Net asset value and offering price per share – Class B (b)	$	26.32		$	35.88		$	26.27		$	25.45
(Net assets/shares)		($45,604/1,733)			($21,112/588)			($1,627/62)			($1,364/53)
Net asset value and offering price per share – Class C (b)	$	25.92		$	35.73		$	25.99		$	25.32
(Net assets/shares)		($749,753/28,929)			($92,746/2,596)			($31,666/1,218)			($8,585/339)
Net asset value and offering price per share – Class I (d)	$	29.76		$	37.13		$	29.75		$	26.88
(Net assets/shares)		($32,680/1,098)			($62,855/1,693)			($618/21)		($	3/—	(e))
Net asset value and offering price per share – Class R	$	—		$	36.97		$	—		$	—
(Net assets/shares)	($	—/—	)		($961/26)		($	—/—	)	($	—/—	)
Net asset value and offering price per share – Class R5	$	—		$	37.10		$	—		$	—
(Net assets/shares)	($	—/—	)		($2,179/59)		($	—/—	)	($	—/—	)
Net asset value and offering price per share – Class Z (d)	$	29.74		$	37.10		$	29.72		$	26.88
(Net assets/shares)		($13,046,746/438,699)			($4,919,716/132,598)			($1,396,425/46,989)			($270,900/10,078)

(a)  Rounds to less than $500.

(b)  Redemption price per share is equal to net asset value less any applicable contingent deferred sales charge.

(c)  On sales of $50,000 or more the offering price is reduced.

(d)  Redemption price per share is equal to net asset value.

(e)  Rounds to less than 500 shares.

See accompanying notes to financial statements.

86

June 30, 2012	Columbia Acorn Select			Columbia Thermostat Fund			Columbia Acorn Emerging Markets Fund			Columbia Acorn European Fund
(in thousands)
Assets:
Unaffiliated investments, at cost	$	709,773		$	—		$	5,608		$	1,880
Affiliated investments, at cost (See Note 4)		152,247			404,568			—			—
Unaffiliated investments, at value (including securities on loan: Columbia Acorn Fund $302,684; Columbia Acorn International $110,353; Columbia Acorn USA $52,943; Columbia Acorn International Select $—; Columbia Acorn Select $25,542; Columbia Thermostat Fund $—; Columbia Acorn Emerging Markets Fund $105; Columbia Acorn European Fund $6)	$	1,037,312		$	—		$	5,694		$	1,963
Affiliated investments, at value (See Note 4)		65,984			429,478			—			—
Cash		19,892			4,565			219			153
Foreign currency (cost: Columbia Acorn Fund $—; Columbia Acorn International $978; Columbia Acorn USA $—; Columbia Acorn International Select $183; Columbia Acorn Select $—; Columbia Thermostat Fund $—; Columbia Acorn Emerging Markets Fund $1; Columbia Acorn European Fund $—)		—			—			1			—
Receivable for:
Investments sold		1,867			—			2			38
Fund shares sold		677			9,061			10			—
Dividends and interest		670			1,251			9			1
Securities lending income		290			—			—	(a)		—	(a)
Foreign tax reclaims		—			—			1			2
Expense reimbursement due from Advisor		—			—	(a)		—			—
Trustees' Deferred Compensation Investments		237			—			—			—
Other assets		6			—	(a)		8			8
Total Assets		1,126,935			444,355			5,944			2,165
Liabilities:
Collateral on securities loaned		26,067			—			105			6
Unrealized depreciation on forward foreign currency exchange contracts		—			—			—			—
Payable to advisor		—			—			8			7
Payable for:
Investments purchased		—			3,645			18			11
Fund shares redeemed		1,180			591			—			—
Management fee		24			1			—	(a)		—	(a)
Administration fee		1			1			—	(a)		—	(a)
12b-1 Service and Distribution fees		4			4			—	(a)		—	(a)
Reports to shareholders		122			8			10			10
Deferred Trustees' fees		237			—			—			—
Transfer agent fees		124			23			—	(a)		—	(a)
Trustees' fees		1			23			—	(a)		—	(a)
Custody fees		2			—	(a)		11			5
Professional fee		38			8			12			15
Chief compliance officer expenses		6			—			—	(a)		—	(a)
Deferred foreign capital gains tax payable		—			—			4			—
Other liabilities		9			—			4			5
Total Liabilities		27,815			4,304			172			59
Net Assets	$	1,099,120		$	440,051		$	5,772		$	2,106
Composition of Net Assets:
Paid-in capital	$	820,730		$	434,121		$	5,754		$	2,021
Undistributed (overdistributed) net investment income		(2,288	)		2,831			10			23
Accumulated net realized gain (loss)		39,399			(21,811	)		(74	)		(21	)
Net unrealized appreciation (depreciation) on:
Unaffiliated investments		327,539			—			86			83
Affiliated investments		(86,263	)		24,910			—			—
Foreign currency translations		3			—			—	(a)		—	(a)
Forward foreign currency exchange contracts		—			—			—			—
Foreign capital gains tax		—			—			(4	)		—
Net Assets	$	1,099,120		$	440,051		$	5,772		$	2,106
Net asset value per share – Class A (b)	$	24.17		$	13.65		$	10.15		$	10.50
(Net assets/shares)		($303,485/12,557)			($171,091/12,535)			($1,274/125)			($203/19)
Maximum offering price per share – Class A (c)	$	25.64		$	14.48		$	10.77		$	11.14
(Net asset value per share/front-end sales charge)		($24.17/0.9425)			($13.65/0.9425)			($10.15/0.9425)			($10.50/0.9425)
Net asset value and offering price per share – Class B (b)	$	22.43		$	13.71		$	—		$	—
(Net assets/shares)		($15,343/684)			($5,833/425)		($	—/—	)	($	—/—	)
Net asset value and offering price per share – Class C (b)	$	22.20		$	13.69		$	10.10		$	10.46
(Net assets/shares)		($60,556/2,728)			($111,865/8,170)			($216/21)			($18/2)
Net asset value and offering price per share – Class I (d)	$	24.96		$	—		$	10.19		$	10.51
(Net assets/shares)		($21,778/872)		($	—/—	)		($5/1)			($5/1)
Net asset value and offering price per share – Class R	$	—		$	—		$	—		$	—
(Net assets/shares)	($	—/—	)	($	—/—	)	($	—/—	)	($	—/—	)
Net asset value and offering price per share – Class R5	$	—		$	—		$	—		$	—
(Net assets/shares)	($	—/—	)	($	—/—	)	($	—/—	)	($	—/—	)
Net asset value and offering price per share – Class Z (d)	$	24.92		$	13.51		$	10.19		$	10.52
(Net assets/shares)		($697,958/28,005)			($151,262/11,198)			($4,277/420)			($1,880/178)

See accompanying notes to financial statements.

87

Columbia Acorn Family of Funds

Statements of Operations (Unaudited) For the Six Months Ended June 30, 2012

(in thousands)	Columbia Acorn Fund			Columbia Acorn International			Columbia Acorn USA			Columbia Acorn International Select
Investment Income:
Dividend income	$	68,183		$	86,067		$	5,295		$	5,357
Dividend income from affiliates (See Note 4)		9,504			2,251			—			—
Interest income		—	(a)		—	(a)		—			3
Securities lending income, net		4,039			707			536			15
Dividends from affiliated investment company shares		—			—			—			—
		81,726			89,025			5,831			5,375
Foreign taxes withheld		(1,840	)		(8,503	)		(7	)		(469	)
Total Investment Income		79,886			80,522			5,824			4,906
Expenses:
Management fee		56,115			22,639			7,167			1,578
Administration fee		3,398			1,155			323			65
12b-1 Service and Distribution fees:
Class A		4,288			1,203			214			72
Class B		219			89			7			6
Class C		3,851			491			162			44
Class R		—			2			—			—
Transfer agent fees:
Class A		1,487			758			84			38
Class B		53			48			3			2
Class C		339			71			15			7
Class R		—			1			—			—
Class R5		—			—	(a)		—			—
Class Z		2,916			1,058			560			74
Custody fees		—			547			7			42
Trustees' fees		496			171			49			10
Registration and blue sky fees		109			89			55			41
Reports to shareholders		1,207			692			249			93
Audit fees		39			62			19			20
Legal fees		773			291			87			18
Interest expense (See Note 5)		—			—			—			—
Chief compliance officer expenses (See Note 4)		247			83			23			5
Organizational expenses (See Note 4)		—			—			—			—
Other expenses		355			133			36			13
Total Expenses		75,892			29,583			9,060			2,128
Less reimbursement of expenses by Investment Advisor (See Note 4)		—			(206	)		—			—
Net Expenses		75,892			29,377			9,060			2,128
Net Investment Income/(Loss)		3,994			51,145			(3,236	)		2,778
Net Realized and Unrealized Gain/(Loss) on Portfolio Positions:
Net Realized Gain/(Loss) on:
Unaffiliated investments		669,444			118,555			106,876			14,604
Affiliated investments (See Note 4)		560			—			—			—
Foreign currency translations		(99	)		(1,108	)		—			(108	)
Forward foreign currency exchange contracts		—			5,423			—			210
Distributions from affiliated investment company shares		—			—			—			—
Net realized gain/(loss)		669,905			122,870			106,876			14,706
Net change in net unrealized appreciation/(depreciation) on:
Unaffiliated investments		667,791			317,503			52,933			15,607
Affiliated investments (See Note 4)		169,764			(10,385	)		231			—
Foreign currency translations		35			70			—			6
Forward foreign currency exchange contracts		—			(4,539	)		—			16
Foreign capital gains tax		—			(1,703	)		—			—
Net change in unrealized appreciation/(depreciation)		837,590			300,946			53,164			15,629
Net realized and unrealized gain		1,507,495			423,816			160,040			30,335
Net Increase in Net Assets resulting from Operations	$	1,511,489		$	474,961		$	156,804		$	33,113

(a)  Rounds to less than $500.

See accompanying notes to financial statements.

88

(in thousands)	Columbia Acorn Select			Columbia Thermostat Fund			Columbia Acorn Emerging Markets Fund			Columbia Acorn European Fund
Investment Income:
Dividend income	$	4,297		$	—		$	55		$	44
Dividend income from affiliates (See Note 4)		—			—			—			—
Interest income		—			—			—			—	(a)
Securities lending income, net		1,292			—			—	(a)		—	(a)
Dividends from affiliated investment company shares		—			3,776			—			—
		5,589			3,776			55			44
Foreign taxes withheld		(47	)		—			(3	)		(5	)
Total Investment Income		5,542			3,776			52			39
Expenses:
Management fee		5,314			154			31			12
Administration fee		249			60			1			—	(a)
12b-1 Service and Distribution fees:
Class A		428			153			1			—	(a)
Class B		81			31			—			—
Class C		331			330			1			—	(a)
Class R		—			—			—			—
Transfer agent fees:
Class A		193			58			1			—	(a)
Class B		22			7			—			—
Class C		35			30			—	(a)		—	(a)
Class R		—			—			—			—
Class R5		—			—			—			—
Class Z		264			31			1			—	(a)
Custody fees		—			3			30			2
Trustees' fees		44			7			—	(a)		—	(a)
Registration and blue sky fees		52			65			56			57
Reports to shareholders		226			65			14			14
Audit fees		20			10			27			23
Legal fees		66			9			—	(a)		—	(a)
Interest expense (See Note 5)		1			—			—			—
Chief compliance officer expenses (See Note 4)		18			4			—	(a)		—	(a)
Organizational expenses (See Note 4)		—			—			23			21
Other expenses		162			10			2			3
Total Expenses		7,506			1,027			188			132
Less reimbursement of expenses by Investment Advisor (See Note 4)		—			(127	)		(149	)		(118	)
Net Expenses		7,506			900			39			14
Net Investment Income/(Loss)		(1,964	)		2,876			13			25
Net Realized and Unrealized Gain/(Loss) on Portfolio Positions:
Net Realized Gain/(Loss) on:
Unaffiliated investments		73,373			—			(19	)		(8	)
Affiliated investments (See Note 4)		(12,823	)		(2,082	)		—			—
Foreign currency translations		(8	)		—			(1	)		(1	)
Forward foreign currency exchange contracts		—			—			—			—
Distributions from affiliated investment company shares		—			1,621			—			—
Net realized gain/(loss)		60,542			(461	)		(20	)		(9	)
Net change in net unrealized appreciation/(depreciation) on:
Unaffiliated investments		34,747			—			220			169
Affiliated investments (See Note 4)		19,182			10,983			—			—
Foreign currency translations		3			—			—	(a)		—	(a)
Forward foreign currency exchange contracts		—			—			—			—
Foreign capital gains tax		—			—			(3	)		—
Net change in unrealized appreciation/(depreciation)		53,932			10,983			217			169
Net realized and unrealized gain		114,474			10,522			197			160
Net Increase in Net Assets resulting from Operations	$	112,510		$	13,398		$	210		$	185

See accompanying notes to financial statements.

89

Columbia Acorn Family of Funds

Statements of Changes in Net Assets

	Columbia Acorn Fund						Columbia Acorn International						Columbia Acorn USA						Columbia Acorn International Select
Increase (Decrease) in Net Assets	(Unaudited) Six months ended June 30,			Year ended December 31,			(Unaudited) Six months ended June 30,			Year ended December 31,			(Unaudited) Six months ended June 30,			Year ended December 31,			(Unaudited) Six months ended June 30,			Year ended December 31,
(in thousands)	2012			2011			2012			2011 (a)			2012			2011			2012			2011
Operations:
Net investment income/(loss)	$	3,994		$	(26,858	)	$	51,145		$	70,394		$	(3,236	)	$	(9,383	)	$	2,778		$	3,857
Net realized gain/(loss) on investments, foreign currency transactions, forward foreign currency exchange contracts and foreign capital gains tax		669,345			756,714			122,870			226,124			106,876			41,208			14,706			45,952
Net realized gain/(loss) on affiliated investments and distributions from affiliated investment companies and affiliated investment company shares		560			(10,817	)		—			(3,603	)		—			(512	)		—			—
Reimbursement from affiliate (See Note 4)		—			—			—			174			—			—			—			—
Net change in net unrealized appreciation/(depreciation) on investments, foreign currency translations, forward foreign currency exchange contracts and foreign capital gains tax		667,826			(1,530,794	)		311,331			(1,230,965	)		52,933			(112,790	)		15,629			(89,001	)
Net change in net unrealized appreciation/(depreciation) on affiliated investment companies and affiliated investment company shares		169,764			(43,544	)		(10,385	)		22,440			231			876			—			—
Net Increase/(Decrease) from Operations		1,511,489			(855,299	)		474,961			(915,436	)		156,804			(80,601	)		33,113			(39,192	)
Distributions to Shareholders From:
Net investment income – Class A		—			(2,049	)		(1,509	)		(21,972	)		—			—			—			(1,392	)
Net realized gain – Class A		(41,199	)		(144,445	)		—			—			(285	)		(1,096	)		(256	)		(901	)
Net investment income – Class B		—			—			—			(600	)		—			—			—			(23	)
Net realized gain – Class B		(649	)		(4,964	)		—			—			(3	)		(21	)		(7	)		(31	)
Net investment income – Class C		—			—			—			(2,369	)		—			—			—			(70	)
Net realized gain – Class C		(10,281	)		(35,291	)		—			—			(62	)		(217	)		(40	)		(150	)
Net investment income – Class I		—			(34	)		(385	)		(676	)		—			—			—			—	(c)
Net realized gain – Class I		(431	)		(670	)		—			—			(1	)		(16	)		—	(c)		—	(c)
Net investment income – Class R5		—			—			(13	)		—			—			—			—			—
Net investment income – Class Z		—			(36,823	)		(25,320	)		(131,455	)		—			—			—			(9,039	)
Net realized gain – Class Z		(154,079	)		(521,915	)		—			—			(2,401	)		(8,481	)		(1,201	)		(4,186	)
Total Distributions to Shareholders		(206,639	)		(746,191	)		(27,227	)		(157,072	)		(2,752	)		(9,831	)		(1,504	)		(15,792	)
Share Transactions:
Subscriptions – Class A		281,631			881,347			99,830			302,659			11,204			41,839			7,107			18,154
Distributions reinvested – Class A		38,957			134,125			1,446			18,983			262			993			248			2,039
Net assets of shares issued in connection with Merger – Class A		—			—			—			204,930			—			—			—			—
Redemptions – Class A		(528,484	)		(1,072,697	)		(170,050	)		(251,677	)		(37,979	)		(80,479	)		(11,843	)		(26,422	)
Net Increase/(Decrease) – Class A		(207,896	)		(57,225	)		(68,774	)		274,895			(26,513	)		(37,647	)		(4,488	)		(6,229	)
Distributions reinvested – Class B (d)		639			4,777			—	(c)		558			3			27			8			51
Net assets of shares issued in connection with Merger – Class B		—			—			—			12,517			—			—			—			—
Redemptions – Class B		(27,729	)		(215,636	)		(5,444	)		(13,183	)		(847	)		(6,779	)		(579	)		(1,017	)
Net Decrease – Class B		(27,090	)		(210,859	)		(5,444	)		(108	)		(844	)		(6,752	)		(571	)		(966	)
Subscriptions – Class C		40,316			101,181			4,825			19,819			896			2,255			363			966
Distributions reinvested – Class C		8,259			27,313			—			1,845			56			193			36			188
Net assets of shares issued in connection with Merger – Class C		—			—			—			25,563			—			—			—			—
Redemptions – Class C		(72,750	)		(154,450	)		(17,087	)		(42,187	)		(2,816	)		(5,937	)		(1,317	)		(2,975	)
Net Increase/(Decrease) – Class C		(24,175	)		(25,956	)		(12,262	)		5,040			(1,864	)		(3,489	)		(918	)		(1,821	)
Subscriptions – Class I		27,185			17,610			37,921			27,930			2,148			11,070			—			—
Distributions reinvested – Class I		431			704			385			676			1			16			—			—
Net assets of shares issued in connection with Merger – Class I		—			—			—			152,987			—			—			—			—
Redemptions – Class I		(12,325	)		(13,595	)		(30,100	)		(184,760	)		(4,296	)		(38,709	)		—			—
Net Increase/(Decrease) – Class I		15,291			4,719			8,206			(3,167	)		(2,147	)		(27,623	)		—			—

(a)  Class R and Class R5 shares reflect activity for the period August 15, 2011 (commencement of operations) through December 31, 2011.

(b)  For the period from August 19, 2011 (commencement of operations) to December 31, 2011.

(c)  Rounds to less than $500.

(d)  Presentation for fiscal year 2011 has been changed to conform to that of the current year.

See accompanying notes to financial statements.

90

	Columbia Acorn Select						Columbia Thermostat Fund						Columbia Acorn Emerging Markets Fund						Columbia Acorn European Fund
Increase (Decrease) in Net Assets	(Unaudited) Six months ended June 30,			Year ended December 31,			(Unaudited) Six months ended June 30,			Year ended December 31,			(Unaudited) Six months ended June 30,			Year ended December 31,			(Unaudited) Six months ended June 30,			Year ended December 31,
(in thousands)	2012			2011			2012			2011			2012			2011 (b)			2012			2011 (b)
Operations:
Net investment income/(loss)	$	(1,964	)	$	(7,972	)	$	2,876		$	2,784		$	13		$	1		$	25		$	(3	)
Net realized gain/(loss) on investments, foreign currency transactions, forward foreign currency exchange contracts and foreign capital gains tax		73,365			209,796			—			—			(20	)		(57	)		(9	)		6
Net realized gain/(loss) on affiliated investments and distributions from affiliated investment companies and affiliated investment company shares		(12,823	)		(66,391	)		(461	)		8,878			—			—			—			—
Reimbursement from affiliate (See Note 4)		—			—			—			—			—			—			—			—
Net change in net unrealized appreciation/(depreciation) on investments, foreign currency translations, forward foreign currency exchange contracts and foreign capital gains tax		34,750			(347,748	)		—			—			217			(135	)		169			(86	)
Net change in net unrealized appreciation/(depreciation) on affiliated investment companies and affiliated investment company shares		19,182			(112,603	)		10,983			(4,866	)		—			—			—			—
Net Increase/(Decrease) from Operations		112,510			(324,918	)		13,398			6,796			210			(191	)		185			(83	)
Distributions to Shareholders From:
Net investment income – Class A		—			(7,162	)		(201	)		(1,706	)		—			—			—	(c)		(1	)
Net realized gain – Class A		(6,620	)		—			—			—			—			—			—	(c)		—	(c)
Net investment income – Class B		—			(500	)		(8	)		(351	)		—			—			—			—
Net realized gain – Class B		(386	)		—			—			—			—			—			—			—
Net investment income – Class C		—			(672	)		(125	)		(405	)		—			—			—	(c)		—	(c)
Net realized gain – Class C		(1,438	)		—			—			—			—			—			—	(c)		—	(c)
Net investment income – Class I		—			(141	)		—			—			—	(c)		—			—	(c)		—	(c)
Net realized gain – Class I		(494	)		—			—			—			—			—			—	(c)		—	(c)
Net investment income – Class R5		—			—			—			—			—			—			—			—
Net investment income – Class Z		—			(22,715	)		(182	)		(1,460	)		(2	)		—			(2	)		(11	)
Net realized gain – Class Z		(14,894	)		—			—			—			—			—			(1	)		(3	)
Total Distributions to Shareholders		(23,832	)		(31,190	)		(516	)		(3,922	)		(2	)		—			(3	)		(15	)
Share Transactions:
Subscriptions – Class A		27,104			72,441			102,772			44,385			1,051			351			63			164
Distributions reinvested – Class A		6,159			6,307			180			1,391			—			—			—	(c)		1
Net assets of shares issued in connection with Merger – Class A		—			—			—			—			—			—			—			—
Redemptions – Class A		(91,503	)		(203,499	)		(17,032	)		(11,539	)		(86	)		(13	)		(29	)		—
Net Increase/(Decrease) – Class A		(58,240	)		(124,751	)		85,920			34,237			965			338			34			165
Distributions reinvested – Class B (d)		325			464			18			381			—			—			—			—
Net assets of shares issued in connection with Merger – Class B		—			—			—			—			—			—			—			—
Redemptions – Class B		(13,176	)		(37,412	)		(6,155	)		(18,369	)		—			—			—			—
Net Decrease – Class B		(12,851	)		(36,948	)		(6,137	)		(17,988	)		—			—			—			—
Subscriptions – Class C		1,768			3,603			79,175			15,268			79			138			13			5
Distributions reinvested – Class C		1,143			494			89			313			—			—			—	(c)		—	(c)
Net assets of shares issued in connection with Merger – Class C		—			—			—			—			—			—			—			—
Redemptions – Class C		(8,647	)		(23,948	)		(2,845	)		(4,725	)		—			(10	)		—			—
Net Increase/(Decrease) – Class C		(5,736	)		(19,851	)		76,419			10,856			79			128			13			5
Subscriptions – Class I		18,526			12,447			—			—			—			5			—			5
Distributions reinvested – Class I		494			141			—			—			—	(c)		—			—	(c)		—	(c)
Net assets of shares issued in connection with Merger – Class I		—			—			—			—			—			—			—			—
Redemptions – Class I		(8,175	)		(8,782	)		—			—			—			—			—			—
Net Increase/(Decrease) – Class I		10,845			3,806			—			—			—	(c)		5			—	(c)		5

See accompanying notes to financial statements.

91

Columbia Acorn Family of Funds

Statements of Changes in Net Assets, continued

	Columbia Acorn Fund						Columbia Acorn International						Columbia Acorn USA						Columbia Acorn International Select
Increase (Decrease) in Net Assets	(Unaudited) Six months ended June 30,			Year ended December 31,			(Unaudited) Six months ended June 30,			Year ended December 31,			(Unaudited) Six months ended June 30,			Year ended December 31,			(Unaudited) Six months ended June 30,			Year ended December 31,
(in thousands)	2012			2011			2012			2011 (a)			2012			2011			2012			2011
Subscriptions – Class R		—			—			356			370			—			—			—			—
Net assets of shares issued in connection with Merger – Class R		—			—			—			2,027			—			—			—			—
Redemptions – Class R		—			—			(1,617	)		(77	)		—			—			—			—
Net Increase/(Decrease) – Class R		—			—			(1,261	)		2,320			—			—			—			—
Subscriptions – Class R5		—			—			—	(c)		3			—			—			—			—
Distributions reinvested – Class R5		—			—			2			—			—			—			—			—
Net assets of shares issued in connection with Merger – Class R5		—			—			—			2,232			—			—			—			—
Redemptions – Class R5		—			—			(27	)		—	(c)		—			—			—			—
Net Increase/(Decrease) – Class R5		—			—			(25	)		2,235			—			—			—			—
Subscriptions – Class Z		958,888			2,172,346			681,137			965,616			109,255			349,841			19,696			45,936
Distributions reinvested – Class Z		133,961			471,639			19,181			91,324			2,158			7,534			524			5,069
Redemptions – Class Z		(1,325,932	)		(2,515,311	)		(458,986	)		(973,865	)		(204,681	)		(331,533	)		(34,101	)		(113,289	)
Net Increase/(Decrease) – Class Z		(233,083	)		128,674			241,332			83,075			(93,268	)		25,842			(13,881	)		(62,284	)
Net Increase/(Decrease) from Share Transactions		(476,953	)		(160,647	)		161,772			364,290			(124,636	)		(49,669	)		(19,858	)		(71,300	)
Increase from regulatory settlements (See Note 7)		—			—			108			108			—			—			—			—
Increase from contribution from affiliate (See Note 4)		—			—			—			—			—			—			—			—
Total Increase/(Decrease) in Net Assets		827,897			(1,762,137	)		609,614			(708,110	)		29,416			(140,101	)		11,751			(126,284	)
Net Assets:
Beginning of period		16,336,575			18,098,712			5,416,953			6,125,063			1,558,445			1,698,546			326,383			452,667
End of period	$	17,164,472		$	16,336,575		$	6,026,567		$	5,416,953		$	1,587,861		$	1,558,445		$	338,134		$	326,383
Undistributed (Overdistributed) Net Investment Income	$	(28,080	)	$	(32,074	)	$	(36,596	)	$	(60,514	)	$	(3,403	)	$	(167	)	$	(2,516	)	$	(5,294	)

(a)  Class R and Class R5 shares reflect activity for the period August 15, 2011 (commencement of operations) through December 31, 2011.

(b)  For the period from August 19, 2011 (commencement of operations) to December 31, 2011.

(c)  Rounds to less than $500.

See accompanying notes to financial statements.

92

	Columbia Acorn Select						Columbia Thermostat Fund						Columbia Acorn Emerging Markets Fund						Columbia Acorn European Fund
Increase (Decrease) in Net Assets	(Unaudited) Six months ended June 30,			Year ended December 31,			(Unaudited) Six months ended June 30,			Year ended December 31,			(Unaudited) Six months ended June 30,			Year ended December 31,			(Unaudited) Six months ended June 30,			Year ended December 31,
(in thousands)	2012			2011			2012			2011			2012			2011 (b)			2012			2011 (b)
Subscriptions – Class R		—			—			—			—			—			—			—			—
Net assets of shares issued in connection with Merger – Class R		—			—			—			—			—			—			—			—
Redemptions – Class R		—			—			—			—			—			—			—			—
Net Increase/(Decrease) – Class R		—			—			—			—			—			—			—			—
Subscriptions – Class R5		—			—			—			—			—			—			—			—
Distributions reinvested – Class R5		—			—			—			—			—			—			—			—
Net assets of shares issued in connection with Merger – Class R5		—			—			—			—			—			—			—			—
Redemptions – Class R5		—			—			—			—			—			—			—			—
Net Increase/(Decrease) – Class R5		—			—			—			—			—			—			—			—
Subscriptions – Class Z		57,480			177,362			120,997			42,102			1,290			2,949			195			1,589
Distributions reinvested – Class Z		11,596			17,488			116			1,165			2			—			3			13
Redemptions – Class Z		(283,273	)		(653,289	)		(39,753	)		(14,914	)		(1	)		—	(c)		—	(c)		—	(c)
Net Increase/(Decrease) – Class Z		(214,197	)		(458,439	)		81,360			28,353			1,291			2,949			198			1,602
Net Increase/(Decrease) from Share Transactions		(280,179	)		(636,183	)		237,562			55,458			2,335			3,420			245			1,777
Increase from regulatory settlements (See Note 7)		—			—			—			—			—			—			—			—
Increase from contribution from affiliate (See Note 4)		—			57			—			—			—			—			—			—
Total Increase/(Decrease) in Net Assets		(191,501	)		(992,234	)		250,444			58,332			2,543			3,229			427			1,679
Net Assets:
Beginning of period		1,290,621			2,282,855			189,607			131,275			3,229			—			1,679			—
End of period	$	1,099,120		$	1,290,621		$	440,051		$	189,607		$	5,772		$	3,229		$	2,106		$	1,679
Undistributed (Overdistributed) Net Investment Income	$	(2,288	)	$	(324	)	$	2,831		$	471		$	10		$	(1	)	$	23		$	—	(c)

See accompanying notes to financial statements.

93

Columbia Acorn Family of Funds

Statements of Changes in Net Assets, continued

	Columbia Acorn Fund						Columbia Acorn International						Columbia Acorn USA						Columbia Acorn International Select
Changes in Shares of Beneficial Interest:	(Unaudited) Six months ended June 30,			Year ended December 31,			(Unaudited) Six months ended June 30,			Year ended December 31,			(Unaudited) Six months ended June 30,			Year ended December 31,			(Unaudited) Six months ended June 30,			Year ended December 31,
(in thousands)	2012			2011			2012			2011 (a)			2012			2011			2012			2011
Subscriptions – Class A		9,628			30,309			2,671			7,713			391			1,507			274			666
Shares issued in reinvestment and capital gains – Class A		1,388			4,849			40			463			9			38			9			78
Shares issued in connection with merger – Class A		—			—			—			5,467			—			—			—			—
Less shares redeemed – Class A		(18,258	)		(37,725	)		(4,553	)		(6,592	)		(1,318	)		(2,879	)		(454	)		(980	)
Net Increase/(Decrease) – Class A		(7,242	)		(2,567	)		(1,842	)		7,051			(918	)		(1,334	)		(171	)		(236	)
Shares issued in reinvestment and capital gains – Class B (d)		25			185			—			14			—	(c)		1			—	(c)		2
Shares issued in connection with merger – Class B		—			—			—			343			—			—			—			—
Less shares redeemed – Class B		(1,030	)		(8,046	)		(151	)		(353	)		(32	)		(267	)		(23	)		(39	)
Net Increase/(Decrease) – Class B		(1,005	)		(7,861	)		(151	)		4			(32	)		(266	)		(23	)		(37	)
Subscriptions – Class C		1,516			3,779			134			519			34			90			14			36
Shares issued in reinvestment and capital gains – Class C		325			1,086			—			46			2			8			1			8
Shares issued in connection with merger – Class C		—			—			—			703			—			—			—			—
Less shares redeemed – Class C		(2,746	)		(5,913	)		(484	)		(1,110	)		(107	)		(231	)		(52	)		(115	)
Net Increase/(Decrease) – Class C		(905	)		(1,048	)		(350	)		158			(71	)		(133	)		(37	)		(71	)
Subscriptions – Class I		901			639			1,013			764			70			371			—			—
Shares issued in reinvestment and capital gains – Class I		15			25			11			17			—	(c)		1			—			—
Shares issued in connection with merger – Class I		—			—			—			4,062			—			—			—			—
Less shares redeemed – Class I		(413	)		(454	)		(797	)		(5,004	)		(147	)		(1,289	)		—			—
Net Increase/(Decrease) – Class I		503			210			227			(161	)		(77	)		(917	)		—			—
Subscriptions – Class R		—			—			10			10			—			—			—			—
Shares issued in connection with merger – Class R		—			—			—			54			—			—			—			—
Less shares redeemed – Class R		—			—			(46	)		(2	)		—			—			—			—
Net Increase/(Decrease) – Class R		—			—			(36	)		62			—			—			—			—
Subscriptions – Class R5		—			—			—	(c)		—	(c)		—			—			—			—
Shares issued in reinvestment and capital gains – Class R5		—			—			—	(c)		—			—			—			—			—
Shares issued in connection with merger – Class R5		—			—			—			59			—			—			—			—
Less shares redeemed – Class R5		—			—			—	(c)		—			—			—			—			—
Net Increase – Class R5		—			—			—	(c)		59			—			—			—			—
Subscriptions – Class Z		31,901			72,817			18,269			24,482			3,627			12,164			743			1,655
Shares issued in reinvestment and capital gains – Class Z		4,605			16,442			535			2,222			75			274			20			192
Less shares redeemed – Class Z		(43,613	)		(85,040	)		(12,206	)		(25,537	)		(6,966	)		(11,564	)		(1,298	)		(4,157	)
Net Increase/(Decrease) – Class Z		(7,107	)		4,219			6,598			1,167			(3,264	)		874			(535	)		(2,310	)
Net Increase/(Decrease) in Shares of Beneficial Interest		(15,756	)		(7,047	)		4,446			8,340			(4,362	)		(1,776	)		(766	)		(2,654	)

(a)  Class R and Class R5 shares reflect activity for the period August 15, 2011 (commencement of operations) through December 31, 2011.

(b)  For the period from August 19, 2011 (commencement of operations) to December 31, 2011.

(c)  Rounds to less than 500 shares.

(d)  Presentation for fiscal year 2011 has been changed to conform to that of the current year.

See accompanying notes to financial statements.

94

	Columbia Acorn Select						Columbia Thermostat Fund						Columbia Acorn Emerging Markets Fund						Columbia Acorn European Fund
Changes in Shares of Beneficial Interest:	(Unaudited) Six months ended June 30,			Year ended December 31,			(Unaudited) Six months ended June 30,			Year ended December 31,			(Unaudited) Six months ended June 30,			Year ended December 31,			(Unaudited) Six months ended June 30,			Year ended December 31,
(in thousands)	2012			2011			2012			2011			2012			2011 (b)			2012			2011 (b)
Subscriptions – Class A		1,056			2,804			7,563			3,467			97			37			6			16
Shares issued in reinvestment and capital gains – Class A		256			242			13			109			—			—			—	(c)		—	(c)
Shares issued in connection with merger – Class A		—			—			—			—			—			—			—			—
Less shares redeemed – Class A		(3,581	)		(8,092	)		(1,260	)		(898	)		(8	)		(1	)		(3	)		—
Net Increase/(Decrease) – Class A		(2,269	)		(5,046	)		6,316			2,678			89			36			3			16
Shares issued in reinvestment and capital gains – Class B (d)		14			19			1			30			—			—			—			—
Shares issued in connection with merger – Class B		—			—			—			—			—			—			—			—
Less shares redeemed – Class B		(551	)		(1,569	)		(453	)		(1,427	)		—			—			—			—
Net Increase/(Decrease) – Class B		(537	)		(1,550	)		(452	)		(1,397	)		—			—			—			—
Subscriptions – Class C		75			145			5,788			1,196			7			15			1			1
Shares issued in reinvestment and capital gains – Class C		52			21			7			24			—			—			—	(c)		—	(c)
Shares issued in connection with merger – Class C		—			—			—			—			—			—			—			—
Less shares redeemed – Class C		(365	)		(1,011	)		(210	)		(368	)		—			(1	)		—			—
Net Increase/(Decrease) – Class C		(238	)		(845	)		5,585			852			7			14			1			1
Subscriptions – Class I		708			520			—			—			—			1			—			1
Shares issued in reinvestment and capital gains – Class I		20			5			—			—			—			—			—	(c)		—	(c)
Shares issued in connection with merger – Class I		—			—			—			—			—			—			—			—
Less shares redeemed – Class I		(319	)		(335	)		—			—			—			—			—			—
Net Increase/(Decrease) – Class I		409			190			—			—			—			1			—	(c)		1
Subscriptions – Class R		—			—			—			—			—			—			—			—
Shares issued in connection with merger – Class R		—			—			—			—			—			—			—			—
Less shares redeemed – Class R		—			—			—			—			—			—			—			—
Net Increase/(Decrease) – Class R		—			—			—			—			—			—			—			—
Subscriptions – Class R5		—			—			—			—			—			—			—			—
Shares issued in reinvestment and capital gains – Class R5		—			—			—			—			—			—			—			—
Shares issued in connection with merger – Class R5		—			—			—			—			—			—			—			—
Less shares redeemed – Class R5		—			—			—			—			—			—			—			—
Net Increase – Class R5		—			—			—			—			—			—			—			—
Subscriptions – Class Z		2,182			6,576			8,991			3,338			122			298			17			159
Shares issued in reinvestment and capital gains – Class Z		467			654			9			92			—	(c)		—			—	(c)		2
Less shares redeemed – Class Z		(10,647	)		(25,141	)		(2,944	)		(1,192	)		—	(c)		—	(c)		—	(c)		—	(c)
Net Increase/(Decrease) – Class Z		(7,998	)		(17,911	)		6,056			2,238			122			298			17			161
Net Increase/(Decrease) in Shares of Beneficial Interest		(10,633	)		(25,162	)		17,505			4,371			218			349			21			179

See accompanying notes to financial statements.

95

Columbia Acorn Family of Funds

Financial Highlights

Columbia Acorn Fund

Class Z Shares	(Unaudited) Six months ended June 30,			Year ended December 31,
Selected data for a share outstanding throughout each period	2012			2011			2010			2009			2008			2007
Net Asset Value, Beginning of Period	$	27.56		$	30.19		$	24.68		$	17.71		$	29.61		$	29.71
Income from Investment Operations
Net investment income/(loss) (a)		0.02			(0.01	)		0.02			0.04			0.06			0.15	(b)
Net realized and unrealized gain/(loss)		2.52			(1.34	)		6.37			6.98			(11.29	)		2.17
Total from Investment Operations		2.54			(1.35	)		6.39			7.02			(11.23	)		2.32
Less Distributions to Shareholders
From net investment income		—			(0.09	)		(0.04	)		(0.05	)		(0.01	)		(0.12	)
From net realized gains		(0.36	)		(1.19	)		(0.84	)		—			(0.66	)		(2.30	)
Total Distributions to Shareholders		(0.36	)		(1.28	)		(0.88	)		(0.05	)		(0.67	)		(2.42	)
Increase from regulatory settlements		—			—			0.00	(c)		0.00	(c)		—			—
Net Asset Value, End of Period	$	29.74		$	27.56		$	30.19		$	24.68		$	17.71		$	29.61
Total Return (d)		9.23	%(e)		(4.61	)%		26.00	%		39.65	%		(38.55	)%		7.69	%(f)(g)
Ratios to Average Net Assets/Supplemental Data
Net expenses		0.76	%(h)		0.76	%(i)		0.76	%(i)		0.77	%(i)		0.76	%(i)		0.74	%(i)
Net investment income/(loss)		0.15	%(h)		(0.03	)%(i)		0.09	%(i)		0.18	%(i)		0.26	%(i)		0.46	%(i)
Waiver/Reimbursement		—			—			—			—			—			0.00	%(j)
Portfolio turnover rate		8	%(e)		18	%		28	%		27	%		21	%		20	%
Net assets at end of period (in millions)	$	13,047		$	12,285		$	13,330		$	10,527		$	7,446		$	13,038

(a)  Per share data was calculated using the average shares outstanding during the period.

(b)  Net investment income per share includes special dividends. The effect of these dividends amounted to $0.03 per share.

(c)  Rounds to less than $0.01 per share.

(d)  Total return at net asset value assuming all distributions reinvested.

(e)  Not annualized.

(f)  Had the Investment Manager and/or Transfer Agent not waived fees and/or reimbursed a portion of expenses, total return would have been reduced.

(g)  Total return includes a voluntary reimbursement by the Investment Manager for a realized investment loss due to a trading error. This reimbursement increased total return and net asset value per share by less than 0.01% and less than $0.01, respectively.

(h)  Annualized.

(i)  The benefits derived from custody fees paid indirectly had an impact of less than 0.01%.

(j)  Rounds to less than 0.01%.

See accompanying notes to financial statements.

Columbia Acorn International

Class Z Shares	(Unaudited) Six months ended June 30,			Year ended December 31,
Selected data for a share outstanding throughout each period	2012			2011			2010			2009			2008			2007
Net Asset Value, Beginning of Period	$	34.31		$	40.92		$	34.26		$	23.13		$	43.60		$	40.31
Income from Investment Operations
Net investment income (a)		0.34			0.48			0.35			0.34			0.60			0.43
Net realized and unrealized gain/(loss)		2.65			(6.07	)		7.23			11.31			(20.26	)		6.56
Reimbursement from affiliate		—			0.00	(b)		—			—			—			—
Total from Investment Operations		2.99			(5.59	)		7.58			11.65			(19.66	)		6.99
Less Distributions to Shareholders
From net investment income		(0.20	)		(1.02	)		(0.92	)		(0.53	)		(0.21	)		(0.34	)
From net realized gains		—			—			—			—			(0.60	)		(3.36	)
Total Distributions to Shareholders		(0.20	)		(1.02	)		(0.92	)		(0.53	)		(0.81	)		(3.70	)
Redemption fees added to paid in capital (a)		—			—			0.00	(b)		0.00	(b)		0.00	(b)		0.00	(b)
Increase from regulatory settlements		0.00	(b)		0.00	(b)		0.00	(b)		0.01			—			—
Net Asset Value, End of Period	$	37.10		$	34.31		$	40.92		$	34.26		$	23.13		$	43.60
Total Return (c)		8.72	%(d)		(14.06	)%(e)		22.70	%		50.97	%		(45.89	)%		17.28	%(f)
Ratios to Average Net Assets/Supplemental Data
Net expenses		0.91	%(g)		0.95	%(h)		0.97	%(h)		0.99	%(h)		0.96	%(h)		0.91	%(h)
Net investment income		1.80	%(g)		1.24	%(h)		0.99	%(h)		1.23	%(h)		1.72	%(h)		0.96	%(h)
Waiver/Reimbursement		—			—			—			—			—			0.00	%(i)
Portfolio turnover rate		18	%(d)		32	%		25	%		31	%		38	%		28	%
Net assets at end of period (in millions)	$	4,920		$	4,323		$	5,108		$	3,728		$	2,372		$	4,918

(a)  Per share data was calculated using the average shares outstanding during the period.

(b)  Rounds to less than $0.01 per share.

(c)  Total return at net asset value assuming all distributions reinvested.

(d)  Not annualized.

(e)  During the year ended December 31, 2011, Columbia Management reimbursed the Fund for a loss on a trading error. Had the Fund not received this reimbursement total return would have been lower by less than 0.01%.

(f)  Had the Investment Manager and/or Transfer Agent not waived fees and/or reimbursed a portion of expenses, total return would have been reduced.

(g)  Annualized.

(h)  The benefits derived from custody fees paid indirectly had an impact of less than 0.01%.

(i)  Rounds to less than 0.01%.

96

Columbia Acorn USA

Class Z Shares	(Unaudited) Six months ended June 30,			Year ended December 31,
Selected data for a share outstanding throughout each period	2012			2011			2010			2009			2008			2007
Net Asset Value, Beginning of Period	$	26.98		$	28.56		$	23.19		$	16.39		$	27.97		$	28.66
Income from Investment Operations
Net investment loss (a)		(0.05	)		(0.14	)		(0.08	)		(0.07	)		(0.07	)		(0.01	)(b)
Net realized and unrealized gain/(loss)		2.84			(1.27	)		5.45			6.87			(10.55	)		1.03
Total from Investment Operations		2.79			(1.41	)		5.37			6.80			(10.62	)		1.02
Less Distributions to Shareholders
From net realized gains		(0.05	)		(0.17	)		—			—			(0.96	)		(1.71	)
Total Distributions to Shareholders		(0.05	)		(0.17	)		—			—			(0.96	)		(1.71	)
Increase from regulatory settlements		—			—			—			0.00	(c)		—			—
Net Asset Value, End of Period	$	29.72		$	26.98		$	28.56		$	23.19		$	16.39		$	27.97
Total Return (d)		10.35	%(e)		(4.95	)%		23.16	%		41.49	%		(39.22	)%		3.46	%(f)(g)
Ratios to Average Net Assets/Supplemental Data
Net expenses		1.04	%(h)		1.00	%(i)		1.01	%(i)		1.03	%(i)		1.01	%(i)		0.98	%(i)
Net investment loss		(0.34	)%(h)		(0.48	)%(i)		(0.34	)%(i)		(0.36	)%(i)		(0.32	)%(i)		(0.03	)%(i)
Waiver/Reimbursement		—			—			—			—			—			0.00	%(j)
Portfolio turnover rate		8	%(e)		20	%		32	%		28	%		23	%		21	%
Net assets at end of period (in millions)	$	1,396		$	1,356		$	1,410		$	1,158		$	758		$	1,214

(a)  Per share data was calculated using the average shares outstanding during the period.

(b)  Net investment income per share includes special dividends. The effect of these dividends amounted to $0.09 per share.

(c)  Rounds to less than $0.01 per share.

(d)  Total return at net asset value assuming all distributions reinvested and no initial sales charge or contingent deferred sales charge.

(e)  Not annualized.

(f)  Had the Investment Manager and/or Transfer Agent not waived fees and/or reimbursed a portion of expenses, total return would have been reduced.

(g)  Total return includes a voluntary reimbursement by the Investment Manager for a realized investment loss due to a trading error. This reimbursement increased total return and net asset value per share by less than 0.01% and less than $0.01, respectively.

(h)  Annualized.

(i)  The benefits derived from custody fees paid indirectly had an impact of less than 0.01%.

(j)  Rounds to less than 0.01%.

Columbia Acorn International Select

Class Z Shares	(Unaudited) Six months ended June 30,			Year ended December 31,
Selected data for a share outstanding throughout each period	2012			2011			2010			2009			2008			2007
Net Asset Value, Beginning of Period	$	24.46		$	28.33		$	23.64		$	18.19		$	32.02		$	27.97
Income from Investment Operations
Net investment income (a)		0.23			0.29			0.18			0.17			0.28			0.14	(b)
Net realized and unrealized gain/(loss)		2.31			(2.98	)		4.89			5.50			(13.53	)		5.96
Total from Investment Operations		2.54			(2.69	)		5.07			5.67			(13.25	)		6.10
Less Distributions to Shareholders
From net investment income		—			(0.79	)		(0.38	)		(0.24	)		(0.04	)		(0.28	)
From net realized gains		(0.12	)		(0.39	)		—			—			(0.54	)		(1.77	)
Total Distributions to Shareholders		(0.12	)		(1.18	)		(0.38	)		(0.24	)		(0.58	)		(2.05	)
Redemption fees added to paid in capital (a)		—			—			0.00	(c)		0.00	(c)		0.00	(c)		0.00	(c)
Increase from regulatory settlements		—			—			0.00	(c)		0.02			—			—
Net Asset Value, End of Period	$	26.88		$	24.46		$	28.33		$	23.64		$	18.19		$	32.02
Total Return (d)		10.39	%(e)		(9.76	)%		21.89	%		31.52	%		(42.10	)%		21.86	%(f)
Ratios to Average Net Assets/Supplemental Data
Net expenses		1.18	%(g)		1.14	%(h)		1.16	%(h)		1.20	%(h)		1.21	%(h)		1.18	%(h)
Net investment income		1.75	%(g)		1.03	%(h)		0.75	%(h)		0.84	%(h)		1.09	%(h)		0.44	%(h)
Waiver/Reimbursement		—			—			—			—			—			0.00	%(i)
Portfolio turnover rate		29	%(e)		44	%		42	%		56	%		68	%		57	%
Net assets at end of period (in millions)	$	271		$	260		$	366		$	331		$	186		$	204

(a)  Per share data was calculated using the average shares outstanding during the period.

(b)  Net investment income per share includes special dividends. The effect of these dividends amounted to $0.07 per share.

(c)  Rounds to less than $0.01 per share.

(d)  Total return at net asset value assuming all distributions reinvested.

(e)  Not annualized.

(f)  Had the Investment Manager and/or Transfer Agent not waived fees and/or reimbursed a portion of expenses, total return would have been reduced.

(g)  Annualized.

(h)  The benefits derived from custody fees paid indirectly had an impact of less than 0.01%.

(i)  Rounds to less than 0.01%.

See accompanying notes to financial statements.

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Columbia Acorn Family of Funds

Financial Highlights, continued

Columbia Acorn Select

Class Z Shares	(Unaudited) Six months ended June 30,			Year ended December 31,
Selected data for a share outstanding throughout each period	2012			2011			2010			2009			2008			2007
Net Asset Value, Beginning of Period	$	23.62		$	28.73		$	23.38		$	14.07		$	28.41		$	26.59
Income from Investment Operations
Net investment loss (a)		(0.02	)		(0.07	)		(0.10	)		(0.08	)		(0.12	)		(0.07	)
Net realized and unrealized gain/(loss)		1.85			(4.58	)		5.45			9.39			(13.53	)		2.53
Reimbursement from affiliate		—			0.00	(b)		—			—			—			—
Total from Investment Operations		1.83			(4.65	)		5.35			9.31			(13.65	)		2.46
Less Distributions to Shareholders
From net investment income		—			(0.46	)		—			—			—			—
From net realized gains		(0.53	)		—			—			—			(0.69	)		(0.64	)
Total Distributions to Shareholders		(0.53	)		(0.46	)		—			—			(0.69	)		(0.64	)
Net Asset Value, End of Period	$	24.92		$	23.62		$	28.73		$	23.38		$	14.07		$	28.41
Total Return (c)		7.76	%(d)		(16.37	)%(e)		22.88	%		66.17	%		(49.18	)%(f)		9.20	%(g)
Ratios to Average Net Assets/Supplemental Data
Net expenses before interest expense		1.02	%(h)		0.97	%(i)		0.97	%(i)		0.99	%(i)		0.95	%(i)		0.91	%(i)
Interest expense		0.00	%(h)(j)		—			—			—			—			—
Net expenses		1.02	%(h)		0.97	%(i)		0.97	%(i)		0.99	%(i)		0.95	%(i)		0.91	%(i)
Net investment loss		(0.16	)%(h)		(0.28	)%(i)		(0.41	)%(i)		(0.47	)%(i)		(0.51	)%(i)		(0.24	)%(i)
Waiver/Reimbursement		—			—			—			—			—			0.00	%(j)
Portfolio turnover rate		8	%(d)		21	%		28	%		19	%		28	%		14	%
Net assets at end of period (in millions)	$	698		$	850		$	1,549		$	1,241		$	780		$	1,571

(a)  Per share data was calculated using the average shares outstanding during the period.

(b)  Rounds to less than $0.01 per share.

(c)  Total return at net asset value assuming all distributions reinvested.

(d)  Not annualized.

(e)  During the year ended December 31, 2011, the Fund received a reimbursement by an affiliate. Had the Fund not received this payment, the total return would have been lower by 0.01%.

(f)  Total return includes a voluntary reimbursement by the Investment Manager for a realized investment loss due to a trading error. This reimbursement increased total return and net asset value per share by less than 0.01% and less than $0.01, respectively.

(g)  Had the Investment Manager and/or Transfer Agent not waived fees and/or reimbursed a portion of expenses, total return would have been reduced.

(h)  Annualized.

(i)  The benefits derived from custody fees paid indirectly had an impact of less than 0.01%.

(j)  Rounds to less than 0.01%.

Columbia Thermostat Fund

Class Z Shares	(Unaudited) Six months ended June 30,			Year ended December 31,
Selected data for a share outstanding throughout each period	2012			2011			2010			2009			2008			2007
Net Asset Value, Beginning of Period	$	12.67		$	12.44		$	10.80		$	8.19		$	12.26		$	12.57
Income from Investment Operations
Net investment income (a)		0.15			0.31			0.21			0.13			0.24			0.52
Net realized and unrealized gain/(loss)		0.71			0.29			1.66			2.51			(3.96	)		0.53
Total from Investment Operations		0.86			0.60			1.87			2.64			(3.72	)		1.05
Less Distributions to Shareholders
From net investment income		(0.02	)		(0.37	)		(0.23	)		(0.03	)		(0.28	)		(0.57	)
From net realized gains		—			—			—			—			(0.07	)		(0.79	)
Total Distributions to Shareholders		(0.02	)		(0.37	)		(0.23	)		(0.03	)		(0.35	)		(1.36	)
Net Asset Value, End of Period	$	13.51		$	12.67		$	12.44		$	10.80		$	8.19		$	12.26
Total Return (b)(c)		6.77	%(d)		4.85	%		17.58	%		32.29	%		(30.53	)%		8.49	%
Ratios to Average Net Assets/Supplemental Data
Net expenses (e)		0.25	%(f)		0.25	%(g)		0.25	%(g)		0.25	%(g)		0.25	%(g)		0.25	%(g)
Net investment income		2.20	%(f)		2.43	%(g)		1.87	%(g)		1.48	%(g)		2.23	%(g)		4.05	%(g)
Waiver/Reimbursement		0.05	%(f)		0.09	%		0.12	%		0.14	%		0.08	%		0.15	%
Portfolio turnover rate		47	%(d)		130	%		118	%		17	%		130	%		128	%
Net assets at end of period (in millions)	$	151		$	65		$	36		$	42		$	35		$	36

(a)  Per share data was calculated using the average shares outstanding during the period.

(b)  Total return at net asset value assuming all distributions reinvested and no initial sales charge or contingent deferred sales charge.

(c)  Had the Investment Manager and/or Transfer Agent not waived fees and/or reimbursed a portion of expenses, total return would have been reduced.

(d)  Not annualized.

(e)  Does not include expenses of the investment companies in which the Fund invests.

(f)  Annualized.

(g)  The benefits derived from custody fees paid indirectly had an impact of less than 0.01%.

See accompanying notes to financial statements.

98

Columbia Acorn Emerging Markets Fund

Class Z Shares	(Unaudited) Six months ended June 30,			Year ended December 31,
Selected data for a share outstanding throughout each period	2012			2011 (a)
Net Asset Value, Beginning of Period	$	9.28		$	10.00
Income from Investment Operations
Net investment income (b)		0.03			0.01
Net realized and unrealized gain/(loss)		0.88			(0.73	)
Total from Investment Operations		0.91			(0.72	)
Less Distributions to Shareholders
From net investment income		(0.00	)(c)		—
Total Distributions to Shareholders		(0.00	)(c)		—
Net Asset Value, End of Period	$	10.19		$	9.28
Total Return (d)(e)		9.85	%		(7.20	)%
Ratios to Average Net Assets/Supplemental Data
Net expenses (f)		1.44	%		1.46	%
Net investment income (f)		0.56	%		0.15	%
Waiver/Reimbursement (f)		5.91	%		18.06	%
Portfolio turnover rate (e)		15	%		9	%
Net assets at end of period (in millions)	$	4		$	3

(a)  Class Z shares commenced operations on August 19, 2011. Per share data and total return reflect activity from that date.

(b)  Per share data was calculated using the average shares outstanding during the period.

(c)  Rounds to less than $0.01 per share.

(d)  Total return at net asset value assuming all distributions reinvested and no initial sales charge or contingent deferred sales charge.

(e)  Not annualized.

(f)  Annualized.

Columbia Acorn European Fund

Class Z Shares	(Unaudited) Six months ended June 30,			Year ended December 31,
Selected data for a share outstanding throughout each period	2012			2011 (a)
Net Asset Value, Beginning of Period	$	9.44		$	10.00
Income from Investment Operations
Net investment income/(loss) (b)		0.14			(0.02	)
Net realized and unrealized gain/(loss)		0.96			(0.46	)
Total from Investment Operations		1.10			(0.48	)
Less Distributions to Shareholders
From net investment income		(0.01	)		(0.06	)
From net realized gains		(0.01	)		(0.02	)
Total Distributions to Shareholders		(0.02	)		(0.08	)
Net Asset Value, End of Period	$	10.52		$	9.44
Total Return (d)(e)		11.62	%		(4.78	)%
Ratios to Average Net Assets/Supplemental Data
Net expenses (f)		1.33	%		1.37	%
Net investment income/(loss) (f)		2.67	%		(0.52	)%
Waiver/Reimbursement (f)		12.21	%		28.89	%
Portfolio turnover rate (e)		18	%		17	%
Net assets at end of period (in millions)	$	2		$	2

(a)  Class Z shares commenced operations on August 19, 2011. Per share data and total return reflect activity from that date.

(b)  Per share data was calculated using the average shares outstanding during the period.

(c)  Rounds to less than $0.01 per share.

(d)  Total return at net asset value assuming all distributions reinvested.

(e)  Not annualized.

(f)  Annualized.

See accompanying notes to financial statements.

99

Columbia Acorn Family of Funds

Notes to Financial Statements (Unaudited)

1.  Nature of Operations

Columbia Acorn Fund, Columbia Acorn International, Columbia Acorn USA, Columbia Acorn International Select, Columbia Acorn Select, Columbia Thermostat Fund, Columbia Acorn Emerging Markets Fund and Columbia Acorn European Fund (the Funds) are each a series of Columbia Acorn Trust (the Trust). The Trust is registered under The Investment Company Act of 1940, as amended (the 1940 Act), as an open-end management investment company organized as a Massachusetts business trust. The investment objective of each Fund is to seek long-term capital appreciation.

Columbia Thermostat Fund pursues its investment objective by investing in shares of other mutual funds. As a "fund of funds" under normal circumstances, the Fund allocates at least 95% of its net assets among a selected group of affiliated stock and bond mutual funds (underlying portfolio funds) according to the current level of the Standard & Poor's (S&P) 500 Index in relation to predetermined ranges set by Columbia Wanger Asset Management, LLC (the Investment Manager). The Fund may invest up to 5% of its net assets plus any cash received that day in cash, repurchase agreements, high quality short-term paper and government securities.

Each Fund may issue an unlimited number of shares. Columbia Acorn Fund, Columbia Acorn USA, Columbia Acorn International Select and Columbia Acorn Select each currently offers Class A, Class B, Class C, Class I and Class Z shares. Columbia Acorn International currently offers Class A, Class B, Class C, Class I, Class R, Class R5 and Class Z shares. Columbia Acorn Emerging Markets Fund and Columbia Acorn European Fund each currently offers Class A, Class C, Class I and Class Z shares. Columbia Thermostat Fund currently offers Class A, Class B, Class C and Class Z shares. Effective February 29, 2008, the Funds generally no longer accept investments by new or existing investors in the Fund's Class B shares, except in connection with the reinvestment of any dividend and/or capital gain distributions in Class B shares of the Funds and exchanges by existing Class B shareholders of certain other funds within the Columbia Family of Funds.

Class A shares are sold with a front-end sales charge. Class A shares bought without an initial sales charge in accounts aggregating $1 million to $50 million at the time of purchase are subject to a 1.00% contingent deferred sales charge (CDSC) if the shares are redeemed within 18 months of purchase.

Class B shares are subject to CDSC if redeemed within six years of purchase. Class B shares will convert to Class A shares automatically eight years after purchase.

Class C shares are offered at net asset value but are subject to a CDSC on redemptions made within one year after purchase.

Class I, Class R and Class R5 shares are offered at net asset value. There are certain restrictions on who may purchase Class I, Class R and Class R5 shares.

Class Z shares are offered at net asset value. There are certain restrictions on who may purchase Class Z shares. Generally, Class Z shares of a Fund may be exchanged for shares of another fund distributed by Columbia Management Distributors, Inc. at no additional charge.

The financial highlights for the Fund's Class A, Class B, Class C, Class I, Class R and Class R5 shares are presented in a separate semiannual report.

Investment income, realized and unrealized gains and losses, and certain fund-level expenses are allocated pro rata on the basis of the relative net assets of all classes, except that each class bears certain expenses specific to that class such as distribution services, transfer agent fees, and certain other class specific expenses. Differences in class expenses may result in payment of different dividend distributions for each class. All of the Funds' share classes have equal rights with respect to voting, subject to Fund or class specific matters.

2.  Significant Accounting Policies

The preparation of financial statements in accordance with accounting principles generally accepted in the United States of America (GAAP) requires management to make certain estimates and assumptions that affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenue and expenses during the reporting period. Actual results could differ from those estimates.

>Security valuation

Securities of the Funds are valued at market value or, if a market quotation for a security is not readily available or is deemed not to be reliable because of events or circumstances that have occurred between the market quotation and the time as of which the security is to be valued, the security is valued at a fair value determined in good faith under consistently applied procedures established by the Board of Trustees. With respect to Columbia Thermostat Fund, investments in portfolio funds are valued at their net asset values as reported by the portfolio funds. A security traded on a securities exchange or in an over-the-counter market in which transaction prices are reported is valued at the last sales price at the time of valuation. A security traded principally on NASDAQ is valued at the

100

NASDAQ official closing price. Mutual Funds and Exchange Traded Funds are valued at their closing net asset value as reported to NASDAQ.

Short-term investments maturing in 60 days or less are valued at amortized cost, which approximates market value.

Forward foreign currency exchange contracts are marked-to-market based upon foreign currency exchange rates provided by a pricing service.

A security for which a market quotation is not readily available and any other assets are valued at their fair value determined in good faith under consistently applied procedures established by the Board of Trustees. The Trust has retained an independent statistical fair value pricing service that employs a systematic methodology to assist in the fair valuation process for securities principally traded in a foreign market in order to adjust for possible changes in value that may occur between the close of the foreign exchange and the time as of which the securities are to be valued. If a security is valued at fair value, that value may be different from the last quoted market price for the security. A security for which there is no reported sale on the valuation date is valued at the mean of the latest bid and ask quotations.

>Foreign currency translations

Values of investments denominated in foreign currencies are converted into U.S. dollars using the New York spot market rate of exchange at the time of valuation. Purchases and sales of investments and dividend and interest income are translated into U.S. dollars using the spot market rate of exchange prevailing on the respective dates of such transactions. The gain or loss resulting from changes in foreign exchange rates is included with net realized and unrealized gain or loss from investments, as appropriate.

>Repurchase agreements

Each Fund may engage in repurchase agreement transactions. Each Fund, through its custodian, receives delivery of underlying securities collateralizing repurchase agreements. The counterparty is required to maintain collateral that is at all times at least equal to the repurchase price including interest. In the event of default or bankruptcy by the counterparty to the agreement, realization and/or retention of the collateral may be subject to legal proceedings.

>Restricted securities

Restricted securities are securities that may only be resold upon registration under federal securities laws or in transactions exempt from registration. In some cases, the issuer of restricted securities has agreed to register such securities for resale at the issuer's expense either upon demand by the Fund or in connection with another registered offering of the securities. Many restricted securities may be resold in the secondary market in transactions exempt from registration. Such restricted securities may be determined to be liquid under criteria established by the Board of Trustees.

>Derivative instruments

Columbia Acorn International and Columbia Acorn International Select invest in certain derivative instruments as detailed below to meet their investment objectives. Derivatives are instruments whose values depend on, or are derived from, in whole or in part, the value of one or more other assets, such as securities, currencies, commodities or indices. Derivative instruments may be used to maintain cash reserves while maintaining exposure to certain other assets, to offset anticipated declines in values of investments, to facilitate trading, to reduce transaction costs and to pursue higher investment returns. The Funds may also use derivative instruments to mitigate certain investment risks, such as foreign currency exchange rate risk, interest rate risk and credit risk. Derivatives may involve various risks, including the potential inability of the counterparty to fulfill its obligation under the terms of the contract, the potential for an illiquid secondary market and the potential for market movements which may expose the Funds to gains or losses in excess of the amount shown in the Statements of Assets and Liabilities.

>Forward foreign currency exchange contracts

Forward foreign currency exchange contracts are agreements between two parties to buy and sell a currency at a set price on a future date. These contracts are intended to be used to minimize the exposure to foreign exchange rate fluctuations during the period between the trade and settlement dates of the contracts. Columbia Acorn International and Columbia International Select utilize forward foreign currency exchange contracts to hedge the currency exposure associated with some or all of the Fund's securities or to hedge out of a currency that is off benchmark.

The values of forward foreign currency exchange contracts fluctuate with changes in foreign currency exchange rates. Each Fund will record a realized gain or loss when the forward foreign currency exchange contract is closed.

The use of forward foreign currency exchange contracts does not eliminate fluctuations in the prices of the Funds' portfolio securities. The risks of forward foreign currency exchange contracts include movement in the values of the foreign currencies relative to the U.S. dollar (or other foreign

101

Columbia Acorn Family of Funds

Notes to Financial Statements (Unaudited), continued

currencies) and the possibility that counterparties will not complete their contractual obligations, which may be in excess of the amount reflected, if any, in the Statements of Assets and Liabilities.

>Effects of Derivative Transactions in the Financial Statements

The following tables are intended to provide additional information about the effect of derivatives on the financial statements of Columbia Acorn International and Columbia Acorn International Select including: the fair value of derivatives by risk category and the location of those fair values in the Statements of Assets and Liabilities; the impact of derivative transactions on the Funds' operations over the period including realized gains or losses and unrealized gains or losses. The derivative schedules following the Statements of Investments present additional information regarding derivative instruments outstanding at the end of the period, if any.

During the six months ended June 30, 2012, Columbia Acorn International entered into three forward foreign currency exchange contracts.

The effect of derivative instruments on Columbia Acorn International's Statement of Operations for the six months ended June 30, 2012 was as follows:

Amount of Realized Gain (Loss) and Change in Unrealized Appreciation (Depreciation)
on Derivatives Recognized in Income

	Risk Exposure Category	Realized Gain (Loss)		Change in Unrealized Appreciation (Depreciation)
(in thousands)
Forward foreign currency exchange contracts	Foreign Exchange Rate Risk	$	5,423	$	(4,539	)

During the six months ended June 30, 2012, Columbia Acorn International Select entered into 12 forward foreign currency exchange contracts.

The following table is a summary of the value of Columbia Acorn International Select's derivative instruments as of June 30, 2012.

Liability Derivatives

Risk Exposure Category	Statement of Assets and Liabilities Location	Fair Value
(in thousands)
Foreign exchange contracts	Unrealized depreciation on forward foreign currency exchange contracts		$(932)

The effect of derivative instruments on Columbia Acorn International Select's Statement of Operations for the six months ended June 30, 2012 was as follows:

Amount of Realized Gain (Loss) and Change in Unrealized Appreciation (Depreciation)
on Derivatives Recognized in Income

	Risk Exposure Category	Realized Gain (Loss)		Change in Unrealized Appreciation (Depreciation)
(in thousands)
Forward foreign currency exchange contracts	Foreign Exchange Rate Risk	$	210	$	16

>Security transactions and investment income

Security transactions, investment income and shareholder fund transactions are accounted for on the trade date (date the order to buy or sell is executed) and dividend income and realized gain distributions from other funds are recorded on the ex-dividend date, except that certain dividends from foreign securities are recorded as soon as the information is available to the Funds. Interest income is recorded on the accrual basis and includes amortization of discounts on debt obligations when required for federal income tax purposes. Realized gains and losses from security transactions are recorded on an identified cost basis.

Awards, if any, from class action litigation related to securities owned may be recorded as a reduction of cost of those securities. If the applicable securities are no longer owned, the proceeds are recorded as realized gains.

The Funds estimate the tax character of distributions from real estate investment trusts (REITs). Distributions received in excess of income are recorded as a reduction of the cost of the related investments. If the applicable securities are no longer owned, any distributions received in excess of income are recorded as realized gains.

>Fund share valuation

Fund shares are sold and redeemed on a daily basis at net asset value, subject to any applicable sales charge. Net asset value per share is determined daily as of the close of trading on the New York Stock Exchange (NYSE) on each day the NYSE is open for trading. Generally, income, expenses and realized and unrealized gain/(losses) of a Fund are allocated to each class proportionately on a daily basis for purposes of determining the net asset value of each class. The Rule 12b-1 distribution and service fees and transfer agent fees are charged to each specific class as expenses are incurred. Redemption fees are accounted for as an addition to paid in capital for purposes of determining the net asset value of each class.

102

>Securities lending

Each Fund, except Columbia Thermostat Fund, may lend securities up to one-third of the value of its total assets to certain approved brokers, dealers and other financial institutions to earn additional income. The Fund retains the benefits of owning the securities, including receipt of dividends or interest generated by the security. Each Fund also receives a fee for the loan. Each Fund has the ability to recall the loans at any time and could do so in order to vote proxies or to sell the loaned securities. Each loan is collateralized by cash that exceeds the value of the securities on loan. The market value of the loaned securities is determined daily at the close of business of each Fund and any additional required collateral is delivered to each Fund on the next business day. Each Fund has elected to invest the cash collateral in the Dreyfus Government Cash Management Fund, and the income earned is paid to each Fund, net of any fees remitted to Goldman Sachs Agency Lending, the lending agent, and net of any borrower rebates. The Investment Manager does not retain any fees earned by the lending program. Generally, in the event of borrower default, a Fund has the right to use the collateral to offset any losses incurred. In the event a Fund is delayed or prevented from exercising its right to dispose of the collateral, there may be a potential loss to the Fund. Some of these losses may be indemnified by the lending agent. Each Fund bears the risk of loss with respect to the investment of collateral.

The net securities lending income earned as of June 30, 2012 by each Fund is included in the Statements of Operations.

>Federal income taxes

It is each Fund's policy to comply with the provisions of the Internal Revenue Code available to regulated investment companies and, in the manner provided therein, distribute substantially all their taxable income, as well as any net realized gain on sales of investments and foreign currency transactions reportable for federal income tax purposes. Columbia Thermostat Fund distributes all of its taxable income, as well as any net realized gain on sales of portfolio fund shares and any distributions of net realized gains received by the Fund from its portfolio funds, reportable for federal income tax purposes. Accordingly, the Funds paid no federal income taxes and no federal income tax provision was required.

>Foreign capital gains taxes

Realized gains in certain countries may be subject to foreign taxes at the fund level. The Funds accrue for such foreign taxes on net realized and unrealized gains at the appropriate rate for each jurisdiction. The amount, if any, is disclosed as a liability on the Statements of Assets and Liabilities.

>Distributions to shareholders

Distributions to shareholders are recorded on the ex-dividend date.

>Indemnification

In the normal course of business, the Trust on behalf of the Funds enters into contracts that contain a variety of representations and warranties and that provide general indemnities. A Fund's maximum exposure under these arrangements is unknown, as this would involve future claims against the Fund. Also, under the Trust's organizational documents, the trustees and officers of the Trust are indemnified against certain liabilities that may arise out of their duties to the Trust. However, based on experience, the Funds expect the risk of loss due to these warranties and indemnities to be remote.

>Recent Accounting Pronouncement

Disclosures about Offsetting Assets and Liabilities

In December 2011, the Financial Accounting Standards Board (FASB) issued ASU No. 2011-11, Disclosures about Offsetting Assets and Liabilities. The objective of the FASB is to enhance current disclosure requirements on offsetting of certain assets and liabilities and to enable financial statement users to compare financial statements prepared under GAAP and International Financial Reporting Standards.

Specifically, ASU No. 2011-11 requires an entity to disclose both gross and net information for derivatives and other financial instruments that are subject to a master netting arrangement or similar agreement. The standard requires disclosure of collateral received in connection with the master netting agreements or similar agreements. The effective date of ASU No. 2011-11 is for interim and annual periods beginning on or after January 1, 2013. At this time, management is evaluating the implications of this guidance and the impact it will have on the financial statement amounts and footnote disclosures, if any.

3.  Federal Tax Information

The timing and character of income and capital gain distributions are determined in accordance with income tax regulations, which may differ from GAAP. Reclassifications are made to the Funds' capital accounts for permanent tax differences to reflect income and gains available for distribution (or available capital loss carryforwards) under income tax regulations.

The following capital loss carryforward, determined as of December 31, 2011, may be available to reduce taxable

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Columbia Acorn Family of Funds

Notes to Financial Statements (Unaudited), continued

income arising from future net realized gains on investments, if any, to the extent permitted by the Internal Revenue Code:

	Year of Expiration
Fund	2015		2016		2017		2018		Unlimited		Total
(in thousands)
Columbia Acorn International	$	15,640	$	82,683	$	189,008	$	—	$	—	$	287,331
Columbia Thermostat Fund		—		—		17,733		2,955		—		20,688
Columbia Acorn Emerging Markets Fund		—		—		—		—		11		11

Unlimited capital loss carryforwards are required to be utilized prior to any capital losses which carry an expiration date. As a result of this ordering rule, capital loss carryforwards which carry an expiration date may be more likely to expire unused.

Columbia Acorn International acquired capital loss carryforwards in connection with the merger with RiverSource Partners International Select Growth Fund and RiverSource Partners International Small Cap Fund of $121,174,098 and $73,618,287, respectively (Note 8). In addition to the acquired capital loss carryforwards, the Fund also acquired unrealized capital gains as a result of the merger. The yearly utilization of the acquired capital loss carryforwards may be limited by the Internal Revenue Code. Any capital loss carryforwards acquired as part of a merger that are permanently lost due to the provisions under the Internal Revenue Code are included as being expired.

Under current tax rules, regulated investment companies can elect to treat certain late-year ordinary losses incurred and post-October capital losses (capital losses realized after October 31) as arising on the first day of the following taxable year. At December 31, 2011, the Funds elected to treat the following late year ordinary losses and post-October capital losses as arising on January 1, 2012:

Fund	Late year ordinary losses		Post-October capital losses
(in thousands)
Columbia Acorn Fund	$	9,350	$	50,163
Columbia Acorn International		—		12,775
Columbia Acorn USA		—		3,057
Columbia Acorn International Select		2,622		3,120
Columbia Acorn Select		107		3,172
Columbia Acorn Emerging Markets Fund		—		42
Columbia Acorn European Fund		2		7

Management of the Funds has concluded that there are no significant uncertain tax positions that would require recognition in the financial statements. However, management's conclusion may be subject to review and adjustment at a later date based on factors including, but not limited to, new tax laws, regulations, and administrative interpretations (including relevant court decisions). Generally, the Funds' federal tax returns for the prior three fiscal years remain subject to examination by the Internal Revenue Service.

4.  Transactions with Affiliates

Columbia Wanger Asset Management, LLC (CWAM) is a wholly-owned subsidiary of Columbia Management Investment Advisers, LLC (Columbia Management), which is a wholly-owned subsidiary of Ameriprise Financial, Inc. (Ameriprise Financial). CWAM furnishes continuing investment supervision to the Funds and is responsible for the overall management of the Funds' business affairs.

CWAM receives a monthly advisory fee based on each Fund's average daily net assets at the following annual rates:

Columbia Acorn Fund

Average Daily Net Assets	Annual Fee Rate
Up to $700 million		0.74	%
$700 million to $2 billion		0.69	%
$2 billion to $6 billion		0.64	%
$6 billion and over		0.63	%

Columbia Acorn International

Average Daily Net Assets	Annual Fee Rate
Up to $100 million		1.19	%
$100 million to $500 million		0.94	%
$500 million and over		0.74	%

Columbia Acorn USA

Average Daily Net Assets	Annual Fee Rate
Up to $200 million		0.94	%
$200 million to $500 million		0.89	%
$500 million to $2 billion		0.84	%
$2 billion to $3 billion		0.80	%
$3 billion and over		0.70	%

Columbia Acorn International Select

Average Daily Net Assets	Annual Fee Rate
Up to $500 million		0.94	%
$500 million and over		0.90	%

Columbia Acorn Select

Average Daily Net Assets	Annual Fee Rate
Up to $700 million		0.85	%
$700 million to $2 billion		0.80	%
$2 billion to $3 billion		0.75	%
$3 billion and over		0.70	%

Columbia Thermostat Fund

	Annual Fee Rate
All Average Daily Net Assets		0.10	%

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Columbia Acorn Emerging Markets Fund

Average Daily Net Assets	Annual Fee Rate
Up to $100 million		1.25	%
$100 million to $500 million		1.00	%
$500 million and over		0.80	%

Columbia Acorn European Fund

Average Daily Net Assets	Annual Fee Rate
Up to $100 million		1.19	%
$100 million to $500 million		0.94	%
$500 million and over		0.74	%

For the six months ended June 30, 2012, the annualized effective investment advisory fee rate were as follows:

Fund
Columbia Acorn Fund	0.64	%
Columbia Acorn International	0.76	%
Columbia Acorn USA	0.86	%
Columbia Acorn International Select	0.94	%
Columbia Acorn Select	0.83	%
Columbia Thermostat Fund	0.10	%
Columbia Acorn Emerging Markets Fund	1.25	%
Columbia Acorn European Fund	1.19	%

>Expense Limit

CWAM has voluntarily agreed to reimburse the ordinary operating expenses (exclusive of brokerage commissions, interest, taxes and extraordinary expenses, but inclusive of custodial charges relating to overdrafts, if any) after giving effect to any balance credits from the Funds' custodian, exceeding annually each Fund's average daily net assets attributable to Class Z shares as follows:

Fund	Class Z
Columbia Acorn International Select		1.45	%
Columbia Acorn Select		1.35	%

This arrangement may be modified or terminated by either the Funds or CWAM on 30 days notice.

CWAM has contractually agreed to waive fees and/or reimburse expenses of Columbia Thermostat Fund through April 30, 2013 so that the ordinary operating expenses (exclusive of interest and fees on borrowings, and expenses associated with the Fund's investment in other investment companies, but including custodian charges relating to overdrafts, if any) will not exceed 0.25% annually of the Fund's average daily net assets attributable to Class Z shares. There is no guarantee that this arrangement will continue after April 30, 2013.

CWAM has contractually agreed to waive fees and/or reimburse expenses of Columbia Acorn Emerging Markets Fund and Columbia Acorn European Fund through April 30, 2013, so that the ordinary operating expenses (exclusive of interest and fees on borrowings, and expenses associated with each Fund's investment in other investment companies, but including custodian charges relating to overdrafts, if any), do not exceed the following annual rates based on each Fund's average daily net assets attributable to Class Z shares:

Fund	Class Z
Columbia Acorn Emerging Markets Fund		1.60	%
Columbia Acorn European Fund		1.50	%

There is no guarantee that these arrangements will continue after April 30, 2013.

CWAM may recoup any fees waived and/or expenses reimbursed with respect to any share class of Columbia Acorn Emerging Markets Fund and Columbia Acorn European Fund for a one-year period following the date of such fee waiver and/or reimbursement if such recovery does not cause the Funds' ordinary operating expenses (excluding interest and fees on borrowings and expenses associated with the Funds' investment in other investment companies, if any) to exceed the annual expense limitations above, or to exceed such annual expense limitations as may be in place at the time of the recoupment, whichever is less.

Effective August 15, 2011, CWAM and its affiliates have contractually agreed to waive a portion of total annual Fund operating expenses incurred by Class A shares, Class B shares and Class C shares of Columbia Acorn International such that the Fund's total annual Fund operating expenses will be reduced by 0.04%, 0.03% and 0.02% for Class A, Class B and Class C shares of the Fund, respectively, through August 14, 2013. There is no guarantee that this arrangement will continue thereafter.

Expenses reimbursed by CWAM and its affiliates for the six months ended June 30, 2012, were as follows:

Fund	Expenses Reimbursed
(in thousands)
Columbia Acorn International	$	206
Columbia Thermostat Fund		127
Columbia Acorn Emerging Markets Fund		149
Columbia Acorn European Fund		118

CWAM provides administrative services and receives an administration fee from the Funds at the following annual rates:

Columbia Acorn Trust

Aggregate Average Daily Net Assets of the Trust	Annual Fee Rate
Up to $8 billion		0.050	%
$8 billion to $16 billion		0.040	%
$16 billion to $35 billion		0.030	%
$35 billion to $45 billion		0.025	%
$45 billion and over		0.015	%

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Columbia Acorn Family of Funds

Notes to Financial Statements (Unaudited), continued

For the six months ended June 30, 2012, the annualized effective administration fee rate was 0.04% of each Fund's average daily net assets. CWAM has delegated to Columbia Management responsibility to provide certain sub-administrative services to the Funds.

Columbia Management Investment Distributors, Inc. (CMID), a wholly owned subsidiary of Ameriprise Financial, is the distributor of the Funds.

Each Fund has adopted a Rule 12b-1 (distribution and service) plan which requires it to pay CMID a monthly service fee equal to 0.25% annually of the average daily net assets attributable to Class A, Class B and Class C shares and a monthly distribution fee equal to 0.50%, 0.75% and 0.50%, annually, of the average daily net assets attributable to Class B, Class C and Class R shares, respectively. CMID receives no compensation with respect to Class R5 and Class Z shares.

Columbia Management Investment Services Corp. (CMIS), a wholly owned subsidiary of Ameriprise Financial, is the transfer agent of the Funds. Effective May 1, 2012, CMIS receives monthly account-based service fees based on the number of open Fund accounts. CMIS is also reimbursed by the Funds for the fees and expenses that it pays retirement plan sponsors, defined contribution plans and 529 Plans (the Plans) or other financial intermediaries that maintain omnibus accounts with the Funds and provide record keeping services to shareholders invested through the Plans. Such fees are calculated as a percentage of the average aggregate value of each Fund's shares maintained by a Plan. CMIS is also reimbursed for the fees and expenses that it pays each fund supermarket, broker-dealer firm or other financial intermediary that maintains an omnibus account with a Fund. Such fees are based on the number of sub-accounts comprising the omnibus position. Each Fund paid CMIS a monthly fee at the annual rate of $17.00 per open account prior to May 1, 2012, and $20.00 per open account thereafter.

The Transfer Agent also receives compensation from fees for various shareholder services and reimbursements for certain out-of-pocket fees. Class I shares do not pay transfer agent fees.

For the six months ended June 30, 2012, the Funds' annualized effective transfer agent fee rates as a percentage of average daily net assets of each class were as follows:

Fund	Class Z
Columbia Acorn Fund		0.04	%
Columbia Acorn International		0.04	%
Columbia Acorn USA		0.08	%
Columbia Acorn International Select		0.06	%
Columbia Acorn Select		0.06	%
Columbia Thermostat		0.06	%
Columbia Acorn Emerging Markets Fund		0.03	%
Columbia Acorn European Fund		0.02	%

In connection with the acquisition that closed August 15, 2011, Columbia Acorn International assumed the assets and obligations of RiverSource Partners International Small Cap Fund and RiverSource Partners International Select Growth Fund (See Note 8), which together with certain other associated investment companies, have severally, but not jointly, guaranteed the performance and observance of all the terms and conditions of a lease (including the payment of rent (the Guaranty)) entered into by Seligman Data Corp. (SDC), the former transfer agent of Seligman Global Smaller Companies Fund and Seligman International Growth Fund, which were acquired by RiverSource Partners International Small Cap Fund and RiverSource Partners International Select Growth Fund, respectively, in previous years. The lease and the Guaranty expire in January 2019. At June 30, 2012, Columbia Acorn International's total potential future obligation over the life of the Guaranty is $131,390. The liability remaining at June 30, 2012 for non-recurring charges associated with the lease amounted to $75,951 and is included within payable for other liabilities in the Statements of Assets and Liabilities.

Certain officers and trustees of the Trust are also officers of CWAM. The Trust makes no direct payments to its officers and trustees who are affiliated with CWAM.

The Board of Trustees has appointed a Chief Compliance Officer of the Trust in accordance with federal securities regulations. The Funds, along with other affiliated funds, pay their pro-rata share of the expenses associated with the Office of the Chief Compliance Officer. These expenses are disclosed separately as "Chief compliance officer expenses" in the Statements of Operations.

The Trust offers a deferred compensation plan for its independent trustees. Under that plan, a trustee may elect to defer all or a portion of his or her compensation. Amounts deferred are retained by the Trust and may represent an unfunded obligation of the Trust. The value of amounts deferred is determined by reference to the change in value of Class Z shares of one or more series of the Trust or a money market fund as specified by the trustee. Benefits under the deferred compensation plan are payable in accordance with the plan.

Organizational expenses for Columbia Emerging Markets Fund and Columbia European Fund consist of offering costs which were incurred prior to the initial public offering of shares of the Funds and include, among other things, state registration filing fees and printing costs. The offering costs were paid by CWAM as incurred. The Funds have capitalized these offering costs and are amortizing them to expense over a period of 12 months from the commencement of the initial public offering of

106

shares. The Funds reimburse CWAM during the 12 month period on a monthly basis an amount equal to the offering costs amortized to expense by each Fund during that month.

An affiliated person of a Fund may include any company in which a Fund owns five percent or more of its outstanding voting shares. On June 30, 2012, Columbia Acorn Fund, Columbia Acorn International, Columbia Acorn USA, Columbia Acorn Select and Columbia Thermostat Fund each held five percent or more of the outstanding voting securities of one or more companies. Details of investments in those affiliated companies are presented on pages 35, 47, 56, 68 and 72, respectively.

For the six months ended June 30, 2012, the Funds engaged in purchase and sales transactions with funds that have a common investment adviser (or affiliated investment advisers), common directors/trustees, and/or common officers. Those transactions complied with Rule 17a-7 under the Investment Company Act of 1940 and were as follows:

	Purchases		Sales
(in thousands)
Columbia Acorn Fund	$	800	$	—
Columbia Acorn International		1,450		—
Columbia Acorn Select		—		1,446
Columbia Acorn Emerging Markets Fund		12		—

During the year ended December 31, 2011, Columbia Management reimbursed Columbia Acorn International $174,055 for a loss on a trading error.

During the year ended December 31, 2011, Columbia Acorn Select Class Z shares received a payment of $56,666 from Columbia Management as a reimbursement for certain shareholder transactions processed at an incorrect price. The payment has been included in "Increase from contribution from affiliate" on the Statements of Changes in Net Assets.

5.  Borrowing Arrangements

The Trust participates in a $150 million credit facility, along with another Trust managed by CWAM, which was entered into to facilitate portfolio liquidity. Under the facility, as in effect for the six months ended June 30, 2012, interest is charged to each participating fund based on its borrowings at a rate per annum equal to the higher of Federal Funds Rate or Overnight LIBOR plus 1.25%. In addition, a commitment fee of 0.10% per annum of the unutilized line of credit is accrued and apportioned among the participating funds based on their relative net assets. The commitment fee is included in "Other expenses" in the Statements of Operations. The Trust expects to renew this line of credit for one year durations annually in July at then current market rates and terms.

Except for Columbia Acorn Select, no Fund had borrowings during the six months ended June 30, 2012. For Columbia Acorn Select, the average daily loan balance outstanding on days when borrowing existed was $8,500,000 at a weighted average interest rate of 1.49%.

6.  Investment Transactions

The aggregate cost of purchases and proceeds from sales, other than short-term obligations, for the six months ended June 30, 2012, were:

	Purchases		Proceeds from Sales
(in thousands)
Columbia Acorn Fund	$	1,335,545	$	2,296,276
Columbia Acorn International		1,052,221		1,021,815
Columbia Acorn USA		129,533		261,587
Columbia Acorn International Select		93,008		111,597
Columbia Acorn Select		99,446		423,716
Columbia Thermostat Fund		382,471		144,148
Columbia Acorn Emerging Markets Fund		3,240		715
Columbia Acorn European Fund		503		331

7.  Regulatory Settlements with Third Parties

During the six months ended June 30, 2012, Columbia Acorn International received payments of $107,802 resulting from certain regulatory settlements with third parties in which the Fund had participated. The payments have been included in "Increase from regulatory settlements" in the Statements of Changes in Net Assets.

During the year ended December 31, 2011, Columbia Acorn International received payments of $107,617 resulting from certain regulatory settlements with third parties in which the Fund had participated. The payments have been included in "Increase from regulatory settlements" in the Statements of Changes in Net Assets.

8.  Fund Merger

On August 15, 2011, Columbia Acorn International acquired the assets and assumed the identified liabilities of RiverSource Partners International Select Growth Fund and RiverSource Partners International Small Cap Fund, both series of RiverSource International Managers Series, Inc., which were sub-advised by CWAM. The reorganization was completed after shareholders approved the plan on May 11, 2011. The purpose of the transaction was to combine funds managed by CWAM with comparable investment objectives and strategies.

The aggregate net assets of Columbia Acorn International immediately before the acquisitions were $5,887,634,436 and the combined net assets immediately after the acquisitions were $6,287,891,195.

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Columbia Acorn Family of Funds

Notes to Financial Statements (Unaudited), continued

The merger was accomplished by a tax-free exchange of 48,230,699 shares of RiverSource Partners International Select Growth Fund valued at $311,482,971 (including $29,840,736 of unrealized appreciation) and 15,801,504 shares of RiverSource Partners International Small Cap Fund valued at $88,773,788 (including $6,322,097 of unrealized appreciation).

In exchange for RiverSource Partners International Select Growth Fund and RiverSource Partners International Small Cap Fund shares, Columbia Acorn International issued the following number of shares:

	RiverSource Partners International Select Growth Fund		RiverSource Partners International Small Cap Fund
Class A		3,800,227		1,666,707
Class B		267,259		75,499
Class C		183,761		518,779
Class I		4,010,380		51,634
Class R		35,341		48,348
Class R5		5,711		23,983

For financial reporting purposes, net assets received and shares issued by Columbia Acorn International were recorded at fair value; however, RiverSource Partners International Select Growth Fund and RiverSource Partners International Small Cap Fund's cost of investments was carried forward.

The financial statements reflect the operations of Columbia Acorn International for the period prior to the merger and the combined fund for the period subsequent to the merger. Because the combined investment portfolios have been managed as a single integrated portfolio since the merger was completed, it is not practicable to separate the amounts of revenue and earnings of RiverSource Partners International Select Growth Fund and RiverSource Partners International Small Cap Fund that have been included in the combined Fund's Statement of Operations since the merger was completed.

Assuming the merger had been completed on January 1, 2011, Columbia Acorn International's pro-forma net investment income, net gain on investments, net change in unrealized depreciation and net increase in net assets from operations for the year ended December 31, 2011 would have been approximately $76.7 million, $260.0 million, $(1,274.8) million and $(938.1) million, respectively.

9.  Shareholder Concentration

At June 30, 2012, the table below details the affiliated and significant unaffiliated shareholder account ownership of outstanding shares of each Fund. The Funds have no knowledge about whether any portion of those shares was owned beneficially. Subscription and redemption activity of these accounts may have a significant effect on the operations of the Funds.

	Number of unaffiliated accounts		Percentage of shares outstanding held – unaffiliated			Percentage of shares outstanding held – affiliated
Columbia Acorn Fund		1		11.1	%		—
Columbia Acorn International		3		38.7	%		—
Columbia Acorn USA		3		51.7	%		—
Columbia Acorn International Select		1		43.6	%		—
Columbia Acorn Select		2		26.5	%		—
Columbia Thermostat Fund		2		38.2	%		—
Columbia Acorn Emerging Markets Fund		1		17.4	%		29.7	%
Columbia Acorn European Fund		1		18.0	%		53.7	%

10.  Subsequent Events

Management has evaluated the events and transactions that have occurred through the date the financial statements were issued and noted no items requiring adjustment of the financial statements or additional disclosure.

11.  Information Regarding Pending and Settled Legal Proceedings

Ameriprise Financial and certain of its affiliates have historically been involved in a number of legal, arbitration and regulatory proceedings, including routine litigation, class actions, and governmental actions, concerning matters arising in connection with the conduct of their business activities. Ameriprise Financial believes that the Funds are not currently the subject of, and that neither Ameriprise Financial nor any of its affiliates are the subject of, any pending legal, arbitration or regulatory proceedings that are likely to have a material adverse effect on the Funds or the ability of Ameriprise Financial or its affiliates to perform under their contracts with the Funds. Ameriprise Financial is required to make 10-Q, 10-K and, as necessary, 8-K filings with the Securities and Exchange Commission on legal and regulatory matters that relate to Ameriprise Financial and its affiliates. Copies of these filings may be obtained by accessing the SEC website at www.sec.gov.

There can be no assurance that these matters, or the adverse publicity associated with them, will not result in increased fund redemptions, reduced sale of fund shares or other adverse consequences to the Funds. Further, although we believe proceedings are not likely to have a material adverse effect on the Funds or the ability of Ameriprise Financial or its affiliates to perform under their contracts with the Funds, these proceedings are subject to uncertainties and, as such, we are unable to estimate the possible loss or range of loss that may result. An adverse outcome in one or more of these proceedings could result in adverse judgments, settlements, fines, penalties or other relief that could have a material adverse effect on the consolidated financial condition or results of operations of Ameriprise Financial.

108

Board Approval of the Advisory Agreement

Columbia Acorn Trust (the "Trust") has an investment advisory agreement (the "Advisory Agreement") with Columbia Wanger Asset Management, LLC ("Columbia WAM") under which Columbia WAM manages the Columbia Acorn Funds (each, a "Fund", and together, the "Funds"). More than 75% of the trustees of the Trust (the "Trustees") are persons who have no direct or indirect interest in the Advisory Agreement and are not "interested persons" (as defined in the Investment Company Act of 1940, as amended (the "1940 Act")) of the Trust (the "Independent Trustees"). The Trustees oversee the management of each Fund and, as required by law, determine at least annually whether to continue the Advisory Agreement for each Fund.

The Contract Committee (the "Committee") of the Board of Trustees (the "Board"), which is comprised solely of Independent Trustees, makes recommendations to the Board regarding any proposed continuation of the Advisory Agreement. After the Committee has made its recommendations, the full Board determines whether to approve continuation of the Advisory Agreement. The Board also considers matters bearing on the Advisory Agreement at its various meetings throughout the year, meets at least quarterly with Columbia WAM's portfolio managers and receives monthly reports from Columbia WAM on the performance of the Funds.

In connection with their most recent consideration of the Advisory Agreement for each Fund, the Committee and all Trustees received and reviewed a substantial amount of information provided by Columbia WAM, Columbia Management Investment Advisers, LLC ("Columbia Management") and Ameriprise Financial, Inc. ("Ameriprise") in response to written requests from the Independent Trustees and their independent legal counsel. Throughout the process, the Trustees had numerous opportunities to ask questions of and request additional materials from Columbia WAM, Columbia Management and Ameriprise.

During each meeting at which the Committee or the Independent Trustees considered the Advisory Agreement, they met in executive session with their independent legal counsel. The Committee also met with representatives of Columbia WAM, Columbia Management and Ameriprise on several occasions. In all, the Committee convened formally on six separate occasions to consider the continuation of the Advisory Agreement. The Board and/or some or all of the Independent Trustees met on other occasions to receive the Committee's status reports, receive presentations from Columbia WAM, Columbia Management and Ameriprise representatives, and to discuss outstanding issues. In addition, the Investment Performance Analysis Committee of the Board, also comprised exclusively of Independent Trustees, reviewed the performance of the Funds and presented its findings to the Board and the Committee throughout the year. The Compliance Committee of the Board also provided information to the Committee with respect to relevant matters.

The Trustees reviewed the Advisory Agreement, as well as certain information obtained through Columbia WAM's, Columbia Management's and Ameriprise's responses to independent legal counsel's questionnaires. In addition, the Trustees reviewed the Management Fee Evaluation dated June 2012 (the "Fee Evaluation") prepared by the Trust's chief compliance officer, senior vice president and general counsel, at the request of the Board.

The materials reviewed by the Committee and the Trustees included, among other items, (i) information on the investment performance of each Fund and of independently selected peer groups of funds and of the Funds' performance benchmarks over various time periods, (ii) information on each Fund's advisory fees and other expenses, including information comparing the Fund's fees and expenses to those of peer groups of funds and information about any applicable expense limitations and fee breakpoints, (iii) data on sales and redemptions of Fund shares, and (iv) information on the profitability to Columbia WAM and Ameriprise, as well as potential "fall-out" or ancillary benefits that Columbia WAM and its affiliates may receive as a result of their relationships with the Funds. The Trustees also considered other information such as (i) Columbia WAM's financial condition, (ii) each Fund's investment objective and strategy, (iii) the size, education and experience of Columbia WAM's investment staff and its use of technology, external research and trading cost measurement tools, (iv) the portfolio manager compensation framework, (v) the allocation of the Funds' brokerage, and the use of "soft" commission dollars to pay for research products and services, (vi) Columbia WAM's risk management program, and (vii) the resources devoted to, and the record of compliance with, the Funds' investment policies and restrictions, policies on personal securities transactions and other compliance policies.

At a meeting held on June 6, 2012, upon recommendations of the Committee, the Board of Trustees unanimously approved the continuation of the Advisory Agreement.

109

Board Approval of the Advisory Agreement, continued

In considering the continuation of the Advisory Agreement, the Trustees reviewed and analyzed various factors that they determined were relevant, none of which by itself was considered dispositive. The material factors and conclusions that formed the basis for the Trustees' determination to approve the continuation of the Advisory Agreement are discussed below.

Nature, quality and extent of services. The Trustees reviewed the nature, quality and extent of the services provided by Columbia WAM and its affiliates to the Funds under the Advisory Agreement, taking into account the investment objective and strategy of each Fund and knowledge gained from meetings with management, which were held on at least a quarterly basis. In addition, the Trustees reviewed the available resources and key personnel of Columbia WAM and its affiliates, especially those providing investment management services to the Funds. The Trustees also considered other services provided to the Funds by Columbia WAM and its affiliates, including: managing the execution of portfolio transactions and selecting broker-dealers for those transactions; monitoring adherence to the Funds' investment restrictions; producing shareholder reports; providing support services for the Board and committees of the Board; managing the Funds' securities lending program; communicating with shareholders; serving as the Funds' administrator; and overseeing the activities of the Funds' other service providers, including monitoring for compliance with various policies and procedures as well as applicable securities laws and regulations.

The Trustees concluded that the nature, quality and extent of the services provided by Columbia WAM and its affiliates to each Fund under the Advisory Agreement were appropriate for the Funds and that the Funds were likely to benefit from the continued provision of those services by Columbia WAM. They also concluded that Columbia WAM currently had sufficient personnel, with appropriate education and experience, to serve the Funds effectively, and that the firm had demonstrated its continuing ability to attract and retain well-qualified personnel. In addition, they took note of the quality of Columbia WAM's compliance record.

Performance of the Funds. The Trustees received and considered detailed performance information at various meetings of the Board, the Committee and the Investment Performance Analysis Committee of the Board throughout the year. They reviewed information comparing each Fund's performance with that of its benchmark(s) and with the performance of comparable funds and peer groups as identified by Lipper Inc. ("Lipper") and Morningstar, Inc. ("Morningstar"). The Trustees evaluated the performance of the Funds over various time periods, including over the one-, three- and five-year periods ending December 31, 2011. The Trustees also considered peer performance rankings for similar time periods although they focused more on the five-year period, or the since inception periods in the case of the two newer Funds, Columbia Acorn Emerging Markets Fund and Columbia Acorn European Fund.

The Trustees noted that Columbia Acorn International and Columbia Acorn International Select had delivered excellent results over the past five years, and had done so while exposing investors to less risk than competing funds, according to Morningstar. They also considered that Columbia Acorn Emerging Markets Fund and Columbia Acorn European Fund had delivered excellent returns since inception versus their respective Morningstar peer groups, although their returns were below median compared to their respective Lipper peer groups. The Trustees considered that these newer Funds had operated for less than one year and that the Funds had relatively few peers in their peer groups compared to peer groups for other Funds.

The Trustees considered that the domestic Funds have had mixed results. Columbia Acorn Fund underperformed its peers over the five-year period, ending December 31, 2011, but the Fund beat its benchmark during the same period. Columbia Acorn Fund underperformed its peer groups for the one- and three-year periods as well, and outperformed its benchmark for the three-year but not the one-year period. The Trustees considered, however, that Morningstar and Lipper ranked Columbia Acorn Fund as the best-performing fund over the past ten years. Columbia Acorn Select underperformed its peers and benchmark over the five-year period ending December 31, 2011 and exposed investors to more risk versus its peers. The Trustees considered that Columbia Acorn Select had performed better over the three-year period, but that its one-year returns were well below the peer group median and benchmark. Columbia Acorn USA's returns were behind its peer group median over the five-year period ending December 31, 2011, though it outperformed its benchmark for the same period. The Trustees noted that the Fund also had underperformed its peers for the one- and three-year periods but had outperformed its benchmark for the same periods. Over the ten-year period, Columbia Acorn USA ranked above

110

median according to Morningstar and Lipper. The Fund also exposed shareholders to more risk than its peers. Columbia Thermostat Fund outperformed its stated benchmark, a 50/50 blend of the Fund's primary equity and debt benchmarks, over the three- and five-year periods ending December 31, 2011, and enjoyed strong rankings from Morningstar and Lipper versus its peer groups over these periods.

The Trustees concluded that Fund performance was satisfactory with respect to the international Funds and Columbia Thermostat Fund. The Trustees determined that performance with respect to Columbia Acorn Select, in particular, and with respect to Columbia Acorn Fund and Columbia Acorn USA needed to be improved, although performance of these three Funds had been ahead of their benchmarks at the time of the June 6th Board meeting. The Trustees concluded, however, that Columbia WAM had taken and continued to take a number of corrective steps to improve performance of the underperforming domestic Funds, that Columbia WAM had reported that these steps were being successfully implemented, and that the Investment Performance Analysis Committee of the Board was monitoring these Funds' performance closely. In addition the Trustees considered that the Chief Investment Officer (the "CIO") of Columbia WAM had reported to them at numerous committee and Board meetings on the corrective steps being taken to improve performance, and committee representatives met separately with the CIO on multiple occasions to discuss the underperforming Funds.

The Trustees concluded that, although past performance is not necessarily indicative of future results, the strong overall longer-term performance record of the international Funds, Columbia Acorn Fund and Columbia Thermostat Fund, and the steps taken by Columbia WAM to correct performance in the underperforming domestic Funds, were an important factor in their evaluation of the quality of services provided by Columbia WAM under the Advisory Agreement for these Funds.

Costs of Services and Profits Realized by Columbia WAM. At various Committee and Board meetings, the Trustees examined detailed information on the fees and expenses of each Fund in comparison to information for comparable funds provided by Lipper and Morningstar. The Trustees reviewed data from Lipper and Morningstar and noted that in general the Funds' total net operating expenses were equal to or below their Morningstar median peer group rankings, except that Columbia Acorn USA, Columbia Acorn European Fund, and Columbia Acorn Select had total net operating expenses above their Morningstar peer group medians. All of the Funds' total net operating expenses, however, were below their Lipper peer group medians.

The actual advisory fees paid by Columbia Acorn Fund, Columbia Acorn International and Columbia Thermostat Fund were lower than both their Morningstar and Lipper peer groups; the actual advisory fees paid by Columbia Acorn Select and Columbia Acorn USA were higher than the median advisory fee of the Funds' Lipper and Morningstar peer groups; the actual advisory fees paid by Columbia Acorn Emerging Markets Fund and Columbia Acorn European Fund were higher than the median advisory fees paid by the Funds' Morningstar peer groups but not their Lipper peer groups; and the actual advisory fee paid by Columbia Acorn International Select was higher than the median advisory fee of the Fund's Lipper peer group, but not of its Morningstar peer group.

The Trustees also reviewed the advisory fee rates charged by Columbia WAM for managing other investment companies (including the Columbia Wanger Funds), sub-advised funds and other institutional separate accounts, as detailed in materials provided to the Committee by Columbia WAM and in the Fee Evaluation. The Trustees noted that the Funds' advisory fees were generally comparable to the Columbia Wanger Funds' advisory fees at the same asset levels. The Trustees also examined Columbia WAM's institutional separate account fees for various investment strategies; in some cases those fees were higher than the advisory fees charged to the Funds, and in a few instances the fees were lower. The Trustees noted that Columbia WAM performs significant additional services for the Funds that it does not provide to sub-advised funds or non-mutual fund clients, including administrative services, oversight of the Funds' other service providers, Trustee support, regulatory compliance and numerous other services, and that, in servicing the Funds, Columbia WAM assumes many legal and business risks that it does not assume in servicing many of its non-fund clients.

The Trustees concluded that the rates of advisory fees payable to Columbia WAM were reasonable in relation to the nature and quality of the services to be provided. The Trustees also concluded that the Funds' overall expense ratios were reasonable, considering the quality of the services provided by Columbia WAM and its affiliates and the investment performance of the Funds, taking into account Columbia WAM's continuing steps to improve performance of the underperforming domestic Funds.

111

Board Approval of the Advisory Agreement, continued

The Trustees reviewed the analysis of the historic profitability of Columbia WAM in serving as each Fund's investment adviser and of Columbia WAM and its affiliates in their relationships with each Fund. The Committee and Trustees met with representatives from Ameriprise to discuss its methodologies for calculating profitability and allocating costs. They considered that Ameriprise calculated profitability and allocated costs on a contract-by-contract and fund-by-fund basis. The Trustees also considered the methodology used by Columbia WAM and Ameriprise in determining compensation payable to portfolio managers and the competitive market for investment management talent. The Trustees were also provided with profitability information from Lipper, which compared Columbia WAM's profitability to other similar investment advisers in the mutual fund industry. The Trustees concluded that Columbia WAM's and its affiliates' profits were within a reasonable range of those of competitors with similar business models. The Trustees discussed, however, that profitability comparisons among fund managers may not always be meaningful due to the lack of consistency in data, small number of publicly-owned managers, and the fact that profitability of any investment manager is affected by numerous factors, including its particular organizational structure, the types of funds and other accounts managed, other lines of business, expense allocation methodology, capital structure and cost of capital.

Economies of Scale. At various Committee and Board meetings and other informal meetings, the Trustees considered information about the extent to which Columbia WAM realizes economies of scale in connection with an increase in Fund assets. The Trustees also discussed the potential for Fund sales growth. The Trustees noted that the advisory fee schedule for each Fund, other than Columbia Thermostat Fund, includes breakpoints in the rate of fees at various asset levels. The Trustees concluded that the fee structure of each Fund was reflective of a sharing between Columbia WAM and the Funds of economies of scale.

Other Benefits to Columbia WAM. The Trustees also reviewed benefits that accrue to Columbia WAM and its affiliates from their relationships with the Funds, based upon information provided to them by Ameriprise and as outlined in the Fee Evaluation. They noted that the Funds' transfer agency services are performed by Columbia Management Investment Services Corp., an affiliate of Ameriprise, which receives compensation from the Funds for its services provided. They considered that an affiliate of Ameriprise, Columbia Management Investment Distributors, Inc. ("CMID"), serves as the Funds' distributor under a distribution agreement, and that it receives fees under the Trust's Rule 12b-1 Plan, most of which CMID pays to broker-dealers. In addition, Columbia Management provides sub-administration services to the Funds. The Committee received information regarding the profitability of each Fund agreement with Columbia WAM affiliates. The Committee and the Board also reviewed information about and discussed the capabilities of each affiliated entity in performing its duties.

The Trustees considered other ways that the Funds and Columbia WAM may potentially benefit from their relationship with each other. For example, the Trustees considered Columbia WAM's use of commissions paid by each Fund on its portfolio brokerage transactions to obtain research products and services benefiting the Funds and/or other clients of Columbia WAM. The Committee reviewed Columbia WAM's annual "soft dollar" report and met with representatives from Columbia WAM to review Columbia WAM's soft dollar spending. The Committee also considered that the Compliance Committee of the Board regularly reviewed third-party prepared reports that evaluated the quality of Columbia WAM's execution of the Funds' portfolio transactions. The Trustees noted that these reports showed that Columbia WAM's execution capabilities were generally better than industry peers. The Trustees determined that Columbia WAM's use of the Funds' "soft" commission dollars to obtain research products and services was consistent with current regulatory requirements and guidance. They also concluded that Columbia WAM benefits from the receipt of proprietary research products and services acquired through commissions paid on portfolio transactions of the Funds, and that the Funds benefit from Columbia WAM's receipt of those products and services as well as research products and services acquired through commissions paid by other clients of Columbia WAM.

After full consideration of the above factors, as well as other factors that were instructive in evaluating the Advisory Agreement, the Trustees, including the Independent Trustees, concluded that the continuation of the Advisory Agreement was in the best interest of each Fund. On June 6, 2012, the Trustees approved continuation of the Advisory Agreement through July 31, 2013.

112

Columbia Acorn Family of Funds

Second Quarter Class Z Share Information (Unaudited)

Minimum Initial Investment in all Funds:	$0 to $2,000, available only to certain eligible investors
Exchange Fee:	None

Columbia Acorn Fund	ACRNX
Management Fee		0.64	%
12b-1 Fee		0.00	%
Other Expenses		0.12	%
Net Expense Ratio		0.76	%
Columbia Acorn International	ACINX
Management Fee		0.76	%
12b-1 Fee		0.00	%
Other Expenses		0.15	%
Net Expense Ratio		0.91	%
Columbia Acorn USA	AUSAX
Management Fee		0.86	%
12b-1 Fee		0.00	%
Other Expenses		0.18	%
Net Expense Ratio		1.04	%
Columbia Acorn International Select	ACFFX
Management Fee		0.94	%
12b-1 Fee		0.00	%
Other Expenses		0.24	%
Net Expense Ratio		1.18	%
Columbia Acorn Select	ACTWX
Management Fee		0.83	%
12b-1 Fee		0.00	%
Other Expenses		0.19	%
Net Expense Ratio		1.02	%
Columbia Thermostat Fund	COTZX
Management Fee		0.10	%
12b-1 Fee		0.00	%
Other Expenses		0.15	%*
Net Expense Ratio		0.25	%*
Columbia Acorn Emerging Markets Fund	CEFZX
Management Fee		1.25	%
12b-1 Fee		0.00	%
Other Expenses		0.19	%
Net Expense Ratio		1.44	%
Columbia Acorn European Fund	CAEZX
Management Fee		1.19	%
12b-1 Fee		0.00	%
Other Expenses		0.14	%
Net Expense Ratio		1.33	%

    Fees and expenses are for the six months ended June 30, 2012.

    The fees and expenses of Columbia Acorn Select and Columbia Acorn International Select include the effect of the voluntary undertaking by Columbia Wanger Asset Management, LLC (CWAM) to waive fees and/or reimburse the Funds for any ordinary operating expenses (exclusive of brokerage commissions, interest, taxes and extraordinary expenses, but inclusive of custodian charges relating to overdrafts, if any), after giving effect to any balance credits from the Funds' custodian, in excess of the following annual rates:

Fund	Class Z
Columbia Acorn International Select		1.45	%
Columbia Acorn Select		1.35	%

    These arrangements may be modified or terminated by either the Funds or CWAM upon 30 days notice.

    Columbia Thermostat Fund's fees and expenses include the effect of CWAM's contractual undertaking to waive fees and/or reimburse the Fund for any ordinary operating expenses (exclusive of distribution and service fees, interest and fees on borrowings and expenses associated with the Fund's investments in other investment companies, but including custodian charges relating to overdrafts, if any), after giving effect to any balance credits from the Fund's custodian, in excess of the annual rate of 0.25% of the average daily net assets. Columbia Thermostat Fund's waiver/reimbursement arrangement is contractual through April 30, 2013. There is no guarantee that this arrangement will continue thereafter.

    The fees and expenses of Columbia Acorn Emerging Markets Fund and Columbia Acorn European Fund also include the effect of fee waivers/reimbursements. CWAM has contractually undertaken to waive fees and/or reimburse Columbia Acorn Emerging Markets Fund so that the Fund's ordinary operating expenses (excluding interest and fees on borrowings and expenses associated with the Fund's investment in other investment companies, if any) do not exceed the annual rate of 1.60% of the Fund's average daily net assets attributable to Class Z shares, through April 30, 2013. There is no guarantee that this arrangement will continue thereafter. CWAM has contractually undertaken to waive fees and/or reimburse Columbia Acorn European Fund so that its ordinary operating expenses (excluding interest and fees on borrowings and expenses associated with the Fund's investment in other investment companies, if any) do not exceed the annual rate of 1.50% of the Fund's average daily net assets attributable to Class Z shares, through April 30, 2013. There is no guarantee that this arrangement will continue thereafter.

  *  Does not include estimated fees and expenses of 0.61% incurred by the Fund from the underlying portfolio funds in which it invests.

113

Columbia Acorn Family of Funds

Trustees

Laura M. Born

Chair of the Board

Steven N. Kaplan

Vice Chair of the Board

Michelle L. Collins

Maureen M. Culhane

Margaret M. Eisen

John C. Heaton

Charles P. McQuaid

David J. Rudis

David B. Small

Ralph Wanger (Trustee Emeritus)

Officers

Charles P. McQuaid

President

Ben Andrews

Vice President

Robert A. Chalupnik

Vice President

Michael G. Clarke

Assistant Treasurer

Joseph F. DiMaria

Assistant Treasurer

P. Zachary Egan

Vice President

Fritz Kaegi

Vice President

John M. Kunka

Assistant Treasurer

Stephen Kusmierczak

Vice President

Joseph C. LaPalm

Vice President

Bruce H. Lauer

Vice President, Secretary and Treasurer

Louis J. Mendes III

Vice President

Robert A. Mohn

Vice President

Christopher J. Olson

Vice President

Christopher O. Petersen

Assistant Secretary

Scott R. Plummer

Assistant Secretary

Andreas Waldburg-Wolfegg

Vice President

Linda K. Roth-Wiszowaty

Assistant Secretary

Robert P. Scales

Chief Compliance Officer, Chief Legal Officer,
Senior Vice President and General Counsel

Investment Manager

Columbia Wanger Asset Management, LLC
227 West Monroe Street, Suite 3000
Chicago, Illinois 60606

1-800-922-6769

Distributor

Columbia Management Investment Distributors, Inc.
225 Franklin Street
Boston, Massachusetts 02110

Transfer Agent, Dividend Disbursing Agent

Columbia Management Investment Services Corp.
P. O. Box 8081
Boston, Massachusetts 02266-8081

1-800-345-6611

Legal Counsel to the Funds

Perkins Coie LLP
Washington, DC

Legal Counsel to the Independent Trustees

Drinker Biddle & Reath LLP
Philadelphia, Pennsylvania

Independent Registered Public Accounting Firm

PricewaterhouseCoopers LLP
Chicago, Illinois

This report, including the schedules of investments, is submitted for the general information of the shareholders of Columbia Acorn Trust.

A description of the policies and procedures that the Funds use to determine how to vote proxies and a copy of the Funds' voting record are available (i) without charge, upon request, by calling 800-922-6769 and (ii) on the Securities and Exchange Commission's website at www.sec.gov. Information regarding how the Funds voted proxies relating to portfolio securities during the 12-month period ended June 30, is available from the SEC's website. Information regarding how the Funds voted proxies relating to portfolio securities is also available at www.columbiamanagement.com under "About Us." From there, click on "Disclosures."

The Funds file a complete schedule of portfolio holdings with the SEC for the first and third quarters of each fiscal year on Form N-Q. The Funds' Form N-Q is available on the SEC's website at www.sec.gov and may be reviewed and copied at the SEC's Public Reference Room in Washington, D.C. Information on the operation of the Public Reference Room may be obtained by calling 1-800-SEC-0330. The Funds' complete portfolio holdings are disclosed at www.columbiamanagement.com approximately 30 to 40 days after each month-end.

Investors should consider the investment objectives, risks, charges and expenses of a mutual fund carefully before investing. For a free prospectus, which contains this and other important information about the funds, visit www.columbiamanagement.com. Read the prospectus carefully before investing.

Columbia Acorn Funds are distributed by Columbia Management Investment Distributors, Inc., member FINRA and managed by Columbia Wanger Asset Management, LLC.

Find out what's new – visit our web site at:

www.columbiamanagement.com

Our e-mail address is:

ServiceInquiries@ColumbiaManagement.com

Shareholders should not include personal information such as account numbers, Social Security numbers or taxpayer identification numbers in e-mail. We are unable to accept account transactions sent via e-mail.

114

This document contains Global Industry Classification Standard data. The Global Industry Classification Standard ("GICS") was developed by and is the exclusive property and a service mark of MSCI Inc. ("MSCI") and Standard & Poor's Financial Services LLC ("S&P") and is licensed for use by Columbia Wanger Asset Management, LLC. Neither MSCI, S&P, nor any other party involved in making or compiling the GICS or any GICS classifications makes any express or implied warranties or representations with respect to such standard or classification (or the results to be obtained by the use thereof), and all such parties hereby expressly disclaim all warranties of originality, accuracy, completeness, merchantability and fitness for a particular purpose with respect to any of such standard or classification. Without limiting any of the foregoing, in no event shall MSCI, S&P, any of their affiliates or any third party involved in making or compiling the GICS or any GICS classifications have any liability for any direct, indirect, special, punitive, consequential or any other damages (including lost profits) even if notified of the possibility of such damages.

Columbia Management^®

Columbia Acorn Family of Funds
Class Z Shares

Semiannual Report, June 30, 2012

For More Information

You'll find more information about the Columbia Acorn Family of Funds in the documents described below. Contact Columbia Funds as follows to obtain these documents free of charge:

By Mail:  Columbia Funds
c/o Columbia Management Investment Services Corp.
P. O. Box 8081 Boston, MA 02266-8081

By Telephone: 800.345.6611

Online: www.columbiamanagement.com

Shareholder Communications with the Board

The Funds' Board of Trustees has adopted procedures by which shareholders may communicate with the Board. Shareholders who wish to communicate with the Board should send their written communications to the Board by mail, c/o Columbia Wanger Asset Management, LLC, 227 West Monroe Street, Suite 3000, Chicago, Illinois 60606, Attention: Secretary. Shareholder communications must (i) be in writing, (ii) identify the Columbia Acorn Fund to which the communication relates and (iii) state the particular class of shares and number of shares held by the communicating shareholder.

Prospectuses and the Statement of Additional Information (SAI)

The prospectuses and the SAI provide more detailed information about the Funds and their policies. The SAI is legally part of each prospectus (it's incorporated by reference). A copy of each has been filed with the SEC.

Information Provided by the SEC

You can review and copy information about the Funds (including their prospectuses, the SAI and shareholder reports) at the SEC's Public Reference Room in Washington, DC. To find out more about the operation of the Public Reference Room, call the SEC at 202.551.8090. Reports and other information about the Fund are also available in the EDGAR Database on the SEC's website at http://www.sec.gov, or you can receive copies of this information, for a fee, by electronic request at the following e-mail address: publicinfo@sec.gov. You can also obtain copies of this information by writing the Public Reference Section, Securities and Exchange Commission, Washington, DC 20549-0102.

The investment company registration number of Columbia Acorn Trust, of which each of these Funds is a series, is 811-01829.

© 2012 Columbia Management Investment Advisers, LLC. All rights reserved.

225 Franklin Street, Boston, MA 02110

800.345.6611 www.columbiamanagement.com

C-1565 D (8/12) 142538

Q2 2012

Columbia Acorn Family of Funds

Class A, B, C, I, R and R5 Shares

Managed by Columbia Wanger Asset Management, LLC

Semiannual Report

June 30, 2012

n  Columbia
Acorn® Fund

n  Columbia
Acorn International®

n  Columbia
Acorn USA®

n  Columbia
Acorn International Select^SM

n  Columbia
Acorn Select^SM

n  Columbia
Thermostat Fund^SM

n  Columbia
Acorn Emerging Markets Fund^SM

n  Columbia
Acorn European Fund^SM

Not FDIC insured • No bank guarantee • May lose value

The views expressed in the "Chattering Squirrels" and "In a Nutshell" commentaries reflect the current views of the respective authors. These views are not guarantees of future performance and involve certain risks, uncertainties and assumptions that are difficult to predict so actual outcomes and results may differ significantly from the views expressed. These views are subject to change at any time based upon economic, market or other conditions and the respective authors disclaim any responsibility to update such views. These views may not be relied upon as investment advice and, because investment decisions for a Columbia Acorn Fund are based on numerous factors, may not be relied upon as an indication of trading intent on behalf of any particular Columbia Acorn Fund. References to specific company's securities should not be construed as a recommendation or investment advice and there can be no assurance that as of the date of publication of this report, the securities mentioned in each Fund's portfolio are still held or that the securities sold have not been repurchased.

Acorn®, Acorn USA® and Acorn International® are service marks owned and registered by Columbia Acorn Trust. Columbia^SM, Columbia Management®, and the Columbia Management Logo® are service marks owned and/or registered by Ameriprise Financial, Inc.

You are invited to the 2012 Columbia Acorn Funds Shareholder Information Meeting

Join us to hear presentations by Columbia Acorn Fund's lead portfolio manager Chuck McQuaid and other members of the Columbia Wanger Asset Management investment team.

Where: Drinker Biddle & Reath LLP
191 North Wacker Drive, Suite 3700
Chicago, IL

When: Wednesday, September 19, 2012
12 p.m. CSTA buffet lunch will be served beginning at 11:30.

RSVP: 800.922.6769 by September 14, 2012

Webcast Replay: Available at columbiamanagement.com in October.

Public Transportation

For directions using public transportation, call 312.836.7000 or visit the Chicago Transit Authority website at transitchicago.com. Metra information is also available by calling this number or can be found at metrarail.com.

Parking Information

Two parking options are located on Lake Street in the same block as the meeting location, which is between N. Wacker Drive and N. Franklin Street. Lake Street runs one way east after crossing N. Wacker Drive. Hourly parking rates apply at both locations. The first, with signage stating "Public Parking" (phone: 312.267.6867), provides direct access to the building in which the meeting will be held. The second option is a "Self Park" garage (phone: 312.201.1795) located next to the first but without direct access to the building.

Driving Directions

From the south:
Take 1-57 to the Dan Ryan Expressway. Follow the signs for the Kennedy Expressway West. Travel on the Kennedy and exit using the Washington exit (Exit 51C). Turn right onto W. Washington. Proceed east on Washington until you reach Canal Street. Turn left on Canal Street. Travel on Canal to Lake Street. Turn right on Lake Street. Take Lake Street across N. Wacker Drive to the southeast corner of Lake Street and N. Wacker Drive.

From the north:
Take the Kennedy Expressway (I-90/94) south to Chicago. Exit in the city using the W. Randolph Street exit (Exit 51B). Turn right onto W. Randolph Street. Proceed west on Randolph Street until you reach N. Halsted Street. Turn right onto N. Halsted Street. Travel on Halsted to W. Lake Street. Turn right on Lake Street. Take Lake Street across N. Wacker Drive to the southeast corner of Lake Street and N. Wacker Drive.

From the west:
Take the Eisenhower Expressway (I-290) from the west. Follow the signs for the Kennedy Expressway West. Travel on the Kennedy and exit using the Washington exit (Exit 51C). Turn right onto W. Washington. Proceed east on Washington until you reach Canal Street. Turn left on Canal Street. Travel on Canal to Lake Street. Turn right on Lake Street. Take Lake Street across N. Wacker Drive to the southeast corner of Lake Street and N. Wacker Drive.

From the southwest:
Take the Stevenson Expressway (I-55). Exit to the Kennedy Expressway (North-Wisconsin). Travel on the Kennedy and exit using the Washington exit (Exit 51C). Turn right onto W. Washington. Proceed east on Washington until you reach Canal Street. Turn left on Canal Street. Travel on Canal to Lake Street. Turn right on Lake Street. Take Lake Street across N. Wacker Drive to the southeast corner of Lake Street and N. Wacker Drive.

Wacker Drive Construction

Please keep Chicago's Wacker Drive construction project in mind when planning your route. Current information on the project can be found at wackerdrive.org.

Columbia Acorn Family of Funds

Table of Contents

Share Class Performance	2
Fund Performance vs. Benchmarks	3
Descriptions of Indexes	4
Chattering Squirrels: Columbia Thermostat Fund Turns 10	5
Understanding Your Expenses	9
Columbia Acorn Fund
In a Nutshell	12
At a Glance	13
Major Portfolio Changes	28
Statement of Investments	30
Columbia Acorn International
In a Nutshell	14
At a Glance	15
Major Portfolio Changes	43
Statement of Investments	45
Portfolio Diversification	54
Columbia Acorn USA
In a Nutshell	16
At a Glance	17
Major Portfolio Changes	55
Statement of Investments	56
Columbia Acorn International Select
In a Nutshell	18
At a Glance	19
Major Portfolio Changes	63
Statement of Investments	64
Portfolio Diversification	68
Columbia Acorn Select
In a Nutshell	20
At a Glance	21
Major Portfolio Changes	69
Statement of Investments	70
Columbia Thermostat Fund
In a Nutshell	22
At a Glance	23
Statement of Investments	76
Columbia Acorn Emerging Markets Fund
In a Nutshell	24
At a Glance	25
Major Portfolio Changes	77
Statement of Investments	79
Portfolio Diversification	83
Columbia Acorn European Fund
In a Nutshell	26
At a Glance	27
Major Portfolio Changes	84
Statement of Investments	85
Portfolio Diversification	89
Columbia Acorn Family of Funds
Statements of Assets and Liabilities	90
Statements of Operations	92
Statements of Changes in Net Assets	94
Financial Highlights	100
Notes to Financial Statements	116
Board Approval of the Advisory Agreement	126
Columbia Acorn Family of Funds Information	130

Columbia Acorn Family of Funds

2012 Mid-year Distributions

The following table lists the mid-year distributions for the Columbia Acorn Funds. The record date was June 5, 2012, and the ex-dividend date and the payable date was June 6, 2012. Share classes that are not listed did not have any distributions at mid-year.

	Short-term Capital Gains		Long-term Capital Gains		Ordinary Income		Reinvestment Price
Columbia Acorn Fund Class A		None	$	0.35688		None	$	28.07
Columbia Acorn Fund Class B		None	$	0.35688		None	$	25.76
Columbia Acorn Fund Class C		None	$	0.35688		None	$	25.37
Columbia Acorn Fund Class I		None	$	0.35688		None	$	29.11
Columbia Acorn International Class A		None		None	$	0.05961	$	35.80
Columbia Acorn International Class I		None		None	$	0.21123	$	35.90
Columbia Acorn International Class R5		None		None	$	0.21123	$	35.87
Columbia Acorn USA Class A		None	$	0.05114		None	$	27.80
Columbia Acorn USA Class B		None	$	0.05114		None	$	25.61
Columbia Acorn USA Class C		None	$	0.05114		None	$	25.34
Columbia Acorn USA Class I		None	$	0.05114		None	$	28.99
Columbia Acorn International Select Class A		None	$	0.11963		None	$	26.04
Columbia Acorn International Select Class B		None	$	0.11963		None	$	24.90
Columbia Acorn International Select Class C		None	$	0.11963		None	$	24.77
Columbia Acorn International Select Class I		None	$	0.11963		None	$	26.29
Columbia Acorn Select Class A		None	$	0.53050		None	$	24.07
Columbia Acorn Select Class B		None	$	0.53050		None	$	22.35
Columbia Acorn Select Class C		None	$	0.53050		None	$	22.12
Columbia Acorn Select Class I		None	$	0.53050		None	$	24.86
Columbia Thermostat Fund Class A		None		None	$	0.01739	$	13.40
Columbia Thermostat Fund Class B		None		None	$	0.01739	$	13.46
Columbia Thermostat Fund Class C		None		None	$	0.01739	$	13.45
Columbia Acorn Emerging Markets Fund Class I		None		None	$	0.00610	$	9.84
Columbia Acorn European Fund Class A	$	0.00458		None	$	0.01203	$	10.13
Columbia Acorn European Fund Class C	$	0.00458		None	$	0.01203	$	10.10
Columbia Acorn European Fund Class I	$	0.00458		None	$	0.01203	$	10.14

Net Asset Value Per Share as of 6/30/12

	Columbia Acorn Fund		Columbia Acorn International		Columbia Acorn USA		Columbia Acorn International Select		Columbia Acorn Select		Columbia Thermostat Fund		Columbia Acorn Emerging Markets Fund		Columbia Acorn European Fund
Class A	$	28.69	$	37.01	$	28.52	$	26.62	$	24.17	$	13.65	$	10.15	$	10.50
Class B	$	26.32	$	35.88	$	26.27	$	25.45	$	22.43	$	13.71		NA		NA
Class C	$	25.92	$	35.73	$	25.99	$	25.32	$	22.20	$	13.69	$	10.10	$	10.46
Class I	$	29.76	$	37.13	$	29.75	$	26.88	$	24.96		NA	$	10.19	$	10.51
Class R		NA	$	36.97		NA		NA		NA		NA		NA		NA
Class R5		NA	$	37.10		NA		NA		NA		NA		NA		NA

1

Columbia Acorn Family of Funds

Share Class Performance Average Annual Total Returns through 6/30/12

	Class A						Class B*						Class C						Class I			Class R			Class R5
	Without Sales Charge			With Sales Charge			Without Sales Charge			With Sales Charge			Without Sales Charge			With Sales Charge			Without Sales Charge			Without Sales Charge			Without Sales Charge
Columbia Acorn Fund
3 months**		-5.48	%		-10.93	%		-5.61	%		-10.26	%		-5.65	%		-6.59	%		-5.42	%		NA			NA
Year to date**		9.11	%		2.85	%		8.78	%		3.78	%		8.70	%		7.70	%		9.27	%		NA			NA
1 year		-3.03	%		-8.62	%		-3.42	%		-8.02	%		-3.76	%		-4.67	%		-2.75	%		NA			NA
5 years		1.40	%		0.21	%		0.81	%		0.47	%		0.61	%		0.61	%		1.72	%		NA			NA
10 years		9.22	%		8.57	%		8.53	%		8.53	%		8.39	%		8.39	%		9.60	%		NA			NA
Life of Fund		14.18	%		14.02	%		13.48	%		13.48	%		13.31	%		13.31	%		14.56	%		NA			NA
Columbia Acorn International
3 months**		-5.60	%		-11.04	%		-5.75	%		-10.46	%		-5.75	%		-6.69	%		-5.49	%		-5.66	%		-5.50	%
Year to date**		8.56	%		2.32	%		8.17	%		3.17	%		8.17	%		7.17	%		8.79	%		8.38	%		8.77	%
1 year		-9.63	%		-14.82	%		-10.23	%		-14.72	%		-10.27	%		-11.17	%		-9.24	%		-9.87	%		-9.27	%
5 years		-1.20	%		-2.36	%		-1.83	%		-2.18	%		-1.96	%		-1.96	%		-0.81	%		-1.47	%		-0.84	%
10 years		10.67	%		10.01	%		9.94	%		9.94	%		9.84	%		9.84	%		11.09	%		10.38	%		11.07	%
Life of Fund		10.38	%		10.05	%		9.69	%		9.69	%		9.57	%		9.57	%		10.82	%		10.12	%		10.81	%
Columbia Acorn USA
3 months**		-5.26	%		-10.71	%		-5.42	%		-10.14	%		-5.40	%		-6.35	%		-5.18	%		NA			NA
Year to date**		10.15	%		3.82	%		9.77	%		4.77	%		9.79	%		8.79	%		10.38	%		NA			NA
1 year		-4.18	%		-9.69	%		-4.62	%		-9.35	%		-4.88	%		-5.82	%		-3.83	%		NA			NA
5 years		0.68	%		-0.50	%		0.05	%		-0.31	%		-0.09	%		-0.09	%		0.99	%		NA			NA
10 years		7.48	%		6.84	%		6.78	%		6.78	%		6.68	%		6.68	%		7.86	%		NA			NA
Life of Fund		9.47	%		9.06	%		8.77	%		8.77	%		8.67	%		8.67	%		9.87	%		NA			NA
Columbia Acorn International Select
3 months**		-0.95	%		-6.66	%		-1.11	%		-6.03	%		-1.12	%		-2.10	%		-0.87	%		NA			NA
Year to date**		10.23	%		3.89	%		9.89	%		4.89	%		9.81	%		8.81	%		10.44	%		NA			NA
1 year		-4.30	%		-9.80	%		-4.85	%		-9.49	%		-5.03	%		-5.96	%		-3.93	%		NA			NA
5 years		-0.20	%		-1.38	%		-0.83	%		-1.19	%		-0.99	%		-0.99	%		0.18	%		NA			NA
10 years		10.15	%		9.50	%		9.43	%		9.43	%		9.31	%		9.31	%		10.54	%		NA			NA
Life of Fund		8.75	%		8.28	%		8.04	%		8.04	%		7.93	%		7.93	%		9.13	%		NA			NA
Columbia Acorn Select
3 months**		-8.51	%		-13.78	%		-8.66	%		-13.12	%		-8.67	%		-9.56	%		-8.46	%		NA			NA
Year to date**		7.64	%		1.45	%		7.30	%		2.30	%		7.23	%		6.23	%		7.79	%		NA			NA
1 year		-10.17	%		-15.34	%		-10.65	%		-15.02	%		-10.82	%		-11.69	%		-9.76	%		NA			NA
5 years		-2.93	%		-4.07	%		-3.55	%		-3.90	%		-3.70	%		-3.70	%		-2.60	%		NA			NA
10 years		7.05	%		6.42	%		6.34	%		6.34	%		6.23	%		6.23	%		7.41	%		NA			NA
Life of Fund		8.67	%		8.20	%		7.96	%		7.96	%		7.85	%		7.85	%		9.04	%		NA			NA
Columbia Thermostat Fund†
3 months**		-1.46	%		-7.15	%		-1.59	%		-6.51	%		-1.67	%		-2.65	%		NA			NA			NA
Year to date**		6.61	%		0.50	%		6.33	%		1.33	%		6.18	%		5.18	%		NA			NA			NA
1 year		6.80	%		0.67	%		6.24	%		1.24	%		5.98	%		4.98	%		NA			NA			NA
5 years		4.43	%		3.21	%		3.90	%		3.55	%		3.64	%		3.64	%		NA			NA			NA
Life of Fund		7.57	%		6.92	%		6.97	%		6.97	%		6.77	%		6.77	%		NA			NA			NA
Columbia Acorn Emerging Markets Fund
3 months**		-7.05	%		-12.42	%		NA			NA			-7.17	%		-8.10	%		-6.97	%		NA			NA
Year to date**		9.61	%		3.36	%		NA			NA			9.31	%		8.31	%		9.76	%		NA			NA
Life of Fund**		1.50	%		-4.34	%		NA			NA			1.00	%		0.00	%		1.96	%		NA			NA
Columbia Acorn European Fund
3 months**		-5.25	%		-10.72	%		NA			NA			-5.53	%		-6.47	%		-5.25	%		NA			NA
Year to date**		11.53	%		5.07	%		NA			NA			10.99	%		9.99	%		11.64	%		NA			NA
Life of Fund**		5.99	%		-0.11	%		NA			NA			5.28	%		4.28	%		6.26	%		NA			NA

The inception date for Class A, B and C shares is 10/16/00 for all Funds except Columbia Thermostat Fund, Columbia Acorn Emerging Markets Fund and Columbia Acorn European Fund. The inception date for Class A, B and C shares of Columbia Thermostat Fund is 3/03/03. The inception date for all share classes of Columbia Acorn Emerging Markets Fund and Columbia Acorn European Fund is 8/19/11. The inception date for Class R and R5 shares of Columbia Acorn International is 9/27/10.

The returns shown for "Life of Fund" are calculated from the inception date of the Fund. In cases where the inception date of the Fund is earlier than the inception date of a share class, or where a period shown dates to before the inception date of a share class, the returns shown may append the returns of the Fund's Class Z shares, the Fund's oldest share class. These returns are adjusted to reflect any higher class-related operating expenses of the newer share classes, as applicable. Please visit columbiamanagement.com/mutual-funds/appended-performance for more information.

All results shown assume reinvestment of distributions and do not reflect the deduction of taxes that a shareholder would pay on fund distributions or on the redemption of fund shares.

*The Funds generally no longer accept investments by new or existing investors in Class B shares, except in connection with the reinvestment of any dividend and/or capital gain distributions in Class B shares of the Funds and exchanges by existing Class B shareholders of certain other funds within the Columbia Family of Funds.

**Not annualized.

Performance data shown represents past performance and is not a guarantee of future results. The investment return and principal value of an investment will fluctuate so that shares, when redeemed, may be worth more or less than their original cost.

Performance results reflect any fee waivers or reimbursements of Fund expenses by the investment manager and/or any of its affiliates. Absent these fee waivers and/or expense reimbursement arrangements, performance results would have been lower.

Current performance may be lower or higher than the performance data shown. Please visit columbiamanagement.com for daily and most recent month-end updates.

The "with sales charge" returns include the maximum initial sales charge of 5.75% for Class A shares, the applicable contingent deferred sales charge (CDSC) for Class B shares (5%, 4%, 3%, 3%, 2%, 1%, 0% for the first through seventh years after purchase, respectively), and the maximum CDSC of 1.00% of Class C shares during the first year after purchase.

Please see Page 130 of this report for each Fund's operating expense ratio as of the end of the second quarter. On this page, you will find information on fee waiver/expense reimbursement arrangements in place for Columbia Acorn International, Columbia Thermostat Fund, Columbia Acorn Emerging Markets Fund and Columbia Acorn European Fund.

†A "fund of funds" bears its allocable share of the costs and expenses of the underlying funds in which it invests. Such funds are thus subject to two levels of fees and potentially higher expense ratios than would be associated with an investment in a fund that invests and trades directly in financial instruments under the direction of a single manager.

2

Columbia Acorn Family of Funds

Fund Performance vs. Benchmarks Average Annual Total Returns through 6/30/12

Class A Shares, without sales charge	2nd quarter*			Year to date*			1 year			5 years			10 years			Life of Fund
Columbia Acorn Fund (LACAX) (10/16/00)		-5.48	%		9.11	%		-3.03	%		1.40	%		9.22	%		14.18	%
Russell 2500 Index		-4.14	%		8.31	%		-2.29	%		1.18	%		8.01	%		NA
S&P 500 Index**		-2.75	%		9.49	%		5.45	%		0.22	%		5.33	%		10.54	%
Russell 2000 Index		-3.47	%		8.53	%		-2.08	%		0.54	%		7.00	%		NA
Lipper Mid-Cap Growth Funds Index		-6.32	%		7.72	%		-5.16	%		1.61	%		7.29	%		NA
Columbia Acorn International (LAIAX) (10/16/00)		-5.60	%		8.56	%		-9.63	%		-1.20	%		10.67	%		10.38	%
S&P Global Ex-U.S. Between $500M and $5B Index		-8.03	%		4.82	%		-15.17	%		-2.48	%		10.95	%		7.95	%
S&P Global Ex-U.S. SmallCap Index		-8.62	%		4.96	%		-16.34	%		-3.88	%		10.06	%		7.18	%
MSCI EAFE Index		-7.13	%		2.96	%		-13.83	%		-6.10	%		5.14	%		5.22	%
Lipper International Small/Mid Growth Funds Index		-6.03	%		7.68	%		-10.22	%		-2.99	%		9.65	%		NA
Columbia Acorn USA (LAUAX) (10/16/00)		-5.26	%		10.15	%		-4.18	%		0.68	%		7.48	%		9.47	%
Russell 2000 Index		-3.47	%		8.53	%		-2.08	%		0.54	%		7.00	%		7.08	%
Lipper Small-Cap Growth Funds Index		-4.56	%		8.95	%		-3.50	%		0.76	%		6.23	%		5.62	%
Columbia Acorn Int'l Select (LAFAX) (10/16/00)		-0.95	%		10.23	%		-4.30	%		-0.20	%		10.15	%		8.75	%
S&P Developed Ex-U.S. Between $2B and $10B Index		-7.60	%		3.47	%		-14.48	%		-4.59	%		8.19	%		6.49	%
MSCI EAFE Index		-7.13	%		2.96	%		-13.83	%		-6.10	%		5.14	%		2.76	%
Lipper International Small/Mid Growth Funds Index		-6.03	%		7.68	%		-10.22	%		-2.99	%		9.65	%		9.40	%
Columbia Acorn Select (LTFAX) (10/16/00)		-8.51	%		7.64	%		-10.17	%		-2.93	%		7.05	%		8.67	%
S&P MidCap 400 Index		-4.93	%		7.90	%		-2.33	%		2.55	%		8.21	%		8.85	%
S&P 500 Index**		-2.75	%		9.49	%		5.45	%		0.22	%		5.33	%		3.01	%
Lipper Mid-Cap Growth Funds Index		-6.32	%		7.72	%		-5.16	%		1.61	%		7.29	%		5.92	%
Columbia Thermostat Fund (CTFAX) (3/3/03)†		-1.46	%		6.61	%		6.80	%		4.43	%		—			7.57	%
S&P 500 Index		-2.75	%		9.49	%		5.45	%		0.22	%		—			7.48	%
Barclays U.S. Aggregate Bond Index		2.06	%		2.37	%		7.47	%		6.79	%		—			5.31	%
Lipper Flexible Portfolio Funds Index		-2.89	%		5.75	%		-0.55	%		1.82	%		—			7.34	%
50/50 Blended Benchmark		-0.29	%		6.02	%		6.92	%		3.94	%		—			6.73	%
Columbia Acorn Emerging Markets Fund (CAGAX) (8/19/11)		-7.05	%		9.61	%		—			—			—			1.50	%*
S&P Emerging Markets Between $500M and $5B Index		-8.09	%		8.88	%		—			—			—			-5.77	%*
MSCI Emering Markets Small Cap Index		-8.02	%		7.27	%		—			—			—			-10.59	%*
Lipper Emerging Markets Index		-7.84	%		5.57	%		—			—			—			-1.62	%*
Columbia Acorn European Fund (CAEAX) (8/19/11)		-5.25	%		11.53	%		—			—			—			5.99	%*
S&P Europe Between $500M and $5B Index		-8.62	%		7.65	%		—			—			—			-0.07	%*
HSBC Smaller European Companies Index		-10.14	%		5.53	%		—			—			—			-4.53	%*
Lipper European Region Index		-7.82	%		5.05	%		—			—			—			3.75	%*

*Not annualized.

**Although the Fund typically invests in small- and mid-sized companies, the comparison to the S&P 500 Index is presented to show performance against a widely recognized market index over the life of the Fund.

Performance data shown represents past performance and is not a guarantee of future results. The investment return and principal value of an investment will fluctuate so that shares, when redeemed, may be worth more or less than their original cost. Current performance may be lower or higher than the performance data shown. Please visit columbiamanagement.com for daily and most recent month-end updates.

Performance results reflect any fee waivers or reimbursements of Fund expenses by the investment manager and/or its affiliates. Please see Page 130 of this report for information on contractual fee waiver/expense reimbursement arrangements in place for Columbia Acorn International, Columbia Thermostat Fund, Columbia Acorn Emerging Markets Fund and Columbia Acorn European Fund. Absent these fee waivers/expense reimbursement arrangements, performance results would have been lower. Annual operating expense ratios are stated as of each Fund's current prospectus dated May 1, 2012, and differences in expense ratios disclosed elsewhere in this report may result from application of any fee waivers/expense reimbursements as well as different time periods used in calculating the ratios. Columbia Acorn Fund: Class A: 1.11%; Class B: 1.81%; Class C: 1.94%; Class I: 0.71%. Columbia Acorn International: Class A: 1.35%; Class B: 2.08%; Class C: 2.14%; Class I: 0.86%; Class R: 1.42%; Class R5: 0.87%. Columbia Acorn USA: Class A: 1.33%; Class B: 2.10%; Class C: 2.18%; Class I: 0.95%. Columbia Acorn International Select: Class A: 1.62%; Class B: 2.32%; Class C: 2.44%; Class I: 1.08%. Columbia Acorn Select: Class A: 1.35%; Class B: 2.05%; Class C: 2.17%; Class I: 0.91%. Columbia Thermostat Fund: Class A: 1.15%; Class B: 1.65%; Class C: 1.90%. Columbia Acorn Emerging Markets Fund Class A: 1.85%; Class C: 2.60%; Class I: 1.41%. Columbia Acorn European Fund Class A: 1.75%; Class C: 2.50%; Class I: 1.31%.

†A "fund of funds" bears its allocable share of the costs and expenses of the underlying funds in which it invests. Such funds are thus subject to two levels of fees and potentially higher expense ratios than would be associated with an investment in a fund that invests and trades directly in financial instruments under the direction of a single manager.

The returns shown for "Life of Fund" are calculated from the inception date of the Fund. The returns shown for periods prior to inception of a Fund's Class A shares may append the returns of the Fund's Class Z shares, the Fund's oldest share class. These returns are adjusted to reflect any higher class-related operating expenses of the newer share classes, as applicable. Please visit columbiamanagement.com/mutual-funds/appended-performance for more information.

All results shown assume reinvestment of distributions and do not reflect the deduction of taxes that a shareholder would pay on fund distributions or on the redemption of Fund shares. Unlike mutual funds, indexes are not actively managed and do not incur fees or expenses. It is not possible to invest directly in an index.

3

Columbia Acorn Family of Funds

Descriptions of Indexes Included in this Report

•  50/50 Blended Benchmark, established by the Fund's investment manager, is an equally weighted custom composite of Columbia Thermostat Fund's primary equity and primary debt benchmarks, the S&P 500 Index and the Barclays U.S. Aggregate Bond Index, respectively. The percentage of the Fund's assets allocated to underlying stock and bond portfolio funds will vary, and accordingly the composition of the Fund's portfolio will not always reflect the composition of the 50/50 Blended Benchmark.

•  Barclays U.S. Aggregate Bond Index is a market value-weighted index that tracks the daily price, coupon, pay-downs and total return performance of fixed-rate, publicly placed, dollar-denominated and non-convertible investment grade debt issues with at least $250 million par amount outstanding and with at least one year to final maturity.

•  HSBC Smaller European Companies (inc UK) Index is a weighted combination of two indexes: the HSBC Smaller Europe (ex UK) Index and the HSBC Smaller UK Index. The index is rebalanced on a quarterly basis.

•  Lipper Indexes include the largest funds tracked by Lipper, Inc. in the named category. Lipper Mid-Cap Growth Funds Index, 30 largest mid-cap growth funds, including Columbia Acorn Fund and Columbia Acorn Select; Lipper International Small/Mid Growth Funds Index, 10 largest non-U.S. small/mid growth funds, including Columbia Acorn International; Lipper Small-Cap Growth Funds Index, 30 largest small-cap growth funds, including Columbia Acorn USA; Lipper Flexible Portfolio Funds Index, an equal-weighted index of the 30 largest mutual funds within the Flexible Portfolio fund classification, as defined by Lipper. Lipper Emerging Markets Index, 30 largest emerging markets funds; Lipper European Region Index, 10 largest European funds.

•  MSCI Europe, Australasia, Far East (EAFE) Index (Net) is a capitalization-weighted index that tracks the total return of common stocks in 22 developed-market countries within Europe, Australasia and the Far East. The returns of the MSCI EAFE Index (Net) are presented net of the withholding tax rate applicable to foreign non-resident institutional investors in the foreign companies included in the index who do not benefit from double taxation treaties.

•  MSCI Emerging Markets Small Cap Index, a widely recognized international benchmark, is a free float-adjusted market capitalization index that is designed to measure small-cap emerging market equity performance. The MSCI Emerging Markets Small Cap Index currently consists of the following 21 emerging market country indexes: Brazil, Chile, China, Colombia, Czech Republic, Egypt, Hungary, India, Indonesia, Korea, Malaysia, Mexico, Morocco, Peru, Philippines, Poland, Russia, South Africa, Taiwan, Thailand and Turkey.

•  Russell 2000 Index measures the performance of the 2,000 smallest companies in the Russell 3000 Index, which represents approximately 10% of the total market capitalization of the Russell 3000 Index.

•  Russell 2500 Index measures the performance of the 2,500 smallest companies in the Russell 3000 Index, which represents approximately 17% of the total market capitalization of the Russell 3000 Index.

•  Standard & Poor's (S&P) 500 Index tracks the performance of 500 widely held, large-capitalization U.S. stocks.

•  Standard & Poor's (S&P) MidCap 400 Index is a market value-weighted index that tracks the performance of 400 mid-cap U.S. companies.

•  S&P Developed Ex-U.S. Between $2B and $10B Index is a subset of the broad market selected by the index sponsor representing the mid-cap developed market, excluding the United States.

•  S&P Emerging Markets Between $500M and $5B Index represents the institutionally investable capital of emerging market countries with market caps ranging between $500 million to $5 billion, as selected by S&P. The index currently consists of the following 21 emerging market country indexes: Brazil, Chile, China, Colombia, Czech Republic, Egypt, Hungary, India, Indonesia, Korea, Malaysia, Mexico, Morocco, Peru, Philippines, Poland, Russia, South Africa, Taiwan, Thailand and Turkey.

•  S&P Europe Between $500M and $5B Index represents the institutionally investable capital of European countries with market caps ranging between $500 million to $5 billion, as selected by S&P. The index currently consists of the following 17 developed market country indexes: Austria, Belgium, Denmark, Finland, France, Germany, Greece, Ireland, Italy, Luxembourg, the Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and the United Kingdom.

•  S&P Global Ex-U.S. SmallCap Index consists of the bottom 20% of institutionally investable capital of developed and emerging countries, excluding the United States.

•  S&P Global Ex-U.S. Between $500M and $5B Index is a subset of the broad market selected by the index sponsor representing the mid- and small-cap developed and emerging markets, excluding the United States.

Unlike mutual funds, indexes are not managed and do not incur fees or expenses. It is not possible to invest directly in an index.

4

Chattering Squirrels: Columbia Thermostat Fund Turns 10

On September 25, 2002, Columbia Wanger Asset Management, LLC (CWAM) launched Columbia Thermostat Fund. To mark the Fund's 10-year anniversary, CWAM's founder, Ralph Wanger, who now serves as a trustee emeritus on the Columbia Acorn Funds board of trustees, and CWAM's chief investment officer and Columbia Thermostat Fund's current lead portfolio manager, Chuck McQuaid, got together to talk about the Fund. Ralph came up with the idea for the Columbia Thermostat Fund and was a portfolio manager of the Fund until 2005. Chuck has been a portfolio manager of the Fund since its inception.

Q: What drove you to launch the Columbia Thermostat Fund in 2002?

Ralph: In 2001, I started to give some thought to what the market was likely to do next. The bull market had died following the tech/media/telecom collapse. Could it be that the days of successfully investing using a buy-and-hold strategy were behind us? I studied the major tops in the stock market, especially 1929, 1968 and the Japanese market in 1989. All of these bull markets were followed by periods in which the market fluctuated wildly with no uptrend for an average of 25 years.

Dow Jones Industrial Average (1925 – 2012)

Source: Columbia Management Investment Advisers, LLC

While the Columbia Acorn Funds have always believed that good stock selection will do well in all market environments, if the market was going to be in a frustrating trading pattern for a long time, I figured a mutual fund that could take advantage of this pattern might be a worthwhile product.

I defined the bull market as the exponential state. A prime example of this type of market was the period from 1982 to 1999. I defined the second state as a sine wave market or a prolonged period during which the market moves up and down in a very quick and volatile fashion and equity investors make no forward progress. Previous periods of sine-wave movement occurred from 1930 to 1954 and from 1969 to 1981.

Exponential Market

Dow Jones Industrial Average 1982 – 1999

Source: Columbia Management Investment Advisers, LLC

Sine Wave Market

Dow Jones Industrial Average 1969 – 1981

Source: Columbia Management Investment Advisers, LLC

Chuck: I think it is fair to say that Columbia Thermostat Fund came about because Ralph is a student of market history. In a memo Ralph distributed within CWAM in May of 2002 titled, "How to Survive the Next Ten Years," he made the case for a Thermostat-type fund. He noted that the March 2000 peak was a three-way peak: a business cycle peak, a valuation peak and a psychological peak.

After such peaks a sine wave market can start. I believe this is because the stock market has a feedback loop into the economy itself and if the market goes up a lot companies raise a lot of capital and then put that capital to work. During the tech/media/telecom boom, companies raised enormous amounts of money that led to huge overcapacity. For example, loads of fiber optic cable was put in the ground and to this day the price just keeps going down for high-capacity internet connections. When you have a long capital cycle with too much capital invested, it increases competition and hurts profits. During sine wave periods, excess capital in the economy gets burned off and valuations in the market

5

drop from too high to too low. Sine wave markets also have the volatility we're experiencing now.

Q: So how does Columbia Thermostat Fund take advantage of these volatile conditions?

Ralph: The Fund is made up of a mix of stock and bond mutual funds. When the Standard & Poor's (S&P)® 500 Index goes up, the Fund sells a portion of its stock funds and invests more in its bond funds. When the S&P 500 Index goes down, the Fund increases its investment in stock funds and sells shares from the bond funds. It's as simple as that. I consider this rebalancing the real secret of the Fund. By doing this, we are essentially trying to use the market tides to pump energy into the Fund.

S&P Price Range & Columbia Thermostat's Equity Allocation

Source: Columbia Wanger Asset Management, LLC

There are other asset allocation funds that move assets from stocks to bonds based on market moves. Most asset allocation funds, however, are run by sophisticated investment professionals who make subjective decisions based on economic and financial data and complex graphs of market behavior. By contrast, the day-to-day investment decisions for the Columbia Thermostat Fund are made according to predetermined rules based on the current level of the S&P 500 Index. Because the Fund invests according to a pre-set program, there is no need for subjective day-to-day management.

Chuck: The Fund is designed for those who doubt the wisdom of trying to "time" the market. It simply buys stocks when they go down and sells them when they go up. The Fund takes psychology out of investing; it avoids the temptation to buy more stocks because the stock market is currently going up or to sell stocks because the market is declining. The Fund operates by investing its stock and bond assets according to a predetermined asset allocation table based on S&P 500 Index trading ranges described in the prospectus. For example, at June 30, 2012, the Fund had a 50% stock and 50% bond allocation because the S&P 500 Index fell into the 1350 to 1400 price level band. A 5% rebalance in one direction or the other will be triggered when the S&P 500 Index moves out of that range. The only exception is the result of our "31-day Rule." In order to reduce taxable events, after the Fund has increased its percentage allocation to either stock funds or bond funds, it will not decrease that allocation for at least 31 days. The 31-day Rule can also prevent the Fund from buying stock funds too soon during a sudden steep downward reversal in the market.

Stock/Bond Allocation Table

How the Fund will invest the stock/bond assets

Level of the S&P 500® Index	Stock Percentage			Bond Percentage
over 1750		10	%		90	%
over 1700-1750		15	%		85	%
over 1650-1700		20	%		80	%
over 1600-1650		25	%		75	%
over 1550-1600		30	%		70	%
over 1500-1550		35	%		65	%
over 1450-1500		40	%		60	%
over 1400-1450		45	%		55	%
over 1350-1400		50	%		50	%
over 1300-1350		55	%		45	%
over 1250-1300		60	%		40	%
over 1200-1250		65	%		35	%
over 1150-1200		70	%		30	%
over 1100-1150		75	%		25	%
over 1050-1100		80	%		20	%
over 1000-1050		85	%		15	%
1000 and under		90	%		10	%

Q: The name is a bit unusual. How did you come up with it?

Ralph: With this Fund, I wanted to create a very simple investment option, something that was easy to understand for investors at every level. I thought about my stepmother Elaine. She was very sweet and very sensible but she had no knowledge of finance. I wanted this fund to make sense to people like her. When thinking about what to name the Fund, I thought about familiar things, items we all have in our houses. The thermostat was an obvious choice: it keeps your house cool when it's hot and hot when it's cool. Columbia Thermostat Fund attempts to adjust the temperature of your investments in the same way.

Q: How has Columbia Thermostat Fund performed?

Chuck: Better than expected, actually. With this type of Fund, our hope was to provide Fund shareholders with returns that fell between the bond market and the S&P 500 Index, but to offer these returns with less volatility than the stock market. From inception through June 30, 2012, the Fund's Class A shares, without sales charge, had an annualized return of 7.57% and topped both the S&P 500 Index, which was up 7.48% for the period, and the Barclays U.S. Aggregate Bond Index, which was up 5.31%.¹ The Fund has a five-star overall Morningstar rating and is ranked in the top decile of the Morningstar aggressive allocation category for the one-, three- and five-year periods ended June 30, 2012.²

6

Q: What about the underlying investments? How do you choose the funds you use within this fund-of-funds?

Ralph: We want to have Columbia Thermostat Fund invested broadly across the stock and bond universes, while being biased toward segments and funds that we think are relatively attractive. We initially selected from among the Columbia Acorn Funds managed by CWAM, which provided fine opportunities in the small- and mid-cap equity segments. We also added mid-cap and large-cap stock funds and bond funds managed by Columbia Management Investment Advisers, LLC (CMIA). When the Fund launched in 2002, we had a bias toward small- and mid-caps in our weighting because they appeared relatively cheap.

Allocation of Stock/Bond Assets Within Asset Classes

As of June 30, 2012

Columbia Stock Funds	Type of Fund	Allocation
Acorn Fund	Small/Mid-cap growth		15	%
Acorn Select	Mid-cap growth		10	%
Acorn International	Small/Mid-cap international growth		20	%
Dividend Income Fund	Large-cap value		20	%
Large Cap Enhanced Core Fund	Large-cap blend		10	%
Contrarian Core Fund	Large-cap blend		15	%
Select Large Cap Growth Fund	Large-cap growth		10	%
Columbia Bond Funds	Type of Fund	Allocation
Intermediate Bond Fund	Intermediate-term bonds		50	%
Income Opportunities Fund	High-yield bonds		30	%
U.S. Treasury Index Fund	U.S. Treasury notes/bonds		20	%

Chuck: CMIA and CWAM combined manage 56 mutual funds rated four or five stars overall by Morningstar. As of June 30, 2012, Columbia Thermostat Fund was invested in 10 funds, nine of which had overall Morningstar ratings of four or five stars. We certainly have lots of highly rated funds to choose from.³ However, past performance does not guarantee future results.

Q: Since Columbia Thermostat Fund was designed largely to buy stocks low and sell them high, why does the Fund own bond funds instead of money market funds?

Ralph: Bond funds usually yield more than money market funds, tend to have much lower volatility than stock funds, and their short-term returns are generally not correlated much with stock funds. I also thought that in a sine wave scenario, bond funds would have returns not far from stock funds. We choose bond funds with relatively short durations to reduce risk from rising interest rates, though interest rates have instead fallen for much of Columbia Thermostat Fund's history.

Q: How has the Fund changed over time?

Chuck: We do a review of the allocation table and underlying funds held in the portfolio at least annually. We take a long-term perspective on what the trading range of the stock market might be and, as Ralph mentioned, which market segments and funds appear relatively attractive.

Our first adjustments to the portfolio were made in September 2005. At that time, we changed the stock allocation table to allow for more equities within the new ranges. We also changed the equity fund line-up to reduce domestic small- and mid-cap exposure from 50% to 25% because smaller cap stock valuations seemed to be getting high. Equity large-cap exposure was increased from 50% to 60% and, with the addition of Columbia Acorn International, we invested in an international component for the first time. International stocks looked relatively attractive, international investing tends to provide excellent diversification and Columbia Acorn International's performance was gaining traction.

During the Fund's 10-year history, we've adjusted the allocation table three times to hike the stock weighting and one time to cut it, each time in response to what we perceived as changes in stock trading ranges. Additional adjustments have also been made to the underlying funds. Most recently, in December 2011, we rebalanced the Fund's bond exposure after looking at interest rate spreads. Treasury rates looked pretty low and corporate bond rates looked more attractive so we did some swapping. We also fine-tuned the investment mix of the Fund's large-cap equity portion.

One other thing we consider is expenses. When debating between similar investments, the lower-cost funds have an edge. In 2011, we exchanged from the Class Z shares of each underlying fund to the newly introduced Class I shares, which is a lower-cost Columbia share class available only to fund-of-funds, such as Columbia Thermostat Fund.

Q: Have there been any times during the past 10 years when the Fund didn't work as you'd expected?

Ralph: Well, there was one law of economics that we forgot about when we launched the Fund: Murphy's Law. In September 2002, the market was at a low and then in 2003, there was a roaring upswing, which dampened interest in an asset allocation fund. As it turned out, the mini bull market of 2003 was just the upside of the sine.

Chuck: Also, Columbia Thermostat Fund was never set up to be a doomsday fund for the ultra bears who thought the market was going to go to zero. It was always meant for a market that was trading within a range and so we set the allocation table based on our expectations for the market. The real estate collapse in 2008 and the subsequent market turmoil was not something we anticipated so we were 100% invested in stocks for nine months from October 2008 through June 2009. We had raised the allocation table in January of 2008 because we felt price-to-earnings ratios had compressed enough and because we didn't want to go to a zero percentage weight in stocks. Well, that didn't happen! In effect, we had over-estimated earnings but the important thing was not to compound the impact in a knee-jerk reaction and sell stocks at or near the bottom. As it turned out, we

7

rode out the storm and caught every bit of the initial upside when the wave turned, starting in March 2009.

Q: Do you dare speculate on how long you think this sine wave will last?

Ralph: That is the question, isn't it? Let's say it's July and it's 97 degrees. What do you wear to work? Likely very light-weight clothing. In February in Chicago when it's 10 below zero, we dress entirely differently with coats, hats and gloves on top of wool suits. If you dress for the weather, you ought to invest for the weather. Investing in a long-only fund is basically a summer idea, best followed when things are optimistic and warm and beautiful. Columbia Thermostat Fund is a winter-time fund that is designed to be variable and that seeks to help you weather stormy and cold days. I believe a long-only fund and an asset allocation fund ought to both be owned within a long-term investment strategy. The tricky part is knowing when to switch from one to the other. The good news is that the failure consequence is different. If you own a long-only fund and you hold it too long and the market goes down dramatically, you lose money and feel lousy. With Columbia Thermostat Fund, if the next exponential market starts, the Fund is designed to turn into more of a bond fund that seeks to preserve your capital and go up a little bit.

If we look to history for the answer, we see that the sine wave markets have lasted quite a while. As I mentioned earlier, after 1929 it took 25 years to reach the old high. After 1968, it also took 25 years, adjusted for inflation. In Japan, their market peaked in late 1989 at 38,000 and it's now about 9,000 after 22 years. It's certainly going to take more than 25 years for that country to get back to the old high. After more than 20 years of a sine wave market, you can be assured of one thing: almost everyone will be disgusted with stocks.

Japanese Great Recession

Source: Columbia Management Investment Advisers, LLC

Chuck: I can attest to that from my own experience. I began my career in the investment industry in 1976 and friends I had in my MBA program thought I was nuts for choosing this sector. They didn't think anyone could make money in stocks because stocks had been flat or down for a very long time. As it turned out, it was a great time to launch a career in this industry. The term I use is stocks were "in the wilderness." No one cared about stocks and no one wanted to talk about them. People weren't bragging about their portfolios but were taking cover in other investment options. While I still believe that investing in stocks with good fundamentals and growth potential can yield good results in the market, stocks generally seem to be somewhat in the wilderness now.

Ralph: Yes, I suppose we could get to the point where the word "stock" will first bring to mind cattle or a task assigned to supermarket employees. When that happens, go long!

Charles P. McQuaid

President and Chief Investment Officer
Columbia Wanger Asset Management, LLC
Trustee, Columbia Acorn Trust and Wanger Advisors Trust
Current Portfolio Manager, Columbia Thermostat Fund

Ralph Wanger

Retired Founder, Columbia Wanger Asset Management, LLC
Trustee Emeritus, Columbia Acorn Trust and Wanger Advisors Trust
Former Portfolio Manager, Columbia Thermostat Fund

The information and data provided in this analysis are derived from sources that we deem to be reliable and accurate. These views are not guarantees of future performance and involve certain risks, uncertainties and assumptions that are difficult to predict so actual outcomes and results may differ significantly from the views expressed. The views/opinions expressed in "Chattering Squirrels" are those of the authors and not of the Columbia Acorn Trust Board, are subject to change at any time based upon economic, market or other conditions, may differ from views expressed by other Columbia Management associates and the respective parties disclaim any responsibility to update such views. These views may not be relied on as investment advice and, because investment decisions for a Columbia Acorn Fund are based on numerous factors, may not be relied on as an indication of trading intent on behalf of any particular Columbia Acorn Fund.

¹  Please see Page 3 of this report for additional performance data for Columbia Thermostat Fund and its benchmarks.

²  Overall rating among 371 Aggressive Allocation funds. The Fund received a Morningstar Rating of 5 stars among 371 funds and 5 stars among 345 funds for the 3- and 5-year periods, respectively.

³  All ratings are for Class Z shares as of 06/30/12. Other classes may have different performance characteristics and may have different ratings. Out of 118 Z-share Columbia funds rated by Morningstar, eight funds received a 5-star Overall Rating and 48 funds received a 4-star Overall Rating. The Overall Morningstar Rating^TM for a fund is derived from a weighted average of the performance figures associated with its 3-, 5- and 10-year Morningstar Rating metrics.

For each fund with at least a 3-year history, Morningstar calculates a Morningstar Rating based on a Morningstar Risk-Adjusted Return measure that accounts for variation in a fund's monthly performance (including the effects of sales charges, loads and redemption fees), placing more emphasis on downward variations and rewarding consistent performance. The top 10% of funds in each category receive 5 stars, the next 22.5% receive 4 stars, the next 35% receive 3 stars, the next 22.5% receive 2 stars and the bottom 10% receive 1 star. (Each share class is counted as a fraction of one fund within this scale and rated separately, which may cause slight variations in the distribution percentages.)

  © 2012 Morningstar, Inc. All rights reserved. The Morningstar information contained herein: (1) is proprietary to Morningstar and/or its content providers; (2) may not be copied or distributed; and (3) is not warranted to be accurate, complete or timely. Neither Morningstar nor its content providers are responsible for any damages or losses arising from any use of this information.

8

Understanding Your Expenses

As a shareholder, you incur two types of costs. There are transaction costs, which generally include sales charges on purchases and may include redemption fees. There are also ongoing costs, which generally include management fees, distribution and service (Rule 12b-1) fees, and other Fund expenses. The following information is intended to help you understand your ongoing costs (in dollars) of investing in the Fund and to help you compare these costs with the ongoing costs of investing in other mutual funds.

Analyzing Your Fund's Expenses

To illustrate these ongoing costs, we have provided examples and calculated the expenses paid by investors in Class A, B, C, I, R and R5 shares of the Funds during the period. The actual and hypothetical information in the tables is based on an initial investment of $1,000 at the beginning of the period indicated and held for the entire period. Expense information is calculated two ways and each method provides you with different information. The amount listed in the "Actual" column is calculated using the Funds' actual operating expenses and total return for the period. You may use the Actual information, together with the amount invested, to estimate the expenses that you paid over the period. Simply divide your account value by $1,000 (for example, an $8,600 account value divided by $1,000 = 8.6), then multiply the results by the expenses paid during the period under the Actual column. The amount listed in the "Hypothetical" column assumes a 5% annual rate of return before expenses (which is not the Funds' actual return) and then applies the Funds' actual expense ratio for the period to the hypothetical return. You should not use the hypothetical account values and expenses to estimate either your actual account balance at the end of the period or the expenses you paid during the period. See "Compare With Other Funds" below for details on how to use the hypothetical data.

In addition to the ongoing expenses which the Funds bear directly, Columbia Thermostat Fund's shareholders indirectly bear the Fund's allocable share of the costs and expenses of each underlying fund in which the Fund invests. You can also estimate the effective expenses paid during the period, which includes the indirect fees associated with investing in the underlying funds, by using the amounts listed in the effective expenses paid during the period column in the "Fund of Funds" table on Page 11.

Compare With Other Funds

Since all mutual funds are required to include the same hypothetical calculations about expenses in shareholder reports, you can use this information to compare the ongoing cost of investing in the Funds with other funds. To do so, compare the hypothetical example with the 5% hypothetical examples that appear in the shareholder reports of other funds. As you compare hypothetical examples of other funds, it is important to note that hypothetical examples are meant to highlight the ongoing costs of investing in a fund only and do not reflect any transaction costs, such as sales charges, or redemption or exchange fees. Therefore, the hypothetical calculations are useful in comparing ongoing costs only, and will not help you determine the relative total costs of owning different funds. If transaction costs were included in these calculations, your costs would be higher.

January 1, 2012 – June 30, 2012

	Account value at the beginning of the period ($)				Account value at the end of the period ($)				Expenses paid during the period ($)				Fund's annualized expense ratio (%)
	Actual		Hypothetical		Actual		Hypothetical		Actual		Hypothetical		Actual
Columbia Acorn Fund
Class A		1,000.00		1,000.00		1,091.10		1,019.64		5.46		5.27		1.05
Class B		1,000.00		1,000.00		1,087.80		1,016.66		8.57		8.27		1.65
Class C		1,000.00		1,000.00		1,087.00		1,015.91		9.34		9.02		1.80
Class I		1,000.00		1,000.00		1,092.70		1,021.28		3.75		3.62		0.72

9

Understanding Your Expenses

continued

	Account value at the beginning of the period ($)				Account value at the end of the period ($)				Expenses paid during the period ($)				Fund's annualized expense ratio (%)
	Actual		Hypothetical		Actual		Hypothetical		Actual		Hypothetical		Actual
Columbia Acorn International
Class A		1,000.00		1,000.00		1,085.60		1,018.70		6.43		6.22		1.24
Class B		1,000.00		1,000.00		1,081.70		1,014.97		10.30		9.97		1.99
Class C		1,000.00		1,000.00		1,081.70		1,014.97		10.30		9.97		1.99
Class I		1,000.00		1,000.00		1,087.90		1,020.54		4.52		4.37		0.87
Class R		1,000.00		1,000.00		1,083.80		1,017.55		7.62		7.37		1.47
Class R5		1,000.00		1,000.00		1,087.20		1,020.34		4.57		4.42		0.88
Columbia Acorn USA
Class A		1,000.00		1,000.00		1,101.50		1,018.35		6.84		6.57		1.31
Class B		1,000.00		1,000.00		1,097.70		1,014.87		10.48		10.07		2.01
Class C		1,000.00		1,000.00		1,097.90		1,014.67		10.69		10.27		2.05
Class I		1,000.00		1,000.00		1,103.80		1,020.09		5.02		4.82		0.96
Columbia Acorn International Select
Class A		1,000.00		1,000.00		1,102.30		1,017.40		7.84		7.52		1.50
Class B		1,000.00		1,000.00		1,098.90		1,014.37		11.01		10.57		2.11
Class C		1,000.00		1,000.00		1,098.10		1,013.48		11.95		11.46		2.29
Class I		1,000.00		1,000.00		1,104.40		1,019.19		5.96		5.72		1.14
Columbia Acorn Select
Class A		1,000.00		1,000.00		1,076.40		1,018.30		6.81		6.62		1.32
Class B		1,000.00		1,000.00		1,073.00		1,015.42		9.79		9.52		1.90
Class C		1,000.00		1,000.00		1,072.30		1,014.57		10.67		10.37		2.07
Class I		1,000.00		1,000.00		1,077.90		1,020.04		5.01		4.87		0.97
Columbia Acorn Emerging Markets Fund
Class A		1,000.00		1,000.00		1,096.10		1,015.96		9.33		8.97		1.79
Class C		1,000.00		1,000.00		1,093.10		1,012.18		13.27		12.76		2.55
Class I		1,000.00		1,000.00		1,097.60		1,017.85		7.35		7.07		1.41
Columbia Acorn European Fund
Class A		1,000.00		1,000.00		1,115.30		1,016.91		8.41		8.02		1.60
Class C		1,000.00		1,000.00		1,109.90		1,012.98		12.54		11.96		2.39
Class I		1,000.00		1,000.00		1,116.40		1,018.35		6.89		6.57		1.31

10

Fund of Funds—Columbia Thermostat Fund

January 1, 2012 – June 30, 2012

	Account value at the beginning of the period ($)				Account value at the end of the period ($)				Expenses paid during period ($)				Fund's annualized expense ratio (%)		Effective expenses paid during the period				Fund's effective annualized expense ratio (%)
	Actual		Hypothetical		Actual		Hypothetical		Actual		Hypothetical		Actual		Actual		Hypothetical		Actual
Columbia Thermostat Fund
Class A		1,000.00		1,000.00		1,066.10		1,022.38		2.57		2.51		0.50		5.70		5.58		1.11
Class B		1,000.00		1,000.00		1,063.30		1,019.89		5.13		5.02		1.00		8.26		8.09		1.61
Class C		1,000.00		1,000.00		1,061.80		1,018.65		6.41		6.27		1.25		9.53		9.34		1.86

Expenses paid during the period are equal to the annualized expense ratio, multiplied by the average account value over the period and then multiplied by the number of days in the Fund's most recent fiscal half year and divided by 366.

Expenses do not include fees and expenses incurred indirectly by the Fund from the underlying funds in which the Fund may invest (also referred to as "acquired funds"), including affiliated and non-affiliated pooled investments vehicles (including mutual funds and exchange traded funds).

In the case of Columbia Thermostat Fund, effective expenses paid during the period and the Fund's effective annualized expense ratio include expenses borne directly by the class plus the Fund's pro rata portion of the ongoing expenses charged by the underlying funds using the expense ratio of each class of the underlying funds as of the underlying fund's most recent shareholder report.

Had the investment adviser and/or certain of its affiliates not waived/reimbursed certain fees and expenses, account value at the end of the period would have been reduced.

11

Columbia Acorn Fund

In a Nutshell

Charles P. McQuaid	Robert A. Mohn
Lead Portfolio Manager	Co-Portfolio Manager

Performance data shown represents past performance and is not a guarantee of future results. The investment return and principal value will fluctuate so that shares, when redeemed, may be worth more or less than the original cost. Current performance may be lower or higher than the performance data shown. Please visit columbiamanagement.com for daily and most recent month-end performance updates.

Fund Positions
in Mentioned Holdings

As a percentage of net assets, as of 6/30/12

lululemon athletica	1.6	%
Crown Castle International	1.5	%
tw telecom	1.4	%
FMC Technologies	1.2	%
SBA Communications	1.1	%
Biomarin Pharmaceuticals	1.0	%
Seattle Genetics	0.9	%
Alexion Pharmaceuticals	0.9	%
Coach	0.7	%
Auxilium Pharmaceuticals	0.5	%
Pacific Rubiales Energy	0.5	%
Onyx Pharmaceuticals	0.3	%
Fossil	0.2	%

Columbia Acorn Fund fell 5.48% (Class A shares, without sales charge) in the second quarter, offsetting some of the first quarter gains to end up 9.11% for the first half of 2012. The Fund's primary benchmark, the Russell 2500 Index, dropped 4.14% in the quarter and rose 8.31% during the half year. In both periods, Columbia Acorn Fund beat the Lipper Mid-Cap Growth Index, which fell 6.32% in the quarter and gained 7.72% in the half.

Driven by explosive growth in data transmission, telecom stocks helped performance during both the quarter and the half. Cell tower companies Crown Castle International and SBA Communications rose 10% and 12%, respectively, in the quarter and 31% and 33%, respectively, in the half. tw telecom, which provides fiber optic connections to over 15,000 buildings, grew 16% in the second quarter and 32% in the half.

Pharmaceutical and biotech stocks bolstered performance in the second quarter. Onyx Pharmaceuticals, Auxilium Pharmaceuticals, Seattle Genetics and Biomarin Pharmaceuticals all reported good news about drugs either recently approved and/or in development pipelines. The stocks' gains in the quarter ranged from 16% to 77%. Alexion Pharmaceuticals rose 7% in the quarter, resulting in a 39% gain in the half and making it the Fund's second largest dollar winner year to date through June 30.

Consumer durable and apparel stocks helped performance in the first quarter but hurt in the second. The Fund's largest dollar loser in the second quarter was premium active apparel retailer lululemon athletica, down 20% on disappointing earnings guidance. Last year investors were wrongly concerned that inventories were too high but, in the second quarter of 2012, low inventories reduced near-term earnings upside. Due to fine first quarter performance, lululemon was still the Fund's largest dollar winner for the half, up 28%. Other consumer stocks fell in the second quarter due to concerns about sales overseas; handbag maker Coach dropped 24% and watch designer and retailer Fossil fell 42%.

Energy stocks were also disappointing in the second quarter, largely due to declining oil prices and low natural gas prices. In addition, offshore oil equipment maker FMC Technologies had problems ramping up production. Its stock fell 22% in the quarter and was down 25% in the half, making it the Fund's second largest dollar loser in the quarter and the largest loser in the half. Colombian oil producer Pacific Rubiales Energy continued to be volatile; after surging 59% in the first quarter, it fell 27% in the second. The company suffered from delays in receiving drilling permits and lacked new oil discoveries. We cut the Fund's weighting in energy stocks during the second quarter to 6.2%, about matching the benchmark.

Columbia Acorn Fund's international stocks were off 12.74% in the quarter and up just 2.31% in the half.* While we see lots of foreign companies with good business models and attractively valued stocks, we fear macroeconomic concerns could keep their stocks depressed. Foreign holdings accounted for 8.3% of assets at the end of the half, down from 9.2% at the end of the first quarter and 9.3% at the end of 2011. Investors that desire greater exposure to foreign stocks may wish to consider one or more of the Columbia Acorn international funds.

As of press time, a majority of companies in Columbia Acorn Fund seem to be achieving their earnings targets, though many are cutting their outlooks somewhat. Corporations and consumers have generally improved their balance sheets since the Great Recession. As a percentage of income, minimum required payments on consumer mortgages and consumer credit are near 20-year lows. However, federal government deficit, tax and regulatory issues appear to be hindering economic growth and causing uncertainty in the markets. We can't predict when uncertainty will lessen, but when it does, stock prices may be a lot higher. We continue to pursue investments in good businesses at reasonable prices.

*These returns are not comparable to mutual fund returns, as they are gross of fees and other expenses and do not portray the cash effects incurred by actual mutual funds. Columbia Acorn Fund's foreign stockholdings were not purchased as a balanced, stand-alone portfolio.

Stocks of small- and mid-cap companies pose special risks, including possible illiquidity and greater price volatility than stocks of larger, more established companies. International investing involves special risks, including foreign taxation, currency risks, risks associated with possible differences in financial standards and other risks associated with future political and economic developments.

Portfolio holdings are subject to change periodically and may not be representative of current holdings.

12

Columbia Acorn Fund

At a Glance (Class A Shares - LACAX)

Performance data shown represents past performance and is not a guarantee of future results. The investment return and principal value of an investment will fluctuate so that shares, when redeemed, may be worth more or less than their original cost. Current performance may be lower or higher than the performance data shown. Performance results reflect any fee waivers or reimbursements of Fund expenses by the investment manager and/or any of its affiliates. Absent these fee waivers and/or expense reimbursement arrangements, performance results would have been lower. Please visit columbiamanagement.com for daily and most recent month-end updates.

Pretax and After-tax Average Annual Total Returns (Based on Class A Share Returns, inception 10/16/00)

through June 30, 2012

		Year to date*			1 year			5 years			10 years
Returns before taxes	NAV POP		9.11 2.85	%		-3.03 -8.62	%		1.40 0.21	%		9.22 8.57	%
Returns after taxes on distributions	NAV POP		8.90 2.66			-3.68 -9.22			0.88 -0.31			8.63 7.99
Returns after taxes on distributions and sale of fund shares	NAV POP		6.18 2.10			-1.18 -4.86			1.16 0.14			8.12 7.53
Russell 2500 Index** (pretax)			8.31			-2.29			1.18			8.01

All results shown assume reinvestment of distributions.

*Year to date data is not annualized.

**The Fund's primary benchmark.

After-tax returns are calculated using the highest historical individual federal marginal income tax rates, and do not reflect the impact of state and local taxes. Returns after taxes on distributions and sale of Fund shares reflect the additional tax impact of long-term gains or losses realized when Fund shares are sold. The returns are taxed at the maximum rate and assume shares were purchased at the beginning of the period. Actual after-tax returns depend on the investor's tax situation and may differ from those shown. After-tax returns are not relevant to investors who hold their Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts. After-tax returns are shown for Class A shares only; after-tax returns for other share classes will vary. Indexes do not reflect any deduction for fees, expenses or taxes.

Public offering price (POP) returns include the maximum sales charge of 5.75% for Class A shares. Net asset value (NAV) returns do not include sales charges or contingent deferred sales charges (CDSC).

The Fund's Class A shares annual operating expense ratio, as stated in the May 1, 2012, prospectus, is 1.11%.

Columbia Acorn Fund Portfolio Diversification

as a percentage of net assets, as of 6/30/12

Columbia Acorn Fund Top 10 Holdings

as a percentage of net assets, as of 6/30/12

1.	Ametek Aerospace/Industrial Instruments	2.0	%
2.	Donaldson Industrial Air Filtration	1.6	%
3.	lululemon athletica Premium Active Apparel Retailer	1.6	%
4.	Crown Castle International Communications Towers	1.5	%
5.	Mettler-Toledo International Laboratory Equipment	1.5	%
6.	tw telecom Fiber Optic Telephone/Data Services	1.4	%
7.	Informatica Enterprise Data Integration Software	1.2	%
8.	Cepheid Molecular Diagnostics	1.2	%
9.	FMC Technologies Oil & Gas Well Head Manufacturer	1.2	%
10.	SBA Communications Communications Towers	1.1	%

The Fund's top 10 holdings and portfolio diversification vary with changes in portfolio investments. See the Statement of Investments for a complete list of the Fund's holdings.

The Growth of a $10,000 Investment in Columbia Acorn Fund (Class A)

June 10, 1970 (Fund inception) through June 30, 2012

The chart shows the change in value of a hypothetical $10,000 investment in Class A shares of the Fund during the stated time period. Although the indexes are provided for use in assessing the Fund's performance, the Fund's holdings may differ significantly from those in the index. It is not possible to invest directly in an index. The graph does not reflect taxes that a shareholder may pay on Fund distributions or on a sale of Fund shares.

The returns shown for periods prior to the inception date of the Fund's Class A shares are calculated from the inception date of the Fund and append the returns of the Fund's Class Z shares, the Fund's oldest share class. These returns are adjusted to reflect any higher class-related operating expenses of the newer share classes, as applicable. Please visit columbiamanagement.com/mutual-funds/appended-performance for more information.

Total Net Assets of the Fund: $17.2 billion

*  A $10,000 investment in Columbia Acorn Fund at inception appreciated to $30,945 on December 31, 1978, the inception date of the Russell 2500 Index. For comparison with the Russell 2500 Index, we assigned the index the same value as the Fund at index inception.

**Although the Fund typically invests in small- and mid-sized companies, the comparison to the S&P 500 Index is presented to show performance against a widely recognized market index over the life of the Fund.

13

Columbia Acorn International

In a Nutshell

P. Zachary Egan	Louis J. Mendes III
Co-Portfolio Manager	Co-Portfolio Manager

Performance data shown represents past performance and is not a guarantee of future results. The investment return and principal value will fluctuate so that shares, when redeemed, may be worth more or less than the original cost. Current performance may be lower or higher than the performance data shown. Please visit columbiamanagement.com for daily and most recent month-end performance updates.

Fund's Positions
in Mentioned Holdings

As a percentage of net assets, as of 6/30/12

Eurofins Scientific	1.1	%
Gemalto	0.9	%
Mongolian Mining	0.6	%
Nagacorp	0.4	%
Northam Platinum	0.4	%
Archipelago Resources	0.4	%
FMC Technologies	0.3	%
Celtic Exploration	0.1	%

Columbia Acorn International fell 5.60% (Class A shares, without sales charge) in the second quarter of 2012, which was 2.43% better than its primary benchmark, the S&P Global Ex-U.S. between $500M and $5B Index. This comes on the heels of a strong first quarter, during which the Fund was up 14.99%. The Fund's return for the first half of the year was 8.56%, 3.74% ahead of the benchmark. For comparison, the large-cap, developed-market MSCI EAFE Index rose 2.96% during the six month period.

This reversal of fortune in the markets in the second quarter occurred in a context of high anxiety regarding the financial stability of peripheral eurozone states and the worsening outlook for Chinese growth. Markets do not like uncertainty and the lack of a resolution to European budget crises continues to rattle the confidence of long-term investors in the region. As confidence falls, sovereign borrowing costs rise, which further deteriorates the long-term financial outlook. Aside from this unhelpful, self-reinforcing mechanism, signs of a slowing Chinese economy further fueled market volatility. Despite the ebb and flow of sentiment, however, many of the Fund's holdings have continued to post a pleasing growth in earnings.

Most notable about the Fund's first-half results is the relatively strong performance of classic "Acorn-style" companies. By this we refer to companies that are taking advantage of structural changes within the market for their products or services—whether related to regulation, technology, energy efficiency, social change or otherwise. These can be contrasted with companies that primarily depend on macroeconomic factors to drive earnings. Top performers for the half year included Nagacorp (+85%), a Cambodian-based casino operator catering to the growing needs of Indochina's emerging middle class for quality entertainment facilities. Two French companies, Eurofins Scientific (+72%) and Gemalto (+47%) performed well despite eurozone concerns. Eurofins Scientific provides laboratory analysis of food, pharmaceuticals and cosmetics products globally and, after a long period of consolidation, looms as a one-stop solution for multinational companies and others increasingly concerned with the safety and purity of traded goods. Gemalto is a leader in developing smart-chip technology for use in credit cards and mobile handsets. These mobile devices are finding increasingly valuable applications in secure payment systems.

Macroeconomic worries did hurt the Fund in commodity-related holdings. Fears of slower global growth drove down a number of energy and basic material stocks. Indonesian gold miner Archipelago Resources (-26%), Mongolian coal miner Mongolian Mining (-24%) and South African platinum miner Northam Platinum (-23%) all fell during the half year on weakened outlook for demand. Similarly, oil exploration-related companies Celtic Exploration (-41%) and FMC Technologies (-25%) declined on expectations that oil prices would soften.

We expect continued volatility in the second half of the year. The euro debt crisis does not lend itself to a tidy resolution in the short- or even mid-term. The most likely outcome in our view is piecemeal structural reform within uncompetitive states, incented by explicit and tacit German support and the fact that the alternatives entail a lower standard of living for these states on a long-term basis. We believe that will be a political process fraught with complexity and made more complicated by the way Europe is organized. In the fall, the presidential election in the United States and the transition of leadership in China will also likely become a focus for continued sentiment shifts in the marketplace. As always, we will strive to work through the noise to identify companies where reasonable valuations are supported by good or improving fundamentals. Thank you for your continued investment in the Fund.

International investing involves special risks, including foreign taxation, currency risks, risks associated with possible differences in financial standards and other risks associated with future political and economic developments. Stocks of small- and mid-cap companies pose special risks, including possible illiquidity and greater price volatility than stocks of larger, more established companies. Investing in emerging markets may involve greater risks than investing in more developed countries. In addition, concentration of investments in a single region may result in greater volatility.

Portfolio holdings are subject to change periodically and may not be representative of current holdings.

14

Columbia Acorn International

At a Glance (Class A Shares - LAIAX)

Performance data shown represents past performance and is not a guarantee of future results. The investment return and principal value of an investment will fluctuate so that shares, when redeemed, may be worth more or less than their original cost. Current performance may be lower or higher than the performance data shown. Performance results reflect any fee waivers or reimbursements of Fund expenses by the investment manager and/or any of its affiliates. Absent these fee waivers and/or expense reimbursement arrangements, performance results would have been lower. Please visit columbiamanagement.com for daily and most recent month-end updates.

Pretax and After-tax Average Annual Total Returns (Based on Class A Share Returns, inception 10/16/00)

through June 30, 2012

		Year to date*			1 year			5 years			10 years
Returns before taxes	NAV POP		8.56 2.32	%		-9.63 -14.82	%		-1.20 -2.36	%		10.67 10.01	%
Returns after taxes on distributions	NAV POP		8.49 2.26			-9.57 -14.76			-1.66 -2.81			10.19 9.54
Returns after taxes on distributions and sale of fund shares	NAV POP		5.56 1.51			-6.15 -9.53			-1.04 -2.01			9.55 8.94
S&P Global Ex-US Between $500M and $5B Index** (pretax)			4.82			-15.17			-2.48			10.95

All results shown assume reinvestment of distributions.

*Year to date data is not annualized.

**The Fund's primary benchmark.

After-tax returns are calculated using the highest historical individual federal marginal income tax rates, and do not reflect the impact of state and local taxes. Returns after taxes on distributions and sale of Fund shares reflect the additional tax impact of long-term gains or losses realized when Fund shares are sold. The returns are taxed at the maximum rate and assume shares were purchased at the beginning of the period. Actual after-tax returns depend on the investor's tax situation and may differ from those shown. After-tax returns are not relevant to investors who hold their Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts. After-tax returns are shown for Class A shares only; after-tax returns for other share classes will vary. Indexes do not reflect any deduction for fees, expenses or taxes.

Public offering price (POP) returns include the maximum sales charge of 5.75% for Class A shares. Net asset value (NAV) returns do not include sales charges or contingent deferred sales charges (CDSC).

The Fund's Class A shares annual operating expense ratio, as stated in the May 1, 2012, prospectus, is 1.35%.

Columbia Acorn International Portfolio Diversification

as a percentage of net assets, as of 6/30/12

Columbia Acorn International Top 10 Holdings

as a percentage of net assets, as of 6/30/12

1.	Far EasTone Telecom (Taiwan) Taiwan's Third Largest Mobile Operator	1.3	%
2.	Melco Crown Entertainment (Hong Kong) Macau Casino Operator	1.2	%
3.	Hexagon (Sweden) Design, Measurement & Visualization Software & Equipment	1.2	%
4.	Eurofins Scientific (France) Food, Pharmaceuticals & Materials Screening & Testing	1.1	%
5.	Naspers (South Africa) Media in Africa, China, Russia & Other Emerging Markets	1.0	%
6.	Kansai Paint (Japan) Paint Producer in Japan, India, China & Southeast Asia	1.0	%
7.	Localiza Rent A Car (Brazil) Car Rental	0.9	%
8.	Partners Group (Switzerland) Private Markets Asset Management	0.9	%
9.	Taiwan Mobile (Taiwan) Taiwan's Second Largest Mobile Operator	0.9	%
10.	Gemalto (France) Digital Security Solutions	0.9	%

The Fund's top 10 holdings and portfolio diversification vary with changes in portfolio investments. See the Statement of Investments for a complete list of the Fund's holdings.

The Growth of a $10,000 Investment in Columbia Acorn International (Class A)

September 23, 1992 (Fund inception) through June 30, 2012

The chart shows the change in value of a hypothetical $10,000 investment in Class A shares of the Fund during the stated time period. Although the index is provided for use in assessing the Fund's performance, the Fund's holdings may differ significantly from those in the index. It is not possible to invest directly in an index. The graph does not reflect taxes that a shareholder may pay on Fund distributions or on a sale of Fund shares.

The returns shown for periods prior to the inception date of the Fund's Class A shares are calculated from the inception date of the Fund and append the returns of the Fund's Class Z shares, the Fund's oldest share class. These returns are adjusted to reflect any higher class-related operating expenses of the newer share classes, as applicable. Please visit columbiamanagement.com/mutual-funds/appended-performance for more information.

Total Net Assets of the Fund: $6.0 billion

15

Columbia Acorn USA

In a Nutshell

Robert A. Mohn

Lead Portfolio Manager

Performance data shown represents past performance and is not a guarantee of future results. The investment return and principal value will fluctuate so that shares, when redeemed, may be worth more or less than the original cost. Current performance may be lower or higher than the performance data shown. Please visit columbiamanagement.com for daily and most recent month-end performance updates.

Fund's Positions
in Mentioned Holdings

As a percentage of net assets, as of 6/30/12

Informatica	2.4	%
tw telecom	2.4	%
lululemon athletica	2.2	%
Gaylord Entertainment	2.1	%
SBA Communications	1.9	%
Abercrombie & Fitch	1.0	%
Atmel	0.8	%
Auxilium Pharmaceuticals	0.7	%
Finisar	0.7	%
Akorn	0.6	%
Onyx Pharmaceuticals	0.4	%
SM Energy	0.4	%
Houston American Energy	0.0	%*

*Rounds to less than 0.1%.

Columbia Acorn USA ended the second quarter of 2012 down 5.26% (Class A shares, without sales charge), underperforming the 3.47% drop of its primary benchmark, the Russell 2000 Index. For the half year ended June 30, 2012, the Fund was up 10.15%, outpacing the 8.53% gain of its benchmark. It was a rough quarter for the markets in general, but lagging performance in Fund retail and technology stocks further dampened returns relative to the benchmark.

On the positive side, two deal announcements positively impacted results. Cost management software company Ariba is to be taken over by SAP. Ariba's stock rose 37% in the quarter on the news and ended the half year up 60%. Convention hotel operator Gaylord Entertainment announced it would convert to a real estate investment trust, news that sent its stock up 25% for the quarter and 60% for the half year.

The Fund's two large investments in the telecom sector, tw telecom, a provider of fiber optic telephone and data services, and SBA Communications, a mobile communications tower company, both benefited from a surge in data usage and reported solid growth in cash flow year-over-year. Their stocks responded favorably, with tw telecom ending the quarter up 16% and the half year up 32%. SBA Communications had a 12% gain in the quarter and was up 33% year-to-date through June.

Several Fund biopharmaceutical stocks were strong in the second quarter. Auxilium Pharmaceuticals gained 45% on news of a successful phase three drug trial. Onyx Pharmaceuticals gained 77% upon receiving approval from an FDA advisory panel for one of its medications. Generic drug manufacturer Akorn rose 34% in the quarter as sales of its generic injectable drugs tripled versus the prior year.

Laggards for the second quarter included several tech stocks. Informatica, an enterprise data integration software company, fell 20% in the quarter (but was up 15% year to date) on concerns over slowing sales activity. Those concerns were confirmed after quarter end as the company pre-announced a drop in software license revenue. The economic turmoil overseas is impacting Informatica's near-term results, as 25% of the company's revenues are generated in Europe. Semiconductor manufacturer Atmel fell 32% in the quarter and ended the half year down 17%. Atmel's revenues dropped 22% versus the prior year due to the loss of an anticipated touchscreen microcontroller contract. Optical components manufacturer Finisar fell 26% in the quarter and was down 11% for the half year as its business suffered from weakening global demand.

Several Fund retail stocks also struggled during the period ended June 30. Premium active apparel retailer lululemon athletica announced a fantastic first quarter, with same-store sales up 25% over the prior year, but company guidance of slower growth in the second quarter sent the stock down 21%. For the half year lululemon gained 27%. Teen apparel retailer Abercrombie & Fitch experienced a sales shortfall on woeful sales in woebegone Europe. Its stock was down roughly 30% for the quarter and for the half year.

Our energy investments were also weak. Oil and gas producer SM Energy fell more than 30% for both the second quarter and the half year as prices of natural gas liquids fell more than crude oil during the second quarter. Houston American Energy was down 79% for the quarter and 91% for the half year on disappointing drilling results in Colombia.

These days the financial press seems to enjoy obsessing over existential economic issues. Certainly, talk of euro woes and fiscal cliffs can be as riveting and entertaining as a good horror flick. "Experts" claim that investing is all about getting the macro right, given the current uncertain economic environment (truthfully, when has the economic outlook ever been certain?). But when the investment community is so overly focused on the big picture, we believe it pays to go small. We'll leave the macro anguish to others who can't see the trees for the forest, and instead dig for what we believe are well-run companies able to grow faster than their peers and that thrive in our current much-maligned, but still growing, economy.

Stocks of small- and mid-cap companies pose special risks, including possible illiquidity and greater price volatility than stocks of larger, more established companies.

Portfolio holdings are subject to change periodically and may not be representative of current holdings.

16

Columbia Acorn USA

At a Glance (Class A Shares - LAUAX)

Performance data shown represents past performance and is not a guarantee of future results. The investment return and principal value of an investment will fluctuate so that shares, when redeemed, may be worth more or less than their original cost. Current performance may be lower or higher than the performance data shown. Performance results reflect any fee waivers or reimbursements of Fund expenses by the investment manager and/or any of its affiliates. Absent these fee waivers and/or expense reimbursement arrangements, performance results would have been lower. Please visit columbiamanagement.com for daily and most recent month-end updates.

Pretax and After-tax Average Annual Total Returns (Based on Class A Share Returns, inception 10/16/00)

through June 30, 2012

		Year to date*			1 year			5 years			10 years
Returns before taxes	NAV POP		10.15 3.82	%		-4.18 -9.69	%		0.68 -0.50	%		7.48 6.84	%
Returns after taxes on distributions	NAV POP		10.12 3.80			-4.30 -9.80			0.39 -0.79			7.18 6.55
Returns after taxes on distributions and sale of fund shares	NAV POP		6.64 2.52			-2.58 -6.16			0.55 -0.45			6.58 6.00
Russell 2000 Index**(pretax)			8.53			-2.08			0.54			7.00

All results shown assume reinvestment of distributions.

*Year to date data is not annualized.

**The Fund's primary benchmark.

After-tax returns are calculated using the highest historical individual federal marginal income tax rates, and do not reflect the impact of state and local taxes. Returns after taxes on distributions and sale of Fund shares reflect the additional tax impact of long-term gains or losses realized when Fund shares are sold. The returns are taxed at the maximum rate and assume shares were purchased at the beginning of the period. Actual after-tax returns depend on the investor's tax situation and may differ from those shown. After-tax returns are not relevant to investors who hold their Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts. After-tax returns are shown for Class A shares only; after-tax returns for other share classes will vary. Indexes do not reflect any deduction for fees, expenses or taxes.

Public offering price (POP) returns include the maximum sales charge of 5.75% for Class A shares. Net asset value (NAV) returns do not include sales charges or contingent deferred sales charges (CDSC).

The Fund's Class A shares annual operating expense ratio, as stated in the May 1, 2012, prospectus, is 1.33%.

Columbia Acorn USA Portfolio Diversification

as a percentage of net assets, as of 6/30/12

Columbia Acorn USA Top 10 Holdings

as a percentage of net assets, as of 6/30/12

1.	Ametek Aerospace/Industrial Instruments	2.8	%
2.	Informatica Enterprise Data Integration Software	2.4	%
3.	Nordson Dispensing Systems for Adhesives & Coatings	2.4	%
4.	tw telecom Fiber Optic Telephone/Data Services	2.4	%
5.	Micros Systems Information Systems for Hotels, Restaurants & Retailers	2.3	%
6.	lululemon athletica Premium Active Apparel Retailer	2.2	%
7.	Gaylord Entertainment Convention Hotels	2.1	%
8.	Bally Technologies Slot Machines & Software	1.9	%
9.	ESCO Technologies Automatic Electric Meter Readers	1.9	%
10.	SBA Communications Communications Towers	1.9	%

The Fund's top 10 holdings and portfolio diversification vary with changes in portfolio investments. See the Statement of Investments for a complete list of the Fund's holdings.

The Growth of a $10,000 Investment in Columbia Acorn USA (Class A)

September 4, 1996 (Fund inception) through June 30, 2012

The chart shows the change in value of a hypothetical $10,000 investment in Class A shares of the Fund during the stated time period. Although the index is provided for use in assessing the Fund's performance, the Fund's holdings may differ significantly from those in the index. It is not possible to invest directly in an index. The graph does not reflect taxes that a shareholder may pay on Fund distributions or on a sale of Fund shares.

The returns shown for periods prior to the inception date of the Fund's Class A shares are calculated from the inception date of the Fund and append the returns of the Fund's Class Z shares, the Fund's oldest share class. These returns are adjusted to reflect any higher class-related operating expenses of the newer share classes, as applicable. Please visit columbiamanagement.com/mutual-funds/appended-performance for more information.

Total Net Assets of the Fund: $1.6 billion

17

Columbia Acorn International Select

In a Nutshell

Christopher J. Olson

Lead Portfolio Manager

Performance data shown represents past performance and is not a guarantee of future results. The investment return and principal value will fluctuate so that shares, when redeemed, may be worth more or less than the original cost. Current performance may be lower or higher than the performance data shown. Please visit columbiamanagement.com for daily and most recent month-end performance updates.

Fund's Positions
in Mentioned Holdings

As a percentage of net assets, as of 6/30/12

Far EasTone Telecom	7.1	%
Ascendas REIT	6.6	%
Mapletree Industrial Trust	5.8	%
Seven Bank	4.4	%
Rand Merchant Insurance	4.1	%
Taiwan Mobile	3.1	%
Mapletree Logistics Trust	2.6	%
Archipelago Resources	2.2	%
Zhaojin Mining Industry	1.6	%

Columbia Acorn International Select ended the second quarter of 2012 down 0.95% (Class A shares, without sales charge), holding up much better than the 7.60% drop of its primary benchmark, the S&P Developed Ex-U.S. Between $2B and $10B Index. Year to date through June 30, 2012, the Fund was up 10.23%, strongly outperforming the 3.47% gain of its benchmark.

Financial stocks provided the biggest boost to Fund gains relative to the benchmark for both the second quarter and the half year. Singapore's Ascendas REIT, Mapletree Industrial Trust and Mapletree Logistics Trust had gains ranging from 4% to 12% in the quarter and each was up 20% or more year to date. These industrial property landlords continue to benefit from a resilient Singaporean economic outlook and investor interest in their strong dividend yields. Japan's Seven Bank, a provider of ATM processing services, rose 17% in the quarter and was up 34% for the half year as its ATM expansion within Japan continued to benefit the company's stock. Rand Merchant Insurance, a South African insurance company, led gains in the first quarter but cooled in the second quarter, falling 4.93%. Despite the drop in the second quarter, Rand Merchant was still up 31% for the half year.

Fund holdings in the telecom services sector also performed strongly for both the second quarter and half year. Far EasTone Telecom, Taiwan's third largest mobile operator, gained 6% in the second quarter and ended the half year up 16%. The company benefited from accelerated smartphone sales that are driving increased data usage. Taiwan Mobile, the second largest mobile operator in Taiwan, saw its stock rise 8% in the second quarter, leading to a 6% gain for the half year. Taiwan Mobile's stock fell in the first quarter, despite an improving earnings outlook, but investors returned in the second quarter after their brief flight to more cyclical names.

Mining companies did not fare well in the first half of 2012 as fears of slower global growth decreased demand. The biggest detractor to Fund performance in the second quarter was Indonesian gold miner Archipelago Resources, which fell 23% in the quarter and was down 26% for the half year. In China, Zhaojin Mining Industry fell 20% in the second quarter and ended the half year off 15%. Northam Platinum, a South African platinum miner, was off 26% in the quarter and down 22% year to date. We opted to sell the Fund's position in Northam Platinum and invested the proceeds elsewhere.

While fears of a global recession eased in the first quarter, the second quarter saw renewed uncertainty regarding the financial stability of Europe and signs of slowing economic growth in China. We are also concerned and have maintained a focus on defensive, secular growth companies with good dividend yields and strong balance sheets. As we mentioned last quarter, the Fund remains underweight in areas such as Europe, the United Kingdom and Japan, where the concerns about global debt are greatest, and is overweight in Asia ex-Japan and emerging markets.

International investing involves special risks, including foreign taxation, currency risks, risks associated with possible differences in financial standards and other risks associated with future political and economic developments. Stocks of small- and mid-cap companies pose special risks, including possible illiquidity and greater price volatility than stocks of larger, more established companies. Investing in emerging markets may involve greater risks than investing in more developed countries.

Portfolio holdings are subject to change periodically and may not be representative of current holdings.

18

Columbia Acorn International Select

At a Glance (Class A Shares - LAFAX)

Performance data shown represents past performance and is not a guarantee of future results. The investment return and principal value of an investment will fluctuate so that shares, when redeemed, may be worth more or less than their original cost. Current performance may be lower or higher than the performance data shown. Performance results reflect any fee waivers or reimbursements of Fund expenses by the investment manager and/or any of its affiliates. Absent these fee waivers and/or expense reimbursement arrangements, performance results would have been lower. Please visit columbiamanagement.com for daily and most recent month-end updates.

Pretax and After-tax Average Annual Total Returns (Based on Class A Share Returns, inception 10/16/00)

through June 30, 2012

		Year to date*			1 year			5 years			10 years
Returns before taxes	NAV POP		10.23 3.89	%		-4.30 -9.80	%		-0.20 -1.38	%		10.15 9.50	%
Returns after taxes on distributions	NAV POP		10.16 3.82			-4.62 -10.10			-0.55 -1.72			9.98 9.33
Returns after taxes on distributions and sale of fund shares	NAV POP		6.75 2.62			-2.15 -5.76			-0.12 -1.11			9.15 8.55
S&P Developed Ex-US Between $2B and $10B Index** (pretax)			3.47			-14.48			-4.59			8.19

All results shown assume reinvestment of distributions.

*Year to date data is not annualized.

**The Fund's primary benchmark.

After-tax returns are calculated using the highest historical individual federal marginal income tax rates, and do not reflect the impact of state and local taxes. Returns after taxes on distributions and sale of Fund shares reflect the additional tax impact of long-term gains or losses realized when Fund shares are sold. The returns are taxed at the maximum rate and assume shares were purchased at the beginning of the period. Actual after-tax returns depend on the investor's tax situation and may differ from those shown. After-tax returns are not relevant to investors who hold their Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts. After-tax returns are shown for Class A shares only; after-tax returns for other share classes will vary. Indexes do not reflect any deduction for fees, expenses or taxes.

Public offering price (POP) returns include the maximum sales charge of 5.75% for Class A shares. Net asset value (NAV) returns do not include sales charges or contingent deferred sales charges (CDSC).

The Fund's Class A shares annual operating expense ratio, as stated in the May 1, 2012, prospectus, is 1.62%.

Columbia Acorn International Select Portfolio Diversification

as a percentage of net assets, as of 6/30/12

The Growth of a $10,000 Investment in Columbia Acorn International Select (Class A)

November 23, 1998 (Fund inception) through June 30, 2012

Columbia Acorn International Select
Top 10 Holdings

as a percentage of net assets, as of 6/30/12

1.	Far EasTone Telecom (Taiwan) Taiwan's Third Largest Mobile Operator	7.1	%
2.	Ascendas REIT (Singapore) Industrial Property Landlord	6.6	%
3.	Mapletree Industrial Trust (Singapore) Industrial Property Landlord	5.8	%
4.	Seven Bank (Japan) ATM Processing Services	4.4	%
5.	Rand Merchant Insurance (South Africa) Directly Sold Property & Casualty Insurance; Holdings in Other Insurers	4.1	%
6.	Fresnillo (Mexico) Silver & Metal Byproduct Mining in Mexico	4.0	%
7.	Goldcorp (Canada) Gold Mining	3.8	%
8.	UGL (Australia) Engineering & Facilities Management	3.8	%
9.	Wirecard (Germany) Online Payment Processing & Risk Management	3.6	%
10.	Commonwealth Property Office Fund (Australia) Australia Prime Office REIT	3.2	%

The Fund's top 10 holdings and portfolio diversification vary with changes in portfolio investments. See the Statement of Investments for a complete list of the Fund's holdings.

The chart shows the change in value of a hypothetical $10,000 investment in Class A shares of the Fund during the stated time period. Although the index is provided for use in assessing the Fund's performance, the Fund's holdings may differ significantly from those in the index. It is not possible to invest directly in an index. The graph does not reflect taxes that a shareholder may pay on Fund distributions or on a sale of Fund shares.

The returns shown for periods prior to the inception date of the Fund's Class A shares are calculated from the inception date of the Fund and append the returns of the Fund's Class Z shares, the Fund's oldest share class. These returns are adjusted to reflect any higher class-related operating expenses of the newer share classes, as applicable. Please visit columbiamanagement.com/mutual-funds/appended-performance for more information.

Total Net Assets of the Fund: $338.1 million

19

Columbia Acorn Select

In a Nutshell

Ben Andrews	Robert A. Chalupnik
Lead Portfolio Manager	Co-Portfolio Manager

Performance data shown represents past performance and is not a guarantee of future results. The investment return and principal value will fluctuate so that shares, when redeemed, may be worth more or less than the original cost. Current performance may be lower or higher than the performance data shown. Please visit columbiamanagement.com for daily and most recent month-end performance updates.

Fund's Positions
in Mentioned Holdings

As a percentage of net assets, as of 6/30/12

Discover Financial Services	6.1	%
Hertz	5.2	%
CNO Financial Group	5.1	%
SBA Communications	3.8	%
Gaylord Entertainment	3.3	%
Coach	3.0	%
Sanmina-SCI	2.3	%
Akorn	1.9	%
Abercrombie & Fitch	1.4	%
Canacol	1.2	%
Vail Resorts	1.1	%
Houston American Energy	0.1	%

Columbia Acorn Select fell 8.51% (Class A shares, without sales charge) in the second quarter, but year to date through June 30, 2012, was up 7.64%. The Fund's primary benchmark, the S&P MidCap 400 Index was down 4.93% in the second quarter and was up 7.90% year to date. The S&P 500 Index, a general barometer of U.S. market large-cap performance, was down 2.75% in the quarter and year to date was up 9.49%.

In our first quarter report, we noted that we were seeing some strengthening in U.S. economic indicators and speculated that improvements might continue for a little while. Unfortunately, they didn't. U.S., European and Asian economic indicators turned down in the second quarter. Many of the stocks that added to the Fund's outperformance in the first quarter took it away this quarter.

On the downside, Sanmina-SCI, Hertz and Coach each cost the Fund close to one percent of portfolio performance in the second quarter. On the upside, we saw Gaylord Entertainment, Akorn and SBA Communications each add between 40 and 65 basis points to the Fund's performance in the quarter. For the first six months of the year, Discover Financial Services added two percent to the Fund's performance, while Gaylord Entertainment, CNO Financial Group and SBA Communications each added a little more than one percent. The larger detractors to the Fund's six-month performance were Houston American Energy, Abercrombie & Fitch and Canacol, which each cost the portfolio between 60 and 75 basis points.

When an economy is over leveraged, we believe a country has a choice to either grow, collapse, or inflate its way out of the problem. In our opinion, the western world has been doing a pretty good job of inflating but political leadership has done a poor job of providing a path to growth. The United States' path has been fraught with consistently changing regulation, controversial interpretations of legislation and court rulings, and concerns that new anti-business legislation will be passed. Each has helped cause businesses to sit back and wait. The western economies have been driven by huge government deficit spending and have bumped along with growth rates in the low single digits, prompting continuous investor concerns of possible recession.

We have struggled to outperform the Fund's primary benchmark. As we've mentioned in previous "Nutshells," we have been slowly changing the mix of the Fund's core growth holdings and the Fund's opportunistic holdings. In an environment in which the economy is struggling to deliver consecutive quarters of increasing growth, we believe core growth stocks should perform better than companies trying to turn around their operations in a weak economic environment (which is the case with many of the Fund's opportunistic holdings). Though the Fund's performance was disappointing this quarter, we feel strongly that we are on the right path as we near the end of this transition within the Fund's portfolio.

During the second quarter, we added one new stock to the portfolio and exited from one position. Our new position is Vail Resorts, a ski resort operator that we believe we picked up cheaply due to the warm winter. On the sell side, we exited from Safeway as we believe the supermarket industry's gross margin pressure is not going to subside.

As investors along with you in the Fund, we are anxious to see performance improve. We believe we are making adjustments to help our Fund seek to outperform its benchmark. Thank you for your investment in the Fund.

Risks include stock market fluctuations due to economic and business developments. The Fund also has potentially greater price volatility due to the Fund's concentration in a limited number of stocks of mid-size companies. International investments involve greater potential risks, including less regulation, currency fluctuations, economic instability and political developments.

Portfolio holdings are subject to change periodically and may not be representative of current holdings.

20

Columbia Acorn Select

At a Glance (Class A Shares - LTFAX)

Performance data shown represents past performance and is not a guarantee of future results. The investment return and principal value of an investment will fluctuate so that shares, when redeemed, may be worth more or less than their original cost. Current performance may be lower or higher than the performance data shown. Performance results reflect any fee waivers or reimbursements of Fund expenses by the investment manager and/or any of its affiliates. Absent these fee waivers and/or expense reimbursement arrangements, performance results would have been lower. Please visit columbiamanagement.com for daily and most recent month-end updates.

Pretax and After-tax Average Annual Total Returns (Based on Class A Share Returns, inception 10/16/00)

through June 30, 2012

		Year to date*			1 year			5 years			10 years
Returns before taxes	NAV POP		7.64 1.45	%		-10.17 -15.34	%		-2.93 -4.07	%		7.05 6.42	%
Returns after taxes on distributions	NAV POP		7.29 1.12			-10.46 -15.62			-3.22 -4.35			6.76 6.12
Returns after taxes on distributions and sale of fund shares	NAV POP		5.43 1.38			-6.23 -9.61			-2.52 -3.46			6.18 5.60
S&P MidCap 400 Index** (pretax)			7.90			-2.33			2.55			8.21

All results shown assume reinvestment of distributions.

*Year to date data is not annualized.

**The Fund's primary benchmark.

After-tax returns are calculated using the highest historical individual federal marginal income tax rates, and do not reflect the impact of state and local taxes. Returns after taxes on distributions and sale of Fund shares reflect the additional tax impact of long-term gains or losses realized when Fund shares are sold. The returns are taxed at the maximum rate and assume shares were purchased at the beginning of the period. Actual after-tax returns depend on the investor's tax situation and may differ from those shown. After-tax returns are not relevant to investors who hold their Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts. After-tax returns are shown for Class A shares only; after-tax returns for other share classes will vary. Indexes do not reflect any deduction for fees, expenses or taxes.

Public offering price (POP) returns include the maximum sales charge of 5.75% for Class A shares. Net asset value (NAV) returns do not include sales charges or contingent deferred sales charges (CDSC).

The Fund's Class A shares annual operating expense ratio, as stated in the May 1, 2012, prospectus, is 1.35%.

Columbia Acorn Select Portfolio Diversification

as a percentage of net assets, as of 6/30/12

Columbia Acorn Select Top 10 Holdings

as a percentage of net assets, as of 6/30/12

1.	Ametek Aerospace/Industrial Instruments	6.2	%
2.	Discover Financial Services Credit Card Company	6.1	%
3.	Hertz Largest U.S. Rental Car Operator	5.2	%
4.	CNO Financial Group Life, Long-term Care & Medical Supplement Insurance	5.1	%
5.	SBA Communications Communications Towers	3.8	%
6.	Crown Castle International Communications Towers	3.7	%
7.	Donaldson Industrial Air Filtration	3.5	%
8.	Gaylord Entertainment Convention Hotels	3.3	%
9.	Pall Filtration & Fluids Clarification	3.1	%
10.	WNS (India) Offshore BPO (Business Process Outsourcing) Services	3.0	%

The Fund's top 10 holdings and portfolio diversification vary with changes in portfolio investments. See the Statement of Investments for a complete list of the Fund's holdings.

The Growth of a $10,000 Investment in Columbia Acorn Select (Class A)

November 23, 1998 (Fund inception) through June 30, 2012

The chart shows the change in value of a hypothetical $10,000 investment in Class A shares of the Fund during the stated time period. Although the index is provided for use in assessing the Fund's performance, the Fund's holdings may differ significantly from those in the index. It is not possible to invest directly in an index. The graph does not reflect taxes that a shareholder may pay on Fund distributions or on a sale of Fund shares.

The returns shown for periods prior to the inception date of the Fund's Class A shares are calculated from the inception date of the Fund and append the returns of the Fund's Class Z shares, the Fund's oldest share class. These returns are adjusted to reflect any higher class-related operating expenses of the newer share classes, as applicable. Please visit columbiamanagement.com/mutual-funds/appended-performance for more information.

Total Net Assets of the Fund: $1.1 billion

21

Columbia Thermostat Fund

In a Nutshell

Charles P. McQuaid

Lead Portfolio Manager

Performance data shown represents past performance and is not a guarantee of future results. The investment return and principal value will fluctuate so that shares, when redeemed, may be worth more or less than the original cost. Current performance may be lower or higher than the performance data shown. Please visit columbiamanagement.com for daily and most recent month-end performance updates.

A "fund of fund" bears its allocable share of the costs and expenses of the underlying funds in which it invests. Such funds are thus subject to two levels of fees and potentially higher expense ratios than would be associated with a fund that invests and trades directly in financial instruments under the direction of a single manager.

Columbia Thermostat Fund ended the second quarter of 2012 off 1.46% (Class A shares, without sales charge), above the 2.75% drop of its primary equity benchmark, the S&P 500 Index, and below the 2.06% gain of its primary debt benchmark, the Barclays U.S. Aggregate Bond Index. Year to date through June 30, 2012, the Fund was up 6.61%, falling below the 9.49% S&P 500 Index return and above the 2.37% gain of the Barclays U.S. Aggregate Bond Index.

The Fund hit four reallocation triggers in the second quarter, increasing stock exposure in April and twice in May as the markets cooled, then reducing stocks in June as the equity markets turned. At quarter end, the Fund had an even weighting in its underlying stock and bond investments.

For the quarter, the equity portion of the Fund had a weighted average loss of 4.96%, while the bond portion provided a 2.11% gain. Columbia U.S. Treasury Index Fund led performance among both groups with a 2.76% return for the three months.

Year to date through the end of June, the equity portion of the Fund had an 8.66% return, while the income portion posted a 4.01% gain. Top contributors for the half year were Columbia LargeCap Enhanced Core Fund, up 10.05%, and Columbia Contrarian Core Fund, up 9.67%.

On September 25, Columbia Thermostat Fund will reach its 10-year anniversary. The "Chattering Squirrels" essay at the front of this report looks back at how a fund called "Thermostat" came to be and how it is managed. As always, we thank you for your investment in the Fund. We are pleased to report that, since inception through the end of June, the Fund has, once again, exceeded our expectations by besting both its stock and bond benchmarks.

Results of the Funds Owned in Columbia Thermostat Fund as of June 30, 2012

Stock Funds	Weightings			2nd			Year to
Fund	in category			quarter			date
Columbia Acorn International, Class I		20	%		-5.49	%		8.79	%
Columbia Dividend Income Fund, Class I		20	%		-0.45	%		7.79	%
Columbia Acorn Fund, Class I		15	%		-5.42	%		9.27	%
Columbia Contrarian Core Fund, Class I		15	%		-4.37	%		9.67	%
Columbia Select Large Cap Growth Fund, Class I		10	%		-11.47	%		6.22	%
Columbia Acorn Select, Class I		10	%		-8.46	%		7.79	%
Columbia Large Cap Enhanced Core Fund, Class I		10	%		-2.98	%		10.05	%
Weighted Average Equity Gain/Loss		100	%		-4.96	%		8.66	%
Bond Funds	Weightings			2nd			Year to
Fund	in category			quarter			date
Columbia Intermediate Bond Fund, Class I		50	%		1.87	%		3.62	%
Columbia Income Opportunities Fund, Class I		30	%		2.02	%		6.33	%
Columbia U.S. Treasury Index Fund, Class I		20	%		2.76	%		1.41	%
Weighted Average Income Gain		100	%		2.11	%		4.01	%

Columbia Thermostat Fund
Rebalancing in the Second Quarter

April 16, 2012	50% stocks, 50% bonds
May 15, 2012	55% stocks, 45% bonds
May 21, 2012	60% stocks, 40% bonds
June 21, 2012	50% stocks, 50% bonds

The value of an investment in the Fund is based primarily on the performance of the underlying portfolio funds and the allocation of the Fund's assets among them. An investment in the underlying portfolio funds may present certain risks, including stock market fluctuations that occur in response to economic and business developments; and a greater degree of social, political and economic volatility associated with international investing. Stocks of small- and mid-cap companies pose special risks, including possible illiquidity and greater price volatility than stocks of larger, more established companies. Value stocks may also be subject to specific business risks that have caused the stocks to be out of favor. Lower-rated and medium quality debt securities are more speculative and incur more risk. International investing involves special risks, including foreign taxation, currency risks, risks associated with possible differences in financial standards and other risks associated with future political and economic developments. Changes in interest rates and changes in the financial strength of issuers of lower-rated bonds may also affect underlying fund performance. The Fund is also subject to the risk that the investment advisor's decisions regarding asset classes and underlying portfolio funds will not anticipate market trends successfully, resulting in a failure to preserve capital or lower total return. In addition, the Fund may buy and sell shares of the portfolio funds frequently. This may result in higher transaction costs and additional tax liability. This is not an offer of the shares of any other mutual fund mentioned herein.

22

Columbia Thermostat Fund

At a Glance (Class A Shares - CTFAX)

Performance data shown represents past performance and is not a guarantee of future results. The investment return and principal value of an investment will fluctuate so that shares, when redeemed, may be worth more or less than their original cost. Current performance may be lower or higher than the performance data shown. Performance results reflect any fee waivers or reimbursements of Fund expenses by the investment manager and/or any of its affiliates. Absent these fee waivers and/or expense reimbursement arrangements, performance results would have been lower. Please visit columbiamanagement.com for daily and most recent month-end updates.

Pretax and After-tax Average Annual Total Returns (Based on Class A Share Returns, inception 3/3/03)

through June 30, 2012

		Year to date*			1 year			5 years			Life of fund
Returns before taxes	NAV POP		6.61 0.50	%		6.80 0.67	%		4.43 3.21	%		7.57 6.92	%
Returns after taxes on distributions	NAV POP		6.56 0.45			6.36 0.26			3.58 2.36			6.50 5.85
Returns after taxes on distributions and sale of fund shares	NAV POP		4.30 0.32			4.53 0.54			3.35 2.29			6.12 5.54
S&P 500 Index** (pretax)			9.49			5.45			0.22			7.48
Barclays U.S. Aggregate Bond Index** (pretax)			2.37			7.47			6.79			5.31
Lipper Flexible Portfolio Funds Index (pretax)			5.75			-0.55			1.82			7.34

All results shown assume reinvestment of distributions.

*Year to date data is not annualized.

**The Fund's primary stock and bond benchmarks.

After-tax returns are calculated using the highest historical individual federal marginal income tax rates, and do not reflect the impact of state and local taxes. Returns after taxes on distributions and sale of Fund shares reflect the additional tax impact of long-term gains or losses realized when Fund shares are sold. The returns are taxed at the maximum rate and assume shares were purchased at the beginning of the period. Actual after-tax returns depend on the investor's tax situation and may differ from those shown. After-tax returns are not relevant to investors who hold their Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts. After-tax returns are shown for Class A shares only; after-tax returns for other share classes will vary. Indexes do not reflect any deduction for fees, expenses or taxes.

Public offering price (POP) returns include the maximum sales charge of 5.75% for Class A shares. Net asset value (NAV) returns do not include sales charges or contingent deferred sales charges (CDSC).

The Fund's annual operating expense ratio, as stated in the May 1, 2012, prospectus, reflects a contractual fee waiver and expense reimbursement with CWAM that expires April 30, 2013. Class A expense ratios without and with the contractual waiver/reimbursement, including fees and expenses associated with the Fund's investment in other investment companies, are 1.46% and 1.15%, respectively. Absent the waiver or reimbursement, performance results would have been lower.

Columbia Thermostat Fund Asset Allocation

as a percentage of net assets, as of 6/30/12

Columbia Thermostat Fund Portfolio Weightings

as a percentage of assets in each investment category, as of 6/30/12

Stock Mutual Funds

Columbia Acorn International, Class I	20	%
Columbia Dividend Income Fund, Class I	20	%
Columbia Acorn Fund, Class I	15	%
Columbia Contrarian Core Fund, Class I	15	%
Columbia Select Large Cap Growth Fund, Class I	10	%
Columbia Acorn Select, Class I	10	%
Columbia Large Cap Enhanced Core Fund, Class I	10	%

Bond Mutual Funds

Columbia Intermediate Bond Fund, Class I	50	%
Columbia Income Opportunities Fund, Class I	30	%
Columbia U.S. Treasury Index Fund, Class I	20	%

The Growth of a $10,000 Investment in Columbia Thermostat Fund (Class A)

September 25, 2002 (Fund inception) through June 30, 2012

The chart shows the change in value of a hypothetical $10,000 investment in Class A shares of the Fund during the stated time period. Although the indexes are provided for use in assessing the Fund's performance, the Fund's holdings may differ significantly from those in the index. It is not possible to invest directly in an index. The graph does not reflect taxes that a shareholder may pay on Fund distributions or on a sale of Fund shares.

The returns shown for periods prior to the inception date of the Fund's Class A shares are calculated from the inception date of the Fund and append the returns of the Fund's Class Z shares, the Fund's oldest share class. These returns are adjusted to reflect any higher class-related operating expenses of the newer share classes, as applicable. Please visit columbiamanagement.com/mutual-funds/appended-performance for more information.

Total Net Assets of the Fund: $440.1 million

23

Columbia Acorn Emerging Markets Fund

In a Nutshell

Fritz Kaegi		Stephen Kusmierczak
Lead Portfolio Manager		Lead Portfolio Manager
P. Zachary Egan		Louis J. Mendes
Co-Portfolio Manager		Co-Portfolio Manager

Performance data shown represents past performance and is not a guarantee of future results. The investment return and principal value will fluctuate so that shares, when redeemed, may be worth more or less than the original cost. Current performance may be lower or higher than the performance data shown. Please visit columbiamanagement.com for daily and most recent month-end performance updates.

Fund's Positions
in Mentioned Holdings

As a percentage of net assets, as of 6/30/12

Grupo Aeroportuario del Sureste	2.4	%
Surya Citra Media	1.8	%
Multiplus	1.4	%
Mongolian Mining	1.4	%
Mayora Indah	0.6	%
Americas Petrogas	0.6	%
Northam Platinum	0.5	%
Madalena Ventures	0.2	%

Columbia Acorn Emerging Markets Fund fell 7.05% (Class A shares, without sales charge) in the second quarter of 2012 versus the 8.09% decline in the Fund's primary benchmark, the S&P Emerging Markets Between $500M and $5B Index. The Fund's more conservative positioning in very volatile markets has helped it outperform the benchmark since inception. Since the Fund's launch on August 19, 2011, it has returned a positive 1.50%, outperforming the benchmark's 5.77% decline. For the half year ended June 30, the Fund was up 9.61%, outpacing the 8.88% gain of its benchmark.

In the second quarter, the Fund benefited from its continued overweight in companies that we believe should benefit from rising incomes in emerging markets. Mayora Indah, an Indonesian maker of biscuits and chocolates, was added to the Fund during the quarter and gained nearly 29%. Grupo Aeroportuario del Sureste operates airports in Mexico, where air travel for tourism is growing strongly. Its stock gained over 18% following positive news about possible expansion into Puerto Rico. Surya Citra Media is Indonesia's most profitable private free-to-air broadcaster and gained 17% to reach a new record since its listing in 2002. Multiplus is Brazil's largest operator of loyalty programs and is a beneficiary of secular growth in credit and travel. Despite somewhat disappointing results due to higher airline ticket prices used in rewards, Multiplus gained over 15%.

The largest performance detractors in the second quarter were the Fund's energy and basic materials stocks. Two Canadian-listed oil and gas exploration companies with substantial assets in Argentina dropped sharply in the quarter following government moves to nationalize a large energy company. While we see no evidence of specific government action against our holdings, Madalena Ventures dropped nearly 63% and Americas Petrogas declined 48% as the risk premium for Argentina jumped substantially. Mongolian Mining is a world-class coking coal deposit in Southern Mongolia near the Chinese border. The stock fell 40% to a record low on concerns about tightening investment rules following recent elections. Northam Platinum owns one of the world's best undeveloped deposits of platinum, a precious metal used in important industrial applications like catalytic converters. Northam fell 35% in the wake of weak platinum prices and a leak at its smelter.

An important element of the Fund's relatively conservative positioning is its focus on investing in companies that pay dividends. We believe that a meaningful and growing dividend is the ultimate proof that a company is generating free cash flow, and that reinvested dividends represent the largest component of total shareholder returns over time. The current dividend yield of the Fund's portfolio is slightly below the benchmark's, yet the Fund's more concentrated portfolio is a higher quality one as measured by return on shareholder equity. We think companies that earn higher returns on capital should grow faster than their peers. We do not believe we have to sacrifice growth for higher dividends, and we have tried to identify companies with defensible business models and above-average returns that are exposed to durable growth trends in the emerging markets.

International investing involves special risks, including foreign taxation, currency risks, risks associated with possible differences in financial standards and other risks associated with future political and economic developments. Stocks of small- and mid-cap companies pose special risks, including possible illiquidity and greater price volatility than stocks of larger, more established companies. Investing in emerging markets may involve greater risks than investing in more developed countries.

Portfolio holdings are subject to change periodically and may not be representative of current holdings.

24

Columbia Acorn Emerging
Markets Fund

At a Glance (Class A Shares - CAGAX)

Performance data shown represents past performance and is not a guarantee of future results. The investment return and principal value of an investment will fluctuate so that shares, when redeemed, may be worth more or less than their original cost. Current performance may be lower or higher than the performance data shown. Performance results reflect any fee waivers or reimbursements of Fund expenses by the investment manager and/or any of its affiliates. Absent these fee waivers and/or expense reimbursement arrangements, performance results would have been lower. Please visit columbiamanagement.com for daily and most recent month-end updates.

Pretax and After-tax Average Annual Total Returns (Based on Class A Share Returns, inception 8/19/11)

through June 30, 2012

		Year to date*			Life of fund†*
Returns before taxes	NAV POP		9.61 3.36	%		1.50 -4.34	%
Returns after taxes on distributions	NAV POP		9.61 3.36			1.51 -4.33
Returns after taxes on distributions and sale of fund shares	NAV POP		6.25 2.18			0.98 -2.81
S&P Emerging Markets Between $500M and $5B Index (pretax)**			8.88			-5.77

All results shown assume reinvestment of distributions.

*Not annualized.

†Reflects performance from Fund inception on 8/19/11 through 6/30/12.

**The Fund's primary benchmark.

After-tax returns are calculated using the highest historical individual federal marginal income tax rates, and do not reflect the impact of state and local taxes. Returns after taxes on distributions and sale of Fund shares reflect the additional tax impact of long-term gains or losses realized when Fund shares are sold. The returns are taxed at the maximum rate and assume shares were purchased at the beginning of the period. Actual after-tax returns depend on the investor's tax situation and may differ from those shown. After-tax returns are not relevant to investors who hold their Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts. After-tax returns are shown for Class A shares only; after-tax returns for other share classes will vary. Indexes do not reflect any deduction for fees, expenses or taxes.

Public offering price (POP) returns include the maximum sales charge of 5.75% for Class A shares. Net asset value (NAV) returns do not include sales charges or contingent deferred sales charges (CDSC).

The Fund's annual operating expense ratio, as stated in the May 1, 2012, prospectus, reflects a contractual fee waiver and expense reimbursement agreement with CWAM that expires April 30, 2013; Class A share expense ratios without and with the contractual fee waiver/reimbursement are 14.22% and 1.85%, respectively.

Columbia Acorn Emerging Markets Fund Portfolio Diversification

as a percentage of net assets, as of 6/30/12

Columbia Acorn Emerging Markets Fund
Top 10 Holdings

as a percentage of net assets, as of 6/30/12

1.	Ace Indonesia (Indonesia) Home Improvement Retailer	3.5	%
2.	Tower Bersama Infrastructure (Indonesia) Communications Towers	3.3	%
3.	Nagacorp (Cambodia) Casino/Entertainment Complex in Cambodia	3.3	%
4.	Far EasTone Telecom (Taiwan) Taiwan's Third Largest Mobile Operator	2.8	%
5.	Rand Merchant Insurance (South Africa) Directly Sold Property & Casualty Insurance; Holdings in Other Insurers	2.8	%
6.	Coronation Fund Managers (South Africa) South African Fund Manager	2.7	%
7.	Dufry Group (Switzerland) Operators Airport Duty Free & Duty Paid Shops	2.5	%
8.	CTCI Corp (Taiwan) International Engineering Firm	2.4	%
9.	Grupo Aeroportuario del Sureste (Mexico) Mexican Airport Operator	2.4	%
10.	Hexagon (Sweden) Design, Measurement & Visualization Software & Equipment	2.1	%

The Fund's top 10 holdings and portfolio diversification vary with changes in portfolio investments. See the Statement of Investments for a complete list of the Fund's holdings.

The Growth of a $10,000 Investment in Columbia Acorn Emerging Markets Fund (Class A)

August 19, 2011 (Fund inception) through June 30, 2012

The chart shows the change in value of a hypothetical $10,000 investment in Class A shares of the Fund during the stated time period. Although the index is provided for use in assessing the Fund's performance, the Fund's holdings may differ significantly from those in the index. It is not possible to invest directly in an index. The graph does not reflect taxes that a shareholder may pay on Fund distributions or on a sale of Fund shares.

Total Net Assets of the Fund:
$5.8 million

25

Columbia Acorn European Fund

In a Nutshell

Andreas Waldburg-Wolfegg	Stephen Kusmierczak
Lead Portfolio Manager	Co-Portfolio Manager

Performance data shown represents past performance and is not a guarantee of future results. The investment return and principal value will fluctuate so that shares, when redeemed, may be worth more or less than the original cost. Current performance may be lower or higher than the performance data shown. Please visit columbiamanagement.com for daily and most recent month-end performance updates.

Fund's Positions
in Mentioned Holdings

As a percentage of net assets, as of 6/30/12

Eurofins Scientific	3.6	%
Gemalto	3.4	%
Aalberts Industries	2.0	%
Domino's Pizza UK & Ireland	1.9	%
Geox	1.1	%

Columbia Acorn European Fund was up 11.53% (Class A shares, without sales charge) for the six months ended June 30, 2012, outperforming the 7.65% return of its primary benchmark, the S&P Europe Between $500M and $5B Index. In absolute numbers, the Fund had a very strong first quarter, up 17.71%, followed by a lackluster second quarter, in which the Fund was down 5.25%. But the real story was in the relative numbers. Whereas the Fund closely matched the 17.80% gain in the first quarter of its benchmark, it contained the losses from the general downdraft in the second quarter better than the benchmark, which fell 8.62%.

French Fund holdings continued to perform strongly in the second quarter. Smart card products and solutions company Gemalto was up 9%, and food, drug and materials testing provider Eurofins Scientific gained 15%. Gemalto released a very positive first quarter sales report that showed sales in the mobile phone division up 11%, the first such growth in a few quarters. This turn confirmed our thesis that the change to fourth-generation wireless technology should increasingly feed through the company's top line. Eurofins Scientific announced a near doubling of its net profit in the first quarter of 2012, which, in itself, is not very significant because the bulk of the business's sales happen in the second half. What we were more interested to see was that Eurofins Scientific's business grew 10% organically in Europe, proof that when you're in the right business, macro issues can take second place. We shaved some off our position in Gemalto and added some in Eurofins Scientific to reflect short-term performance. Both continue to be in the Fund's top-five stocks by size.

Retailers like to complain about the weather: it's never right. Not so for Domino's Pizza UK & Ireland, the U.S. pizza maker's British, Irish and German franchise. The rainiest April on record in the United Kingdom caused people to stay home and order in. Domino's was only too happy to deliver, and so did the stock, up 17% in the quarter and 29% for the half year.

There were few strong detractors in the portfolio, largely because the largest slides came from small positions. Geox, the Italian maker of casual shoes, saw its stock decline 26% in the second quarter following a profit warning that accompanied the release of first quarter figures. Start-up costs related to expansion in Asia, Russia and Eastern Europe have negatively impacted Geox's margins. We believe that the strength of the company's patents, brand and balance sheet will help it gain market share over competitors, especially now that franchisees will be willing to ally themselves closer to a strong operator.

Another detractor to performance in the second quarter was Aalberts Industries, a manufacturer of flow control and heat treatment equipment based in the Netherlands, down almost 23%. An update on quarterly sales and management's outlook at the beginning of May were cautious, which hurt the stock. This diversified industrial company has strong market positions in most European countries and is suffering from lower capacity utilization in its industrial services division. For 2012, we believe the company is likely to show flat growth. On the other hand, we believe Aalberts's strong market positions, outstanding margins and excellent management are unlikely to go away, even during this time of weak demand. We believe its competitive position is bound to improve.

International investing involves special risks, including foreign taxation, currency risks, risks associated with possible differences in financial standards and other risks associated with future political and economic developments. Stocks of small- and mid-cap companies pose special risks, including possible illiquidity and greater price volatility than stocks of larger, more established companies. Investing in emerging markets may involve greater risks than investing in more developed countries.

Portfolio holdings are subject to change periodically and may not be representative of current holdings.

26

Columbia Acorn
European Fund

At a Glance (Class A Shares - CAEAX)

Performance data shown represents past performance and is not a guarantee of future results. The investment return and principal value of an investment will fluctuate so that shares, when redeemed, may be worth more or less than their original cost. Current performance may be lower or higher than the performance data shown. Performance results reflect any fee waivers or reimbursements of Fund expenses by the investment manager and/or any of its affiliates. Absent these fee waivers and/or expense reimbursement arrangements, performance results would have been lower. Please visit columbiamanagement.com for daily and most recent month-end updates.

Pretax and After-tax Average Annual Total Returns (Based on Class A Share Returns, inception 8/19/11)

through June 30, 2012

		Year to date*			Life of fund†*
Returns before taxes	NAV POP		11.53 5.07	%		5.99 -0.11	%
Returns after taxes on distributions	NAV POP		11.47 5.01			5.71 -0.36
Returns after taxes on distributions and sale of fund shares	NAV POP		7.49 3.29			3.95 -0.02
S&P Europe Between $500M and $5B Index (pretax)**			7.65			-0.07

All results shown assume reinvestment of distributions.

*Not annualized.

†Reflects performance from Fund inception on 8/19/11 through 6/30/12.

**The Fund's primary benchmark.

After-tax returns are calculated using the highest historical individual federal marginal income tax rates, and do not reflect the impact of state and local taxes. Returns after taxes on distributions and sale of Fund shares reflect the additional tax impact of long-term gains or losses realized when Fund shares are sold. The returns are taxed at the maximum rate and assume shares were purchased at the beginning of the period. Actual after-tax returns depend on the investor's tax situation and may differ from those shown. After-tax returns are not relevant to investors who hold their Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts. After-tax returns are shown for Class A shares only; after-tax returns for other share classes will vary. Indexes do not reflect any deduction for fees, expenses or taxes.

Public offering price (POP) returns include the maximum sales charge of 5.75% for Class A shares. Net asset value (NAV) returns do not include sales charges or contingent deferred sales charges (CDSC).

The Fund's annual operating expense ratio, as stated in the May 1, 2012, prospectus, reflects a contractual fee waiver and expense reimbursement agreement with CWAM that expires April 30, 2013; Class A share expense ratios without and with the contractual fee waiver/reimbursement are 19.73% and 1.75%, respectively.

Columbia Acorn European Fund Portfolio Diversification

as a percentage of net assets, as of 6/30/12

Columbia Acorn European Fund Top 10 Holdings

as a percentage of net assets, as of 6/30/12

1.	Eurofins Scientific (France) Food, Pharmaceuticals & Materials Screening & Testing		3.6	%
2.	Gemalto (France) Digital Security Solutions		3.4	%
3.	Wirecard (Germany) Online Payment Processing & Risk Management		3.0	%
4.	Geberit (Switzerland) Plumbing Supplies		2.8	%
5.	Charles Taylor (United Kingdom) Insurance Services		2.7	%
6.		1000 mercis (France) Interactive Advertising and Marketing	2.6	%
7.	Marel (Iceland) Largest Manufacturer of Poultry & Fish Processing Equipment		2.5	%
8.	Hexagon (Sweden) Design, Measurement & Visualization Software & Equipment		2.5	%
9.	Partners Group (Switzerland) Private Markets Asset Management		2.5	%
10.	Sweco (Sweden) Engineering Consultants		2.3	%

The Fund's top 10 holdings and portfolio diversification vary with changes in portfolio investments. See the Statement of Investments for a complete list of the Fund's holdings.

The Growth of a $10,000 Investment in Columbia Acorn European Fund (Class A)

August 19, 2011 (Fund inception) through June 30, 2012

The chart shows the change in value of a hypothetical $10,000 investment in Class A shares of the Fund during the stated time period. Although the index is provided for use in assessing the Fund's performance, the Fund's holdings may differ significantly from those in the index. It is not possible to invest directly in an index. The graph does not reflect taxes that a shareholder may pay on Fund distributions or on a sale of Fund shares.

Total Net Assets of the Fund:
$2.1 million

27

Columbia Acorn Fund

Major Portfolio Changes in the Second Quarter (Unaudited)

	Number of Shares
	3/31/12		6/30/12
Purchases
Information
Angies list		0		231,700
Cree		380,000		560,000
Genpact		1,575,000		1,705,000
Hexagon (Sweden)		5,164,999		5,450,000
Lamar Advertising		0		1,725,000
SABA		0		2,000,000
Velti		2,500,000		2,700,000
Yandex (Russia)		0		700,100
Industrial Goods & Services
Aalberts Industries (Netherlands)		2,263,654		2,324,833
Ashland		0		800,000
Chicago Bridge & Iron		1,725,000		2,850,000
Forward Air		1,300,000		1,400,000
Generac		1,776,000		2,350,000
Moog		2,775,000		3,000,000
Neopost (France)		210,000		350,000
Polypore International		900,000		1,325,000
Consumer Goods & Services
American Eagle Outfitters		300,000		1,075,000
Arcos Dorados (Brazil)		0		1,800,000
Avis Budget Group		3,800,000		4,400,000
Deckers Outdoor		1,140,000		1,310,000
Fossil		392,500		527,845
GNC Holdings		1,528,500		2,305,000
Interface		1,750,000		2,038,555
Lifestyle International (Hong Kong)		13,500,000		16,857,500
Pier 1 Imports		5,600,000		6,600,000
Finance
Associated Banc-Corp		6,287,800		6,956,800
City National		1,175,000		1,348,000
Eaton Vance		3,700,000		4,036,000
First Commonwealth		1,000,000		2,500,000
FX Alliance		0		300,000
Onex Capital (Canada)		0		450,000
SEI Investments		6,198,000		6,654,000
SVB Financial Group		810,000		985,000
Health Care
ARIAD Pharmaceuticals		0		2,568,248
Cepheid		3,900,000		4,600,000
DENTSPLY International		1,136,500		1,550,000
InterMune		2,950,000		3,850,000
Synageva Biopharma		180,167		569,898

	Number of Shares
	3/31/12		6/30/12
Energy & Minerals
Gulf United (Colombia)		0		50,000,000
Kirkland Lake Gold (Canada)		920,000		1,400,000
Laredo Petroleum		0		1,159,000
Mongolian Mining (Mongolia)		12,000,000		16,000,000
Other Industries
Rush Enterprises, Class A		2,800,000		2,937,175

See accompanying notes to financial statements.

28

	Number of Shares
	3/31/12		6/30/12
Sales
Information
Akamai		250,000		0
Amphenol		3,495,000		3,415,000
Ariba		2,850,000		900,000
Atmel		12,300,000		11,562,000
Blackbaud		1,650,000		960,329
Concur Technologies		1,830,000		1,400,000
Constant Contact		2,350,000		2,000,000
Discovery Series C		1,595,000		900,000
Equinix		585,000		450,000
F5 Networks		685,000		640,000
Finisar		1,695,000		1,345,000
FTI Consulting		868,516		234,615
Global Payments		2,299,000		1,700,000
Ixia		2,330,000		1,730,000
Kenexa		1,700,000		1,173,100
Liberty Global Series A		1,250,000		900,000
Littelfuse		500,000		420,000
Mail.ru - GDR (Russia)		400,000		234,168
NetSuite		1,150,000		800,000
Plexus		1,100,000		960,000
Red Hat		750,000		700,000
Saga Communications		164,991		145,271
SBA Communications		3,700,000		3,400,000
TIBCO		2,150,000		1,450,000
Tyler Technologies		1,700,000		900,000
Zebra Technologies		1,605,000		1,365,000
Industrial Goods & Services
Albany International		900,000		600,000
GrafTech International		3,750,000		2,800,000
Imtech (Netherlands)		1,601,465		1,491,313
Interline Brands		2,399,751		1,400,000
Jain Irrigation Systems (India)		3,450,000		0
Jain Irrigation Systems - DVR (India)		172,500		0
Kaydon		501,000		0
Mersen (France)		260,000		92,046
Pentair		3,100,000		1,890,000
Waste Connections		2,400,000		2,050,000
Consumer Goods & Services
Abercrombie & Fitch		3,460,000		3,040,000
GLG Life Tech (Canada)		1,678,125		1,665,270
lululemon athletica		4,922,800		4,505,000
Monster Beverage		2,340,000		1,700,000
Saks		5,225,000		4,425,000
Snyder's-Lance		240,000		0
True Religion Apparel		393,452		231,452
Universal Technical Institute		612,205		0
Warnaco Group		2,190,000		1,460,000

	Number of Shares
	3/31/12		6/30/12
Finance
Assured Guaranty		500,000		0
BOK Financial		2,691,414		2,638,000
CVB Financial		3,400,000		3,000,000
Green Bankshares		152,569		79,800
Oriental Financial Group		500,000		0
World Acceptance		1,459,555		1,425,202
Health Care
Alexion Pharmaceuticals		2,290,000		1,476,000
Allscripts Healthcare Solutions		1,200,000		0
Gen-Probe		760,000		0
Hill-Rom Holdings		1,873,800		1,275,000
Onyx Pharmaceuticals		1,000,000		750,000
Pacific Biosciences of California		2,525,000		0
Raptor Pharmaceutical		4,200,000		3,609,594
Energy & Minerals
Alexco Resource		2,800,000		2,050,000
Athabasca Oil Sands (Canada)		2,160,000		750,000
Baytex (Canada)		650,000		361,000
Black Diamond Group (Canada)		1,056,600		893,600
Canacol (Colombia)		5,917,100		5,116,000
Celtic Exploration (Canada)		1,140,000		718,000
Core Laboratories (Netherlands)		442,000		387,000
Crew Energy (Canada)		1,547,000		493,000
FMC Technologies		5,298,000		5,150,000
Fugro (Netherlands)		1,988,054		1,289,106
Oil States International		743,000		513,000
Pacific Rubiales Energy (Colombia)		4,250,000		3,700,000
Silver Wheaton (Canada)		1,600,000		550,000
SM Energy		900,000		703,000
Tullow Oil (United Kingdom)		1,697,000		1,050,000
Tuscany International Drilling (Colombia)		4,435,000		4,415,000
Vopak (Netherlands)		300,000		218,000
Other Industries
Genesee & Wyoming		400,000		300,000

See accompanying notes to financial statements.

29

Columbia Acorn Fund

Statement of Investments (Unaudited), June 30, 2012

Number of Shares			Value (000)
			Equities: 95.8%
Information 27.2%
		> Business Software 6.9%
	5,000,000	Informatica (a)	$	211,800
		Enterprise Data Integration Software
	2,550,000	Ansys (a)		160,930
		Simulation Software for Engineers & Designers
	2,700,000	Micros Systems (a)		138,240
		Information Systems for Hotels, Restaurants & Retailers
	1,400,000	Concur Technologies (a)		95,340
		Web Enabled Cost & Expense Management Software
	5,450,000	Hexagon (Sweden)		93,549
		Design, Measurement & Visualization Software & Equipment
	2,350,000	Quality Systems		64,649
		IT Systems for Medical Groups & Ambulatory Care Centers
	800,000	NetSuite (a)		43,816
		End-to-end IT Systems Solutions Delivered Over the Web
	1,450,000	TIBCO (a)		43,384
		Datacenter Software
	900,000	Ariba (a)		40,284
		Cost Management Software
	700,000	Red Hat (a)		39,536
		Maintenance & Support for Opensource Operating Systems & Middleware
	900,000	Tyler Technologies (a)		36,315
		Financial, Tax, Court & Document Management Systems for Local Governments
	2,000,000	Constant Contact (a)(b)(c)		35,760
		Email & Other Marketing Campaign Management Systems Delivered Over the Web
	1,173,100	Kenexa (a)		34,055
		Recruiting & Workforce Management Solutions
	900,000	SPS Commerce (a)(b)		27,342
		Supply Chain Management Software Delivered via the Web
	750,000	Jack Henry & Associates		25,890
		IT Systems & Outsourced IT Solutions for Financial Institutions
	960,329	Blackbaud		24,652
		Software & Services for Non-profits
	690,000	Advent Software (a)		18,706
		Asset Management & Trading Systems
	2,000,000	SABA (a)(b)		18,560
		Learning Management Systems
	2,700,000	Velti (a)(c)		17,550
		Mobile Marketing Software Platform
	900,000	Active Network (a)		13,851
		Web Delivered Software Solution for Managing Events & Activities
	1,000,000	InContact (a)		5,010
		Call Center Systems Delivered Via the Web & Telco Services
	55,000	Solera Holdings		2,298
		Software for Automotive Insurance Claims Processing
				1,191,517

Number of Shares			Value (000)
		> Instrumentation 2.7%
	1,600,000	Mettler-Toledo International (a)(b)	$	249,360
		Laboratory Equipment
	2,780,000	IPG Photonics (a)(b)		121,180
		Fiber Lasers
	2,035,000	Trimble Navigation (a)		93,631
		GPS-based Instruments
				464,171
		> Mobile Communications 2.7%
	4,465,000	Crown Castle International (a)		261,917
		Communications Towers
	3,400,000	SBA Communications (a)		193,970
		Communications Towers
	1,500,000	Globalstar (a)		480
		Satellite Mobile Voice & Data Carrier
				456,367
		> Telephone & Data Services 2.6%
	9,500,000	tw telecom (a)(b)		243,770
		Fiber Optic Telephone/Data Services
	1,400,000	AboveNet (b)		117,600
		Metropolitan Fiber Communications Services
	2,200,000	Cogent Communications (a)		42,350
		Internet Data Pipelines
	1,650,000	Boingo Wireless (a)		19,173
		Wholesale & Retail WiFi Networks
	2,000,000	General Communications (a)(b)		16,620
		Commercial Communication & Consumer CATV, Web & Phone in Alaska
				439,513
		> Computer Hardware & Related Equipment 2.4%
	3,415,000	Amphenol		187,552
		Electronic Connectors
	4,550,000	II-VI (a)(b)		75,849
		Laser Optics & Specialty Materials
	1,365,000	Zebra Technologies (a)		46,901
		Bar Code Printers
	900,000	Netgear (a)		31,059
		Networking Products for Small Business & Home
	605,000	Stratasys (a)(c)		29,978
		Rapid Prototyping Systems
	800,000	Nice Systems - ADR (Israel) (a)		29,280
		Audio & Video Recording Solutions
	207,000	Gemalto (France)		14,867
		Digital Security Solutions
				415,486
		> Semiconductors & Related Equipment 2.1%
	11,562,000	Atmel (a)		77,465
		Microcontrollers, Radio Frequency & Memory Semiconductors
	7,932,000	ON Semiconductor (a)		56,317
		Mixed Signal & Power Management Semiconductors
	5,000,000	Entegris (a)		42,700
		Semiconductor Materials Management Products
	2,160,000	Microsemi (a)		39,938
		Analog/Mixed Signal Semiconductors

See accompanying notes to financial statements.

30

Number of Shares			Value (000)
		> Semiconductors & Related Equipment—continued
	420,000	Littelfuse	$	23,894
		Little Fuses
	1,165,000	Monolithic Power Systems (a)		23,149
		High Performance Analog & Mixed Signal Integrated Circuits
	1,900,000	IXYS (a)(b)		21,223
		Power Semiconductors
	400,000	Hittite Microwave (a)		20,448
		Radio Frequency, Microwave & Millimeterwave Semiconductors
	615,000	Ultratech (a)		19,373
		Semiconductor Equipment
	1,765,000	Pericom Semiconductor (a)(b)		15,885
		Interface Integrated Circuits & Frequency Control Products
	560,000	Cree (a)(c)		14,375
		LED Lighting, Components & Chips
	2,290,000	TriQuint Semiconductor (a)		12,595
		Radio Frequency Semiconductors
				367,362
		> Computer Services 1.3%
	3,400,000	iGATE (a)(b)		57,868
		IT & Business Process Outsourcing Services
	680,000	Syntel		41,275
		Offshore IT Services
	1,618,000	ExlService Holdings (a)(b)		39,868
		Business Process Outsourcing
	2,125,000	Virtusa (a)(b)		28,369
		Offshore IT Outsourcing
	1,705,000	Genpact (a)		28,354
		Business Process Outsourcing
	3,849,207	Hackett Group (a)(b)		21,440
		IT Integration & Best Practice Research
	1,091,353	WNS - ADR (India) (a)		10,619
		Offshore BPO (Business Process Outsourcing) Services
				227,793
		> Gaming Equipment & Services 1.2%
	3,725,000	Bally Technologies (a)(b)		173,809
		Slot Machines & Software
	1,530,000	WMS Industries (a)		30,523
		Slot Machine Provider
				204,332
		> Internet Related 1.1%
	450,000	Equinix (a)		79,042
		Network Neutral Data Centers
	1,450,000	TripAdvisor		64,801
		Online Travel Research
	304,000	NetEase.com - ADR (China) (a)		17,890
		Chinese Online Gaming Services
	700,100	Yandex (Russia) (a)		13,337
		Search Engine for Russian & Turkish Languages
	234,168	Mail.ru - GDR (Russia) (a)(d)		7,975
		Internet Social Networking & Games for Russian Speakers
	231,700	Angies list (a)		3,670
		Consumer Subscription & Internet Advertising
				186,715

Number of Shares			Value (000)
		> Business Information & Marketing Services 0.9%
	1,900,000	Verisk Analytics (a)	$	93,594
		Risk & Decision Analytics
	3,027,016	Navigant Consulting (a)(b)		38,261
		Financial Consulting Firm
	505,000	RPX (a)		7,247
		Patent Aggregation & Defensive Patent Consulting
	234,615	FTI Consulting (a)		6,745
		Financial Consulting Firm
				145,847
		> Telecommunications Equipment 0.7%
	640,000	F5 Networks (a)		63,718
		Internet Traffic Management Equipment
	1,730,000	Ixia (a)		20,795
		Telecom Network Test Equipment
	1,345,000	Finisar (a)		20,121
		Optical Subsystems & Components
	1,925,000	Infinera (a)		13,167
		Optical Networking Equipment
				117,801
		> CATV 0.6%
	900,000	Discovery Series C (a)		45,081
		Cable TV Programming
	900,000	Liberty Global Series A (a)		44,667
		Cable TV Franchises Outside the USA
	15,770	Jupiter Telecommunications (Japan)		16,079
		Largest Cable Service Provider in Japan
				105,827
		> Financial Processors 0.6%
	1,700,000	Global Payments		73,491
		Credit Card Processor
	5,000,000	Singapore Exchange (Singapore)		25,119
		Singapore Equity & Derivatives Market Operator
				98,610
		> Electronics Distribution 0.6%
	3,125,000	Avnet (a)		96,438
		Electronic Components Distribution
				96,438
		> Contract Manufacturing 0.3%
	3,800,000	Sanmina-SCI (a)		31,122
		Electronic Manufacturing Services
	960,000	Plexus (a)		27,072
		Electronic Manufacturing Services
				58,194
		> Advertising 0.3%
	1,725,000	Lamar Advertising (a)		49,335
		Outdoor Advertising
	1,500,000	VisionChina Media - ADR (China) (a)		1,395
		Advertising on Digital Screens in China's Mass Transit System
				50,730

See accompanying notes to financial statements.

31

Columbia Acorn Fund

Statement of Investments (Unaudited), continued

Number of Shares			Value (000)
		> Entertainment Programming 0.2%
	1,100,000	IMAX (Canada) (a)(c)	$	26,433
		IMAX Movies, Theatre Equipment & Theatre Joint Ventures
				26,433
		> TV Broadcasting —%
	2,500,000	Entravision Communications		3,025
		Spanish Language TV & Radio Stations
	1,750,000	Gray Television (a)(c)		2,573
		Mid-market Affiliated TV Stations
				5,598
		> Radio —%
	145,271	Saga Communications (a)		5,391
		Radio Stations in Small & Mid-sized Cities
				5,391
		> Consumer Software —%
	273,500	Carbonite (a)(c)		2,445
		Online Data Storage
				2,445
Information: Total				4,666,570
Industrial Goods & Services 19.0%
		> Machinery 11.1%
	6,750,000	Ametek		336,893
		Aerospace/Industrial Instruments
	8,400,000	Donaldson (b)		280,308
		Industrial Air Filtration
	3,125,000	Nordson		160,281
		Dispensing Systems for Adhesives & Coatings
	3,000,000	Moog (a)(b)		124,050
		Motion Control Products for Aerospace, Defense & Industrial Markets
	3,725,000	Kennametal		123,484
		Consumable Cutting Tools
	2,325,000	Clarcor		111,972
		Mobile & Industrial Filters
	3,063,000	HEICO (b)		98,812
		FAA Approved Aircraft Replacement Parts
	1,800,000	Pall		98,658
		Filtration & Fluids Clarification
	2,200,000	ESCO Technologies (b)		80,168
		Automatic Electric Meter Readers
	1,890,000	Pentair		72,349
		Pumps & Water Treatment
	805,000	Toro		58,998
		Turf Maintenance Equipment
	2,350,000	Generac		56,541
		Standby Power Generators
	2,675,000	Oshkosh Corporation (a)		56,041
		Specialty Truck Manufacturer
	1,325,000	Polypore International (a)(c)		53,517
		Battery Separators & Filtration Media
	435,000	Valmont Industries		52,622
		Center Pivot Irrigation Systems & Utility Poles
	950,000	WABCO Holdings (a)		50,284
		Truck & Bus Component Supplier

Number of Shares			Value (000)
	600,000	Wabtec	$	46,806
		Freight & Transit Component Supplier
	350,000	Neopost (France)		18,678
		Postage Meter Machines
	170,000	Middleby Corp (a)		16,934
		Manufacturer of Cooking Equipment
	10,000,000	Marel (Iceland)		12,162
		Largest Manufacturer of Poultry & Fish Processing Equipment
	1,000,000	Spartan Motors		5,240
		Specialty Truck & Chassis Manufacturer
				1,914,798
		> Industrial Materials & Specialty Chemicals 2.4%
	1,750,000	Albemarle		104,370
		Refinery Catalysts & Other Specialty Chemicals
	1,520,000	FMC Corporation		81,290
		Niche Specialty Chemicals
	800,000	Ashland		55,448
		Diversified Chemicals Company
	1,880,000	Drew Industries (a)(b)		52,358
		RV & Manufactured Home Components
	1,525,000	Novozymes (Denmark)		39,545
		Industrial Enzymes
	673,000	Sociedad Quimica y Minera de Chile - ADR (Chile) (c)		37,466
		Producer of Specialty Fertilizers, Lithium & Iodine
	2,218,700	Kansai Paint (Japan)		23,775
		Paint Producer in Japan, India, China & Southeast Asia
	600,000	Albany International		11,226
		Paper Machine Clothing & Composites for Aerospace
	200,000	Silgan Holdings		8,538
		Metal & Plastic Packaging
	92,046	Mersen (France)		2,306
		Advanced Industrial Materials
				416,322
		> Other Industrial Services 1.7%
	3,050,000	Expeditors International of Washington		118,187
		International Freight Forwarder
	1,400,000	Forward Air		45,178
		Freight Transportation Between Airports
	1,350,000	LKQ (a)		45,090
		Alternative Auto Parts Distribution
	1,491,313	Imtech (Netherlands)		35,610
		Electromechanical & Information & Communications Technology Installation & Maintenance
	1,600,000	Mobile Mini (a)		23,040
		Portable Storage Units Leasing
	1,500,000	Acorn Energy (b)(c)		12,480
		Frac Well Exploration/Monitoring Device, Sonar Security, Electric Grid Monitoring
	750,000	UTI Worldwide		10,958
		Freight Forwarding & Logistics
				290,543

See accompanying notes to financial statements.

32

Number of Shares			Value (000)
		> Construction 1.3%
	2,850,000	Chicago Bridge & Iron	$	108,186
		Engineering & Construction for Liquefied Natural Gas & Petrochemicals
	66,000	NVR (a)		56,100
		DC Homebuilder
	1,350,000	Fortune Brands Home & Security (a)		30,065
		Home Building Supplies & Small Locks
	1,800,000	Mills Estruturas e Servicos de Engenharia (Brazil)		24,197
		Civil Engineering & Construction
				218,548
		> Electrical Components 0.7%
	1,765,000	Acuity Brands		89,856
		Commercial Lighting Fixtures
	1,500,000	Ushio (Japan)		18,592
		Industrial Light Sources
	351,000	Saft (France)		8,421
		Niche Battery Manufacturer
				116,869
		> Outsourcing Services 0.7%
	2,800,000	Quanta Services (a)		67,396
		Electrical & Telecom Construction Services
	1,359,200	Insperity (b)		36,766
		Professional Employer Organization
	600,000	GP Strategies (a)		11,082
		Training Programs
				115,244
		> Waste Management 0.5%
	2,050,000	Waste Connections		61,336
		Solid Waste Management
	560,000	Clean Harbors (a)		31,595
		Hazardous Waste Services & Disposal
				92,931
		> Conglomerates 0.2%
	2,324,833	Aalberts Industries (Netherlands)		36,200
		Flow Control & Heat Treatment
				36,200
		> Industrial Distribution 0.2%
	1,400,000	Interline Brands (a)		35,098
		Industrial Distribution
				35,098
		> Steel 0.2%
	2,800,000	GrafTech International (a)		27,020
		Industrial Graphite Materials Producer
				27,020
Industrial Goods & Services: Total				3,263,573
Consumer Goods & Services 15.9%
		> Retail 4.3%
	4,505,000	lululemon athletica (a)		268,633
		Premium Active Apparel Retailer
	6,600,000	Pier 1 Imports (b)		108,438
		Home Furnishing Retailer
	3,040,000	Abercrombie & Fitch		103,786
		Teen Apparel Retailer

Number of Shares			Value (000)
	3,370,000	Shutterfly (a)(b)	$	103,425
		Internet Photo-centric Retailer
	4,425,000	Saks (a)(c)		47,126
		Luxury Department Store Retailer
	527,845	Fossil (a)		40,401
		Watch Designer & Retailer
	525,000	DSW		28,560
		Branded Footwear Retailer
	1,075,000	American Eagle Outfitters		21,210
		Teen Apparel Retailer
	971,500	Teavana (a)(c)		13,145
		Specialty Tea Retailer
	1,371,366	Gaiam (a)(b)		5,348
		Healthy Living Catalogs & E-Commerce
	66,000	The Fresh Market (a)		3,540
		Specialty Food Retailer
				743,612
		> Travel 3.0%
	3,850,000	Gaylord Entertainment (a)(b)		148,456
		Convention Hotels
	1,430,000	Vail Resorts		71,614
		Ski Resort Operator & Developer
	1,450,000	Expedia		69,702
		Online Travel Services Company
	4,400,000	Avis Budget Group (a)		66,880
		Second Largest Car Rental Company
	3,750,000	Hertz (a)		48,000
		Largest U.S. Rental Car Operator
	970,000	Choice Hotels		38,732
		Franchisor of Budget Hotel Brands
	1,600,000	HomeAway (a)(c)		34,784
		Vacation Rental Online Marketplace
	2,000,000	Localiza Rent A Car (Brazil)		30,082
		Car Rental
				508,250
		> Apparel 2.3%
	1,660,000	PVH		129,131
		Apparel Wholesaler & Retailer
	2,100,000	Coach		122,808
		Designer & Retailer of Branded Leather Accessories
	1,460,000	Warnaco Group (a)		62,167
		Global Branded Apparel Manufacturer
	1,310,000	Deckers Outdoor (a)(c)		57,653
		Fashion Footwear Wholesaler
	600,000	Steven Madden (a)		19,050
		Wholesaler/Retailer of Fashion Footwear
	231,452	True Religion Apparel		6,708
		Premium Denim
				397,517
		> Food & Beverage 1.1%
	1,700,000	Monster Beverage (a)		121,040
		Alternative Beverages
	32,000,000	Olam International (Singapore)		46,347
		Agriculture Supply Chain Manager
	1,800,000	Arcos Dorados (Brazil)		26,604
		McDonald's Master Franchise for Latin America

See accompanying notes to financial statements.

33

Columbia Acorn Fund

Statement of Investments (Unaudited), continued

Number of Shares			Value (000)
		> Food & Beverage—continued
	45,500	Annie's (a)(c)	$	1,905
		Developer & Marketer of Natural & Organic Food
	1,665,270	GLG Life Tech (Canada) (a)(b)(e)		689
		All-natural Sweetener Extracted from the Stevia Plant
				196,585
		> Consumer Goods Distribution 1.1%
	2,305,000	GNC Holdings		90,356
		Specialty Retailer of Health & Wellness Products
	2,015,000	Pool		81,527
		Distributor of Swimming Pool Supplies & Equipment
	625,000	United Stationers		16,844
		Wholesale Distributor of Business Products
				188,727
		> Other Consumer Services 0.9%
	2,190,000	Lifetime Fitness (a)(b)		101,857
		Sport & Fitness Club Operator
	16,857,500	Lifestyle International (Hong Kong)		37,146
		Mid to High-end Department Store Operator in Hong Kong & China
	1,062,500	Move (a)		9,679
		Real Estate Internet Websites
	441,666	IFM Investments (Century 21 China RE) - ADR (China) (a)		481
		Provide Real Estate Services in China
				149,163
		> Casinos & Gaming 0.8%
	3,950,000	Pinnacle Entertainment (a)(b)		37,999
		Regional Casino Operator
	850,000	Penn National Gaming (a)		37,902
		Regional Casino Operator
	3,000,000	Melco Crown Entertainment - ADR (Hong Kong) (a)		34,560
		Macau Casino Operator
	12,000,000	MGM China Holdings (Hong Kong)		18,400
		Macau Casino Operator
				128,861
		> Furniture & Textiles 0.8%
	4,200,000	Knoll (b)		56,364
		Office Furniture
	2,250,000	Herman Miller		41,670
		Office Furniture
	2,038,555	Interface		27,785
		Modular & Broadloom Carpet
	215,000	Caesarstone (Israel) (a)		2,604
		Quartz Countertops
				128,423
		> Other Durable Goods 0.6%
	1,500,000	Jarden		63,030
		Branded Household Products
	460,000	Cavco Industries (a)(b)		23,589
		Manufactured Homes
	400,000	Tesla Motors (a)(c)		12,516
		Design, Manufacture & Sell High Performance Electric Vehicles
				99,135

Number of Shares			Value (000)
		> Restaurants 0.4%
	2,000,000	AFC Enterprises (a)(b)	$	46,280
		Popeye's Restaurants
	450,000	Cheesecake Factory (a)		14,382
		Casual Dining Restaurants
	675,000	Bravo Brio Restaurant Group (a)		12,035
		Upscale Casual Italian Restaurants
				72,697
		> Nondurables 0.3%
	1,600,000	Helen of Troy (a)(b)		54,224
		Personal Care, Housewares, Healthcare & Home Environment Products
				54,224
		> Educational Services 0.2%
	800,000	New Oriental Education & Technology - ADR (China) (a)		19,600
		Education Service Provider
	300,000	ITT Educational Services (a)(c)		18,225
		Postsecondary Degree Services
	2,000,000	Voyager Learning - Contingent Value Rights (e)(f)		220
		Education Services for the K-12 Market
				38,045
		> Leisure Products 0.1%
	1,290,000	Skullcandy (a)(c)		18,253
		Lifestyle Branded Headphones
				18,253
		> Other Entertainment —%
	265,000	CTS Eventim (Germany)		7,974
		Event Ticket Sales
				7,974
Consumer Goods & Services: Total				2,731,466
Finance 11.0%
		> Banks 4.4%
	2,638,000	BOK Financial		153,532
		Tulsa-based Southwest Bank
	6,956,800	Associated Banc-Corp		91,760
		Midwest Bank
	2,337,313	Hancock Holding		71,148
		Gulf Coast Bank
	1,348,000	City National		65,486
		Bank & Asset Manager
	2,860,000	MB Financial (b)		61,604
		Chicago Bank
	985,000	SVB Financial Group (a)		57,839
		Bank to Venture Capitalists
	5,323,500	Valley National Bancorp		56,429
		New Jersey/New York Bank
	3,000,000	CVB Financial		34,950
		Inland Empire Business Bank
	2,200,000	TCF Financial		25,256
		Great Lakes Bank
	700,000	Wintrust Financial		24,850
		Chicago & Milwaukee Full Service Bank
	1,350,000	TriCo Bancshares (b)		20,790
		California Central Valley Bank

See accompanying notes to financial statements.

34

Number of Shares			Value (000)
		> Banks—continued
	4,299,507	First Busey	$	20,767
		Illinois Bank
	1,121,188	Sandy Spring Bancorp		20,181
		Baltimore, D.C. Bank
	2,500,000	First Commonwealth		16,825
		Western Pennsylvania Bank
	811,295	Hudson Valley		14,685
		Metro New York City Bank
	2,136,500	TrustCo Bank		11,665
		New York State Bank
	706,559	Eagle Bancorp (a)		11,128
		Metro D.C. Bank
	241,405	Pacific Continental Bank		2,141
		Pacific Northwest Bank
	79,800	Green Bankshares (a)		133
		Tennessee Bank
				761,169
		> Insurance 2.4%
	8,900,000	CNO Financial Group		69,420
		Life, Long-term Care & Medical Supplement Insurance
	833,000	Allied World Holdings		66,198
		Commerical Lines Insurance/Reinsurance
	2,764,000	Tower Group (b)		57,685
		Commercial & Personal Lines Insurance
	1,120,000	The Hanover Insurance Group		43,826
		Commercial & Personal Lines Insurance
	2,050,000	Selective Insurance Group		35,690
		Commercial & Personal Lines Insurance
	1,100,000	HCC Insurance Holdings		34,540
		Specialty Insurance
	832,000	Willis Group (Ireland)		30,360
		Insurance Broker
	925,000	Kemper		28,444
		Multi-line Insurance
	250,000	Enstar Group (a)		24,735
		Insurance/Reinsurance & Related Services
	900,000	Brown & Brown		24,543
		Insurance Broker
				415,441
		> Finance Companies 1.6%
	1,425,202	World Acceptance (a)(b)		93,778
		Personal Loans
	2,150,000	McGrath Rentcorp (b)		56,975
		Temporary Space & IT Rentals
	3,400,000	H & E Equipment Services (a)(b)		51,102
		Heavy Equipment Leasing
	1,123,400	CAI International (a)(b)		22,333
		International Container Leasing
	1,091,000	Marlin Business Services (b)		17,882
		Small Equipment Leasing
	450,000	Onex Capital (Canada)		17,472
		Private Equity
	422,500	Regional Management (a)		6,950
		Consumer Loans
	78,500	Textainer Group Holdings		2,897
		Top International Container Leasor
				269,389

Number of Shares			Value (000)
		> Brokerage & Money Management 1.5%
	6,654,000	SEI Investments	$	132,348
		Mutual Fund Administration & Investment Management
	4,036,000	Eaton Vance		108,770
		Specialty Mutual Funds
	300,000	FX Alliance (a)		4,713
		FX Trading Software & Services
	1,000,000	Artio Global Investors (c)		3,500
		International Asset Manager
				249,331
		> Credit Cards 0.5%
	550,000	Alliance Data Systems (a)		74,250
		Diversified Credit Card Provider
	275,000	Wright Express (a)		16,973
		Pay Card Processor
				91,223
		> Diversified Financial Companies 0.4%
	2,820,000	Leucadia National		59,981
		Holding Company
				59,981
		> Savings & Loans 0.2%
	400,000	Financial Engines (a)		8,580
		Asset Management for 401k Plans
	1,010,000	Provident New York Bancorp		7,666
		New York State Thrift
	470,000	ViewPoint Financial		7,351
		Texas Thrift
	452,146	Kaiser Federal		6,682
		Los Angeles Savings & Loan
	65,991	Berkshire Hills Bancorp		1,452
		Northeast Thrift
				31,731
Finance: Total				1,878,265
Health Care 9.7%
		> Biotechnology & Drug Delivery 4.9%
	4,315,000	BioMarin Pharmaceutical (a)		170,787
		Biotech Focused on Orphan Diseases
	6,153,000	Seattle Genetics (a)(b)(c)		156,225
		Antibody-based Therapies for Cancer
	1,476,000	Alexion Pharmaceuticals (a)		146,567
		Biotech Focused on Orphan Diseases
	3,250,000	Auxilium Pharmaceuticals (a)(b)		87,393
		Biotech Focused on Niche Disease Areas
	6,000,000	NPS Pharmaceuticals (a)(b)		51,660
		Orphan Drugs & Healthy Royalties
	750,000	Onyx Pharmaceuticals (a)		49,837
		Commercial-stage Biotech Focused on Cancer
	3,850,000	InterMune (a)(b)		46,007
		Drugs for Pulmonary Fibrosis & Hepatitis C
	2,568,248	ARIAD Pharmaceuticals (a)		44,200
		Biotech Focused on Cancer
	3,430,000	Isis Pharmaceuticals (a)		41,160
		Biotech Pioneer in Antisense Drugs
	569,898	Synageva Biopharma (a)(c)		23,115
		Biotech Focused on Orphan Diseases

See accompanying notes to financial statements.

35

Columbia Acorn Fund

Statement of Investments (Unaudited), continued

Number of Shares			Value (000)
		> Biotechnology & Drug Delivery—continued
	3,609,594	Raptor Pharmaceutical (a)(b)(c)	$	20,178
		Orphan Drug Company
	5,750,000	Chelsea Therapeutics International (a)(b)(c)		8,510
		Biotech Focused on Rare Diseases
	2,990,000	Anthera Pharmaceuticals (a)(b)		2,022
		Biotech Focused on Cardiovascular, Cancer & Immunology
	359,944	MicroDose Therapeutx (e)(f)		252
		Drug Inhaler Development
				847,913
		> Medical Supplies 2.6%
	4,600,000	Cepheid (a)(b)		205,850
		Molecular Diagnostics
	950,000	Henry Schein (a)		74,565
		Largest Distributor of Healthcare Products
	2,126,000	Patterson Companies		73,283
		Dental/Vet/Med Distributor
	1,550,000	DENTSPLY International		58,606
		Leading Dental Supplies Manufacturer
	375,000	Techne		27,825
		Cytokines, Antibodies & Other Reagents for Life Science
				440,129
		> Medical Equipment & Devices 0.9%
	550,000	Haemonetics (a)		40,760
		Blood & Plasma Collection Equipment
	1,275,000	Hill-Rom Holdings		39,334
		Hospital Beds/Patient Handling
	675,000	Sirona Dental Systems (a)		30,382
		Manufacturer of Dental Equipment
	950,000	PerkinElmer Inc.		24,510
		Analytical Instruments for Life Sciences
	570,000	Orthofix International (a)		23,513
		Bone Fixation & Stimulation Devices
				158,499
		> Health Care Services 0.7%
	665,000	Mednax (a)		45,579
		Physician Management for Pediatric & Anesthesia Practices
	4,900,000	eResearch Technology (a)(b)		39,151
		Clinical Research Services
	825,000	HealthSouth (a)		19,189
		Inpatient Rehabalitation Facilities
	1,875,000	Health Management Associates (a)		14,719
		Non-urban Hospitals
				118,638
		> Pharmaceuticals 0.6%
	4,000,000	Akorn (a)		63,080
		Develops, Manufactures & Sells Specialty Generic Drugs
	3,388,000	Adcock Ingram Holdings (South Africa)		24,904
		Manufacturer of Pharmaceuticals & Medical Supplies
	1,095,000	Horizon Pharma (a)(c)		7,807
		Specialty Pharma Company

Number of Shares			Value (000)
	2,040,000	Alimera Sciences (a)(b)(c)	$	6,100
		Ophthalmology-focused Pharmaceutical Company
				101,891
Health Care: Total				1,667,070
Energy & Minerals 6.7%
		> Oil Services 3.2%
	5,150,000	FMC Technologies (a)		202,034
		Oil & Gas Well Head Manufacturer
	2,114,000	Atwood Oceanics (a)		79,994
		Offshore Drilling Contractor
	1,289,106	Fugro (Netherlands)		78,196
		Subsea Oilfield Services
	1,670,000	ShawCor (Canada)		60,445
		Oil & Gas Pipeline Products
	1,000,000	Hornbeck Offshore (a)		38,780
		Supply Vessel Operator in U.S. Gulf of Mexico
	513,000	Oil States International (a)		33,961
		Diversified North American Oil Service Provider
	893,600	Black Diamond Group (Canada)		20,021
		Provides Accommodations/Equipment for Oil Sands Development
	585,000	Rowan (a)		18,913
		Contract Offshore Driller
	2,890,900	Horizon North Logistics (Canada)		16,497
		Provides Diversified Oil Service Offering in Northern Canada
	4,415,000	Tuscany International Drilling (Colombia) (a)		1,713
		South America-based Drilling Rig Contractor
				550,554
		> Oil & Gas Producers 2.4%
	3,700,000	Pacific Rubiales Energy (Colombia)		78,354
		Oil Production & Exploration in Colombia
	695,000	Range Resources		43,000
		Oil & Gas Producer
	2,700,000	Denbury Resources (a)		40,797
		Oil Producer Using CO2 Injection
	974,000	Rosetta Resources (a)		35,687
		Oil & Gas Producer Exploring in South Texas & Montana
	703,000	SM Energy		34,524
		Oil & Gas Producer
	1,050,000	Tullow Oil (United Kingdom)		24,268
		Oil & Gas Producer
	1,159,000	Laredo Petroleum (a)		24,107
		Permian Basin Oil Producer
	500,000	Cabot Oil and Gas		19,700
		Large Natural Gas Producer in Appalachia & Gulf Coast
	361,000	Baytex (Canada) (c)		15,208
		Oil & Gas Producer in Canada
	7,582,928	PetroMagdalena Energy (Colombia) (a)(b)		11,768
		Oil & Gas Exploration/Production in Colombia
	550,000	Swift Energy (a)		10,236
		Oil & Gas Exploration & Production
	718,000	Celtic Exploration (Canada) (a)		9,711
		Canadian Oil & Gas Producer

See accompanying notes to financial statements.

36

Number of Shares			Value (000)
		> Oil & Gas Producers—continued
	1,100,000	Kodiak Oil and Gas (a)	$	9,031
		Bakken Oil & Gas Producer
	340,000	Petroleum Development Corporation (a)		8,337
		Oil & Gas Producer in U.S.
	750,000	Athabasca Oil Sands (Canada) (a)		8,251
		Oil Sands & Unconventional Oil Development
	37,500,000	Petromanas (Canada) (a)(b)		7,919
		Exploring for Oil in Albania
	200,000	Approach Resource (a)		5,108
		Oil & Gas Producer in West Texas Permian
	27,000,000	Shamaran Petroleum (Iraq) (a)		4,509
		Oil Exploration in Kurdistan
	26,000,000	Petrodorado (Colombia) (a)(b)		4,086
	24,000,000	Petrodorado - Warrants (Colombia) (a)(f)		340
		Oil & Gas Exploration & Production in Colombia, Peru & Paraguay
	1,198,100	Pan Orient (Canada) (a)		4,413
		Asian Oil & Gas Explorer
	25,000,000	Petroamerica (Colombia) (a)(c)		3,192
		Oil Exploration & Production in Colombia
	493,000	Crew Energy (Canada) (a)		2,784
		Canadian Oil & Gas Producer
	50,000,000	Gulf United (Colombia) (a)(e)(f)		2,640
		Prospecting for Oil Alongside Large Producers in Colombia
	5,116,000	Canacol (Colombia) (a)		2,286
		Oil Producer in South America
	8,400,000	Canadian Overseas Petroleum (United Kingdom) (a)(f)		1,465
	4,200,000	Canadian Overseas Petroleum - Warrants (United Kingdom) (a)(e)(f)		81
		Oil & Gas Exploration/Production in the North Sea
	4,110,000	Santa Maria Petroleum (Colombia) (a)(f)		1,240
	890,000	Santa Maria Petroleum (Colombia) (a)		280
		Explores for Oil & Gas in Latin America
	393,600	Houston American Energy (a)		441
		Oil & Gas Exploration/Production in Colombia
				413,763
		> Mining 0.8%
	387,000	Core Laboratories (Netherlands)		44,853
		Oil & Gas Reservoir Consulting
	15,000,000	Zhaojin Mining Industry (China)		19,723
		Gold Mining & Refining in China
	1,400,000	Kirkland Lake Gold (Canada) (a)		15,071
		Gold Mining
	550,000	Silver Wheaton (Canada)		14,762
		Silver Mining Royalty Company
	4,432,000	Northam Platinum (South Africa)		12,677
		Platinum Mining in South Africa
	1,150,000	Ivanhoe Mines (Mongolia) (a)(c)		11,341
		Copper Mine Project in Mongolia
	7,500,000	Duluth Metals (Canada) (a)(b)		10,976

Number of Shares			Value (000)
	500,000	Duluth Exploration - Special Warrants (Canada) (a)(e)(f)	$	39
		Copper & Nickel Miner
	16,000,000	Mongolian Mining (Mongolia) (a)		9,079
		Coking Coal Mining in Mongolia
	2,050,000	Alexco Resource (a)		9,041
		Mining, Exploration & Environmental Services
	800,000	Augusta Resource (a)		1,328
		US Copper/Moly Mine
	4,000,000	Wolverine Minerals (Canada) (a)(b)(f)		377
	2,000,000	Wolverine Minerals - Warrants (Canada) (a)(e)(f)		3
		Gold Mining
				149,270
		> Oil Refining, Marketing & Distribution 0.1%
	218,000	Vopak (Netherlands)		13,983
		World's Largest Operator of Petroleum & Chemical Storage Terminals
				13,983
		> Agricultural Commodities 0.1%
	1,306,818	Union Agriculture Group (Uruguay) (a)(e)(f)		12,794
		Farmland Operator in Uruguay
				12,794
		> Alternative Energy 0.1%
	2,000,000	GT Advanced Technologies (a)		10,560
		Largest Manufacturer of Furnaces & Reactors to Produce & Cast Polysilicon
	1,210,300	Synthesis Energy Systems (China) (a)		1,477
		Owner/Operator of Gasification Plants
				12,037
Energy & Minerals: Total				1,152,401
Other Industries 6.3%
		> Real Estate 4.0%
	3,700,000	DuPont Fabros Technology (b)		105,672
		Technology-focused Office Buildings
	750,000	Federal Realty Investment Trust		78,068
		Shopping Centers
	1,850,000	Extra Space Storage		56,610
		Self Storage Facilities
	3,700,000	Associated Estates Realty (b)		55,315
		Multi-family Properties
	720,000	Digital Realty Trust		54,051
		Technology-focused Office Buildings
	975,000	Post Properties		47,726
		Multi-family Properties
	2,450,000	Biomed Realty Trust		45,766
		Life Science-focused Office Buildings
	770,000	Kilroy Realty		37,276
		West Coast Office & Industrial Properties
	43,000,000	Mapletree Logistics Trust (Singapore)		33,434
		Industrial Property Landlord
	3,000,000	Education Realty Trust		33,240
		Student Housing
	15,000,000	Ascendas REIT (Singapore)		25,589
		Industrial Property Landlord

See accompanying notes to financial statements.

37

Columbia Acorn Fund

Statement of Investments (Unaudited), continued

Number of Shares			Value (000)
		> Real Estate—continued
	3,750,000	DCT Industrial Trust	$	23,625
		Industrial Properties
	325,000	Jones Lang LaSalle		22,870
		Real Estate Services
	1,300,000	St. Joe (a)(c)		20,553
		Florida Panhandle Landowner
	3,500,000	Kite Realty Group (b)		17,465
		Community Shopping Centers
	2,000,031	Summit Hotel Properties (b)		16,740
		Owner of Select Service Hotels
	2,800	Orix JREIT (Japan)		12,586
		Diversified REIT
				686,586
		> Transportation 1.3%
	1,155,000	JB Hunt Transport Services		68,838
		Truck & Intermodal Carrier
	2,937,175	Rush Enterprises, Class A (a)(b)		48,023
	550,000	Rush Enterprises, Class B (a)(b)		7,381
		Truck Sales & Service
	1,260,000	World Fuel Services		47,918
		Global Fuel Broker
	2,400,000	Heartland Express		34,344
		Regional Trucker
	300,000	Genesee & Wyoming (a)		15,852
		Short-line Operator
				222,356
		> Regulated Utilities 1.0%
	2,000,000	Northeast Utilities		77,620
		Regulated Electric Utility
	1,660,000	Wisconsin Energy		65,686
		Wisconsin Utility
	500,000	Allete		20,900
		Regulated Electric Utility in Minnesota
	200,000	Red Eléctrica de España (Spain)		8,729
		Spanish Power Transmission
				172,935
Other Industries: Total				1,081,877
Total Equities: 95.8% (Cost: $10,608,838)				16,441,222

Number of Shares			Value (000)
Securities Lending Collateral 1.8%
	303,633,050	Dreyfus Government Cash Management Fund (7 day yield of 0.01%) (g)	$	303,633
Total Securities Lending Collateral: (Cost: $303,633)				303,633
Total Investments: 97.6% (Cost: $10,912,471)(h)(i)				16,744,855
Obligation to Return Collateral for Securities Loaned: (1.8)%				(303,633	)
Cash and Other Assets Less Liabilities: 4.2%				723,250
Total Net Assets: 100.0%			$	17,164,472

ADR - American Depositary Receipts

GDR - Global Depositary Receipts

REIT - Real Estate Investment Trust

See accompanying notes to financial statements.

38

> Notes to Statement of Investments (dollar values in thousands)

(a)  Non-income producing security.

(b)  An affiliated person of the Fund may include any company in which the Fund owns five percent or more of its outstanding voting shares. Holdings and transactions in these affiliated companies during the six months ended June 30, 2012, are as follows:

Security	Balance of Shares Held 12/31/11		Purchases/ Additions		Sales/ Reductions		Balance of Shares Held 6/30/12		Value		Dividend
AboveNet		1,400,000		-		-		1,400,000	$	117,600	$	-
Acorn Energy		1,500,000		-		-		1,500,000		12,480		180
AFC Enterprises		2,000,000		-		-		2,000,000		46,280		-
Alimera Sciences		2,040,000		-		-		2,040,000		6,100		-
Anthera Pharmaceuticals		1,740,000		1,250,000		-		2,990,000		2,022		-
Associated Estates Realty		3,700,000		-		-		3,700,000		55,315		-
Auxilium Pharmaceuticals		3,033,715		216,285		-		3,250,000		87,393		1,295
Bally Technologies		3,725,000		-		-		3,725,000		173,809		-
CAI International		1,123,400		-		-		1,123,400		22,333		-
Cavco Industries		460,000		-		-		460,000		23,589		-
Cepheid		3,200,000		1,400,000		-		4,600,000		205,850		-
Chelsea Therapeutics International		4,550,000		1,200,000		-		5,750,000		8,510		-
Cogent Communications*		2,520,000		-		320,000		2,200,000		42,350		-
Constant Contact		2,350,000		-		350,000		2,000,000		35,760		-
Donaldson**		4,200,000		4,200,000		-		8,400,000		280,308		1,428
Drew Industries		1,500,000		380,000		-		1,880,000		52,358		-
Duluth Metals		7,500,000		-		-		7,500,000		10,976		-
DuPont Fabros Technology		3,350,000		350,000		-		3,700,000		105,672		822
eResearch Technology		4,900,000		-		-		4,900,000		39,151		-
ESCO Technologies		2,200,000		-		-		2,200,000		80,168		352
ExlService Holdings		1,145,000		473,000		-		1,618,000		39,868		-
Gaiam		1,371,366		-		-		1,371,366		5,348		-
Gaylord Entertainment		3,850,000		-		-		3,850,000		148,456		-
General Communications		2,000,000		-		-		2,000,000		16,620		-
GLG Life Tech		1,750,000		-		84,730		1,665,270		689		-
H & E Equipment Services		3,400,000		-		-		3,400,000		51,102		-
Hackett Group+		4,500,000		-		650,793		3,849,207		21,440		-
HEICO***		2,250,000		813,000		-		3,063,000		98,812		135
Helen of Troy		1,600,000		-		-		1,600,000		54,224		-
Horizon Pharma*		1,095,000		-		-		1,095,000		7,807		-
iGATE		3,400,000		-		-		3,400,000		57,868		-
II-VI		4,550,000		-		-		4,550,000		75,849		-
Insperity		1,210,000		149,200		-		1,359,200		36,766		387
Interline Brands*		2,600,000		-		1,200,000		1,400,000		35,098		-
InterMune		2,950,000		900,000		-		3,850,000		46,007		-
IPG Photonics		2,780,000		-		-		2,780,000		121,180		-
IXYS		1,900,000		-		-		1,900,000		21,223		-
Kenexa*		1,700,000		-		526,900		1,173,100		34,055		-
Kite Realty Group		3,500,000		-		-		3,500,000		17,465		420
Knoll		4,200,000		-		-		4,200,000		56,364		1,260
Lifetime Fitness		2,190,000		-		-		2,190,000		101,857		-
lululemon athletica*		5,740,000		-		1,235,000		4,505,000		268,633		-
Marlin Business Services		1,091,000		-		-		1,091,000		17,882		131
MB Financial		2,360,000		500,000		-		2,860,000		61,604		55
McGrath Rentcorp		2,150,000		-		-		2,150,000		56,975		1,000
Mettler-Toledo International		1,600,000		-		-		1,600,000		249,360		-
Micromet*		6,702,347		137,138		6,766,894		72,591		-		-
Moog		2,775,000		225,000		-		3,000,000		124,050		-
Navigant Consulting		2,800,000		227,016		-		3,027,016		38,261		-
NPS Pharmaceuticals		6,000,000		-		-		6,000,000		51,660		-
Pericom Semiconductor		1,765,000		-		-		1,765,000		15,885		-
Petroamerica*		30,275,000		-		5,275,000		25,000,000		3,192		-
Petrodorado		26,000,000		-		-		26,000,000		4,086		-
PetroMagdalena Energy		7,582,928		-		-		7,582,928		11,768		-
Petromanas		37,500,000		-		-		37,500,000		7,919		-
Pier 1 Imports		5,600,000		1,000,000		-		6,600,000		108,438		224
Pinnacle Entertainment		3,950,000		-		-		3,950,000		37,999		-
Raptor Pharmaceutical		3,455,000		745,000		590,406		3,609,594		20,178		-

See accompanying notes to financial statements.

39

Columbia Acorn Fund

Statement of Investments (Unaudited), continued

> Notes to Statement of Investments (dollar values in thousands)

Security	Balance of Shares Held 12/31/11		Purchases/ Additions		Sales/ Reductions		Balance of Shares Held 6/30/12		Value		Dividend
Rush Enterprises		3,350,000		137,175		-		3,487,175	$	55,404	$	-
SABA		-		2,000,000		-		2,000,000		18,560		-
Salem Communications*		1,527,700		-		1,527,700		-		-		-
Santa Maria Petroleum*,****		50,000,000		-		45,000,000		5,000,000		1,520		-
Seattle Genetics		6,153,000		-		-		6,153,000		156,225		-
Shutterfly		3,070,000		300,000		-		3,370,000		103,425		-
SPS Commerce		900,000		-		-		900,000		27,342		-
Summit Hotel Properties		1,500,000		500,031		-		2,000,031		16,740		413
Tower Group		1,675,000		1,089,000		-		2,764,000		57,685		1,038
TriCo Bancshares		1,350,000		-		-		1,350,000		20,790		364
True Religion Apparel*		1,507,000		-		1,275,548		231,452		6,708		46
tw telecom		9,500,000		-		-		9,500,000		243,770		-
Tyler Technologies*		1,700,000		-		800,000		900,000		36,315		-
Virtusa		2,125,000		-		-		2,125,000		28,369		-
Warnaco Group*		2,190,000		-		730,000		1,460,000		62,167		-
Wolverine Minerals		4,000,000		-		-		4,000,000		377		-
World Acceptance		1,505,202		-		80,000		1,425,202		93,778		-
Total of Affiliated Transactions		350,332,658		18,191,845		66,412,971		302,111,532	$	4,463,187	$	9,550

*  At June 30, 2012, the Fund owned less than five percent of the company's outstanding voting shares.

**  Includes the effects of a 2:1 stock split.

***  Includes the effects of a 5:4 stock split.

****  Includes the effects of a 1:10 reverse stock split.

+  Includes the effects of a corporate action.

The aggregate cost and value of these companies at June 30, 2012, were $2,717,367 and $3,965,342, respectively. Investments in affiliated companies represented 23.10% of the Fund's total net assets at June 30, 2012.

(c)  All or a portion of this security was on loan at June 30, 2012. The total market value of securities on loan at June 30, 2012 was $302,684.

(d)  Security exempt from registration under Section 4(2) of the Securities Act of 1933. This security may only be resold in exempt transactions to qualified buyers. Private resales of this security to qualified institutional buyers are also exempt from registration pursuant to Rule 144A under the Securities Act of 1933. At June 30, 2012, this security had an aggregate value of $7,975, which represented 0.05% of total net assets.

(e)  Illiquid security.

(f)  Denotes a restricted security, which is subject to restrictions on resale under federal securities laws. These securities are valued at fair value determined in good faith under consistently applied procedures established by the Board of Trustees. At June 30, 2012, the market value of these securities amounted to $19,451, which represented 0.11% of total net assets.

  Additional information on these securities is as follows:

Security	Acquisition Dates	Shares		Cost		Value
Union Agriculture Group	12/8/10-6/27/12		1,306,818	$	15,000	$	12,794
Gulf United	4/18/12		50,000,000		4,000		2,640
Canadian Overseas Petroleum	11/24/10		8,400,000		3,591		1,465
Santa Maria Petroleum	1/14/11		4,110,000		5,193		1,240
Wolverine Minerals	6/3/11		4,000,000		2,005		377
Petrodorado - Warrants	11/20/09		24,000,000		2,965		340
MicroDose Therapeutx	11/24/00		359,944		2,005		252
Voyager Learning - Contingent Value Rights	12/24/09		2,000,000		-		220
Canadian Overseas Petroleum - Warrants	11/24/10		4,200,000		526		81
Duluth Exploration - Special Warrants	8/19/11		500,000		-		39
Wolverine Minerals - Warrants	6/3/11		2,000,000		243		3
				$	35,528	$	19,451

(g)  Investment made with cash collateral received from securities lending activity.

(h)  At June 30, 2012 for federal income tax purposes, the cost of investments was $10,912,471 and net unrealized appreciation was $5,832,384 consisting of gross unrealized appreciation of $6,608,143 and gross unrealized depreciation of $775,759.

See accompanying notes to financial statements.

40

> Notes to Statement of Investments (dollar values in thousands)

(i)  On June 30, 2012, the market value of foreign securities represented 8.26% of total net assets. The Fund's foreign portfolio was diversified as follows:

Country	Value		Percentage of Net Assets
Canada	$	231,071		1.34
Netherlands		208,842		1.22
Singapore		130,489		0.76
Colombia		105,899		0.62
Sweden		93,549		0.55
Hong Kong		90,106		0.52
Brazil		80,883		0.47
Japan		71,032		0.41
China		60,566		0.35
France		44,272		0.26
Denmark		39,545		0.23
South Africa		37,581		0.22
Chile		37,466		0.22
Country	Value		Percentage of Net Assets
Israel	$	31,884		0.19
Ireland		30,360		0.18
United Kingdom		25,814		0.15
Russia		21,312		0.12
Mongolia		20,420		0.12
Uruguay		12,794		0.07
Iceland		12,162		0.07
India		10,619		0.06
Spain		8,729		0.05
Germany		7,974		0.05
Iraq		4,509		0.03
Total Foreign Portfolio	$	1,417,878		8.26

Fair Value Measurements

  Various inputs are used in determining the value of the Fund's investments, following the input prioritization hierarchy established by GAAP. These inputs are summarized in the three broad levels listed below:

•  Level 1 – quoted prices in active markets for identical securities

•  Level 2 – prices determined using other significant observable inputs (including quoted prices for similar securities, interest rates, prepayment speeds, credit risk and others)

•  Level 3 – prices determined using significant unobservable inputs where quoted prices or observable inputs are unavailable or less reliable (including management's own assumptions about the factors market participants would use in pricing an investment)

  The inputs or methodology used for valuing securities are not necessarily an indication of the risk associated with investing in those securities.

  Examples of the types of securities in which the Fund would typically invest and how they are classified within this hierarchy are as follows. Typical Level 1 securities include exchange traded domestic equities, mutual funds whose NAVs are published each day and exchange traded foreign equities that are not statistically fair valued. Typical Level 2 securities include exchange traded foreign equities that are statistically fair valued and short-term investments valued at amortized cost. Additionally, securities fair valued by the Valuation Committee (the Committee) of the Fund's Board of Trustees (the Board) that rely on significant observable inputs are also included in Level 2. Typical Level 3 securities include any security fair valued by the Committee that relies on significant unobservable inputs.

  Under the direction of the Board, the Committee is responsible for carrying out the valuation procedures approved by the Board.

  The Committee meets as necessary, and no less frequently than quarterly, to determine fair values for securities for which market quotations are not readily available or for which the investment manager believes that available market quotations are unreliable, and to review the continuing appropriateness of the current value of any security subject to the Trust's Portfolio Pricing Policy and the pricing procedures of the investment manager (the Policies). The Policies address, among other things: circumstances under which market quotations will be deemed readily available; selection of third party pricing vendors; appropriate pricing methodologies; events that require fair valuation and fair value techniques; and circumstances under which securities will be deemed to pose a potential for stale pricing, including when securities are illiquid, restricted, or in default. The Committee may also meet to discuss additional valuation matters, which may include review of back-testing results, review of time-sensitive information or approval of other valuation related actions, and to review the appropriateness of the Policies.

  For investments categorized as Level 3, the significant unobservable inputs used in the fair value measurement of the Funds' securities may include: (i) data specific to the issuer or comparable issuers, (ii) general market or specific sector news and (iii) quoted prices and specific or similar security transactions. The Committee considers this data and any changes from prior periods in order to assess the reasonableness of observable and unobservable inputs, any assumptions or internal models used to value those securities and changes in fair value. Significant changes in any of these factors could result in lower or higher fair value measurements. Various factors impact the frequency of monitoring (which may occur as often as daily), however the Committee may determine that changes to inputs, assumptions and models are not required with the same frequency.

See accompanying notes to financial statements.

41

Columbia Acorn Fund

Statement of Investments (Unaudited), continued

> Notes to Statement of Investments (dollar values in thousands)

The following table summarizes the inputs used, as of June 30, 2012, in valuing the Fund's assets:

Investment Type	Quoted Prices (Level 1)		Other Significant Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)		Total
Equities
Information	$	4,508,981	$	157,589	$	-	$	4,666,570
Industrial Goods & Services		3,068,284		195,289		-		3,263,573
Consumer Goods & Services		2,620,690		110,556		220		2,731,466
Finance		1,878,265		-		-		1,878,265
Health Care		1,641,914		24,904		252		1,667,070
Energy & Minerals		975,496		164,072		12,833		1,152,401
Other Industries		1,001,539		80,338		-		1,081,877
Total Equities		15,695,169		732,748		13,305		16,441,222
Total Securities Lending Collateral		303,633		-		-		303,633
Total Investments	$	15,998,802	$	732,748	$	13,305	$	16,744,855

  The Fund's assets assigned to the Level 2 input category are generally valued using a market approach, in which a security's value is determined through its correlation to prices and information from observable market transactions for similar or identical assets. Foreign equities are generally valued at the last sale price on the foreign exchange or market on which they trade. The Fund may use a statistical fair valuation model, in accordance with the policy adopted by the Board, provided by an independent third party to value securities principally traded in foreign markets in order to adjust for possible stale pricing that may occur between the close of the foreign exchanges and the time for valuation. These models take into account available market data including intraday index, ADR, and ETF movements. Securities acquired via private placement that have a holding period or an extended settlement period are valued at a discount to the same shares that are trading freely on the market. These discounts are determined by the investment manager's experience with similar securities or situations. Factors may include, but are not limited to, trade volume, shares outstanding and stock price. Warrants which do not trade are valued as a percentage of the actively trading common stock using a model, based on Black Scholes. Securities which have halted or temporarily stopped trading are valued at the last sale and adjusted by a premium or a discount to account for the anticipated re-opening price. These adjustments are determined by the investment manager's experience with similar securities or situations.

  The following table shows transfers between Level 1 and Level 2 of the fair value hierarchy:

Transfers In				Transfers Out
Level 1		Level 2		Level 1		Level 2
$	-	$	1,575	$	1,575	$	-

  Financial assets were transferred from Level 1 to Level 2 as trading halted during the period.

The following table reconciles asset balances for the period ending June 30, 2012, in which significant observable and/or unobservable inputs (Level 3) were used in determining value:

Investments in Securities	Balance as of December 31, 2011		Realized Gain/(Loss)		Change in Unrealized Appreciation (Depreciation)			Purchases		Sales		Transfers into Level 3		Transfers out of Level 3		Balance as of June 30, 2012
Equities
Consumer Goods & Services	$	180	$	-	$	40		$	-	$	-	$	-	$	-	$	220
Health Care		270		-		(18	)		-		-		-		-		252
Energy & Minerals		12,507		-		326			-		-		-		-		12,833
	$	12,957	$	-	$	348		$	-	$	-	$	-	$	-	$	13,305

  The information in the above reconciliation table represents fiscal year to date activity for any securities identified as using Level 3 inputs at either the beginning or the end of the current fiscal period.

  The change in unrealized appreciation attributed to securities owned at June 30, 2012, which were valued using significant unobservable inputs (Level 3), amounted to $348.

  The Fund does not hold any significant investments categorized as Level 3.

  Certain common stock classified as Level 3 are valued at fair value, using a market approach, as determined in good faith under consistently applied procedures established by and under the general supervision of the Board. To determine fair value for these securities, for which no market exists, the Committee utilizes the valuation technique it deems most appropriate in the circumstances, using some unobservable inputs, which may include but are not limited to trades of similar securities, estimated earnings of the company, market multiples derived from a set of comparable companies, and the position of the security within the company's capital structure. Significant increases or decreases to any of these inputs could result in a significantly lower or higher fair value measurement. Generally, a change in estimated earnings of a company may result in a change to the comparable companies and market multiples utilized.

See accompanying notes to financial statements.

42

Columbia Acorn International

Major Portfolio Changes in the Second Quarter (Unaudited)

	Number of Shares
	3/31/12		6/30/12
Purchases
Asia
> Japan
Daiseki		1,427,129		1,613,429
Doshisha		750,600		828,000
Horiba		257,800		424,000
Miraca Holdings		0		659,500
NGK Insulators		2,400,000		2,552,000
Nihon Parkerizing		145,700		756,900
Sanrio		500,000		865,800
Start Today		1,718,724		2,572,724
> Taiwan
Chroma Ate		10,277,000		10,677,000
CTCI Corp		18,571,200		20,120,000
MStar Semiconductor		2,930,000		3,661,100
Taiwan Mobile		10,329,000		16,405,300
> Hong Kong
Lifestyle International		18,000,000		21,845,000
Vitasoy International		0		4,495,200
> Singapore
Petra Foods		0		3,071,300
> China
AMVIG Holdings		28,763,700		30,000,000
Digital China		13,570,200		18,000,300
> India
Colgate-Palmolive India		0		545,000
Redington India		1,477,269		13,195,000
Titan Industries		791,352		1,600,000
> Korea
Hyundai Home Shopping		10,090		55,000
Kepco Plant Service & Engineering		0		244,530
> Indonesia
Ace Indonesia		10,000,000		15,000,000
Mayora Indah		0		2,176,600
Mitra Adiperkasa		0		12,488,000
MNC Skyvision		0		32,766,000
Tower Bersama Infrastructure		48,560,000		51,767,300
> Mongolia
Mongolian Mining		42,636,400		60,037,500
> Cambodia
Nagacorp		50,000,000		60,000,000
Europe
> United Kingdom
Aggreko		0		596,100
BBA Aviation		3,167,139		8,785,000
Domino's Pizza United Kingdom & Ireland		2,497,000		3,107,000

	Number of Shares
	3/31/12		6/30/12
Greggs		1,060,885		2,300,000
Rightmove		548,000		822,000
Spirax Sarco		0		256,202
WH Smith		0		1,555,000
> Netherlands
TKH Group		403,800		850,468
> France
Compagnie Française de l'Afrique Occidentale		0		134,254
Eurofins Scientific		418,000		553,000
Neopost		430,000		675,000
> Germany
NORMA Group		0		690,000
> Denmark
Solar A/S		130,651		166,013
> Italy
Geox		5,800,000		7,000,000
> Russia
Yandex		0		1,123,695
> Portugal
Redes Energéticas Nacionais		8,531,175		8,635,000
Other Countries
> Australia
Challenger Financial		4,546,885		11,936,400
Commonwealth Property Office Fund		17,451,906		48,533,075
Domino's Pizza Enterprises		0		1,576,290
IAG		0		7,595,003
UGL		2,653,389		3,973,200
> United States
Rowan		0		548,900
> Israel
Caesarstone		125,000		625,000
Latin America
> Brazil
Arcos Dorados		0		1,300,000
MRV Engenharia		2,917,000		3,577,000
> Chile
Viña Concha y Toro		4,016,878		5,640,000

See accompanying notes to financial statements.

43

Columbia Acorn International

Major Portfolio Changes in the Second Quarter (Unaudited), continued

	Number of Shares
	3/31/12		6/30/12
Sales
Asia
> Japan
Aeon Delight		1,860,438		1,417,438
Ain Pharmaciez		589,792		349,792
Gree		246,300		0
Miura		511,450		407,050
Seven Bank		22,694,000		20,227,000
Shinsei Bank		18,673,649		15,024,649
Tsumura		855,604		0
> Taiwan
Simplo Technology		5,614,530		5,058,830
> Hong Kong
Melco Crown Entertainment - ADR		7,000,000		6,500,000
MGM China Holdings		12,500,000		10,000,000
Sasa International		38,000,000		30,000,000
> Singapore
Olam International		27,000,000		25,000,000
> China
NetEase.com - ADR		644,000		381,300
> Indonesia
Jasa Marga		6,937,300		0
> Thailand
Home Product Center		118,000,000		110,000,000
Europe
> United Kingdom
Abcam		2,950,000		2,855,000
Chemring		5,654,735		2,303,000
Intertek Group		1,460,000		1,004,500
JLT Group		3,000,000		2,579,333
Premier Oil		2,636,932		2,027,932
Rotork		730,000		517,000
Tullow Oil		740,581		382,581
Workspace Group		7,500,000		0
> Netherlands
Core Laboratories		177,395		143,395
Fugro		687,967		460,000
Imtech		1,763,611		1,680,623
> Switzerland
Dufry Group		360,000		330,000
Kuehne & Nagel		245,000		170,000
> France
Gemalto		1,073,700		729,700
Mersen		460,000		162,844
Rubis		353,648		0

	Number of Shares
	3/31/12		6/30/12
> Germany
Elringklinger		555,700		333,000
Rheinmetall		679,600		405,000
Rhoen-Klinikum		1,600,000		0
> Sweden
East Capital Explorer		905,452		419,877
> Italy
Ansaldo STS		2,621,149		0
CIR		12,503,754		8,951,757
> Russia
Mail.ru - GDR		629,642		368,493
> Ireland
Paddy Power		289,400		263,400
United Drug		6,750,000		4,237,000
> Greece
Intralot		6,954,400		4,384,185
Other Countries
> Canada
Athabasca Oil Sands		731,000		450,000
Baytex		615,857		263,857
Black Diamond Group		1,049,576		770,576
Celtic Exploration		721,000		454,000
Crew Energy		1,043,000		332,700
Horizon North Logistics		2,411,514		2,096,514
> United States
Alexion Pharmaceuticals		627,431		0
FMC Technologies		461,213		407,213
Oil States International		270,000		0
World Fuel Services		987,228		763,228
Latin America
> Colombia
Canacol		8,353,169		7,850,769

See accompanying notes to financial statements.

44

Columbia Acorn International

Statement of Investments (Unaudited), June 30, 2012

Number of Shares			Value (000)
			Equities: 94.6%
Asia 43.8%
		> Japan 17.6%
	5,582,600	Kansai Paint	$	59,822
		Paint Producer in Japan, India, China & Southeast Asia
	20,227,000	Seven Bank		51,943
		ATM Processing Services
	20,096	Wacom		45,009
		Computer Graphic Illustration Devices
	3,029,900	Park24		44,746
		Parking Lot Operator
	1,582,200	Hoshizaki Electric		40,047
		Commercial Kitchen Equipment
	2,981,100	Kuraray		38,633
		Special Resin, Fine Chemical, Fibers & Textures
	2,572,724	Start Today (a)		35,952
		Online Japanese Apparel Retailer
	1,694,562	Glory		35,351
		Currency Handling Systems & Related Equipment
	7,780	Orix JREIT		34,971
		Diversified REIT
	1,417,438	Aeon Delight		32,546
		Facility Maintenance & Management
	865,800	Sanrio (a)		31,566
		Character Goods & Licensing
	295,762	Nakanishi		30,061
		Dental Tools & Machinery
	937,651	Kintetsu World Express		30,011
		Airfreight Logistics
	15,116	Advance Residence Investment		29,385
		Residential REIT
	2,552,000	NGK Insulators		28,260
		Ceramic Products for Auto, Power & Electronics
	1,613,429	Daiseki		28,052
		Waste Disposal & Recycling
	659,500	Miraca Holdings		27,381
		Outsourced Lab Testing, Diagnostic Equipment & Reagents
	480,000	Disco		27,184
		Semiconductor Dicing & Grinding Equipment
	25,979	Jupiter Telecommunications		26,488
		Largest Cable Service Provider in Japan
	2,137,272	Japan Airport Terminal		26,068
		Airport Terminal Operator at Haneda
	5,540	Mori Hills REIT Investment		23,942
		Tokyo-centric Diversified REIT
	828,000	Doshisha		22,937
		Wholesaler
	2,600,000	Shimadzu		22,498
		Analytical Instrument, Medical & Industrial Equipment
	1,885,600	Asahi Diamond Industrial		21,652
		Consumable Diamond Tools
	349,792	Ain Pharmaciez		21,101
		Dispensing Pharmacy/Drugstore Operator
	339,000	FP Corporation		21,028
		Disposable Food Trays & Containers
	6,140	Kenedix Realty Investment		19,852
		Tokyo Mid-size Office REIT

Number of Shares			Value (000)
	1,940,200	Sintokogio	$	19,450
		Automated Casting Machines, Surface Treatment System & Consumables
	880,474	Aeon Mall		18,762
		Suburban Shopping Mall Developer, Owner & Operator
	15,024,649	Shinsei Bank		18,279
		Commercial Bank
	772,000	Misumi Group		18,192
		Industrial Components Distributor
	732,108	Icom		17,976
		Two Way Radio Communication Equipment
	1,405,739	Ushio		17,424
		Industrial Light Sources
	857,144	Ibiden		15,527
		Electronic Parts & Ceramics
	424,000	Horiba		14,891
		Measuring Instruments & Analyzers
	1,346,963	Torishima Pump Manufacturing		13,541
		Industrial Pump for Power Generation & Water Supply Systems
	1,400	Japan Real Estate Investment		12,836
		Office REIT in Tokyo
	1,821	Fukuoka REIT		12,539
		Diversified REIT in Fukuoka
	756,900	Nihon Parkerizing		11,723
		Metal Surface Treatment Agents & Processing
	407,050	Miura		10,838
		Industrial Boiler
				1,058,464
		> Taiwan 7.2%
	36,606,000	Far EasTone Telecom		79,642
		Taiwan's Third Largest Mobile Operator
	16,405,300	Taiwan Mobile		54,252
		Taiwan's Second Largest Mobile Operator
	20,120,000	CTCI Corp		37,671
		International Engineering Firm
	5,058,830	Simplo Technology		34,938
		Battery Packs for Notebook & Tablet PCs
	12,218,270	Tripod Technologies		34,730
		Printed Circuit Boards (PCB)
	5,910,000	Radiant Opto-Electronics (b)		30,036
		LCD Back Light Units & Modules
	2,492,300	St. Shine Optical		27,893
		World's Leading Disposable Contact Lens OEM
	11,200,000	Taiwan Hon Chuan		25,229
		Beverage Packaging (Bottles, Caps, Labels) Manufacturer
	3,661,100	MStar Semiconductor		24,695
		Integrated Circuits for TV, Digital Set-top-box & Handset
	10,677,000	Chroma Ate		24,374
		Automatic Test Systems, Testing & Measurement Instruments
	6,603,000	Advantech		21,959
		Industrial PC & Components
	3,181,000	President Chain Store		16,973
		Taiwan's Number One Convenience Chain Store Operator
	2,595,000	PC Home		14,711
		Taiwanese Internet Retail Company
	2,469,000	Lung Yen		7,138
		Funeral Services & Columbaria
				434,241

See accompanying notes to financial statements.

45

Columbia Acorn International

Statement of Investments (Unaudited), continued

Number of Shares			Value (000)
		> Hong Kong 3.9%
	6,500,000	Melco Crown Entertainment - ADR (b)	$	74,880
		Macau Casino Operator
	21,845,000	Lifestyle International		48,136
		Mid to High-end Department Store Operator in Hong Kong & China
	15,625,000	L'Occitane International		43,364
		Skin Care & Cosmetics Producer
	8,475,000	AAC Technologies		24,664
		Miniature Acoustic Components
	30,000,000	Sasa International		19,007
		Cosmetics Retailer
	10,000,000	MGM China Holdings		15,333
		Macau Casino Operator
	8,000,000	Melco International		6,472
		Macau Casino Operator
	4,495,200	Vitasoy International		3,778
		Hong Kong Soy Food Brand
				235,634
		> Singapore 3.8%
	25,000,000	Olam International		36,209
		Agriculture Supply Chain Manager
	20,000,000	Ascendas REIT		34,119
		Industrial Property Landlord
	20,000,000	CDL Hospitality Trust		30,934
		Hotel Owner/Operator
	35,000,000	Mapletree Logistics Trust		27,214
		Industrial Property Landlord
	35,000,000	Mapletree Commercial Trust		27,176
		Retail & Office Property Landlord
	28,000,000	Mapletree Industrial Trust		26,822
		Industrial Property Landlord
	15,000,000	Goodpack Limited		20,546
		International Bulk Container Leasing
	3,500,000	Singapore Exchange		17,584
		Singapore Equity & Derivatives Market Operator
	3,071,300	Petra Foods		6,061
		Cocoa Processor & Chocolate Manufacturer
				226,665
		> China 3.1%
	26,565,000	Want Want		32,851
		Chinese Branded Consumer Food Company
	18,000,300	Digital China		31,721
		IT Distribution & Systems Integration Services
	1,100,000	New Oriental Education & Technology - ADR (b)		26,950
		Education Service Provider
	18,920,554	Zhaojin Mining Industry		24,878
		Gold Mining & Refining in China
	381,300	NetEase.com - ADR (b)		22,440
		Chinese Online Gaming Services
	260,000,000	RexLot Holdings		18,625
		Lottery Equipment Supplier in China
	326,700	51job - ADR (a)(b)		14,881
		Integrated Human Resource Services
	30,000,000	AMVIG Holdings		13,284
		Chinese Tobacco Packaging Material Supplier
				185,630

Number of Shares			Value (000)
		> India 2.4%
	341,652	Asian Paints	$	23,850
		India's Largest Paint Company
	2,262,300	United Breweries		22,126
		India's Largest Brewer
	13,195,000	Redington India		18,222
		Supply Chain Solutions for IT & Mobile Handsets in Emerging Markets
	8,052,053	Adani Ports & Special Economic Zone		17,581
		Indian West Coast Shipping Port
	11,163,303	Jain Irrigation Systems		16,751
	558,165	Jain Irrigation Systems - DVR (b)		395
		Agricultural Micro-irrigation Systems & Food Processing
	1,550,000	Shriram Transport Finance		14,786
		Used Truck Finance
	545,000	Colgate-Palmolive India		11,762
		Consumer Products in Oral Care
	1,600,000	Titan Industries		6,443
		Jewlery, Watches & Eyeglasses
	10,249,300	S. Kumars Nationwide		6,361
		Textiles, Clothing & Retail
	32,642,905	REI Agro		5,466
		Basmati Rice Processing
	1,650,000	SKIL Ports and Logistics (b)		2,920
		Indian Container Port Project
				146,663
		> Korea 1.8%
	1,134,000	Grand Korea Leisure		23,541
		Largest 'Foreigner Only' Casino Group in Korea
	101,150	NHN		22,186
		Korean Online Search Services
	623,120	Woongjin Coway		19,457
		Korean Household Appliance Rental Service Provider
	580,000	iMarketKorea		10,751
		Procurement, Distribution of MRO (Maintenance, Repair, Operations) Goods
	474,441	Handsome		10,683
		Korea's Leading High-end Apparel Company
	244,530	Kepco Plant Service & Engineering		10,314
		Power Plant & Grid Maintenance
	182,000	Hana Tour Service		7,146
		Korea's Largest Wholesale Tour Provider
	55,000	Hyundai Home Shopping		5,382
		TV Home Shopping Company
				109,460
		> Indonesia 1.2%
	29,063,787	Archipelago Resources (b)(c)		23,214
		Gold Mining Projects in Indonesia, Vietnam & the Philippines
	51,767,300	Tower Bersama Infrastructure (b)		18,135
		Communications Towers
	12,488,000	Mitra Adiperkasa		9,588
		Operator of Department Store & Specialty Retail Stores
	15,000,000	Ace Indonesia		8,128
		Home Improvement Retailer
	2,176,600	Mayora Indah		5,907
		Consumer Branded Food Manufacturer

See accompanying notes to financial statements.

46

Number of Shares			Value (000)
		> Indonesia—continued
	32,766,000	MNC Skyvision (b)	$	5,486
		Largest Satellite Pay TV Operator in Indonesia
	6,217,500	Southern Arc Minerals (b)(c)		1,710
		Gold & Copper Exploration in Indonesia
				72,168
		> Mongolia 0.9%
	60,037,500	Mongolian Mining (b)		34,069
		Coking Coal Mining in Mongolia
	1,049,943	Ivanhoe Mines (a)(b)		10,354
	914,678	Ivanhoe Mines (a)(b)(d)		8,854
		Copper Mine Project in Mongolia
				53,277
		> Philippines 0.8%
	73,221,250	SM Prime Holdings		22,696
		Shopping Mall Operator
	7,931,700	Int'l Container Terminal		13,923
		Container Handling Terminals & Port Management
	19,454,700	Manila Water Company		11,331
		Water Utility Company in the Philippines
				47,950
		> Thailand 0.7%
	110,000,000	Home Product Center		43,930
		Home Improvement Retailer
				43,930
		> Cambodia 0.4%
	60,000,000	Nagacorp		26,831
		Casino/Entertainment Complex in Cambodia
				26,831
Asia: Total				2,640,913
Europe 29.9%
		> United Kingdom 5.9%
	1,004,500	Intertek Group		42,084
		Testing, Inspection, Certification Services
	3,375,000	Serco		28,343
		Facilities Management
	2,579,333	JLT Group		28,341
		International Business Insurance Broker
	8,785,000	BBA Aviation		28,124
		Aviation Support Services
	3,107,000	Domino's Pizza United Kingdom & Ireland		25,053
		Pizza Delivery in the UK, Ireland & Germany
	822,000	Rightmove		20,540
		Internet Real Estate Listings
	596,100	Aggreko		19,386
		Temporary Power & Temperature Control Services
	2,855,000	Abcam		18,643
		Online Sales of Antibodies
	2,300,000	Greggs		18,169
		Bakery
	1,761,742	Smith and Nephew		17,622
		Medical Equipment & Supplies
	517,000	Rotork		15,990
		Valve Actuators for Oil & Water Pipelines
	1,773,408	Shaftesbury		14,317
		London Prime Retail REIT

Number of Shares			Value (000)
	1,555,000	WH Smith	$	13,276
		Newsprint, Book & General Stationery Retailer
	262,300	Next		13,171
		Clothes & Home Retailer in the UK
	2,027,932	Premier Oil (b)		10,775
		Oil & Gas Producer in Europe, Pakistan & Asia
	2,303,000	Chemring		9,915
		Defense Manufacturer of Countermeasures & Energetics
	4,163,948	PureCircle (a)(b)		9,360
		Natural Sweeteners
	382,581	Tullow Oil		8,842
		Oil & Gas Producer
	256,202	Spirax Sarco		7,985
		Steam Systems for Manufacturing & Process Industries
	2,840,000	Sterling Resources (a)(b)		2,845
		Oil & Gas Exploration - Europe
				352,781
		> Netherlands 4.4%
	1,591,702	UNIT4 (c)		40,567
		Business Software Development
	1,680,623	Imtech		40,130
		Electromechanical & Information & Communications Technology Installation & Maintenance
	2,546,126	Aalberts Industries		39,645
		Flow Control & Heat Treatment
	1,234,758	Koninklijke TenCate		32,962
		Advanced Textiles & Industrial Fabrics
	460,000	Fugro		27,903
		Subsea Oilfield Services
	1,252,514	Arcadis (a)		27,394
		Engineering Consultants
	317,424	Vopak		20,360
		World's Largest Operator of Petroleum & Chemical Storage Terminals
	850,468	TKH Group		18,269
		Dutch Industrial Conglomerate
	143,395	Core Laboratories		16,620
		Oil & Gas Reservoir Consulting
				263,850
		> Switzerland 3.8%
	310,000	Partners Group		55,134
		Private Markets Asset Management
	255,000	Geberit		50,306
		Plumbing Supplies
	330,000	Dufry Group (b)		39,999
		Operates Airport Duty Free & Duty Paid Shops
	15,500	Sika		29,931
		Chemicals for Construction & Industrial Applications
	170,000	Kuehne & Nagel		18,010
		Freight Forwarding/Logistics
	280,000	Zehnder		16,736
		Radiators & Ventilation Systems
	580,000	Bank Sarasin & Cie (b)		16,342
		Private Banking
				226,458
		> France 3.5%
	553,000	Eurofins Scientific		68,673
		Food, Pharmaceuticals & Materials Screening & Testing

See accompanying notes to financial statements.

47

Columbia Acorn International

Statement of Investments (Unaudited), continued

Number of Shares			Value (000)
		> France—continued
	729,700	Gemalto	$	52,410
		Digital Security Solutions
	675,000	Neopost		36,023
		Postage Meter Machines
	971,800	Saft		23,315
		Niche Battery Manufacturer
	232,400	Norbert Dentressangle		14,744
		Leading European Logistics & Transport Group
	134,254	Compagnie Française de l'Afrique Occidentale		6,355
		African Wholesaler & Distributor
	1,831,204	Hi-Media (a)(b)		4,668
		Online Advertiser in Europe
	162,844	Mersen		4,080
		Advanced Industrial Materials
				210,268
		> Germany 3.2%
	2,500,000	Wirecard		48,476
		Online Payment Processing & Risk Management
	148,295	Rational		35,347
		Commercial Ovens
	500,000	Dürr		30,851
		Automotive Plant Engineering & Associated Capital Equipment
	405,000	Rheinmetall		19,909
		Defense & Automotive
	625,000	CTS Eventim		18,808
		Event Ticket Sales
	690,000	NORMA Group		15,161
		Clamps for Automotive & Industrial Applications
	165,400	Bertrandt		12,390
		Outsourced Engineering
	333,000	Elringklinger		7,946
		Automobile Components
	338,886	Deutsche Beteiligungs		6,691
		Private Equity Investment Management
				195,579
		> Sweden 2.2%
	4,056,007	Hexagon		69,621
		Design, Measurement & Visualization Software & Equipment
	4,150,024	Sweco (c)		43,732
		Engineering Consultants
	658,700	Unibet		16,700
		European Online Gaming Operator
	419,877	East Capital Explorer		2,892
		Sweden-based Russia & Central Eastern Europe Investment Fund
				132,945
		> Denmark 1.3%
	1,648,800	Novozymes		42,755
		Industrial Enzymes
	168,042	SimCorp		28,969
		Software for Investment Managers
	166,013	Solar A/S		9,002
		Technical Wholesaler of Electrical, Plumbing & HVAC Equipment
				80,726

Number of Shares			Value (000)
		> Italy 1.1%
	2,661,000	Pirelli (a)	$	28,065
		Global Tire Supplier
	166,200	Tod's (a)		16,671
		Leather Shoes & Bags
	7,000,000	Geox (a)		15,486
		Apparel & Shoe Maker
	8,951,757	CIR		8,829
		Italian Holding Company
				69,051
		> Russia 0.8%
	1,123,695	Yandex (b)		21,406
		Search Engine for Russian & Turkish Languages
	2,109,700	Petropavlovsk		15,114
		Gold & Iron Ore Mining in Russia
	368,493	Mail.ru - GDR (b)(e)		12,550
		Internet Social Networking & Games for Russian Speakers
				49,070
		> Iceland 0.6%
	35,982,499	Marel		36,188
		Largest Manufacturer of Poultry & Fish Processing Equipment
				36,188
		> Ireland 0.5%
	263,400	Paddy Power		17,195
		Irish Betting Services
	4,237,000	United Drug		11,118
		Irish Pharmaceutical Wholesaler & Outsourcer
				28,313
		> Spain 0.4%
	618,320	Red Eléctrica de España		26,987
		Spanish Power Transmission
				26,987
		> Portugal 0.4%
	8,635,000	Redes Energéticas Nacionais		22,858
		Portuguese Power Transmission & Gas Transportation
				22,858
		> Czech Republic 0.4%
	130,682	Komercni Banka		22,798
		Leading Czech Universal Bank
				22,798
		> Norway 0.4%
	2,403,664	Atea		21,165
		Leading Nordic IT Hardware/Software Reseller & Installation Company
				21,165
		> Finland 0.3%
	1,039,429	Stockmann (a)		21,015
		Department Store & Fashion Retailer in Scandinavia & Russia
				21,015
		> Belgium 0.3%
	438,880	EVS Broadcast Equipment		20,704
		Digital Live Mobile Production Software & Systems
				20,704

See accompanying notes to financial statements.

48

Number of Shares			Value (000)
		> Kazakhstan 0.3%
	3,319,000	Halyk Savings Bank of Kazakhstan - GDR (b)	$	16,554
		Largest Retail Bank & Insurer in Kazakhstan
				16,554
		> Greece 0.1%
	4,384,185	Intralot		4,949
		Lottery & Gaming Systems & Services
				4,949
Europe: Total				1,802,259
Other Countries 16.5%
		> South Africa 4.5%
	1,170,188	Naspers		62,503
		Media in Africa, China, Russia & Other Emerging Markets
	3,175,083	Mr. Price		43,531
		South African Retailer of Apparel, Household & Sporting Goods
	19,098,300	Rand Merchant Insurance		40,676
		Directly Sold Property & Casualty Insurance; Holdings in Other Insurers
	11,763,907	Coronation Fund Managers		39,830
		South African Fund Manager
	4,992,200	Adcock Ingram Holdings		36,696
		Manufacturer of Pharmaceuticals & Medical Supplies
	8,679,940	Northam Platinum		24,827
		Platinum Mining in South Africa
	1,025,504	Massmart Holdings		21,233
		General Merchandise, Food & Home Improvement Stores; Wal-Mart Subsidiary
				269,296
		> Canada 3.8%
	1,403,772	CCL Industries		51,499
		Leading Global Label Manufacturer
	1,212,597	ShawCor		43,890
		Oil & Gas Pipeline Products
	653,200	Onex Capital		25,362
		Private Equity
	582,942	AG Growth (a)		21,008
		Leading Manufacturer of Augers & Grain Handling Equipment
	770,576	Black Diamond Group		17,264
		Provides Accommodations/Equipment for Oil Sands Development
	984,500	Alliance Grain Traders		13,209
		Global Leader in Pulse Processing & Distribution
	2,919,000	DeeThree Exploration (b)(c)(f)		9,272
	1,142,377	DeeThree Exploration (b)(c)		3,703
		Canadian Oil & Gas Producer
	2,096,514	Horizon North Logistics		11,964
		Provides Diversified Oil Service Offering in Northern Canada
	263,857	Baytex (a)		11,116
		Oil & Gas Producer in Canada
	454,000	Celtic Exploration (b)		6,141
		Canadian Oil & Gas Producer
	1,607,306	Pan Orient (b)		5,920
		Asian Oil & Gas Explorer

Number of Shares			Value (000)
	450,000	Athabasca Oil Sands (b)	$	4,950
		Oil Sands & Unconventional Oil Development
	1,611,000	Americas Petrogas (a)(b)		2,991
		Oil & Gas Exploration in Argentina, Potash in Peru
	332,700	Crew Energy (b)		1,879
		Canadian Oil & Gas Producer
				230,168
		> Australia 3.6%
	3,973,200	UGL (a)		50,875
		Engineering & Facilities Management
	48,533,075	Commonwealth Property Office Fund		50,591
		Australia Prime Office REIT
	11,936,400	Challenger Financial		40,091
		Largest Annuity Provider
	498,560	Cochlear		33,859
		Cochlear Implants
	7,595,003	IAG		27,240
		General Insurance Provider
	1,576,290	Domino's Pizza Enterprises		16,294
		Domino's Pizza Operator in Australia/New Zealand & France/Benelux
				218,950
		> United States 3.4%
	1,229,871	BioMarin Pharmaceutical (b)		48,678
		Biotech Focused on Orphan Diseases
	952,080	Atwood Oceanics (b)		36,027
		Offshore Drilling Contractor
	965,297	Textainer Group Holdings (a)		35,619
		Top International Container Leasor
	763,228	World Fuel Services		29,026
		Global Fuel Broker
	555,500	Hornbeck Offshore (b)		21,542
		Supply Vessel Operator in U.S. Gulf of Mexico
	548,900	Rowan (b)		17,746
		Contract Offshore Driller
	407,213	FMC Technologies (b)		15,975
		Oil & Gas Well Head Manufacturer
				204,613
		> Israel 1.0%
	4,706,527	Israel Chemicals		52,074
		Producer of Potash, Phosphates, Bromine & Specialty Chemicals
	625,000	Caesarstone (b)		7,569
		Quartz Countertops
				59,643
		> Senegal 0.2%
	42,360	Sonatel		9,316
		Leading Telecoms Operator in Western Africa
				9,316
Other Countries: Total				991,986
Latin America 4.4%
		> Brazil 2.8%
	3,700,000	Localiza Rent A Car		55,652
		Car Rental
	1,200,000	Multiplus		28,618
		Loyalty Program Operator in Brazil

See accompanying notes to financial statements.

49

Columbia Acorn International

Statement of Investments (Unaudited), continued

Number of Shares			Value (000)
		> Brazil—continued
	1,880,200	Mills Estruturas e Servicos de Engenharia	$	25,275
		Civil Engineering & Construction
	4,500,000	Odontoprev		22,696
		Dental Insurance
	1,300,000	Arcos Dorados (a)		19,214
		McDonald's Master Franchise for Latin America
	3,577,000	MRV Engenharia		16,474
		Brazilan Property Developer
				167,929
		> Mexico 0.8%
	600,000	Grupo Aeroportuario del Sureste - ADR		46,842
		Mexican Airport Operator
				46,842
		> Guatemala 0.3%
	1,403,049	Tahoe Resources (b)		19,390
		Silver Project in Guatemala
				19,390
		> Uruguay 0.2%
	1,306,818	Union Agriculture Group (b)(f)(g)		12,794
		Farmland Operator in Uruguay
				12,794
		> Chile 0.2%
	5,640,000	Viña Concha y Toro		11,038
		Global Branded Wine Manufacturer
				11,038
		> Colombia 0.1%
	7,850,769	Canacol (b)		3,509
		Oil Producer in South America
	22,525,000	Gulf United (b)		1,351
		Prospecting for Oil Alongside Large Producers in Colombia
				4,860
		> Argentina —%
	4,950,000	Madalena Ventures (b)(f)		1,634
	2,475,000	Madalena Ventures (b)		851
		Oil & Gas Exploration in Argentina
				2,485
Latin America: Total				265,338
Total Equities: 94.6% (Cost: $4,751,710)				5,700,496

Number of Shares			Value (000)
Securities Lending Collateral 1.8%
	111,196,657	Dreyfus Government Cash Management Fund (7 day yield of 0.01%) (h)	$	111,197
Total Securities Lending Collateral: (Cost: $111,197)				111,197
Total Investments: 96.4% (Cost: $4,862,907)(i)(j)				5,811,693
Obligation to Return Collateral for Securities Loaned: (1.8)%				(111,197	)
Cash and Other Assets Less Liabilities: 5.4%				326,071
Total Net Assets: 100.0%			$	6,026,567

ADR - American Depositary Receipts

DVR - Differential Voting Right Equity Shares

GDR - Global Depositary Receipts

REIT - Real Estate Investment Trust

See accompanying notes to financial statements.

50

> Notes to Statement of Investments (dollar values in thousands)

(a)  All or a portion of this security was on loan at June 30, 2012. The total market value of securities on loan at June 30, 2012 was $110,353.

(b)  Non-income producing security.

(c)  An affiliated person of the Fund may include any company in which the Fund owns five percent or more of its outstanding voting shares. Holdings and transactions in these affiliated companies during the period ended June 30, 2012, are as follows:

Security	Balance of Shares Held 12/31/11		Purchases/ Additions		Sales/ Reductions		Balance of Shares Held 6/30/12		Value		Dividend
Archipelago Resources		29,063,787		-		-		29,063,787	$	23,214	$	-
DeeThree Exploration		4,061,377		-		-		4,061,377		12,975		-
Koninklijke TenCate*		1,371,573		53,685		190,500		1,234,758		32,962		-	**
Southern Arc Minerals		6,217,500		-		-		6,217,500		1,710		-
Sweco		4,150,024		-		-		4,150,024		43,732		1,574
UNIT4		1,591,702		-		-		1,591,702		40,567		677
Wacom*		23,790		-		3,694		20,096		45,009		794
Workspace Group*		8,000,000		-		8,000,000		-		-		298
Total of Affiliated Transactions		54,479,753		53,685		8,194,194		46,339,244	$	200,169	$	3,343

*  At June 30, 2012, the Fund owned less than five percent of the company's outstanding voting shares.

**  Rounds to less than $500.

  The aggregate cost and value of these companies at June 30, 2012 were $93,271 and $122,198 respectively. Investments in affiliated companies represented 2.03% of the Fund's total net assets at June 30, 2012.

(d)  Security is traded on a U.S. exchange.

(e)  Security exempt from registration under Section 4(2) of the Securities Act of 1933. This security may only be resold in exempt transactions to qualified buyers. Private resales of this security to qualified institutional buyers are also exempt from registration pursuant to Rule 144A under the Securities Act of 1933. At June 30, 2012, this security had an aggregate value of $12,550, which represented 0.21% of total net assets.

(f)  Denotes a restricted security, which is subject to restrictions on resale under federal securities laws. These securities are valued at fair value determined in good faith under consistently applied procedures established by the Board of Trustees. At June 30, 2012, the market value of these securities amounted to $23,700, which represented 0.39% of total net assets.

  Additional information on these securities is as follows:

Security	Acquisition Dates	Shares		Cost		Value
Union Agriculture Group	12/8/10-6/27/12		1,306,818	$	15,000	$	12,794
DeeThree Exploration	9/7/10-3/8/11		2,919,000		10,228		9,272
Madalena Ventures	10/21/10		4,950,000		3,136		1,634
				$	28,364	$	23,700

(g)  Illiquid security.

(h)  Investment made with cash collateral received from securities lending activity.

(i)  At June 30, 2012, for federal income tax purposes, the cost of investments was $4,862,907 and net unrealized appreciation was $948,786 consisting of gross unrealized appreciation of $1,372,957 and gross unrealized depreciation of $424,171.

(j)  On June 30, 2012, the Fund's total investments were denominated in currencies as follows:

Currency	Value		Percentage of Net Assets
Japanese Yen	$	1,058,464		17.5
Euro		846,954		14.1
United States Dollar		507,517		8.4
Taiwan Dollar		434,241		7.2
British Pound		391,184		6.5
Hong Kong Dollar		343,012		5.7
Australian Dollar		330,146		5.5
Other currencies less than 5% of total net assets		1,900,175		31.5
Total Portfolio	$	5,811,693		96.4

See accompanying notes to financial statements.

51

Columbia Acorn International

Statement of Investments (Unaudited), continued

> Notes to Statement of Investments (dollar values in thousands)

Fair Value Measurements

  Various inputs are used in determining the value of the Fund's investments, following the input prioritization hierarchy established by GAAP. These inputs are summarized in the three broad levels listed below:

•  Level 1 – quoted prices in active markets for identical securities

•  Level 2 – prices determined using other significant observable inputs (including quoted prices for similar securities, interest rates, prepayment speeds, credit risk and others)

•  Level 3 – prices determined using significant unobservable inputs where quoted prices or observable inputs are unavailable or less reliable (including management's own assumptions about the factors market participants would use in pricing an investment)

  The inputs or methodology used for valuing securities are not necessarily an indication of the risk associated with investing in those securities.

  Examples of the types of securities in which the Fund would typically invest and how they are classified within this hierarchy are as follows. Typical Level 1 securities include exchange traded domestic equities, mutual funds whose NAVs are published each day and exchange traded foreign equities that are not statistically fair valued. Typical Level 2 securities include exchange traded foreign equities that are statistically fair valued, forward foreign currency exchange contracts and short-term investments valued at amortized cost. Additionally, securities fair valued by the Valuation Committee (the Committee) of the Fund's Board of Trustees (the Board) that rely on significant observable inputs are also included in Level 2. Typical Level 3 securities include any security fair valued by the Committee that relies on significant unobservable inputs.

  Under the direction of the Board, the Committee is responsible for carrying out the valuation procedures approved by the Board.

  The Committee meets as necessary, and no less frequently than quarterly, to determine fair values for securities for which market quotations are not readily available or for which the investment manager believes that available market quotations are unreliable, and to review the continuing appropriateness of the current value of any security subject to the Trust's Portfolio Pricing Policy and the pricing procedures of the investment manager (the Policies). The Policies address, among other things: circumstances under which market quotations will be deemed readily available; selection of third party pricing vendors; appropriate pricing methodologies; events that require fair valuation and fair value techniques; and circumstances under which securities will be deemed to pose a potential for stale pricing, including when securities are illiquid, restricted, or in default. The Committee may also meet to discuss additional valuation matters, which may include review of back-testing results, review of time-sensitive information or approval of other valuation related actions, and to review the appropriateness of the Policies.

  For investments categorized as Level 3, the significant unobservable inputs used in the fair value measurement of the Funds' securities may include: (i) data specific to the issuer or comparable issuers, (ii) general market or specific sector news and (iii) quoted prices and specific or similar security transactions. The Committee considers this data and any changes from prior periods in order to assess the reasonableness of observable and unobservable inputs, any assumptions or internal models used to value those securities and changes in fair value. Significant changes in any of these factors could result in lower or higher fair value measurements. Various factors impact the frequency of monitoring (which may occur as often as daily), however the Committee may determine that changes to inputs, assumptions and models are not required with the same frequency.

The following table summarizes the inputs used, as of June 30, 2012, in valuing the Fund's assets:

Investment Type	Quoted Prices (Level 1)		Other Significant Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)		Total
Equities
Asia	$	160,069	$	2,480,844	$	-	$	2,640,913
Europe		40,871		1,761,388		-		1,802,259
Other Countries		433,078		558,908		-		991,986
Latin America		250,910		1,634		12,794		265,338
Total Equities		884,928		4,802,774		12,794		5,700,496
Total Securities Lending Collateral		111,197		-		-		111,197
Total Investments	$	996,125	$	4,802,774	$	12,794	$	5,811,693

  The Fund's assets assigned to the Level 2 input category are generally valued using a market approach, in which a security's value is determined through its correlation to prices and information from observable market transactions for similar or identical assets. Foreign equities are generally valued at the last sale price on the foreign exchange or market on which they trade. The Fund may use a statistical fair valuation model, in accordance with the policy adopted by the Board, provided by an independent third party to value securities principally traded in foreign markets in order to adjust for possible stale pricing that may occur between the close of the foreign exchanges and the time for valuation. These models take into account available market data including intraday index, ADR, and ETF movements. Securities acquired via private placement that have a holding period or an extended settlement period are valued at a discount to the same shares that are trading freely on the market. These discounts are determined by the investment manager's experience with similar securities or situations. Factors may include, but are not limited to, trade volume, shares outstanding and stock price.

  The following table shows transfers between Level 1 and Level 2 of the fair value hierarchy:

Transfers In				Transfers Out
Level 1		Level 2		Level 1		Level 2
$	10,584	$	-	$	-	$	10,584

  Financial assets were transferred from Level 2 to Level 1 as resale restrictions no longer apply.

See accompanying notes to financial statements.

52

> Notes to Statement of Investments (dollar values in thousands)

  The following table reconciles asset balances for the period ending June 30, 2012, in which significant observable and/or unobservable inputs (Level 3) were used in determining value:

Investments in Securities	Balance as of December 31, 2011		Realized Gain/(Loss)		Change in Unrealized Appreciation (Depreciation)		Purchases		Sales		Transfers into Level 3		Transfers out of Level 3		Balance as of June 30, 2012
Equities
Latin America	$	12,462	$	-	$	332	$	-	$	-	$	-	$	-	$	12,794
	$	12,462	$	-	$	332	$	-	$	-	$	-	$	-	$	12,794

  The information in the above reconciliation table represents fiscal year to date activity for any securities identified as using Level 3 inputs at either the beginning or the end of the current fiscal period.

  The change in unrealized appreciation attributed to securities owned at June 30, 2012, which were valued using significant unobservable inputs (Level 3), amounted to $332.

  The Fund does not hold any significant investments categorized as Level 3.

  Certain common stock classified as Level 3 are valued at fair value, using a market approach, as determined in good faith under consistently applied procedures established by and under the general supervision of the Board. To determine fair value for these securities, for which no market exists, the Committee utilizes the valuation technique it deems most appropriate in the circumstances, using some unobservable inputs, which may include but are not limited to trades of similar securities, estimated earnings of the company, market multiples derived from a set of comparable companies, and the position of the security within the company's capital structure. Significant increases or decreases to any of these inputs could result in a significantly lower or higher fair value measurement. Generally, a change in estimated earnings of a company may result in a change to the comparable companies and market multiples utilized.

See accompanying notes to financial statements.

53

Columbia Acorn International

Portfolio Diversification (Unaudited)

At June 30, 2012, the Fund's portfolio investments as a percentage of net assets were diversified as follows:

	Value (000)		Percentage of Net Assets
> Industrial Goods & Services
Other Industrial Services	$	498,256		8.3
Machinery		376,487		6.2
Industrial Materials & Specialty Chemicals		363,320		6.0
Construction		113,252		1.9
Conglomerates		82,269		1.4
Outsourcing Services		79,172		1.3
Electrical Components		78,914		1.3
Industrial Distribution		40,299		0.7
		1,631,969		27.1
> Consumer Goods & Services
Retail		362,751		6.0
Food & Beverage		205,154		3.4
Casinos & Gaming		204,526		3.4
Nondurables		111,534		1.9
Other Consumer Services		89,612		1.5
Travel		62,798		1.0
Apparel		53,546		0.9
Consumer Goods Distribution		52,921		0.9
Other Durable Goods		44,802		0.7
Restaurants		41,347		0.7
Educational Services		26,950		0.5
Other Entertainment		18,807		0.3
Furniture & Textiles		7,569		0.1
		1,282,317		21.3
> Information
Computer Hardware & Related Equipment		264,450		4.4
Mobile Communications		170,006		2.8
Internet Related		161,623		2.7
Business Software		139,157		2.3
Financial Processors		66,059		1.1
Instrumentation		61,762		1.0
Semiconductors & Related Equipment		51,879		0.9
Electronics Distribution		31,721		0.5
CATV		26,488		0.4
Computer Services		21,165		0.3
Telephone & Data Services		9,316		0.2
Satellite Broadcasting & Services		5,486		0.1
Advertising		4,669		0.1
		1,013,781		16.8
> Other Industries
Real Estate		383,867		6.4
Transportation		116,680		1.9
Regulated Utilities		61,175		1.0
		561,722		9.3

	Value (000)			Percentage of Net Assets
> Energy & Minerals
Oil Services	$	192,311			3.2
Mining		179,030			3.0
Oil & Gas Producers		75,778			1.3
Agricultural Commodities		26,003			0.4
Oil Refining, Marketing & Distribution		20,360			0.3
		493,482			8.2
> Finance
Insurance		159,044			2.6
Brokerage & Money Management		120,890			2.0
Banks		109,573			1.8
Finance Companies		75,767			1.3
		465,274			7.7
> Health Care
Medical Equipment & Devices		81,542			1.3
Biotechnology & Drug Delivery		48,678			0.8
Pharmaceuticals		47,814			0.8
Medical Supplies		46,536			0.8
Health Care Services		27,381			0.5
		251,951			4.2
Total Equities:		5,700,496			94.6
Security Lending Collateral:		111,197			1.8
Total Investments:		5,811,693			96.4
Obligation to Return Collateral for Securities Loaned:		(111,197	)		(1.8	)
Cash and Other Assets Less Liabilities:		326,071			5.4
Net Assets:	$	6,026,567			100.0

See accompanying notes to financial statements.

54

Columbia Acorn USA

Major Portfolio Changes in the Second Quarter (Unaudited)

	Number of Shares
	3/31/12		6/30/12
Purchases
Information
SABA		0		337,000
Industrial Goods & Services
Moog		355,000		436,000
Polypore International		100,000		200,000
Consumer Goods & Services
Caesarstone (Israel)		20,000		200,000
Helen of Troy		106,000		262,000
Finance
CAI International		330,000		376,000
First Commonwealth		556,000		834,000
Health Care
ARIAD Pharmaceuticals		0		379,040
Cepheid		488,600		551,600
NPS Pharmaceuticals		1,055,000		1,163,600
Synageva Biopharma		29,671		129,002
Other Industries
DuPont Fabros Technology		519,000		625,000
Energy & Minerals
Approach Resource		100,000		244,000
Hornbeck Offshore		83,000		125,000

	Number of Shares
	3/31/12		6/30/12
Sales
Information
AboveNet		148,000		0
Ariba		408,000		0
Blackbaud		300,000		67,869
Global Payments		170,000		153,000
Ixia		903,000		813,000
NetSuite		281,000		211,000
Nice Systems - ADR (Israel)		177,000		160,000
ON Semiconductor		1,061,750		961,000
Polycom		165,000		0
SBA Communications		560,000		529,000
Trimble Navigation		168,000		151,000
Industrial Goods & Services
GrafTech International		686,000		616,000
Interline Brands		233,400		0
Kennametal		226,000		204,000
Pentair		585,000		0
Waste Connections		176,000		90,000
Consumer Goods & Services
Hertz		750,000		675,000
Lifetime Fitness		259,000		233,000
lululemon athletica		730,000		583,000
Pinnacle Entertainment		775,000		698,000
Saks		790,000		715,000
True Religion Apparel		82,300		0
Finance
Eaton Vance		340,500		306,500
Hancock Holding		278,678		251,000
Valley National Bancorp		675,000		641,750
Health Care
Akorn		733,000		642,000
Alexion Pharmaceuticals		251,000		83,000
Gen-Probe		72,000		0
Pacific Biosciences of California		385,000		0
Seattle Genetics		682,000		614,000
Sirona Dental Systems		224,000		202,000
Other Industries
Associated Estates Realty		600,000		540,000
World Fuel Services		256,000		230,000
Energy & Minerals
FMC Technologies		167,000		0
Rosetta Resources		143,000		129,000

See accompanying notes to financial statements.

55

Columbia Acorn USA

Statement of Investments (Unaudited), June 30, 2012

Number of Shares			Value (000)
			Equities: 99.6%
Information 30.7%
		> Business Software 9.3%
	910,000	Informatica (a)	$	38,548
		Enterprise Data Integration Software
	698,000	Micros Systems (a)		35,738
		Information Systems for Hotels, Restaurants & Retailers
	375,000	Ansys (a)		23,666
		Simulation Software for Engineers & Designers
	243,000	Concur Technologies (a)		16,548
		Web Enabled Cost & Expense Management Software
	211,000	NetSuite (a)		11,557
		End-to-end IT Systems Solutions Delivered Over the Web
	290,000	SPS Commerce (a)		8,810
		Supply Chain Management Software Delivered via the Web
	198,000	Advent Software (a)		5,368
		Asset Management & Trading Systems
	337,000	SABA (a)		3,127
		Learning Management Systems
	400,000	Velti (a)(b)		2,600
		Mobile Marketing Software Platform
	67,869	Blackbaud		1,742
		Software & Services for Non-profits
				147,704
		> Semiconductors & Related Equipment 3.9%
	1,958,000	Atmel (a)		13,119
		Microcontrollers, Radio Frequency & Memory Semiconductors
	690,000	Microsemi (a)		12,758
		Analog/Mixed Signal Semiconductors
	426,000	Monolithic Power Systems (a)		8,465
		High Performance Analog & Mixed Signal Integrated Circuits
	262,000	Ultratech (a)		8,253
		Semiconductor Equipment
	961,000	ON Semiconductor (a)		6,823
		Mixed Signal & Power Management Semiconductors
	1,075,000	TriQuint Semiconductor (a)		5,912
		Radio Frequency Semiconductors
	390,000	Pericom Semiconductor (a)		3,510
		Interface Integrated Circuits & Frequency Control Products
	50,000	Hittite Microwave (a)		2,556
		Radio Frequency, Microwave & Millimeterwave Semiconductors
				61,396
		> Instrumentation 3.6%
	180,000	Mettler-Toledo International (a)		28,053
		Laboratory Equipment
	525,000	IPG Photonics (a)		22,885
		Fiber Lasers
	151,000	Trimble Navigation (a)		6,947
		GPS-based Instruments
				57,885

Number of Shares			Value (000)
		> Telephone & Data Services 2.7%
	1,457,000	tw telecom (a)	$	37,387
		Fiber Optic Telephone/Data Services
	400,000	Boingo Wireless (a)(b)		4,648
		Wholesale & Retail WiFi Networks
				42,035
		> Computer Hardware & Related Equipment 2.6%
	1,317,000	II-VI (a)		21,954
		Laser Optics & Specialty Materials
	292,000	Zebra Technologies (a)		10,033
		Bar Code Printers
	160,000	Nice Systems - ADR (Israel) (a)		5,856
		Audio & Video Recording Solutions
	97,000	Netgear (a)		3,348
		Networking Products for Small Business & Home
				41,191
		> Gaming Equipment & Services 2.2%
	660,000	Bally Technologies (a)		30,796
		Slot Machines & Software
	235,000	WMS Industries (a)		4,688
		Slot Machine Provider
				35,484
		> Computer Services 2.0%
	556,000	ExlService Holdings (a)		13,700
		Business Process Outsourcing
	97,000	Syntel		5,888
		Offshore IT Services
	776,766	Hackett Group (a)		4,326
		IT Integration & Best Practice Research
	640,000	RCM Technologies (a)(c)		3,546
		Technology & Engineering Services
	359,000	WNS - ADR (India) (a)		3,493
		Offshore BPO (Business Process Outsourcing) Services
				30,953
		> Mobile Communications 1.9%
	529,000	SBA Communications (a)		30,179
		Communications Towers
				30,179
		> Telecommunications Equipment 1.6%
	732,000	Finisar (a)		10,951
		Optical Subsystems & Components
	813,000	Ixia (a)		9,772
		Telecom Network Test Equipment
	752,000	Infinera (a)		5,144
		Optical Networking Equipment
				25,867
		> Contract Manufacturing 0.4%
	236,000	Plexus (a)		6,655
		Electronic Manufacturing Services
				6,655
		> Financial Processors 0.4%
	153,000	Global Payments		6,614
		Credit Card Processor
				6,614

See accompanying notes to financial statements.

56

Number of Shares			Value (000)
		> TV Broadcasting 0.1%
	875,000	Entravision Communications	$	1,059
		Spanish Language TV & Radio Stations
				1,059
Information: Total				487,022
Industrial Goods & Services 17.2%
		> Machinery 13.3%
	876,300	Ametek		43,736
		Aerospace/Industrial Instruments
	747,200	Nordson		38,324
		Dispensing Systems for Adhesives & Coatings
	835,000	ESCO Technologies		30,427
		Automatic Electric Meter Readers
	890,000	Donaldson		29,699
		Industrial Air Filtration
	631,000	HEICO		20,356
		FAA Approved Aircraft Replacement Parts
	436,000	Moog (a)		18,029
		Motion Control Products for Aerospace, Defense & Industrial Markets
	150,000	Toro		10,993
		Turf Maintenance Equipment
	200,000	Polypore International (a)(b)		8,078
		Battery Separators & Filtration Media
	204,000	Kennametal		6,763
		Consumable Cutting Tools
	146,000	Oshkosh Corporation (a)		3,059
		Specialty Truck Manufacturer
	26,000	Middleby Corp (a)		2,590
		Manufacturer of Cooking Equipment
				212,054
		> Industrial Materials & Specialty Chemicals 1.1%
	496,000	Drew Industries (a)		13,813
		RV & Manufactured Home Components
	170,000	Albany International		3,181
		Paper Machine Clothing & Composites for Aerospace
				16,994
		> Electrical Components 0.9%
	280,000	Acuity Brands		14,255
		Commercial Lighting Fixtures
				14,255
		> Other Industrial Services 0.8%
	600,000	Acorn Energy (b)		4,992
		Frac Well Exploration/Monitoring Device, Sonar Security, Electric Grid Monitoring
	240,000	TrueBlue (a)		3,715
		Temporary Manual Labor
	109,000	Forward Air		3,518
		Freight Transportation Between Airports
				12,225
		> Waste Management 0.4%
	65,000	Clean Harbors (a)		3,667
		Hazardous Waste Services & Disposal

Number of Shares			Value (000)
	90,000	Waste Connections	$	2,693
		Solid Waste Management
				6,360
		> Steel 0.4%
	616,000	GrafTech International (a)		5,944
		Industrial Graphite Materials Producer
				5,944
		> Construction 0.3%
	200,000	Fortune Brands Home & Security (a)		4,454
		Home Building Supplies & Small Locks
				4,454
Industrial Goods & Services: Total				272,286
Consumer Goods & Services 16.2%
		> Retail 5.4%
	583,000	lululemon athletica (a)		34,764
		Premium Active Apparel Retailer
	468,500	Abercrombie & Fitch		15,994
		Teen Apparel Retailer
	805,000	Pier 1 Imports		13,226
		Home Furnishing Retailer
	356,000	Shutterfly (b)		10,926
		Internet Photo-centric Retailer
	715,000	Saks (a)(b)		7,615
		Luxury Department Store Retailer
	161,500	Teavana (a)(b)		2,185
		Specialty Tea Retailer
	9,000	The Fresh Market (a)		483
		Specialty Food Retailer
				85,193
		> Travel 4.2%
	849,700	Gaylord Entertainment (a)		32,764
		Convention Hotels
	1,300,950	Avis Budget Group (a)		19,775
		Second Largest Car Rental Company
	675,000	Hertz (a)		8,640
		Largest U.S. Rental Car Operator
	64,000	Vail Resorts		3,205
		Ski Resort Operator & Developer
	140,000	HomeAway (a)(b)		3,044
		Vacation Rental Online Marketplace
				67,428
		> Furniture & Textiles 1.6%
	880,000	Knoll		11,810
		Office Furniture
	621,500	Interface		8,471
		Modular & Broadloom Carpet
	148,000	Herman Miller		2,741
		Office Furniture
	200,000	Caesarstone (Israel) (a)		2,422
		Quartz Countertops
				25,444
		> Consumer Goods Distribution 1.2%
	472,000	Pool		19,097
		Distributor of Swimming Pool Supplies & Equipment
				19,097

See accompanying notes to financial statements.

57

Columbia Acorn USA

Statement of Investments (Unaudited), continued

Number of Shares			Value (000)
		> Other Durable Goods 1.0%
	206,000	Cavco Industries (a)	$	10,564
		Manufactured Homes
	126,000	Jarden		5,294
		Branded Household Products
				15,858
		> Apparel 0.8%
	222,000	Warnaco Group (a)		9,453
		Global Branded Apparel Manufacturer
	73,000	Deckers Outdoor (a)(b)		3,212
		Fashion Footwear Wholesaler
				12,665
		> Other Consumer Services 0.7%
	233,000	Lifetime Fitness (a)		10,837
		Sport & Fitness Club Operator
				10,837
		> Nondurables 0.6%
	262,000	Helen of Troy (a)		8,879
		Personal Care, Housewares, Healthcare & Home Environment Products
				8,879
		> Casinos & Gaming 0.4%
	698,000	Pinnacle Entertainment (a)		6,715
		Regional Casino Operator
				6,715
		> Leisure Products 0.2%
	230,000	Skullcandy (a)(b)		3,255
		Lifestyle Branded Headphones
				3,255
		> Educational Services 0.1%
	37,350	ITT Educational Services (a)(b)		2,269
		Postsecondary Degree Services
				2,269
		> Food & Beverage —%
	4,900	Annie's (a)(b)		205
		Developer & Marketer of Natural & Organic Food
				205
Consumer Goods & Services: Total				257,845
Finance 13.4%
		> Banks 7.6%
	833,000	MB Financial		17,943
		Chicago Bank
	1,053,000	Associated Banc-Corp		13,889
		Midwest Bank
	431,597	Lakeland Financial		11,580
		Indiana Bank
	211,000	City National		10,250
		Bank & Asset Manager
	170,000	SVB Financial Group (a)		9,982
		Bank to Venture Capitalists
	251,000	Hancock Holding		7,640
		Gulf Coast Bank
	1,478,200	First Busey		7,140
		Illinois Bank

Number of Shares			Value (000)
	641,750	Valley National Bancorp	$	6,803
		New Jersey/New York Bank
	535,000	TCF Financial		6,142
		Great Lakes Bank
	834,000	First Commonwealth		5,613
		Western Pennsylvania Bank
	844,000	TrustCo Bank		4,608
		New York State Bank
	503,426	Pacific Continental Bank		4,465
		Pacific Northwest Bank
	269,600	Eagle Bancorp (a)		4,246
		Metro D.C. Bank
	178,826	Sandy Spring Bancorp		3,219
		Baltimore, D.C. Bank
	210,000	CVB Financial		2,447
		Inland Empire Business Bank
	105,700	Hudson Valley		1,913
		Metro New York City Bank
	851,247	Guaranty Bancorp (a)		1,796
		Colorado Bank
	90,000	TriCo Bancshares		1,386
		California Central Valley Bank
				121,062
		> Finance Companies 3.8%
	345,000	World Acceptance (a)		22,701
		Personal Loans
	310,000	Textainer Group Holdings (b)		11,439
		Top International Container Leasor
	346,000	McGrath Rentcorp		9,169
		Temporary Space & IT Rentals
	376,000	CAI International (a)		7,475
		International Container Leasing
	397,172	H & E Equipment Services (a)		5,970
		Heavy Equipment Leasing
	100,000	Marlin Business Services		1,639
		Small Equipment Leasing
	45,500	Regional Management (a)		748
		Consumer Loans
				59,141
		> Savings & Loans 1.0%
	602,487	ViewPoint Financial		9,423
		Texas Thrift
	194,000	Berkshire Hills Bancorp		4,268
		Northeast Thrift
	173,073	Kaiser Federal		2,558
		Los Angeles Savings & Loan
				16,249
		> Brokerage & Money Management 0.5%
	306,500	Eaton Vance (b)		8,260
		Specialty Mutual Funds
				8,260
		> Insurance 0.5%
	55,000	Allied World Holdings		4,371
		Commerical Lines Insurance/Reinsurance

See accompanying notes to financial statements.

58

Number of Shares			Value (000)
		> Insurance—continued
	39,000	Enstar Group (a)	$	3,859
		Insurance/Reinsurance & Related Services
				8,230
Finance: Total				212,942
Health Care 10.3%
		> Biotechnology & Drug Delivery 6.3%
	520,000	BioMarin Pharmaceutical (a)		20,582
		Biotech Focused on Orphan Diseases
	614,000	Seattle Genetics (a)(b)		15,589
		Antibody-based Therapies for Cancer
	421,000	Auxilium Pharmaceuticals (a)		11,321
		Biotech Focused on Niche Disease Areas
	1,163,600	NPS Pharmaceuticals (a)		10,019
		Orphan Drugs & Healthy Royalties
	83,000	Alexion Pharmaceuticals (a)		8,242
		Biotech Focused on Orphan Diseases
	643,000	Isis Pharmaceuticals (a)		7,716
		Biotech Pioneer in Antisense Drugs
	100,000	Onyx Pharmaceuticals (a)		6,645
		Commercial-stage Biotech Focused on Cancer
	379,040	ARIAD Pharmaceuticals (a)		6,523
		Biotech Focused on Cancer
	129,002	Synageva Biopharma (a)(b)		5,232
		Biotech Focused on Orphan Diseases
	400,000	InterMune (a)		4,780
		Drugs for Pulmonary Fibrosis & Hepatitis C
	317,506	Raptor Pharmaceutical (a)(b)		1,775
		Orphan Drug Company
	948,000	Chelsea Therapeutics International (a)(b)		1,403
		Biotech Focused on Rare Diseases
	530,000	Anthera Pharmaceuticals (a)		358
		Biotech Focused on Cardiovascular, Cancer & Immunology
	18,181	Metabolex, Series A-1 (d)(e)		10
		Diabetes Drug Development
				100,195
		> Medical Supplies 1.8%
	551,600	Cepheid (a)		24,684
		Molecular Diagnostics
	53,000	Techne		3,933
		Cytokines, Antibodies & Other Reagents for Life Science
				28,617
		> Medical Equipment & Devices 1.1%
	202,000	Sirona Dental Systems (a)		9,092
		Manufacturer of Dental Equipment
	268,000	Hill-Rom Holdings		8,268
		Hospital Beds/Patient Handling
				17,360
		> Pharmaceuticals 0.8%
	642,000	Akorn (a)		10,124
		Develops, Manufactures & Sells Specialty Generic Drugs
	150,000	Horizon Pharma (a)(b)		1,070
		Specialty Pharma Company

Number of Shares			Value (000)
	133,180	Alimera Sciences (a)(b)	$	398
		Ophthalmology-focused Pharmaceutical Company
				11,592
		> Health Care Services 0.3%
	664,900	Health Management Associates (a)		5,219
		Non-urban Hospitals
				5,219
Health Care: Total				162,983
Other Industries 7.3%
		> Real Estate 6.1%
	915,000	Extra Space Storage		27,999
		Self Storage Facilities
	625,000	DuPont Fabros Technology		17,850
		Technology-focused Office Buildings
	561,200	Biomed Realty Trust		10,483
		Life Science-focused Office Buildings
	783,000	Education Realty Trust		8,676
		Student Housing
	540,000	Associated Estates Realty		8,073
		Multi-family Properties
	1,380,000	Kite Realty Group		6,886
		Community Shopping Centers
	958,000	DCT Industrial Trust		6,035
		Industrial Properties
	100,000	Post Properties		4,895
		Multi-family Properties
	77,000	Kilroy Realty		3,728
		West Coast Office & Industrial Properties
	200,000	St. Joe (a)(b)		3,162
		Florida Panhandle Landowner
				97,787
		> Transportation 1.2%
	230,000	World Fuel Services		8,747
		Global Fuel Broker
	515,091	Rush Enterprises, Class A (a)		8,422
	115,000	Rush Enterprises, Class B (a)		1,543
		Truck Sales & Service
				18,712
Other Industries: Total				116,499
Energy & Minerals 4.5%
		> Oil Services 2.0%
	725,000	Atwood Oceanics (a)		27,434
		Offshore Drilling Contractor
	125,000	Hornbeck Offshore (a)		4,847
		Supply Vessel Operator in U.S. Gulf of Mexico
				32,281
		> Oil & Gas Producers 1.8%
	133,000	SM Energy		6,532
		Oil & Gas Producer
	244,000	Approach Resource (a)		6,232
		Oil & Gas Producer in West Texas Permian
	129,000	Rosetta Resources (a)		4,727
		Oil & Gas Producer Exploring in South Texas & Montana

See accompanying notes to financial statements.

59

Columbia Acorn USA

Statement of Investments (Unaudited), continued

Number of Shares			Value (000)
		> Oil & Gas Producers—continued
	170,000	Petroleum Development Corporation (a)	$	4,168
		Oil & Gas Producer in U.S.
	168,000	Swift Energy (a)		3,126
		Oil & Gas Exploration & Production
	510,000	Quicksilver Resources (a)(b)		2,764
		Natural Gas & Coal Seam Gas Producer
	262,200	Houston American Energy (a)(b)		294
		Oil & Gas Exploration/Production in Colombia
				27,843
		> Mining 0.7%
	77,000	Core Laboratories (Netherlands)		8,924
		Oil & Gas Reservoir Consulting
	600,000	Alexco Resource (a)		2,646
		Mining, Exploration & Environmental Services
	180,000	Augusta Resource (a)		299
		US Copper/Moly Mine
				11,869
Energy & Minerals: Total				71,993
Total Equities: 99.6% (Cost: $1,126,154)				1,581,570

Number of Shares			Value (000)
Securities Lending Collateral 3.4%
	53,351,300	Dreyfus Government Cash Management Fund (7 day yield of 0.01%) (f)	$	53,351
Total Securities Lending Collateral: (Cost: $53,351)				53,351
Total Investments: 103.0% (Cost: $1,179,505)(g)(h)				1,634,921
Obligation to Return Collateral for Securities Loaned: (3.4)%				(53,351	)
Cash and Other Assets Less Liabilities: 0.4%				6,291
Total Net Assets: 100.0%			$	1,587,861

ADR - American Depositary Receipts

> Notes to Statement of Investments (dollar values in thousands)

(a)  Non-income producing security.

(b)  All or a portion of this security was on loan at June 30, 2012. The total market value of securities on loan at June 30, 2012 was $52,943.

(c)  An affiliated person of the Fund may include any company in which the Fund owns five percent or more of its outstanding voting shares. Holdings and transactions in these affiliated companies during the period ended June 30, 2012, are as follows:

Security	Balance of Shares Held 12/31/11		Purchases/ Additions		Sales/ Reductions		Balance of Shares Held 6/30/12		Value		Dividend
RCM Technologies		640,000		-		-		640,000	$	3,546	$	-
Total of Affiliated Transactions		640,000		-		-		640,000	$	3,546	$	-

  The aggregate cost and value of this company at June 30, 2012, were $3,624 and $3,546, respectively. Investments in affiliated companies represented 0.22% of the Fund's total net assets at June 30, 2012.

(d)  Denotes a restricted security, which is subject to restrictions on resale under federal securities laws. These securities are valued at fair value determined in good faith under consistently applied procedures established by the Board of Trustees. At June 30, 2012, the market value of these securities amounted to $10, which represented less than 0.01% of total net assets.

  Additional information on these securities is as follows:

Security	Acquisition Dates	Shares		Cost		Value
Metabolex, Series A-1	2/11/00		18,181	$	2,000	$	10
				$	2,000	$	10

(e)  Illiquid security.

(f)  Investment made with cash collateral received from securities lending activity.

(g)  At June 30, 2012, for federal income tax purposes, the cost of investments was $1,179,505 and net unrealized appreciation was $455,416 consisting of gross unrealized appreciation of $563,241 and gross unrealized depreciation of $107,825.

See accompanying notes to financial statements.

60

> Notes to Statement of Investments (dollar values in thousands)

(h)  On June 30, 2012, the market value of foreign securities represented 1.30% of total net assets. The Fund's foreign portfolio was diversified as follows:

Country	Value		Percentage of Net Assets
Netherlands	$	8,924		0.56
Israel		8,278		0.52
India		3,493		0.22
Total Foreign Portfolio	$	20,695		1.30

Fair Value Measurements

  Various inputs are used in determining the value of the Fund's investments, following the input prioritization hierarchy established by GAAP. These inputs are summarized in the three broad levels listed below:

•  Level 1 – quoted prices in active markets for identical securities

•  Level 2 – prices determined using other significant observable inputs (including quoted prices for similar securities, interest rates, prepayment speeds, credit risk and others)

•  Level 3 – prices determined using significant unobservable inputs where quoted prices or observable inputs are unavailable or less reliable (including management's own assumptions about the factors market participants would use in pricing an investment)

  The inputs or methodology used for valuing securities are not necessarily an indication of the risk associated with investing in those securities.

  Examples of the types of securities in which the Fund would typically invest and how they are classified within this hierarchy are as follows. Typical Level 1 securities include exchange traded domestic equities, mutual funds whose NAVs are published each day and exchange traded foreign equities that are not statistically fair valued. Typical Level 2 securities include exchange traded foreign equities that are statistically fair valued and short-term investments valued at amortized cost. Additionally, securities fair valued by the Valuation Committee (the Committee) of the Fund's Board of Trustees (the Board) that rely on significant observable inputs are also included in Level 2. Typical Level 3 securities include any security fair valued by the Committee that relies on significant unobservable inputs.

  Under the direction of the Board, the Committee is responsible for carrying out the valuation procedures approved by the Board.

The Committee meets as necessary, and no less frequently than quarterly, to determine fair values for securities for which market quotations are not readily available or for which the investment manager believes that available market quotations are unreliable, and to review the continuing appropriateness of the current value of any security subject to the Trust's Portfolio Pricing Policy and the pricing procedures of the investment manager (the Policies). The Policies address, among other things: circumstances under which market quotations will be deemed readily available; selection of third party pricing vendors; appropriate pricing methodologies; events that require fair valuation and fair value techniques; and circumstances under which securities will be deemed to pose a potential for stale pricing, including when securities are illiquid, restricted, or in default. The Committee may also meet to discuss additional valuation matters, which may include review of back-testing results, review of time-sensitive information or approval of other valuation related actions, and to review the appropriateness of the Policies.

  For investments categorized as Level 3, the significant unobservable inputs used in the fair value measurement of the Funds' securities may include: (i) data specific to the issuer or comparable issuers, (ii) general market or specific sector news and (iii) quoted prices and specific or similar security transactions. The Committee considers this data and any changes from prior periods in order to assess the reasonableness of observable and unobservable inputs, any assumptions or internal models used to value those securities and changes in fair value. Significant changes in any of these factors could result in lower or higher fair value measurements. Various factors impact the frequency of monitoring (which may occur as often as daily), however the Committee may determine that changes to inputs, assumptions and models are not required with the same frequency.

The following table summarizes the inputs used, as of June 30, 2012, in valuing the Fund's assets:

Investment Type	Quoted Prices (Level 1)		Other Significant Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)		Total
Equities
Information	$	487,022	$	-	$	-	$	487,022
Industrial Goods & Services		272,286		-		-		272,286
Consumer Goods & Services		257,845		-		-		257,845
Finance		212,942		-		-		212,942
Health Care		162,973		-		10		162,983
Other Industries		116,499		-		-		116,499
Energy & Minerals		71,993		-		-		71,993
Total Equities		1,581,560		-		10		1,581,570
Total Securities Lending Collateral		53,351		-		-		53,351
Total Investments	$	1,634,911	$	-	$	10	$	1,634,921

See accompanying notes to financial statements.

61

Columbia Acorn USA

Statement of Investments (Unaudited), continued

> Notes to Statement of Investments (dollar values in thousands)

  There were no transfers of financial assets between levels 1 and 2 during the period.

The following table reconciles asset balances for the period ending June 30, 2012, in which significant observable and/or unobservable inputs (Level 3) were used in determining value:

Investments in Securities	Balance as of December 31, 2011		Realized Gain/(Loss)		Change in Unrealized Appreciation (Depreciation)			Purchases		Sales		Transfers into Level 3		Transfers out of Level 3		Balance as of June 30, 2012
Equities
Health Care	$	27	$	-	$	(17	)	$	-	$	-	$	-	$	-	$	10
	$	27	$	-	$	(17	)	$	-	$	-	$	-	$	-	$	10

  The information in the above reconciliation table represents fiscal year to date activity for any securities identified as using Level 3 inputs at either the beginning or the end of the current fiscal period.

  The change in unrealized depreciation attributed to securities owned at June 30, 2012, which were valued using significant unobservable inputs (Level 3), amounted to $17.

  The Fund does not hold any significant investments categorized as Level 3.

  Certain common stock classified as Level 3 are valued at fair value, using a market approach, as determined in good faith under consistently applied procedures established by and under the general supervision of the Board. To determine fair value for these securities, for which no market exists, the Committee utilizes the valuation technique it deems most appropriate in the circumstances, using some unobservable inputs, which may include but are not limited to trades of similar securities, estimated earnings of the company, market multiples derived from a set of comparable companies, and the position of the security within the company's capital structure. Significant increases or decreases to any of these inputs could result in a significantly lower or higher fair value measurement. Generally, a change in estimated earnings of a company may result in a change to the comparable companies and market multiples utilized.

See accompanying notes to financial statements.

62

Columbia Acorn International Select

Major Portfolio Changes in the Second Quarter (Unaudited)

	Number of Shares
	3/31/12		6/30/12
Purchases
Asia
> Taiwan
CTCI Corp		2,789,400		3,508,400
Taiwan Mobile		1,179,000		3,133,800
> Japan
Start Today		0		496,000
Other Countries
> Australia
Challenger Financial		826,355		2,809,800
Commonwealth Property Office Fund		3,170,358		10,466,968
IAG		0		1,652,046
UGL		0		1,000,050
> Canada
Goldcorp		0		344,400
Latin America
> Mexico
Fresnillo		0		597,400
> Guatemala
Tahoe Resources		0		196,800

	Number of Shares
	3/31/12		6/30/12
Sales
Asia
> Japan
Ain Pharmaciez		74,000		0
Asahi Diamond Industrial		528,000		1,000
Gree		59,400		0
Kansai Paint		1,911,000		319,000
> China
NetEase.com - ADR		84,000		1,000
> Korea
NHN		49,830		32,830
Other Countries
> South Africa
Northam Platinum		1,146,000		0
Rand Merchant Insurance		7,601,015		6,483,015
> Canada
AG Growth		89,000		0
Europe
> Germany
Rheinmetall		109,500		0
Rhoen-Klinikum		175,000		0
> United Kingdom
Chemring		772,800		0
Intertek Group		178,000		79,000
JLT Group		314,000		296,400
Serco		659,000		583,000
> Netherlands
Core Laboratories		28,100		0
Imtech		239,919		190,916
> Switzerland
Kuehne & Nagel		28,000		0
> Denmark
Novozymes		145,000		125,000

See accompanying notes to financial statements.

63

Columbia Acorn International Select

Statement of Investments (Unaudited), June 30, 2012

Number of Shares			Value (000)
			Equities: 94.9%
Asia 44.4%
		> Singapore 15.0%
	13,130,000	Ascendas REIT	$	22,399
		Industrial Property Landlord
	20,395,000	Mapletree Industrial Trust		19,537
		Industrial Property Landlord
	11,142,000	Mapletree Logistics Trust		8,664
		Industrial Property Landlord
				50,600
		> Taiwan 12.2%
	11,103,000	Far EasTone Telecom		24,156
		Taiwan's Third Largest Mobile Operator
	3,133,800	Taiwan Mobile		10,363
		Taiwan's Second Largest Mobile Operator
	3,508,400	CTCI Corp		6,569
		International Engineering Firm
				41,088
		> Japan 10.1%
	5,753,734	Seven Bank		14,776
		ATM Processing Services
	8,970	Jupiter Telecommunications		9,146
		Largest Cable Service Provider in Japan
	496,000	Start Today		6,931
		Online Japanese Apparel Retailer
	319,000	Kansai Paint		3,418
		Paint Producer in Japan, India, China & Southeast Asia
	1,000	Asahi Diamond Industrial		11
		Consumable Diamond Tools
				34,282
		> China 2.7%
	4,146,000	Zhaojin Mining Industry		5,452
		Gold Mining & Refining in China
	3,044,000	Want Want		3,764
		Chinese Branded Consumer Food Company
	1,000	NetEase.com - ADR (a)		59
		Chinese Online Gaming Services
				9,275
		> Indonesia 2.3%
	9,272,000	Archipelago Resources (a)		7,406
		Gold Mining Projects in Indonesia, Vietnam & the Philippines
	1,404,000	MNC Skyvision (a)		235
		Largest Satellite Pay TV Operator in Indonesia
				7,641
		> Korea 2.1%
	32,830	NHN		7,201
		Korean Online Search Services
				7,201
Asia: Total				150,087
Other Countries 28.6%
		> Australia 11.6%
	1,000,050	UGL		12,805
		Engineering & Facilities Management

Number of Shares			Value (000)
	10,466,968	Commonwealth Property Office Fund	$	10,911
		Australia Prime Office REIT
	2,809,800	Challenger Financial		9,437
		Largest Annuity Provider
	1,652,046	IAG		5,925
		General Insurance Provider
				39,078
		> South Africa 8.7%
	6,483,015	Rand Merchant Insurance		13,808
		Directly Sold Property & Casualty Insurance; Holdings in Other Insurers
	1,317,200	Adcock Ingram Holdings		9,682
		Manufacturer of Pharmaceuticals & Medical Supplies
	112,700	Naspers		6,020
		Media in Africa, China, Russia & Other Emerging Markets
				29,510
		> Canada 5.0%
	344,400	Goldcorp		12,943
		Gold Mining
	106,400	CCL Industries		3,903
		Leading Global Label Manufacturer
				16,846
		> United States 1.8%
	94,000	Atwood Oceanics (a)		3,557
		Offshore Drilling Contractor
	52,000	SM Energy		2,554
		Oil & Gas Producer
				6,111
		> Israel 1.5%
	460,000	Israel Chemicals		5,090
		Producer of Potash, Phosphates, Bromine & Specialty Chemicals
				5,090
Other Countries: Total				96,635
Europe 16.4%
		> Germany 3.6%
	630,000	Wirecard		12,216
		Online Payment Processing & Risk Management
				12,216
		> United Kingdom 3.4%
	583,000	Serco		4,896
		Facilities Management
	79,000	Intertek Group		3,310
		Testing, Inspection, Certification Services
	296,400	JLT Group		3,256
		International Business Insurance Broker
				11,462
		> Sweden 3.0%
	595,666	Hexagon		10,225
		Design, Measurement & Visualization Software & Equipment
				10,225

See accompanying notes to financial statements.

64

Number of Shares			Value (000)
		> Iceland 1.7%
	4,800,000	Marel	$	5,838
		Largest Manufacturer of Poultry & Fish Processing Equipment
				5,838
		> Netherlands 1.4%
	190,916	Imtech		4,559
		Electromechanical & Information & Communications Technology Installation & Maintenance
				4,559
		> Switzerland 1.3%
	24,000	Partners Group		4,268
		Private Markets Asset Management
				4,268
		> Belgium 1.0%
	74,000	EVS Broadcast Equipment		3,491
		Digital Live Mobile Production Software & Systems
				3,491
		> Denmark 1.0%
	125,000	Novozymes		3,241
		Industrial Enzymes
				3,241
Europe: Total				55,300
Latin America 5.5%
		> Mexico 4.0%
	597,400	Fresnillo		13,684
		Silver & Metal Byproduct Mining in Mexico
				13,684

Number of Shares			Value (000)
		> Guatemala 0.8%
	196,800	Tahoe Resources (a)	$	2,720
		Silver Project in Guatemala
				2,720
		> Uruguay 0.5%
	191,666	Union Agriculture Group (a)(b)(c)		1,876
		Farmland Operator in Uruguay
				1,876
		> Colombia 0.2%
	1,880,000	Santa Maria Petroleum (a)(b)		567
		Explores for Oil & Gas in Latin America
				567
Latin America: Total				18,847
Total Equities: 94.9% (Cost: $273,433)				320,869
Total Investments: 94.9% (Cost: $273,433)(d)(e)				320,869
Cash and Other Assets Less Liabilities: 5.1%				17,265
Total Net Assets: 100.0%			$	338,134

ADR - American Depositary Receipts

REIT - Real Estate Investment Trust

> Notes to Statement of Investments (dollar values in thousands)

(a)  Non-income producing security.

(b)  Denotes a restricted security, which is subject to restrictions on resale under federal securities laws. These securities are valued at fair value determined in good faith under consistently applied procedures established by the Board of Trustees. At June 30, 2012, the market value of these securities amounted to $2,443, which represented 0.72% of total net assets.

  Additional information on these securities is as follows:

Security	Acquisition Dates	Shares		Cost		Value
Union Agriculture Group	12/8/10-6/27/12		191,666	$	2,200	$	1,876
Santa Maria Petroleum	1/14/11		1,880,000		2,376		567
				$	4,576	$	2,443

(c)  Illiquid security.

(d)  At June 30, 2012, for federal income tax purposes, the cost of investments was $273,433 and net unrealized appreciation was $47,436 consisting of gross unrealized appreciation of $56,811 and gross unrealized depreciation of $9,375.

See accompanying notes to financial statements.

65

Columbia Acorn International Select

Statement of Investments (Unaudited), continued

> Notes to Statement of Investments (dollar values in thousands)

(e)  On June 30, 2012, the Fund's total investments were denominated in currencies as follows:

Currency	Value		Percentage of Net Assets
Singapore Dollar	$	50,600		15.0
Taiwan Dollar		41,089		12.2
Austrailian Dollar		39,078		11.6
Japanese Yen		34,282		10.1
British Pound		32,552		9.6
South African Rand		29,510		8.7
United States Dollar		20,988		6.2
Euro		20,266		6.0
Other currencies less than 5% of total net assets		52,504		15.5
Total Portfolio	$	320,869		94.9

  At June 30, 2012, the Fund had entered into the following forward foreign currency exchange contracts:

Forward Foreign Currency Exchange Contracts to Buy	Forward Foreign Currency Exchange Contracts to Sell	Principal Amount in Foreign Currency		Principal Amount in U.S. Dollar		Settlement Date	Unrealized Appreciation/ (Depreciation)
USD	ZAR		236,888	$	28,000	7/13/12	$	(932	)

The counterparty for all forward foreign currency exchange contracts is State Street Bank and Trust Company.

USD = United States Dollar

ZAR = South African Rand

Fair Value Measurements

  Various inputs are used in determining the value of the Fund's investments, following the input prioritization hierarchy established by GAAP. These inputs are summarized in the three broad levels listed below:

•  Level 1 – quoted prices in active markets for identical securities

•  Level 2 – prices determined using other significant observable inputs (including quoted prices for similar securities, interest rates, prepayment speeds, credit risk and others)

•  Level 3 – prices determined using significant unobservable inputs where quoted prices or observable inputs are unavailable or less reliable (including management's own assumptions about the factors market participants would use in pricing an investment)

  The inputs or methodology used for valuing securities are not necessarily an indication of the risk associated with investing in those securities.

  Examples of the types of securities in which the Fund would typically invest and how they are classified within this hierarchy are as follows. Typical Level 1 securities include exchange traded domestic equities, mutual funds whose NAVs are published each day and exchange traded foreign equities that are not statistically fair valued. Typical Level 2 securities include exchange traded foreign equities that are statistically fair valued, forward foreign currency exchange contracts and short-term investments valued at amortized cost. Additionally, securities fair valued by the Valuation Committee (the Committee) of the Fund's Board of Trustees (the Board) that rely on significant observable inputs are also included in Level 2. Typical Level 3 securities include any security fair valued by the Committee that relies on significant unobservable inputs.

  Under the direction of the Board, the Committee is responsible for carrying out the valuation procedures approved by the Board.

The Committee meets as necessary, and no less frequently than quarterly, to determine fair values for securities for which market quotations are not readily available or for which the investment manager believes that available market quotations are unreliable, and to review the continuing appropriateness of the current value of any security subject to the Trust's Portfolio Pricing Policy and the pricing procedures of the investment manager (the Policies). The Policies address, among other things: circumstances under which market quotations will be deemed readily available; selection of third party pricing vendors; appropriate pricing methodologies; events that require fair valuation and fair value techniques; and circumstances under which securities will be deemed to pose a potential for stale pricing, including when securities are illiquid, restricted, or in default. The Committee may also meet to discuss additional valuation matters, which may include review of back-testing results, review of time-sensitive information or approval of other valuation related actions, and to review the appropriateness of the Policies.

  For investments categorized as Level 3, the significant unobservable inputs used in the fair value measurement of the Funds' securities may include: (i) data specific to the issuer or comparable issuers, (ii) general market or specific sector news and (iii) quoted prices and specific or similar security transactions. The Committee considers this data and any changes from prior periods in order to assess the reasonableness of observable and unobservable inputs, any assumptions or internal models used to value those securities and changes in fair value. Significant changes in any of these factors could result in lower or higher fair value measurements. Various factors impact the frequency of monitoring (which may occur as often as daily), however the Committee may determine that changes to inputs, assumptions and models are not required with the same frequency.

See accompanying notes to financial statements.

66

> Notes to Statement of Investments (dollar values in thousands)

The following table summarizes the inputs used, as of June 30, 2012, in valuing the Fund's assets:

Investment Type	Quoted Prices (Level 1)		Other Significant Observable Inputs (Level 2)			Significant Unobservable Inputs (Level 3)		Total
Equities
Asia	$	59	$	150,028		$	-	$	150,087
Other Countries		22,957		73,678			-		96,635
Europe		-		55,300			-		55,300
Latin America		2,720		14,251			1,876		18,847
Total Equities		25,736		293,257			1,876		320,869
Total Investments	$	25,736	$	293,257		$	1,876	$	320,869
Unrealized Depreciation on Forward Foreign Currency Exchange Contracts		-		(932	)		-		(932	)
Total Investments	$	25,736	$	292,325		$	1,876	$	319,937

  The Fund's assets assigned to the Level 2 input category are generally valued using a market approach, in which a security's value is determined through its correlation to prices and information from observable market transactions for similar or identical assets. Foreign equities are generally valued at the last sale price on the foreign exchange or market on which they trade. The Fund may use a statistical fair valuation model, in accordance with the policy adopted by the Board, provided by an independent third party to value securities principally traded in foreign markets in order to adjust for possible stale pricing that may occur between the close of the foreign exchanges and the time for valuation. These models take into account available market data including intraday index, ADR, and ETF movements. Forward foreign currency exchange contracts are valued at the prevailing forward exchange rate of the underlying currencies. Securities acquired via private placement that have a holding period or an extended settlement period are valued at a discount to the same shares that are trading freely on the market. These discounts are determined by the Investment manager's experience with similar securities or situations. Factors may include, but are not limited to, trade volume, shares outstanding and stock price.

  There were no transfers of financial assets between levels 1 and 2 during the period.

The following table reconciles asset balances for the period ending June 30, 2012, in which significant observable and/or unobservable inputs (Level 3) were used in determining value:

Investments in Securities	Balance as of December 31, 2011		Realized Gain/(Loss)		Change in Unrealized Appreciation (Depreciation)		Purchases		Sales		Transfers into Level 3		Transfers out of Level 3		Balance as of June 30, 2012
Equities
Latin America	$	1,828	$	-	$	48	$	-	$	-	$	-	$	-	$	1,876
	$	1,828	$	-	$	48	$	-	$	-	$	-	$	-	$	1,876

  The information in the above reconciliation table represents fiscal year to date activity for any securities identified as using Level 3 inputs at either the beginning or the end of the current fiscal period.

  The change in unrealized appreciation attributed to securities owned at June 30, 2012, which were valued using significant unobservable inputs (Level 3), amounted to $48.

  The Fund does not hold any significant investments categorized as Level 3.

  Certain common stock classified as Level 3 are valued at fair value, using a market approach, as determined in good faith under consistently applied procedures established by and under the general supervision of the Board. To determine fair value for these securities, for which no market exists, the Committee utilizes the valuation technique it deems most appropriate in the circumstances, using some unobservable inputs, which may include but are not limited to trades of similar securities, estimated earnings of the company, market multiples derived from a set of comparable companies, and the position of the security within the company's capital structure. Significant increases or decreases to any of these inputs could result in a significantly lower or higher fair value measurement. Generally, a change in estimated earnings of a company may result in a change to the comparable companies and market multiples utilized.

See accompanying notes to financial statements.

67

Columbia Acorn International Select

Portfolio Diversification (Unaudited)

At June 30, 2012, the Fund's portfolio investments as a percentage of net assets were diversified as follows:

	Value (000)		Percentage of Net Assets
> Information
Mobile Communications	$	34,520		10.2
Internet Related		13,279		4.0
Financial Processors		12,216		3.6
Business Software		10,224		3.0
CATV		9,146		2.7
Computer Hardware & Related Equipment		3,491		1.0
Satellite Broadcasting & Services		235		0.1
		83,111		24.6
> Other Industries
Real Estate		61,511		18.2
> Finance
Insurance		32,427		9.6
Banks		14,776		4.4
Brokerage & Money Management		4,268		1.2
		51,471		15.2
> Energy & Minerals
Mining		42,204		12.5
Oil Services		3,557		1.0
Oil & Gas Producers		3,121		0.9
Agricultural Commodities		1,876		0.6
		50,758		15.0
> Industrial Goods & Services
Other Industrial Services		20,674		6.1
Industrial Materials & Specialty Chemicals		11,749		3.5
Construction		6,569		1.9
Machinery		5,849		1.7
Outsourcing Services		4,896		1.5
		49,737		14.7

	Value (000)		Percentage of Net Assets
> Consumer Goods & Services
Retail	$	6,931		2.0
Nondurables		3,904		1.2
Food & Beverage		3,764		1.1
		14,599		4.3
> Health Care
Pharmaceuticals		9,682		2.9
Total Equities:		320,869		94.9
Total Investments:		320,869		94.9
Cash and Other Assets Less Liabilities:		17,265		5.1
Net Assets:	$	338,134		100.0

See accompanying notes to financial statements.

68

Columbia Acorn Select

Major Portfolio Changes in the Second Quarter (Unaudited)

	Number of Shares
	3/31/12		6/30/12
Purchases
Industrial Goods & Services
Nordson		160,000		220,000
Information
Globalstar		15,000,000		16,721,800
Consumer Goods & Services
Vail Resorts		0		235,000
Energy & Minerals
Canadian Solar (China)		2,700,000		3,301,200
Houston American Energy		826,400		1,455,000
Tuscany International Drilling (Colombia)		12,700,000		13,613,200

	Number of Shares
	3/31/12		6/30/12
Sales
Industrial Goods & Services
Ametek		1,490,000		1,358,000
Donaldson		1,260,000		1,140,000
Expeditors International of Washington		600,000		475,000
Kennametal		975,000		865,000
Pall		690,000		625,000
Quanta Services		1,420,000		1,000,000
Information
Amphenol		645,000		560,000
Atmel		1,175,000		1,140,000
Sanmina-SCI		4,375,000		3,026,600
SBA Communications		1,010,000		735,000
VisionChina Media - ADR (China)		6,108,437		5,427,200
WNS - ADR (India)		3,940,000		3,405,000
Consumer Goods & Services
Abercrombie & Fitch		555,000		455,000
Coach		615,000		555,000
Gaylord Entertainment		1,020,000		930,000
Hertz		5,225,000		4,495,000
IFM Investments (Century 21 China RE) - ADR (China)		1,143,333		998,000
ITT Educational Services		270,000		223,000
lululemon athletica		390,000		305,000
RexLot Holdings (China)		260,000,000		208,000,000
Safeway		1,100,000		0
Tiffany & Co.		200,000		184,000
Finance
City National		630,000		540,000
CNO Financial Group		8,325,000		7,140,000
Discover Financial Services		2,115,000		1,935,000
Regional Management		84,500		0
SEI Investments		965,000		775,000
Energy & Minerals
Canacol (Colombia)		30,872,300		29,187,400
Eacom Timber (Canada)		33,572,000		8,440,000
Kirkland Lake Gold (Canada)		870,000		835,000
Pacific Rubiales Energy (Colombia)		1,480,000		1,170,000
Petrodorado (Colombia)		34,700,000		33,700,000
Shamaran Petroleum (Iraq)		36,500,000		30,473,500
Health Care
Akorn		1,400,000		1,310,000
NPS Pharmaceuticals		2,510,000		2,340,000
Seattle Genetics		395,000		383,000
Other Industries
Biomed Realty Trust		1,660,000		1,435,000

See accompanying notes to financial statements.

69

Columbia Acorn Select

Statement of Investments (Unaudited), June 30, 2012

Number of Shares			Value (000)
			Equities: 98.0%
Industrial Goods & Services 21.7%
		> Machinery 16.4%
	1,358,000	Ametek	$	67,778
		Aerospace/Industrial Instruments
	1,140,000	Donaldson		38,042
		Industrial Air Filtration
	625,000	Pall		34,256
		Filtration & Fluids Clarification
	865,000	Kennametal		28,675
		Consumable Cutting Tools
	220,000	Nordson		11,284
		Dispensing Systems for Adhesives & Coatings
				180,035
		> Outsourcing Services 2.2%
	1,000,000	Quanta Services (a)		24,070
		Electrical & Telecom Construction Services
				24,070
		> Other Industrial Services 1.7%
	475,000	Expeditors International of Washington		18,406
		International Freight Forwarder
				18,406
		> Industrial Materials & Specialty Chemicals 1.4%
	300,000	FMC Corporation		16,044
		Niche Specialty Chemicals
				16,044
Industrial Goods & Services: Total				238,555
Information 20.1%
		> Mobile Communications 8.0%
	735,000	SBA Communications (a)		41,932
		Communications Towers
	700,000	Crown Castle International (a)		41,062
		Communications Towers
	16,721,800	Globalstar (a)(b)(c)		5,351
		Satellite Mobile Voice & Data Carrier
				88,345
		> Computer Services 3.0%
	3,405,000	WNS - ADR (India) (a)(b)		33,131
		Offshore BPO (Business Process Outsourcing) Services
				33,131
		> Computer Hardware & Related Equipment 2.8%
	560,000	Amphenol		30,755
		Electronic Connectors
				30,755
		> Contract Manufacturing 2.3%
	3,026,600	Sanmina-SCI (a)		24,788
		Electronic Manufacturing Services
				24,788
		> Instrumentation 1.8%
	126,000	Mettler-Toledo International (a)		19,637
		Laboratory Equipment
				19,637

Number of Shares			Value (000)
		> Business Software 1.0%
	167,000	Concur Technologies (a)	$	11,373
		Web Enabled Cost & Expense Management Software
				11,373
		> Semiconductors & Related Equipment 0.7%
	1,140,000	Atmel (a)		7,638
		Microcontrollers, Radio Frequency & Memory Semiconductors
				7,638
		> Advertising 0.5%
	5,427,200	VisionChina Media - ADR (China) (a)(b)(c)		5,047
		Advertising on Digital Screens in China's Mass Transit System
				5,047
Information: Total				220,714
Consumer Goods & Services 19.2%
		> Travel 9.6%
	4,495,000	Hertz (a)		57,536
		Largest U.S. Rental Car Operator
	930,000	Gaylord Entertainment (a)		35,861
		Convention Hotels
	235,000	Vail Resorts		11,769
		Ski Resort Operator & Developer
				105,166
		> Retail 3.9%
	305,000	lululemon athletica (a)		18,187
		Premium Active Apparel Retailer
	455,000	Abercrombie & Fitch		15,534
		Teen Apparel Retailer
	184,000	Tiffany & Co.		9,743
		Luxury Good Retailer
				43,464
		> Apparel 2.9%
	555,000	Coach		32,456
		Designer & Retailer of Branded Leather Accessories
				32,456
		> Casinos & Gaming 1.4%
	208,000,000	RexLot Holdings (China)		14,900
		Lottery Equipment Supplier in China
				14,900
		> Educational Services 1.2%
	223,000	ITT Educational Services (a)(c)		13,547
		Postsecondary Degree Services
				13,547
		> Other Consumer Services 0.1%
	998,000	IFM Investments (Century 21 China RE) - ADR (China) (a)(b)		1,088
		Provide Real Estate Services in China
				1,088

See accompanying notes to financial statements.

70

Number of Shares			Value (000)
		> Food & Beverage 0.1%
	1,500,000	GLG Life Tech (Canada) (a)(c)(d)	$	621
		All-natural Sweetener Extracted from the Stevia Plant
				621
Consumer Goods & Services: Total				211,242
Finance 16.2%
		> Credit Cards 6.1%
	1,935,000	Discover Financial Services		66,912
		Credit Card Company
				66,912
		> Insurance 5.0%
	7,140,000	CNO Financial Group		55,692
		Life, Long-term Care & Medical Supplement Insurance
				55,692
		> Banks 3.7%
	540,000	City National		26,233
		Bank & Asset Manager
	1,075,000	Associated Banc-Corp		14,179
		Midwest Bank
				40,412
		> Brokerage & Money Management 1.4%
	775,000	SEI Investments		15,415
		Mutual Fund Administration & Investment Management
				15,415
Finance: Total				178,431
Energy & Minerals 9.7%
		> Oil & Gas Producers 5.3%
	1,170,000	Pacific Rubiales Energy (Colombia)		24,777
		Oil Production & Exploration in Colombia
	29,187,400	Canacol (Colombia) (a)		13,044
		Oil Producer in South America
	33,700,000	Petrodorado (Colombia) (a)(b)		5,296
	17,144,000	Petrodorado - Warrants (Colombia) (a)(e)		243
		Oil & Gas Exploration & Production in Colombia, Peru & Paraguay
	30,473,500	Shamaran Petroleum (Iraq) (a)		5,088
		Oil Exploration in Kurdistan
	24,000,000	Canadian Overseas Petroleum (United Kingdom) (a)(b)(e)		4,187
	12,000,000	Canadian Overseas Petroleum - Warrants (United Kingdom) (a)(d)(e)		232
		Oil & Gas Exploration/Production in the North Sea
	17,575,000	Petromanas (Canada) (a)		3,711
		Exploring for Oil in Albania
	1,455,000	Houston American Energy (a)(c)		1,630
		Oil & Gas Exploration/Production in Colombia
				58,208

Number of Shares			Value (000)
		> Agricultural Commodities 1.6%
	1,742,424	Union Agriculture Group (Uruguay) (a)(d)(e)	$	17,058
		Farmland Operator in Uruguay
	8,440,000	Eacom Timber (Canada) (a)		829
		Canadian Lumber Producer
				17,887
		> Alternative Energy 1.5%
	3,301,200	Canadian Solar (China) (a)(b)(c)		11,884
		Solar Cell & Module Manufacturer
	2,425,000	Synthesis Energy Systems (China) (a)		2,959
		Owner/Operator of Gasification Plants
	1,165,000	Real Goods Solar (a)		1,316
		Residential Solar Energy Installer
				16,159
		> Mining 0.8%
	835,000	Kirkland Lake Gold (Canada) (a)		8,989
		Gold Mining
				8,989
		> Oil Services 0.5%
	13,613,200	Tuscany International Drilling (Colombia) (a)		5,282
		South America-based Drilling Rig Contractor
				5,282
Energy & Minerals: Total				106,525
Health Care 6.0%
		> Biotechnology & Drug Delivery 2.7%
	2,340,000	NPS Pharmaceuticals (a)		20,148
		Orphan Drugs & Healthy Royalties
	383,000	Seattle Genetics (a)(c)		9,724
		Antibody-based Therapies for Cancer
				29,872
		> Pharmaceuticals 1.9%
	1,310,000	Akorn (a)		20,659
		Develops, Manufactures & Sells Specialty Generic Drugs
				20,659
		> Medical Supplies 1.4%
	190,000	Henry Schein (a)		14,913
		Largest Distributor of Healthcare Products
				14,913
Health Care: Total				65,444
Other Industries 5.1%
		> Real Estate 3.7%
	1,435,000	Biomed Realty Trust		26,806
		Life Science-focused Office Buildings
	475,000	DuPont Fabros Technology		13,566
		Technology-focused Office Buildings
				40,372

See accompanying notes to financial statements.

71

Columbia Acorn Select

Statement of Investments (Unaudited), continued

Number of Shares			Value (000)
		> Regulated Utilities 1.4%
	403,000	Wisconsin Energy	$	15,946
		Wisconsin Utility
				15,946
Other Industries: Total				56,318
Total Equities: 98.0% (Cost: $835,953)				1,077,229
Securities Lending Collateral 2.4%
	26,067,257	Dreyfus Government Cash Management Fund (7 day yield of 0.01%) (f)		26,067
Total Securities Lending Collateral: (Cost: $26,067)				26,067
Total Investments: 100.4% (Cost: $862,020)(g)(h)				1,103,296
Obligation to Return Collateral for Securities Loaned: (2.4)%				(26,067	)
Cash and Other Assets Less Liabilities: 2.0%				21,891
Total Net Assets: 100.0%			$	1,099,120

ADR - American Depositary Receipts

> Notes to Statement of Investments (dollar values in thousands)

(a)  Non-income producing security.

(b)  An affiliated person of the Fund may include any company in which the Fund owns five percent or more of its outstanding voting shares. Holdings and transactions in these affiliated companies during the period ended June 30, 2012, are as follows:

Security	Balance of Shares Held 12/31/11		Purchases/ Additions		Sales/ Reductions		Balance of Shares Held 6/30/12		Value		Dividend
Canacol*		31,372,300		-		2,184,900		29,187,400	$	13,044	$	-
Canadian Overseas Petroleum		24,000,000		-		-		24,000,000		4,187		-
Canadian Solar		2,700,000		601,200		-		3,301,200		11,884		-
Eacom Timber*		36,000,000		-		27,560,000		8,440,000		829		-
GLG Life Tech*		1,850,000		-		350,000		1,500,000		621		-
Globalstar		13,184,322		3,815,678		278,200		16,721,800		5,351		-
IFM Investments (Century 21 China RE) - ADR**		3,430,000		-		2,432,000		998,000		1,088		-
Petrodorado		34,700,000		-		1,000,000		33,700,000		5,296		-
Real Goods Solar*		1,500,000		-		335,000		1,165,000		1,316		-
Sanmina-SCI*		6,100,000		-		3,073,400		3,026,600		24,788		-
Synthesis Energy Systems*		2,950,372		-		525,372		2,425,000		2,959		-
VisionChina Media - ADR		7,000,000		-		1,572,800		5,427,200		5,047		-
WNS - ADR		4,254,230		-		849,230		3,405,000		33,131		-
Total of Affiliated Transactions		169,041,224		4,416,878		40,160,902		133,297,200	$	109,541	$	-

*  At June 30, 2012, the Fund owned less than five percent of the company's outstanding voting shares.

**  Includes the effects of a 1:3 stock split.

See accompanying notes to financial statements.

72

> Notes to Statement of Investments (dollar values in thousands)

  The aggregate cost and value of these companies at June 30, 2012, were $152,247 and $65,984, respectively. Investments in affiliated companies represented 6.00% of the Fund's total net assets at June 30, 2012.

(c)  All or a portion of this security was on loan at June 30, 2012. The total market value of securities on loan at June 30, 2012 was $25,542.

(d)  Illiquid security.

(e)  Denotes a restricted security, which is subject to restrictions on resale under federal securities laws. These securities are valued at fair value determined in good faith under consistently applied procedures established by the Board of Trustees. At June 30, 2012, the market value of these securities amounted to $21,720, which represented 1.98% of total net assets.

  Additional information on these securities is as follows:

Security	Acquisition Dates	Shares		Cost		Value
Union Agriculuture Group	12/8/10-6/27/12		1,742,424	$	20,000	$	17,058
Canadian Overseas Petroleum	11/24/10		24,000,000		10,260		4,187
Petrodorado - Warrants	11/20/09		17,144,000		2,118		243
Canadian Overseas Petroleum - Warrants	11/24/10		12,000,000		1,502		232
				$	33,880	$	21,720

(f)  Investment made with cash collateral received from securities lending activity.

(g)  At June 30, 2012, for federal income tax purposes, the cost of investments was $862,020 and net unrealized appreciation was $241,276 consisting of gross unrealized appreciation of $390,213 and gross unrealized depreciation of $148,937.

(h)  On June 30, 2012, the market value of foreign securities represented 14.41% of total net assets. The Fund's foreign portfolio was diversified as follows:

Country	Value		Percentage of Net Assets
Colombia	$	48,642		4.43
China		35,878		3.27
India		33,131		3.01
Uruguay		17,058		1.55
Canada		14,150		1.29
Iraq		5,088		0.46
United Kingdom		4,419		0.40
Total Foreign Portfolio	$	158,366		14.41

Fair Value Measurements

  Various inputs are used in determining the value of the Fund's investments, following the input prioritization hierarchy established by GAAP. These inputs are summarized in the three broad levels listed below:

•  Level 1 – quoted prices in active markets for identical securities

•  Level 2 – prices determined using other significant observable inputs (including quoted prices for similar securities, interest rates, prepayment speeds, credit risk and others)

•  Level 3 – prices determined using significant unobservable inputs where quoted prices or observable inputs are unavailable or less reliable (including management's own assumptions about the factors market participants would use in pricing an investment)

  The inputs or methodology used for valuing securities are not necessarily an indication of the risk associated with investing in those securities.

  Examples of the types of securities in which the Fund would typically invest and how they are classified within this hierarchy are as follows. Typical Level 1 securities include exchange traded domestic equities, mutual funds whose NAVs are published each day and exchange traded foreign equities that are not statistically fair valued. Typical Level 2 securities include exchange traded foreign equities that are statistically fair valued and short-term investments valued at amortized cost. Additionally, securities fair valued by the Valuation Committee (the Committee) of the Fund's Board of Trustees (the Board) that rely on significant observable inputs are also included in Level 2. Typical Level 3 securities include any security fair valued by the Committee that relies on significant unobservable inputs.

  Under the direction of the Board, the Committee is responsible for carrying out the valuation procedures approved by the Board.

The Committee meets as necessary, and no less frequently than quarterly, to determine fair values for securities for which market quotations are not readily available or for which the investment manager believes that available market quotations are unreliable, and to review the continuing appropriateness of the current value of any security subject to the Trust's Portfolio Pricing Policy and the pricing procedures of the investment manager (the Policies). The Policies address, among other things: circumstances under which market quotations will be deemed readily available; selection of third party pricing vendors; appropriate pricing methodologies; events that require fair valuation and fair value techniques; and circumstances under which securities will be deemed to pose a potential for stale pricing, including when securities are illiquid, restricted, or in default. The Committee may also meet to discuss additional valuation matters, which may include review of back-testing results, review of time-sensitive information or approval of other valuation related actions, and to review the appropriateness of the Policies.

See accompanying notes to financial statements.

73

Columbia Acorn Select

Statement of Investments (Unaudited), continued

> Notes to Statement of Investments (dollar values in thousands)

  For investments categorized as Level 3, the significant unobservable inputs used in the fair value measurement of the Funds' securities may include: (i) data specific to the issuer or comparable issuers, (ii) general market or specific sector news and (iii) quoted prices and specific or similar security transactions. The Committee considers this data and any changes from prior periods in order to assess the reasonableness of observable and unobservable inputs, any assumptions or internal models used to value those securities and changes in fair value. Significant changes in any of these factors could result in lower or higher fair value measurements. Various factors impact the frequency of monitoring (which may occur as often as daily), however the Committee may determine that changes to inputs, assumptions and models are not required with the same frequency.

The following table summarizes the inputs used, as of June 30, 2012, in valuing the Fund's assets:

Investment Type	Quoted Prices (Level 1)		Other Significant Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)		Total
Equities
Industrial Goods & Services	$	238,555	$	-	$	-	$	238,555
Information		220,714		-		-		220,714
Consumer Goods & Services		195,721		15,521		-		211,242
Finance		178,431		-		-		178,431
Energy & Minerals		84,805		4,662		17,058		106,525
Health Care		65,444		-		-		65,444
Other Industries		56,318		-		-		56,318
Total Equities		1,039,988		20,183		17,058		1,077,229
Total Securities Lending Collateral		26,067		-		-		26,067
Total Investments	$	1,066,055	$	20,183	$	17,058	$	1,103,296

  The Fund's assets assigned to the Level 2 input category are generally valued using a market approach, in which a security's value is determined through its correlation to prices and information from observable market transactions for similar or identical assets. Foreign equities are generally valued at the last sale price on the foreign exchange or market on which they trade. The Fund may use a statistical fair valuation model, in accordance with the policy adopted by the Board, provided by an independent third party to value securities principally traded in foreign markets in order to adjust for possible stale pricing that may occur between the close of the foreign exchanges and the time for valuation. These models take into account available market data including intraday index, ADR, and ETF movements. Securities acquired via private placement that have a holding period or an extended settlement period are valued at a discount to the same shares that are trading freely on the market. These discounts are determined by the investment manager's experience with similar securities or situations. Factors may include, but are not limited to, trade volume, shares outstanding and stock price. Warrants which do not trade are valued as a percentage of the actively trading common stock using a model, based on Black Scholes. Securities which have halted or temporarily stopped trading are valued at the last sale and adjusted by a premium or a discount to account for the anticipated re-opening price. These adjustments are determined by the investment manager's experience with similar securities or situations.

  The following table shows transfers between Level 1 and Level 2 of the fair value hierarchy:

Transfers In				Transfers Out
Level 1		Level 2		Level 1		Level 2
$	-	$	1,665	$	1,665	$	-

  Financial assets were transferred from Level 1 to Level 2 as trading halted during the period.

  The following table reconciles asset balances for the period ending June 30, 2012, in which significant observable and/or unobservable inputs (Level 3) were used in determining value:

Investments in Securities	Balance as of December 31, 2011		Realized Gain/(Loss)		Change in Unrealized Appreciation (Depreciation)		Purchases		Sales		Transfers into Level 3		Transfers out of Level 3		Balance as of June 30, 2012
Equities
Energy & Minerals	$	16,617	$	-	$	441	$	-	$	-	$	-	$	-	$	17,058
	$	16,617	$	-	$	441	$	-	$	-	$	-	$	-	$	17,058

  The information in the above reconciliation table represents fiscal year to date activity for any securities identified as using Level 3 inputs at either the beginning or the end of the current fiscal period.

  The change in unrealized appreciation attributed to securities owned at June 30, 2012, which were valued using significant unobservable inputs (Level 3), amounted to $441.

  Quantitative information pertaining to Level 3 unobservable fair value measurements

	Fair Value at 6/30/12		Valuation Technique(s)	Unobservable Input (s)	Range (Weighted Average)
Equities		17,058	Market comparable companies	Discount for lack of marketability	-2% to -28% (-12%)

See accompanying notes to financial statements.

74

> Notes to Statement of Investments (dollar values in thousands)

  Certain common stock classified as Level 3 are valued at fair value, using a market approach, as determined in good faith under consistently applied procedures established by and under the general supervision of the Board. To determine fair value for these securities, for which no market exists, the Committee utilizes the valuation technique it deems most appropriate in the circumstances, using some unobservable inputs which may include, but are not limited to trades of similar securities, estimated earnings of the company, market multiples derived from a set of comparable companies, and the position of the security within the company's capital structure. Significant increases or decreases to any of these inputs could result in a significantly lower or higher fair value measurement. Generally, a change in estimated earnings of a company may result in a change to the comparable companies and market multiples utilized.

See accompanying notes to financial statements.

75

Columbia Thermostat Fund

Statement of Investments (Unaudited), June 30, 2012

Number of Shares			Value (000)
		> Affiliated Stock Funds: 49.4%
	1,176,526	Columbia Acorn International Fund, Class I	$	43,684
	2,984,136	Columbia Dividend Income Fund, Class I		43,240
	1,097,965	Columbia Acorn Fund, Class I		32,675
	2,152,889	Columbia Contrarian Core Fund, Class I		32,487
	1,706,619	Columbia Select Large Cap Growth Fund, Class I (a)		21,862
	872,274	Columbia Acorn Select Fund, Class I		21,772
	1,599,099	Columbia Large Cap Enhanced Core Fund, Class I		21,684
Total Stock Funds: (Cost: $196,004)				217,404

Number of Shares			Value (000)
		> Affiliated Bond Funds: 48.2%
	11,245,529	Columbia Intermediate Bond Fund, Class I	$	105,933
	6,646,182	Columbia Income Opportunities Fund, Class I		63,936
	3,616,501	Columbia U.S. Treasury Index Fund, Class I		42,205
Total Bond Funds: (Cost: $208,564)				212,074
Total Investments: 97.6% (Cost: $404,568)(b)				429,478
Cash and Other Assets Less Liabilities: 2.4%				10,573
Total Net Assets: 100.0%			$	440,051

> Notes to Statement of Investments (dollar values in thousands)

(a)  Non-income producing security.

(b)  At June 30, 2012 for federal income tax purposes, the cost of investments was $404,568 and net unrealized gain was $24,910 consisting of gross unrealized appreciation of $24,910 and gross unrealized depreciation of $0.

Fair Value Measurements

  Various inputs are used in determining the value of the Fund's investments, following the input prioritization hierarchy established by GAAP. These inputs are summarized in the three broad levels listed below:

•  Level 1 – quoted prices in active markets for identical securities

•  Level 2 – prices determined using other significant observable inputs (including quoted prices for similar securities, interest rates, prepayment speeds, credit risk and others)

•  Level 3 – prices determined using significant unobservable inputs where quoted prices or observable inputs are unavailable or less reliable (including management's own assumptions about the factors market participants would use in pricing an investment)

  The inputs or methodology used for valuing securities are not necessarily an indication of the risk associated with investing in those securities.

  Examples of the types of securities in which the Fund would typically invest and how they are classified within this hierarchy are as follows. Typical Level 1 securities include mutual funds whose NAVs are published each day. Typical Level 2 securities include short-term investments valued at amortized cost.

  Under the direction of the Board of Trustees (the Board), the Valuation Committee (the Committee) is responsible for carrying out the valuation procedures approved by the Board.

The Committee meets as necessary, and no less frequently than quarterly, to determine fair values for securities for which market quotations are not readily available or for which the investment manager believes that available market quotations are unreliable, and to review the continuing appropriateness of the current value of any security subject to the Trust's Portfolio Pricing Policy and the pricing procedures of the investment manager (the Policies). The Policies address, among other things: circumstances under which market quotations will be deemed readily available; selection of third party pricing vendors; appropriate pricing methodologies; events that require fair valuation and fair value techniques; and circumstances under which securities will be deemed to pose a potential for stale pricing, including when securities are illiquid, restricted, or in default. The Committee may also meet to discuss additional valuation matters, which may include review of back-testing results, review of time-sensitive information or approval of other valuation related actions, and to review the appropriateness of the Policies.

  For investments categorized as Level 3, the significant unobservable inputs used in the fair value measurement of the Funds' securities may include: (i) data specific to the issuer or comparable issuers, (ii) general market or specific sector news and (iii) quoted prices and specific or similar security transactions. The Committee considers this data and any changes from prior periods in order to assess the reasonableness of observable and unobservable inputs, any assumptions or internal models used to value those securities and changes in fair value. Significant changes in any of these factors could result in lower or higher fair value measurements. Various factors impact the frequency of monitoring (which may occur as often as daily), however the Committee may determine that changes to inputs, assumptions and models are not required with the same frequency.

The following table summarizes the inputs used, as of June 30, 2012, in valuing the Fund's assets:

Investment Type	Quoted Prices (Level 1)		Other Significant Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)		Total
Total Stock Funds	$	217,404	$	-	$	-	$	217,404
Total Bond Funds		212,074		-		-		212,074
Total Investments	$	429,478	$	-	$	-	$	429,478

  There were no transfers of financial assets between levels 1 and 2 during the period.

See accompanying notes to financial statements.

76

Columbia Acorn Emerging Markets Fund

Major Portfolio Changes in the Second Quarter (Unaudited)

	Number of Shares
	3/31/12		6/30/12
Purchases
Asia
> Taiwan
CTCI Corp		64,762		73,762
Far EasTone Telecom		58,126		74,126
MStar Semiconductor		9,800		13,500
PC Home		13,700		15,700
> Indonesia
Archipelago Resources		137,500		150,100
Mayora Indah		0		13,600
Surya Citra Media		93,264		102,764
Tower Bersama Infrastructure		535,709		537,609
> Hong Kong
AAC Technologies		18,027		21,027
Lifestyle International		28,089		52,089
Sasa International		89,999		99,799
> China
RexLot Holdings		823,246		1,196,000
> India
Redington India		7,562		37,794
> Philippines
Int'l Container Terminal		40,787		44,487
> Cambodia
Nagacorp		340,000		420,000
> Mongolia
Mongolian Mining		98,500		140,500
> Singapore
Petra Foods		0		19,900
Other Countries
> South Africa
Mr. Price		6,597		6,797
> United States
Textainer Group Holdings		2,204		2,404
> Canada
Americas Petrogas		17,500		19,000
Europe
> Kazakhstan
Halyk Savings Bank of Kazakhstan - GDR		17,800		19,400
> France
Compagnie Française de l'Afrique Occidentale		0		325

	Number of Shares
	3/31/12		6/30/12
Latin America
> Brazil
Arcos Dorados		0		4,000
MRV Engenharia		11,325		12,425
Multiplus		3,144		3,444
> Mexico
Grupo Aeroportuario del Sureste - ADR		1,647		1,747

See accompanying notes to financial statements.

77

Columbia Acorn Emerging Markets Fund

Major Portfolio Changes in the Second Quarter (Unaudited), continued

	Number of Shares
	3/31/12		6/30/12
Sales
Asia
> Indonesia
Jasa Marga		109,911		0
> China
NetEase.com - ADR		1,277		977
Other Countries
> South Africa
Northam Platinum		15,354		10,854
> Canada
Alliance Grain Traders		10,801		8,801
Crew Energy		4,172		0
Europe
> Sweden
East Capital Explorer		8,806		4,006
> Germany
Dürr		1,229		1,060
> France
Rubis		965		0
Latin America
> Brazil
Mills Estruturas e Servicos de Engenharia		3,361		0

See accompanying notes to financial statements.

78

Columbia Acorn Emerging Markets Fund

Statement of Investments (Unaudited), June 30, 2012

Number of Shares			Value (000)
			Equities: 96.9%
Asia 60.7%
		> Taiwan 19.3%
	74,126	Far EasTone Telecom	$	161
		Taiwan's Third Largest Mobile Operator
	73,762	CTCI Corp		138
		International Engineering Firm
	9,200	St. Shine Optical		103
		World's Leading Disposable Contact Lens OEM
	42,990	Chroma Ate		98
		Automatic Test Systems, Testing & Measurement Instruments
	33,000	Tripod Technologies		94
		Printed Circuit Boards (PCB)
	13,500	MStar Semiconductor		91
		Integrated Circuits for TV, Digital Set-top-box & Handset
	15,700	PC Home		89
		Taiwanese Internet Retail Company
	12,342	Simplo Technology		85
		Battery Packs for Notebook & Tablet PCs
	15,277	Radiant Opto-Electronics (a)		78
		LCD Back Light Units & Modules
	21,169	Advantech		70
		Industrial PC & Components
	18,500	Lung Yen		54
		Funeral Services & Columbaria
	23,689	Taiwan Hon Chuan		53
		Beverage Packaging (Bottles, Caps, Labels) Manufacturer
				1,114
		> Indonesia 11.2%
	369,019	Ace Indonesia		200
		Home Improvement Retailer
	537,609	Tower Bersama Infrastructure (a)		188
		Communications Towers
	150,100	Archipelago Resources (a)		120
		Gold Mining Projects in Indonesia, Vietnam & the Philippines
	102,764	Surya Citra Media		105
		Free to Air TV in Indonesia
	13,600	Mayora Indah		37
		Consumer Branded Food Manufacturer
				650
		> Hong Kong 7.1%
	52,089	Lifestyle International		115
		Mid to High-end Department Store Operator in Hong Kong & China
	128,862	Melco International		105
		Macau Casino Operator
	5,650	Melco Crown Entertainment - ADR (a)		65
		Macau Casino Operator
	99,799	Sasa International		63
		Cosmetics Retailer
	21,027	AAC Technologies		61
		Miniature Acoustic Components
				409

Number of Shares			Value (000)
		> China 6.0%
	54,951	Digital China	$	97
		IT Distribution & Systems Integration Services
	1,196,000	RexLot Holdings		86
		Lottery Equipment Supplier in China
	977	NetEase.com - ADR (a)		57
		Chinese Online Gaming Services
	1,254	51job - ADR (a)(b)		57
		Integrated Human Resource Services
	111,475	AMVIG Holdings		49
		Chinese Tobacco Packaging Material Supplier
				346
		> India 5.2%
	8,635	United Breweries		85
		India's Largest Brewer
	14,240	Titan Industries		57
		Jewlery, Watches & Eyeglasses
	24,700	Adani Ports & Special Economic Zone		54
		Indian West Coast Shipping Port
	37,794	Redington India		52
		Supply Chain Solutions for IT & Mobile Handsets in Emerging Markets
	33,749	Jain Irrigation Systems		51
		Agricultural Micro-irrigation Systems & Food Processing
				299
		> Philippines 3.4%
	44,487	Int'l Container Terminal		78
		Container Handling Terminals & Port Management
	109,465	Manila Water Company		64
		Water Utility Company in the Philippines
	176,818	SM Prime Holdings		55
		Shopping Mall Operator
				197
		> Cambodia 3.3%
	420,000	Nagacorp		188
		Casino/Entertainment Complex in Cambodia
				188
		> Thailand 1.9%
	272,518	Home Product Center		109
		Home Improvement Retailer
				109
		> Mongolia 1.4%
	140,500	Mongolian Mining (a)		80
		Coking Coal Mining in Mongolia
				80
		> Japan 1.2%
	6,760	Kansai Paint		72
		Paint Producer in Japan, India, China & Southeast Asia
				72
		> Singapore 0.7%
	19,900	Petra Foods		39
		Cocoa Processor & Chocolate Manufacturer
				39
Asia: Total				3,503

See accompanying notes to financial statements.

79

Columbia Acorn Emerging Markets Fund

Statement of Investments (Unaudited), continued

Number of Shares			Value (000)
Other Countries 16.9%
		> South Africa 10.9%
	75,000	Rand Merchant Insurance	$	160
		Directly Sold Property & Casualty Insurance; Holdings in Other Insurers
	45,226	Coronation Fund Managers		153
		South African Fund Manager
	16,350	Adcock Ingram Holdings		120
		Manufacturer of Pharmaceuticals & Medical Supplies
	6,797	Mr. Price		93
		South African Retailer of Apparel, Household & Sporting Goods
	3,497	Massmart Holdings		73
		General Merchandise, Food & Home Improvement Stores; Wal-Mart Subsidiary
	10,854	Northam Platinum		31
		Platinum Mining in South Africa
				630
		> United States 3.3%
	2,404	Textainer Group Holdings (b)		89
		Top International Container Leasor
	1,709	Hornbeck Offshore (a)		66
		Supply Vessel Operator in U.S. Gulf of Mexico
	952	Atwood Oceanics (a)		36
		Offshore Drilling Contractor
				191
		> Canada 2.7%
	8,801	Alliance Grain Traders		118
		Global Leader in Pulse Processing & Distribution
	19,000	Americas Petrogas (a)		35
		Oil & Gas Exploration in Argentina, Potash in Peru
				153
Other Countries: Total				974
Europe 11.0%
		> Sweden 2.6%
	7,231	Hexagon		124
		Design, Measurement & Visualization Software & Equipment
	4,006	East Capital Explorer		28
		Sweden-based Russia & Central Eastern Europe Investment Fund
				152
		> Switzerland 2.5%
	1,178	Dufry Group (a)		143
		Operates Airport Duty Free & Duty Paid Shops
				143
		> Kazakhstan 1.7%
	19,400	Halyk Savings Bank of Kazakhstan - GDR (a)		97
		Largest Retail Bank & Insurer in Kazakhstan
				97

Number of Shares			Value (000)
		> Czech Republic 1.4%
	474	Komercni Banka	$	83
		Leading Czech Universal Bank
				83
		> Italy 1.4%
	7,631	Pirelli		80
		Global Tire Supplier
				80
		> Germany 1.1%
	1,060	Dürr		65
		Automotive Plant Engineering & Associated Capital Equipment
				65
		> France 0.3%
	325	Compagnie Française de l'Afrique Occidentale		15
		African Wholesaler & Distributor
				15
Europe: Total				635
Latin America 8.3%
		> Brazil 5.0%
	6,090	Localiza Rent A Car		92
		Car Rental
	3,444	Multiplus		82
		Loyalty Program Operator in Brazil
	4,000	Arcos Dorados (b)		59
		McDonald's Master Franchise for Latin America
	12,425	MRV Engenharia		57
		Brazilan Property Developer
				290
		> Mexico 2.4%
	1,747	Grupo Aeroportuario del Sureste - ADR		136
		Mexican Airport Operator
				136
		> Chile 0.7%
	18,900	Viña Concha y Toro		37
		Global Branded Wine Manufacturer
				37
		> Argentina 0.2%
	40,200	Madalena Ventures (a)		14
		Oil & Gas Exploration in Argentina
				14
Latin America: Total				477
Total Equities: 96.9% (Cost: $5,503)				5,589

See accompanying notes to financial statements.

80

Number of Shares			Value (000)
Securities Lending Collateral 1.8%
	104,775	Dreyfus Government Cash Management Fund (7 day yield of 0.01%) (c)	$	105
Total Securities Lending Collateral: (Cost: $105)				105
Total Investments: 98.7% (Cost: $5,608)(d)(e)				5,694
Obligation to Return Collateral for Securities Loaned: (1.8)%				(105	)
Cash and Other Assets Less Liabilities: 3.1%				183
Total Net Assets: 100.0%			$	5,772

ADR - American Depositary Receipts

GDR - Global Depositary Receipts

> Notes to Statement of Investments (dollar values in thousands)

(a)  Non-income producing security.

(b)  All or a portion of this security was on loan at June 30, 2012. The total market value of securities on loan at June 30, 2012 was $105.

(c)  Investment made with cash collateral received from securities lending activity.

(d)  At June 30, 2012, for federal income tax purposes, the cost of investments was $5,608 and net unrealized appreciation was $86 consisting of gross unrealized appreciation of $549 and gross unrealized depreciation of $463.

(e)  On June 30, 2012, the Fund's total investments were denominated in currencies as follows:

Currency	Value		Percentage of Net Assets
Taiwan Dollar	$	1,114		19.3
Hong Kong Dollar		843		14.6
United States Dollar		663		11.5
South African Rand		630		10.9
Indonesian Rupiah		530		9.2
Indian Rupee		298		5.2
Other currencies less than 5% of total net assets		1,511		26.2
Total Portfolio	$	5,589		96.9

Fair Value Measurements

  Various inputs are used in determining the value of the Fund's investments, following the input prioritization hierarchy established by GAAP. These inputs are summarized in the three broad levels listed below:

•  Level 1 – quoted prices in active markets for identical securities

•  Level 2 – prices determined using other significant observable inputs (including quoted prices for similar securities, interest rates, prepayment speeds, credit risk and others)

•  Level 3 – prices determined using significant unobservable inputs where quoted prices or observable inputs are unavailable or less reliable (including management's own assumptions about the factors market participants would use in pricing an investment)

  The inputs or methodology used for valuing securities are not necessarily an indication of the risk associated with investing in those securities.

  Examples of the types of securities in which the Fund would typically invest and how they are classified within this hierarchy are as follows. Typical Level 1 securities include exchange traded domestic equities, mutual funds whose NAVs are published each day and exchange traded foreign equities that are not statistically fair valued. Typical Level 2 securities include exchange traded foreign equities that are statistically fair valued and short-term investments valued at amortized cost. Additionally, securities fair valued by the Valuation Committee (the Committee) of the Fund's Board of Trustees (the Board) that rely on significant observable inputs are also included in Level 2. Typical Level 3 securities include any security fair valued by the Committee that relies on significant unobservable inputs.

See accompanying notes to financial statements.

81

Columbia Acorn Emerging Markets Fund

Statement of Investments (Unaudited), continued

> Notes to Statement of Investments (dollar values in thousands)

  Under the direction of the Board, the Committee is responsible for carrying out the valuation procedures approved by the Board.

The Committee meets as necessary, and no less frequently than quarterly, to determine fair values for securities for which market quotations are not readily available or for which the investment manager believes that available market quotations are unreliable, and to review the continuing appropriateness of the current value of any security subject to the Trust's Portfolio Pricing Policy and the pricing procedures of the investment manager (the Policies). The Policies address, among other things: circumstances under which market quotations will be deemed readily available; selection of third party pricing vendors; appropriate pricing methodologies; events that require fair valuation and fair value techniques; and circumstances under which securities will be deemed to pose a potential for stale pricing, including when securities are illiquid, restricted, or in default. The Committee may also meet to discuss additional valuation matters, which may include review of back-testing results, review of time-sensitive information or approval of other valuation related actions, and to review the appropriateness of the Policies.

  For investments categorized as Level 3, the significant unobservable inputs used in the fair value measurement of the Funds' securities may include: (i) data specific to the issuer or comparable issuers, (ii) general market or specific sector news and (iii) quoted prices and specific or similar security transactions. The Committee considers this data and any changes from prior periods in order to assess the reasonableness of observable and unobservable inputs, any assumptions or internal models used to value those securities and changes in fair value. Significant changes in any of these factors could result in lower or higher fair value measurements. Various factors impact the frequency of monitoring (which may occur as often as daily), however the Committee may determine that changes to inputs, assumptions and models are not required with the same frequency.

The following table summarizes the inputs used, as of June 30, 2012, in valuing the Fund's assets:

Investment Type	Quoted Prices (Level 1)		Other Significant Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)		Total
Equities
Asia	$	179	$	3,324	$	-	$	3,503
Other Countries		344		630		-		974
Europe		-		635		-		635
Latin America		477		-		-		477
Total Equities		1,000		4,589		-		5,589
Total Securities Lending Collateral		105		-		-		105
Total Investments	$	1,105	$	4,589	$	-	$	5,694

  The Fund's assets assigned to the Level 2 input category are generally valued using a market approach, in which a security's value is determined through its correlation to prices and information from observable market transactions for similar or identical assets. Foreign equities are generally valued at the last sale price on the foreign exchange or market on which they trade. The Fund may use a statistical fair valuation model, in accordance with the policy adopted by the Board, provided by an independent third party to value securities principally traded in foreign markets in order to adjust for possible stale pricing that may occur between the close of the foreign exchanges and the time for valuation. These models take into account available market data including intraday index, ADR, and ETF movements.

  There were no transfers of financial assets between levels 1 and 2 during the period.

See accompanying notes to financial statements.

82

Columbia Acorn Emerging Markets Fund

Portfolio Diversification (Unaudited)

At June 30, 2012, the Fund's portfolio investments as a percentage of net assets were diversified as follows:

	Value (000)		Percentage of Net Assets
> Consumer Goods & Services
Retail	$	827		14.4
Casinos & Gaming		443		7.7
Food & Beverage		354		6.1
Other Consumer Services		225		3.9
Travel		92		1.6
Other Durable Goods		80		1.4
Consumer Goods Distribution		52		0.9
		2,073		36.0
> Information
Computer Hardware & Related Equipment		388		6.7
Mobile Communications		350		6.1
Business Software		124		2.1
TV Broadcasting		104		1.8
Instrumentation		98		1.7
Electronics Distribution		97		1.7
Semiconductors & Related Equipment		91		1.6
Internet Related		58		1.0
		1,310		22.7
> Finance
Brokerage & Money Management		181		3.2
Banks		180		3.1
Insurance		160		2.8
Finance Companies		89		1.5
		610		10.6
> Industrial Goods & Services
Industrial Materials & Specialty Chemicals		175		3.0
Construction		138		2.4
Other Industrial Services		132		2.3
Machinery		116		2.0
		561		9.7
> Energy & Minerals
Mining		231		4.0
Agricultural Commodities		118		2.0
Oil Services		102		1.8
Oil & Gas Producers		49		0.8
		500		8.6
> Other Industries
Transportation		136		2.4
Real Estate		112		1.9
Regulated Utilities		64		1.1
		312		5.4

	Value (000)			Percentage of Net Assets
> Health Care
Pharmaceuticals	$	120			2.1
Medical Supplies		103			1.8
		223			3.9
Total Equities:		5,589			96.9
Security Lending Collateral:		105			1.8
Total Investments:		5,694			98.7
Obligation to Return Collateral for Securities Loaned:		(105	)		(1.8	)
Cash and Other Assets Less Liabilities:		183			3.1
Net Assets:	$	5,772			100.0

See accompanying notes to financial statements.

83

Columbia Acorn European Fund

Major Portfolio Changes in the Second Quarter (Unaudited)

	Number of Shares
	3/31/12		6/30/12
Purchases
Europe
> United Kingdom
Aggreko		0		700
BBA Aviation		0		7,480
Charles Taylor		15,220		22,220
Domino's Pizza United Kingdom & Ireland		3,610		5,090
Greggs		999		3,200
Rightmove		1,000		1,400
WH Smith		0		2,000
> Netherlands
Vopak		0		300
> Switzerland
Dufry Group		170		310
Partners Group		160		295
> Russia
Yandex		0		1,900

	Number of Shares
	3/31/12		6/30/12
Sales
Europe
> United Kingdom
Chemring		4,900		0
Intertek Group		1,100		500
Workspace Group		5,800		0
> France
Mersen		600		213
Rubis		310		0
> Netherlands
Core Laboratories		330		230
Fugro		410		0
> Germany
Rheinmetall		560		360
> Russia
Mail.ru - GDR		1,000		600

See accompanying notes to financial statements.

84

Columbia Acorn European Fund

Statement of Investments (Unaudited), June 30, 2012

Number of Shares			Value (000)
			Equities: 92.9%
Europe 89.8%
		> United Kingdom 18.3%
	22,220	Charles Taylor	$	56
		Insurance Services
	5,090	Domino's Pizza United Kingdom & Ireland		41
		Pizza Delivery in the UK, Ireland & Germany
	1,400	Rightmove		35
		Internet Real Estate Listings
	2,827	JLT Group		31
		International Business Insurance Broker
	3,480	Serco		29
		Facilities Management
	3,180	Shaftesbury		26
		London Prime Retail REIT
	3,200	Greggs		25
		Bakery
	7,480	BBA Aviation		24
		Aviation Support Services
	700	Aggreko		23
		Temporary Power & Temperature Control Services
	500	Intertek Group		21
		Testing, Inspection, Certification Services
	3,190	Abcam		21
		Online Sales of Antibodies
	660	Rotork		20
		Valve Actuators for Oil & Water Pipelines
	2,000	WH Smith		17
		Newsprint, Book & General Stationery Retailer
	2,870	Premier Oil (a)		15
		Oil & Gas Producer in Europe, Pakistan & Asia
	71	Spirax Sarco		2
		Steam Systems for Manufacturing & Process Industries
				386
		> France 14.2%
	600	Eurofins Scientific		75
		Food, Pharmaceuticals & Materials Screening & Testing
	1,000	Gemalto		72
		Digital Security Solutions
	1,200	1000 mercis		55
		Interactive Advertising & Marketing
	1,300	Saft		31
		Niche Battery Manufacturer
	360	Norbert Dentressangle		23
		Leading European Logistics & Transport Group
	400	Neopost		21
		Postage Meter Machines
	7,100	Hi-Media (a)		18
		Online Advertiser in Europe
	213	Mersen		5
		Advanced Industrial Materials
				300
		> Netherlands 12.3%
	1,730	UNIT4		44
		Business Software Development

Number of Shares			Value (000)
	2,785	Aalberts Industries	$	43
		Flow Control & Heat Treatment
	1,412	Koninklijke TenCate		38
		Advanced Textiles & Industrial Fabrics
	1,499	Imtech		36
		Electromechanical & Information & Communications Technology Installation & Maintenance
	1,480	Arcadis		32
		Engineering Consultants
	230	Core Laboratories		27
		Oil & Gas Reservoir Consulting
	917	TKH Group		20
		Dutch Industrial Conglomerate
	300	Vopak		19
		World's Largest Operator of Petroleum & Chemical Storage Terminals
				259
		> Germany 10.1%
	3,250	Wirecard		63
		Online Payment Processing & Risk Management
	520	Dürr		32
		Automotive Plant Engineering & Associated Capital Equipment
	130	Rational		31
		Commercial Ovens
	375	Bertrandt		28
		Outsourced Engineering
	500	Stratec Biomedical Systems		22
		Diagnostic Instrumentation
	590	CTS Eventim		18
		Event Ticket Sales
	360	Rheinmetall		18
		Defense & Automotive
				212
		> Switzerland 9.9%
	300	Geberit		59
		Plumbing Supplies
	295	Partners Group		52
		Private Markets Asset Management
	21	Sika		41
		Chemicals for Construction & Industrial Applications
	310	Dufry Group (a)		38
		Operates Airport Duty Free & Duty Paid Shops
	320	Zehnder		19
		Radiators & Ventilation Systems
				209
		> Sweden 6.0%
	3,070	Hexagon		53
		Design, Measurement & Visualization Software & Equipment
	4,570	Sweco		48
		Engineering Consultants
	1,000	Unibet		25
		European Online Gaming Operator
				126
		> Italy 3.7%
	11,000	Geox		24
		Apparel & Shoe Maker

See accompanying notes to financial statements.

85

Columbia Acorn European Fund

Statement of Investments (Unaudited), continued

Number of Shares			Value (000)
		> Italy—continued
	230	Tod's	$	23
		Leather Shoes & Bags
	2,000	Pirelli		21
		Global Tire Supplier
	9,960	CIR		10
		Italian Holding Company
				78
		> Russia 2.7%
	1,900	Yandex (a)		36
		Search Engine for Russian & Turkish Languages
	600	Mail.ru - GDR (a)(b)		21
		Internet Social Networking & Games for Russian Speakers
				57
		> Iceland 2.5%
	43,750	Marel		53
		Largest Manufacturer of Poultry & Fish Processing Equipment
				53
		> Ireland 1.9%
	300	Paddy Power		20
		Irish Betting Services
	7,300	United Drug		19
		Irish Pharmaceutical Wholesaler & Outsourcer
				39
		> Portugal 1.7%
	13,480	Redes Energéticas Nacionais		36
		Portuguese Power Transmission & Gas Transportation
				36
		> Norway 1.6%
	3,710	Atea		33
		Leading Nordic IT Hardware/Software Reseller & Installation Company
				33
		> Belgium 1.2%
	530	EVS Broadcast Equipment		25
		Digital Live Mobile Production Software & Systems
				25
		> Czech Republic 1.1%
	140	Komercni Banka		24
		Leading Czech Universal Bank
				24
		> Poland 1.1%
	4,000	FX Energy (a)		24
		Oil & Gas Producer in Poland
				24
		> Denmark 0.8%
	300	Solar A/S		16
		Technical Wholesaler of Electrical, Plumbing & HVAC Equipment
				16

Number of Shares			Value (000)
		> Greece 0.7%
	13,330	Intralot	$	15
		Lottery & Gaming Systems & Services
				15
Europe: Total				1,892
Other Countries 1.7%
		> Canada 1.3%
	1,970	Alliance Grain Traders		26
		Global Leader in Pulse Processing & Distribution
				26
		> United States 0.4%
	1,300	Velti (a)(c)		9
		Mobile Marketing Software Platform
				9
Other Countries: Total				35
Asia 1.4%
		> Hong Kong 1.4%
	11,000	L'Occitane International		30
		Skin Care & Cosmetics Producer
				30
Asia: Total				30
Total Equities: 92.9% (Cost: $1,874)				1,957
Securities Lending Collateral 0.3%
	5,850	Dreyfus Government Cash Management Fund (7 day yield of 0.01%) (d)		6
Total Securities Lending Collateral: (Cost: $6)				6
Total Investments: 93.2% (Cost: $1,880)(e)(f)				1,963
Obligation to Return Collateral for Securities Loaned: (0.3)%				(6	)
Cash and Other Assets Less Liabilities: 7.1%				149
Total Net Assets: 100.0%			$	2,106

GDR - Global Depositary Receipts

REIT - Real Estate Investment Trust

See accompanying notes to financial statements.

86

> Notes to Statement of Investments (dollar values in thousands)

(a)  Non-income producing security.

(b)  Security exempt from registration under Section 4(2) of the Securities Act of 1933. This security may only be resold in exempt transactions to qualified buyers. Private resales of this security to qualified institutional buyers are also exempt from registration pursuant to Rule 144A under the Securities Act of 1933. At June 30, 2012, this security had an aggregate value of $21, which represented 1.00% of total net assets.

(c)  All or a portion of this security was on loan at June 30, 2012. The total market value of securities on loan at June 30, 2012 was $6.

(d)  Investment made with cash collateral received from securities lending activity.

(e)  At June 30, 2012, for federal income tax purposes, the cost of investments was $1,880 and net unrealized appreciation was $83 consisting of gross unrealized appreciation of $191 and gross unrealized depreciation of $108.

(f)  On June 30, 2012, the Fund's total investments were denominated in currencies as follows:

Currency	Value		Percentage of Net Assets
Euro	$	937		44.5
British Pound		386		18.3
Swiss Franc		209		9.9
Swedish Krona		126		6.0
United States Dollar		116		5.5
Other currencies less than 5% of total net assets		183		8.7
Total Portfolio	$	1,957		92.9

Fair Value Measurements

  Various inputs are used in determining the value of the Fund's investments, following the input prioritization hierarchy established by GAAP. These inputs are summarized in the three broad levels listed below:

•  Level 1 – quoted prices in active markets for identical securities

•  Level 2 – prices determined using other significant observable inputs (including quoted prices for similar securities, interest rates, prepayment speeds, credit risk and others)

•  Level 3 – prices determined using significant unobservable inputs where quoted prices or observable inputs are unavailable or less reliable (including management's own assumptions about the factors market participants would use in pricing an investment)

  The inputs or methodology used for valuing securities are not necessarily an indication of the risk associated with investing in those securities.

  Examples of the types of securities in which the Fund would typically invest and how they are classified within this hierarchy are as follows. Typical Level 1 securities include exchange traded domestic equities, mutual funds whose NAVs are published each day and exchange traded foreign equities that are not statistically fair valued. Typical Level 2 securities include exchange traded foreign equities that are statistically fair valued and short-term investments valued at amortized cost. Additionally, securities fair valued by the Valuation Committee (the Committee) of the Fund's Board of Trustees (the Board) that rely on significant observable inputs are also included in Level 2. Typical Level 3 securities include any security fair valued by the Committee that relies on significant unobservable inputs.

  Under the direction of the Board, the Committee is responsible for carrying out the valuation procedures approved by the Board.

The Committee meets as necessary, and no less frequently than quarterly, to determine fair values for securities for which market quotations are not readily available or for which the investment manager believes that available market quotations are unreliable, and to review the continuing appropriateness of the current value of any security subject to the Trust's Portfolio Pricing Policy and the pricing procedures of the investment manager (the Policies). The Policies address, among other things: circumstances under which market quotations will be deemed readily available; selection of third party pricing vendors; appropriate pricing methodologies; events that require fair valuation and fair value techniques; and circumstances under which securities will be deemed to pose a potential for stale pricing, including when securities are illiquid, restricted, or in default. The Committee may also meet to discuss additional valuation matters, which may include review of back-testing results, review of time-sensitive information or approval of other valuation related actions, and to review the appropriateness of the Policies.

  For investments categorized as Level 3, the significant unobservable inputs used in the fair value measurement of the Funds' securities may include: (i) data specific to the issuer or comparable issuers, (ii) general market or specific sector news and (iii) quoted prices and specific or similar security transactions. The Committee considers this data and any changes from prior periods in order to assess the reasonableness of observable and unobservable inputs, any assumptions or internal models used to value those securities and changes in fair value. Significant changes in any of these factors could result in lower or higher fair value measurements. Various factors impact the frequency of monitoring (which may occur as often as daily), however the Committee may determine that changes to inputs, assumptions and models are not required with the same frequency.

See accompanying notes to financial statements.

87

Columbia Acorn European Fund

Statement of Investments (Unaudited), continued

> Notes to Statement of Investments (dollar values in thousands)

The following table summarizes the inputs used, as of June 30, 2012, in valuing the Fund's assets:

Investment Type	Quoted Prices (Level 1)		Other Significant Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)		Total
Equities
Europe	$	87	$	1,805	$	-	$	1,892
Other Countries		35		-		-		35
Asia		-		30		-		30
Total Equities		122		1,835		-		1,957
Total Securities Lending Collateral		6		-		-		6
Total Investments	$	128	$	1,835	$	-	$	1,963

  The Fund's assets assigned to the Level 2 input category are generally valued using a market approach, in which a security's value is determined through its correlation to prices and information from observable market transactions for similar or identical assets. Foreign equities are generally valued at the last sale price on the foreign exchange or market on which they trade. The Fund may use a statistical fair valuation model, in accordance with the policy adopted by the Board, provided by an independent third party to value securities principally traded in foreign markets in order to adjust for possible stale pricing that may occur between the close of the foreign exchanges and the time for valuation. These models take into account available market data including intraday index, ADR, and ETF movements.

  There were no transfers of financial assets between levels 1 and 2 during the period.

See accompanying notes to financial statements.

88

Columbia Acorn European Fund

Portfolio Diversification (Unaudited)

At June 30, 2012, the Fund's portfolio investments as a percentage of net assets were diversified as follows:

	Value (000)		Percentage of Net Assets
> Industrial Goods & Services
Other Industrial Services	$	235		11.2
Machinery		178		8.4
Industrial Materials & Specialty Chemicals		84		4.0
Outsourcing Services		81		3.8
Conglomerates		73		3.4
Construction		59		2.8
Electrical Components		31		1.5
Industrial Distribution		16		0.8
		757		35.9
> Information
Business Software		105		5.0
Computer Hardware & Related Equipment		97		4.6
Internet Related		92		4.4
Financial Processors		63		3.0
Business Information & Marketing Services		55		2.6
Computer Services		32		1.5
Advertising		18		0.8
		462		21.9
> Consumer Goods & Services
Casinos & Gaming		60		2.9
Retail		55		2.6
Nondurables		54		2.6
Restaurants		41		1.9
Other Durable Goods		40		1.9
Food & Beverage		25		1.2
Apparel		24		1.1
Other Entertainment		18		0.9
		317		15.1
> Finance
Insurance		87		4.1
Brokerage & Money Management		53		2.5
Banks		24		1.2
		164		7.8
> Energy & Minerals
Oil & Gas Producers		39		1.9
Mining		27		1.3
Agricultural Commodities		26		1.2
Oil Refining, Marketing & Distribution		19		0.9
		111		5.3
> Other Industries
Regulated Utilities		36		1.7
Real Estate		25		1.2
Transportation		23		1.1
		84		4.0

	Value (000)			Percentage of Net Assets
> Health Care
Medical Equipment & Devices	$	22			1.0
Medical Supplies		21			1.0
Pharmaceuticals		19			0.9
		62			2.9
Total Equities:		1,957			92.9
Security Lending Collateral:		6			0.3
Total Investments:		1,963			93.2
Obligation to Return Collateral for Securities Loaned:		(6	)		(0.3	)
Cash and Other Assets Less Liabilities:		149			7.1
Net Assets:	$	2,106			100.0

See accompanying notes to financial statements.

89

Columbia Acorn Family of Funds

Statements of Assets and Liabilities (Unaudited)

June 30, 2012	Columbia Acorn Fund			Columbia Acorn International			Columbia Acorn USA			Columbia Acorn International Select
(in thousands)
Assets:
Unaffiliated investments, at cost	$	8,195,104		$	4,769,636		$	1,175,881		$	273,433
Affiliated investments, at cost (See Note 4)		2,717,367			93,271			3,624			—
Unaffiliated investments, at value (including securities on loan: Columbia Acorn Fund $302,684; Columbia Acorn International $110,353; Columbia Acorn USA $52,943; Columbia Acorn International Select $—; Columbia Acorn Select $25,542; Columbia Thermostat Fund $—; Columbia Acorn Emerging Markets Fund $105; Columbia Acorn European Fund $6)	$	12,779,513		$	5,689,495		$	1,631,375		$	320,869
Affiliated investments, at value (See Note 4)		3,965,342			122,198			3,546			—
Cash		723,080			234,386			5,316			17,891
Foreign currency (cost: Columbia Acorn Fund $—; Columbia Acorn International $978; Columbia Acorn USA $—; Columbia Acorn International Select $183; Columbia Acorn Select $—; Columbia Thermostat Fund $—; Columbia Acorn Emerging Markets Fund $1; Columbia Acorn European Fund $—)		1,468			980			—			184
Receivable for:
Investments sold		14,479			26,099			1,960			4,811
Fund shares sold		13,853			101,107			1,798			719
Dividends and interest		6,953			5,681			386			387
Securities lending income		764			147			111			3
Foreign tax reclaims		309			4,004			—			211
Expense reimbursement due from Advisor		—			1			—			—
Trustees' Deferred Compensation Investments		2,374			659			195			—
Other assets		228			20			10			1
Total Assets		17,508,363			6,184,777			1,644,697			345,076
Liabilities:
Collateral on securities loaned		303,633			111,197			53,351			—
Unrealized depreciation on forward foreign currency exchange contracts		—			—			—			933
Payable to advisor		—			—			—			—
Payable for:
Investments purchased		9,292			35,885			871			5,304
Fund shares redeemed		26,065			5,369			2,043			540
Management fee		292			120			36			8
Administration fee		18			6			2			—	(a)
12b-1 Service and Distribution fees		43			9			2			1
Reports to shareholders		565			263			50			39
Deferred Trustees' fees		2,374			659			195			—
Transfer agent fees		1,403			374			241			25
Trustees' fees		—			1			—			40
Custody fees		75			185			2			16
Professional fee		88			48			39			25
Chief compliance officer expenses		43			13			4			2
Deferred foreign capital gains tax payable		—			4,024			—			—
Other liabilities		—			57			—			9
Total Liabilities		343,891			158,210			56,836			6,942
Net Assets	$	17,164,472		$	6,026,567		$	1,587,861		$	338,134
Composition of Net Assets:
Paid-in capital	$	10,721,070		$	5,301,264		$	1,029,599		$	279,482
Undistributed (overdistributed) net investment income		(28,080	)		(36,596	)		(3,403	)		(2,516	)
Accumulated net realized gain (loss)		639,075			(182,854	)		106,249			14,670
Net unrealized appreciation (depreciation) on:
Unaffiliated investments		4,584,409			919,859			455,494			47,436
Affiliated investments		1,247,975			28,927			(78	)		—
Foreign currency translations		23			(9	)		—			(6	)
Forward foreign currency exchange contracts		—			—			—			(932	)
Foreign capital gains tax		—			(4,024	)		—			—
Net Assets	$	17,164,472		$	6,026,567		$	1,587,861		$	338,134
Net asset value per share – Class A (b)	$	28.69		$	37.01		$	28.52		$	26.62
(Net assets/shares)		($3,289,689/114,676)			($926,998/25,045)			($157,525/5,523)			($57,282/2,152)
Maximum offering price per share – Class A (c)	$	30.44		$	39.27		$	30.26		$	28.24
(Net asset value per share/front-end sales charge)		($28.69/0.9425)			($37.01/0.9425)			($28.52/0.9425)			($26.62/0.9425)
Net asset value and offering price per share – Class B (b)	$	26.32		$	35.88		$	26.27		$	25.45
(Net assets/shares)		($45,604/1,733)			($21,112/588)			($1,627/62)			($1,364/53)
Net asset value and offering price per share – Class C (b)	$	25.92		$	35.73		$	25.99		$	25.32
(Net assets/shares)		($749,753/28,929)			($92,746/2,596)			($31,666/1,218)			($8,585/339)
Net asset value and offering price per share – Class I (d)	$	29.76		$	37.13		$	29.75		$	26.88
(Net assets/shares)		($32,680/1,098)			($62,855/1,693)			($618/21)		($	3/—	(e))
Net asset value and offering price per share – Class R	$	—		$	36.97		$	—		$	—
(Net assets/shares)	($	—/—	)		($961/26)		($	—/—	)	($	—/—	)
Net asset value and offering price per share – Class R5	$	—		$	37.10		$	—		$	—
(Net assets/shares)	($	—/—	)		($2,179/59)		($	—/—	)	($	—/—	)
Net asset value and offering price per share – Class Z (d)	$	29.74		$	37.10		$	29.72		$	26.88
(Net assets/shares)		($13,046,746/438,699)			($4,919,716/132,598)			($1,396,425/46,989)			($270,900/10,078)

(a)  Rounds to less than $500.

(b)  Redemption price per share is equal to net asset value less any applicable contingent deferred sales charge.

(c)  On sales of $50,000 or more the offering price is reduced.

(d)  Redemption price per share is equal to net asset value.

(e)  Rounds to less than 500 shares.

See accompanying notes to financial statements.

90

June 30, 2012	Columbia Acorn Select			Columbia Thermostat Fund			Columbia Acorn Emerging Markets Fund			Columbia Acorn European Fund
(in thousands)
Assets:
Unaffiliated investments, at cost	$	709,773		$	—		$	5,608		$	1,880
Affiliated investments, at cost (See Note 4)		152,247			404,568			—			—
Unaffiliated investments, at value (including securities on loan: Columbia Acorn Fund $302,684; Columbia Acorn International $110,353; Columbia Acorn USA $52,943; Columbia Acorn International Select $—; Columbia Acorn Select $25,542; Columbia Thermostat Fund $—; Columbia Acorn Emerging Markets Fund $105; Columbia Acorn European Fund $6)	$	1,037,312		$	—		$	5,694		$	1,963
Affiliated investments, at value (See Note 4)		65,984			429,478			—			—
Cash		19,892			4,565			219			153
Foreign currency (cost: Columbia Acorn Fund $—; Columbia Acorn International $978; Columbia Acorn USA $—; Columbia Acorn International Select $183; Columbia Acorn Select $—; Columbia Thermostat Fund $—; Columbia Acorn Emerging Markets Fund $1; Columbia Acorn European Fund $—)		—			—			1			—
Receivable for:
Investments sold		1,867			—			2			38
Fund shares sold		677			9,061			10			—
Dividends and interest		670			1,251			9			1
Securities lending income		290			—			—	(a)		—	(a)
Foreign tax reclaims		—			—			1			2
Expense reimbursement due from Advisor		—			—	(a)		—			—
Trustees' Deferred Compensation Investments		237			—			—			—
Other assets		6			—	(a)		8			8
Total Assets		1,126,935			444,355			5,944			2,165
Liabilities:
Collateral on securities loaned		26,067			—			105			6
Unrealized depreciation on forward foreign currency exchange contracts		—			—			—			—
Payable to advisor		—			—			8			7
Payable for:
Investments purchased		—			3,645			18			11
Fund shares redeemed		1,180			591			—			—
Management fee		24			1			—	(a)		—	(a)
Administration fee		1			1			—	(a)		—	(a)
12b-1 Service and Distribution fees		4			4			—	(a)		—	(a)
Reports to shareholders		122			8			10			10
Deferred Trustees' fees		237			—			—			—
Transfer agent fees		124			23			—	(a)		—	(a)
Trustees' fees		1			23			—	(a)		—	(a)
Custody fees		2			—	(a)		11			5
Professional fee		38			8			12			15
Chief compliance officer expenses		6			—			—	(a)		—	(a)
Deferred foreign capital gains tax payable		—			—			4			—
Other liabilities		9			—			4			5
Total Liabilities		27,815			4,304			172			59
Net Assets	$	1,099,120		$	440,051		$	5,772		$	2,106
Composition of Net Assets:
Paid-in capital	$	820,730		$	434,121		$	5,754		$	2,021
Undistributed (overdistributed) net investment income		(2,288	)		2,831			10			23
Accumulated net realized gain (loss)		39,399			(21,811	)		(74	)		(21	)
Net unrealized appreciation (depreciation) on:
Unaffiliated investments		327,539			—			86			83
Affiliated investments		(86,263	)		24,910			—			—
Foreign currency translations		3			—			—	(a)		—	(a)
Forward foreign currency exchange contracts		—			—			—			—
Foreign capital gains tax		—			—			(4	)		—
Net Assets	$	1,099,120		$	440,051		$	5,772		$	2,106
Net asset value per share – Class A (b)	$	24.17		$	13.65		$	10.15		$	10.50
(Net assets/shares)		($303,485/12,557)			($171,091/12,535)			($1,274/125)			($203/19)
Maximum offering price per share – Class A (c)	$	25.64		$	14.48		$	10.77		$	11.14
(Net asset value per share/front-end sales charge)		($24.17/0.9425)			($13.65/0.9425)			($10.15/0.9425)			($10.50/0.9425)
Net asset value and offering price per share – Class B (b)	$	22.43		$	13.71		$	—		$	—
(Net assets/shares)		($15,343/684)			($5,833/425)		($	—/—	)	($	—/—	)
Net asset value and offering price per share – Class C (b)	$	22.20		$	13.69		$	10.10		$	10.46
(Net assets/shares)		($60,556/2,728)			($111,865/8,170)			($216/21)			($18/2)
Net asset value and offering price per share – Class I (d)	$	24.96		$	—		$	10.19		$	10.51
(Net assets/shares)		($21,778/872)		($	—/—	)		($5/1)			($5/1)
Net asset value and offering price per share – Class R	$	—		$	—		$	—		$	—
(Net assets/shares)	($	—/—	)	($	—/—	)	($	—/—	)	($	—/—	)
Net asset value and offering price per share – Class R5	$	—		$	—		$	—		$	—
(Net assets/shares)	($	—/—	)	($	—/—	)	($	—/—	)	($	—/—	)
Net asset value and offering price per share – Class Z (d)	$	24.92		$	13.51		$	10.19		$	10.52
(Net assets/shares)		($697,958/28,005)			($151,262/11,198)			($4,277/420)			($1,880/178)

See accompanying notes to financial statements.

91

Columbia Acorn Family of Funds

Statements of Operations (Unaudited) For the Six Months Ended June 30, 2012

(in thousands)	Columbia Acorn Fund			Columbia Acorn International			Columbia Acorn USA			Columbia Acorn International Select
Investment Income:
Dividend income	$	68,183		$	86,067		$	5,295		$	5,357
Dividend income from affiliates (See Note 4)		9,504			2,251			—			—
Interest income		—	(a)		—	(a)		—			3
Securities lending income, net		4,039			707			536			15
Dividends from affiliated investment company shares		—			—			—			—
		81,726			89,025			5,831			5,375
Foreign taxes withheld		(1,840	)		(8,503	)		(7	)		(469	)
Total Investment Income		79,886			80,522			5,824			4,906
Expenses:
Management fee		56,115			22,639			7,167			1,578
Administration fee		3,398			1,155			323			65
12b-1 Service and Distribution fees:
Class A		4,288			1,203			214			72
Class B		219			89			7			6
Class C		3,851			491			162			44
Class R		—			2			—			—
Transfer agent fees:
Class A		1,487			758			84			38
Class B		53			48			3			2
Class C		339			71			15			7
Class R		—			1			—			—
Class R5		—			—	(a)		—			—
Class Z		2,916			1,058			560			74
Custody fees		—			547			7			42
Trustees' fees		496			171			49			10
Registration and blue sky fees		109			89			55			41
Reports to shareholders		1,207			692			249			93
Audit fees		39			62			19			20
Legal fees		773			291			87			18
Interest expense (See Note 5)		—			—			—			—
Chief compliance officer expenses (See Note 4)		247			83			23			5
Organizational expenses (See Note 4)		—			—			—			—
Other expenses		355			133			36			13
Total Expenses		75,892			29,583			9,060			2,128
Less reimbursement of expenses by Investment Advisor (See Note 4)		—			(206	)		—			—
Net Expenses		75,892			29,377			9,060			2,128
Net Investment Income/(Loss)		3,994			51,145			(3,236	)		2,778
Net Realized and Unrealized Gain/(Loss) on Portfolio Positions:
Net Realized Gain/(Loss) on:
Unaffiliated investments		669,444			118,555			106,876			14,604
Affiliated investments (See Note 4)		560			—			—			—
Foreign currency translations		(99	)		(1,108	)		—			(108	)
Forward foreign currency exchange contracts		—			5,423			—			210
Distributions from affiliated investment company shares		—			—			—			—
Net realized gain/(loss)		669,905			122,870			106,876			14,706
Net change in net unrealized appreciation/(depreciation) on:
Unaffiliated investments		667,791			317,503			52,933			15,607
Affiliated investments (See Note 4)		169,764			(10,385	)		231			—
Foreign currency translations		35			70			—			6
Forward foreign currency exchange contracts		—			(4,539	)		—			16
Foreign capital gains tax		—			(1,703	)		—			—
Net change in unrealized appreciation/(depreciation)		837,590			300,946			53,164			15,629
Net realized and unrealized gain		1,507,495			423,816			160,040			30,335
Net Increase in Net Assets resulting from Operations	$	1,511,489		$	474,961		$	156,804		$	33,113

(a)  Rounds to less than $500.

See accompanying notes to financial statements.

92

(in thousands)	Columbia Acorn Select			Columbia Thermostat Fund			Columbia Acorn Emerging Markets Fund			Columbia Acorn European Fund
Investment Income:
Dividend income	$	4,297		$	—		$	55		$	44
Dividend income from affiliates (See Note 4)		—			—			—			—
Interest income		—			—			—			—	(a)
Securities lending income, net		1,292			—			—	(a)		—	(a)
Dividends from affiliated investment company shares		—			3,776			—			—
		5,589			3,776			55			44
Foreign taxes withheld		(47	)		—			(3	)		(5	)
Total Investment Income		5,542			3,776			52			39
Expenses:
Management fee		5,314			154			31			12
Administration fee		249			60			1			—	(a)
12b-1 Service and Distribution fees:
Class A		428			153			1			—	(a)
Class B		81			31			—			—
Class C		331			330			1			—	(a)
Class R		—			—			—			—
Transfer agent fees:
Class A		193			58			1			—	(a)
Class B		22			7			—			—
Class C		35			30			—	(a)		—	(a)
Class R		—			—			—			—
Class R5		—			—			—			—
Class Z		264			31			1			—	(a)
Custody fees		—			3			30			2
Trustees' fees		44			7			—	(a)		—	(a)
Registration and blue sky fees		52			65			56			57
Reports to shareholders		226			65			14			14
Audit fees		20			10			27			23
Legal fees		66			9			—	(a)		—	(a)
Interest expense (See Note 5)		1			—			—			—
Chief compliance officer expenses (See Note 4)		18			4			—	(a)		—	(a)
Organizational expenses (See Note 4)		—			—			23			21
Other expenses		162			10			2			3
Total Expenses		7,506			1,027			188			132
Less reimbursement of expenses by Investment Advisor (See Note 4)		—			(127	)		(149	)		(118	)
Net Expenses		7,506			900			39			14
Net Investment Income/(Loss)		(1,964	)		2,876			13			25
Net Realized and Unrealized Gain/(Loss) on Portfolio Positions:
Net Realized Gain/(Loss) on:
Unaffiliated investments		73,373			—			(19	)		(8	)
Affiliated investments (See Note 4)		(12,823	)		(2,082	)		—			—
Foreign currency translations		(8	)		—			(1	)		(1	)
Forward foreign currency exchange contracts		—			—			—			—
Distributions from affiliated investment company shares		—			1,621			—			—
Net realized gain/(loss)		60,542			(461	)		(20	)		(9	)
Net change in net unrealized appreciation/(depreciation) on:
Unaffiliated investments		34,747			—			220			169
Affiliated investments (See Note 4)		19,182			10,983			—			—
Foreign currency translations		3			—			—	(a)		—	(a)
Forward foreign currency exchange contracts		—			—			—			—
Foreign capital gains tax		—			—			(3	)		—
Net change in unrealized appreciation/(depreciation)		53,932			10,983			217			169
Net realized and unrealized gain		114,474			10,522			197			160
Net Increase in Net Assets resulting from Operations	$	112,510		$	13,398		$	210		$	185

See accompanying notes to financial statements.

93

Columbia Acorn Family of Funds

Statements of Changes in Net Assets

	Columbia Acorn Fund						Columbia Acorn International						Columbia Acorn USA						Columbia Acorn International Select
Increase (Decrease) in Net Assets	(Unaudited) Six months ended June 30,			Year ended December 31,			(Unaudited) Six months ended June 30,			Year ended December 31,			(Unaudited) Six months ended June 30,			Year ended December 31,			(Unaudited) Six months ended June 30,			Year ended December 31,
(in thousands)	2012			2011			2012			2011 (a)			2012			2011			2012			2011
Operations:
Net investment income/(loss)	$	3,994		$	(26,858	)	$	51,145		$	70,394		$	(3,236	)	$	(9,383	)	$	2,778		$	3,857
Net realized gain/(loss) on investments, foreign currency transactions, forward foreign currency exchange contracts and foreign capital gains tax		669,345			756,714			122,870			226,124			106,876			41,208			14,706			45,952
Net realized gain/(loss) on affiliated investments and distributions from affiliated investment companies and affiliated investment company shares		560			(10,817	)		—			(3,603	)		—			(512	)		—			—
Reimbursement from affiliate (See Note 4)		—			—			—			174			—			—			—			—
Net change in net unrealized appreciation/(depreciation) on investments, foreign currency translations, forward foreign currency exchange contracts and foreign capital gains tax		667,826			(1,530,794	)		311,331			(1,230,965	)		52,933			(112,790	)		15,629			(89,001	)
Net change in net unrealized appreciation/(depreciation) on affiliated investment companies and affiliated investment company shares		169,764			(43,544	)		(10,385	)		22,440			231			876			—			—
Net Increase/(Decrease) from Operations		1,511,489			(855,299	)		474,961			(915,436	)		156,804			(80,601	)		33,113			(39,192	)
Distributions to Shareholders From:
Net investment income – Class A		—			(2,049	)		(1,509	)		(21,972	)		—			—			—			(1,392	)
Net realized gain – Class A		(41,199	)		(144,445	)		—			—			(285	)		(1,096	)		(256	)		(901	)
Net investment income – Class B		—			—			—			(600	)		—			—			—			(23	)
Net realized gain – Class B		(649	)		(4,964	)		—			—			(3	)		(21	)		(7	)		(31	)
Net investment income – Class C		—			—			—			(2,369	)		—			—			—			(70	)
Net realized gain – Class C		(10,281	)		(35,291	)		—			—			(62	)		(217	)		(40	)		(150	)
Net investment income – Class I		—			(34	)		(385	)		(676	)		—			—			—			—	(c)
Net realized gain – Class I		(431	)		(670	)		—			—			(1	)		(16	)		—	(c)		—	(c)
Net investment income – Class R5		—			—			(13	)		—			—			—			—			—
Net investment income – Class Z		—			(36,823	)		(25,320	)		(131,455	)		—			—			—			(9,039	)
Net realized gain – Class Z		(154,079	)		(521,915	)		—			—			(2,401	)		(8,481	)		(1,201	)		(4,186	)
Total Distributions to Shareholders		(206,639	)		(746,191	)		(27,227	)		(157,072	)		(2,752	)		(9,831	)		(1,504	)		(15,792	)
Share Transactions:
Subscriptions – Class A		281,631			881,347			99,830			302,659			11,204			41,839			7,107			18,154
Distributions reinvested – Class A		38,957			134,125			1,446			18,983			262			993			248			2,039
Net assets of shares issued in connection with Merger – Class A		—			—			—			204,930			—			—			—			—
Redemptions – Class A		(528,484	)		(1,072,697	)		(170,050	)		(251,677	)		(37,979	)		(80,479	)		(11,843	)		(26,422	)
Net Increase/(Decrease) – Class A		(207,896	)		(57,225	)		(68,774	)		274,895			(26,513	)		(37,647	)		(4,488	)		(6,229	)
Distributions reinvested – Class B (d)		639			4,777			—	(c)		558			3			27			8			51
Net assets of shares issued in connection with Merger – Class B		—			—			—			12,517			—			—			—			—
Redemptions – Class B		(27,729	)		(215,636	)		(5,444	)		(13,183	)		(847	)		(6,779	)		(579	)		(1,017	)
Net Decrease – Class B		(27,090	)		(210,859	)		(5,444	)		(108	)		(844	)		(6,752	)		(571	)		(966	)
Subscriptions – Class C		40,316			101,181			4,825			19,819			896			2,255			363			966
Distributions reinvested – Class C		8,259			27,313			—			1,845			56			193			36			188
Net assets of shares issued in connection with Merger – Class C		—			—			—			25,563			—			—			—			—
Redemptions – Class C		(72,750	)		(154,450	)		(17,087	)		(42,187	)		(2,816	)		(5,937	)		(1,317	)		(2,975	)
Net Increase/(Decrease) – Class C		(24,175	)		(25,956	)		(12,262	)		5,040			(1,864	)		(3,489	)		(918	)		(1,821	)
Subscriptions – Class I		27,185			17,610			37,921			27,930			2,148			11,070			—			—
Distributions reinvested – Class I		431			704			385			676			1			16			—			—
Net assets of shares issued in connection with Merger – Class I		—			—			—			152,987			—			—			—			—
Redemptions – Class I		(12,325	)		(13,595	)		(30,100	)		(184,760	)		(4,296	)		(38,709	)		—			—
Net Increase/(Decrease) – Class I		15,291			4,719			8,206			(3,167	)		(2,147	)		(27,623	)		—			—

(a)  Class R and Class R5 shares reflect activity for the period August 15, 2011 (commencement of operations) through December 31, 2011.

(b)  For the period from August 19, 2011 (commencement of operations) to December 31, 2011.

(c)  Rounds to less than $500.

(d)  Presentation for fiscal year 2011 has been changed to conform to that of the current year.

See accompanying notes to financial statements.

94

	Columbia Acorn Select						Columbia Thermostat Fund						Columbia Acorn Emerging Markets Fund						Columbia Acorn European Fund
Increase (Decrease) in Net Assets	(Unaudited) Six months ended June 30,			Year ended December 31,			(Unaudited) Six months ended June 30,			Year ended December 31,			(Unaudited) Six months ended June 30,			Year ended December 31,			(Unaudited) Six months ended June 30,			Year ended December 31,
(in thousands)	2012			2011			2012			2011			2012			2011 (b)			2012			2011 (b)
Operations:
Net investment income/(loss)	$	(1,964	)	$	(7,972	)	$	2,876		$	2,784		$	13		$	1		$	25		$	(3	)
Net realized gain/(loss) on investments, foreign currency transactions, forward foreign currency exchange contracts and foreign capital gains tax		73,365			209,796			—			—			(20	)		(57	)		(9	)		6
Net realized gain/(loss) on affiliated investments and distributions from affiliated investment companies and affiliated investment company shares		(12,823	)		(66,391	)		(461	)		8,878			—			—			—			—
Reimbursement from affiliate (See Note 4)		—			—			—			—			—			—			—			—
Net change in net unrealized appreciation/(depreciation) on investments, foreign currency translations, forward foreign currency exchange contracts and foreign capital gains tax		34,750			(347,748	)		—			—			217			(135	)		169			(86	)
Net change in net unrealized appreciation/(depreciation) on affiliated investment companies and affiliated investment company shares		19,182			(112,603	)		10,983			(4,866	)		—			—			—			—
Net Increase/(Decrease) from Operations		112,510			(324,918	)		13,398			6,796			210			(191	)		185			(83	)
Distributions to Shareholders From:
Net investment income – Class A		—			(7,162	)		(201	)		(1,706	)		—			—			—	(c)		(1	)
Net realized gain – Class A		(6,620	)		—			—			—			—			—			—	(c)		—	(c)
Net investment income – Class B		—			(500	)		(8	)		(351	)		—			—			—			—
Net realized gain – Class B		(386	)		—			—			—			—			—			—			—
Net investment income – Class C		—			(672	)		(125	)		(405	)		—			—			—	(c)		—	(c)
Net realized gain – Class C		(1,438	)		—			—			—			—			—			—	(c)		—	(c)
Net investment income – Class I		—			(141	)		—			—			—	(c)		—			—	(c)		—	(c)
Net realized gain – Class I		(494	)		—			—			—			—			—			—	(c)		—	(c)
Net investment income – Class R5		—			—			—			—			—			—			—			—
Net investment income – Class Z		—			(22,715	)		(182	)		(1,460	)		(2	)		—			(2	)		(11	)
Net realized gain – Class Z		(14,894	)		—			—			—			—			—			(1	)		(3	)
Total Distributions to Shareholders		(23,832	)		(31,190	)		(516	)		(3,922	)		(2	)		—			(3	)		(15	)
Share Transactions:
Subscriptions – Class A		27,104			72,441			102,772			44,385			1,051			351			63			164
Distributions reinvested – Class A		6,159			6,307			180			1,391			—			—			—	(c)		1
Net assets of shares issued in connection with Merger – Class A		—			—			—			—			—			—			—			—
Redemptions – Class A		(91,503	)		(203,499	)		(17,032	)		(11,539	)		(86	)		(13	)		(29	)		—
Net Increase/(Decrease) – Class A		(58,240	)		(124,751	)		85,920			34,237			965			338			34			165
Distributions reinvested – Class B (d)		325			464			18			381			—			—			—			—
Net assets of shares issued in connection with Merger – Class B		—			—			—			—			—			—			—			—
Redemptions – Class B		(13,176	)		(37,412	)		(6,155	)		(18,369	)		—			—			—			—
Net Decrease – Class B		(12,851	)		(36,948	)		(6,137	)		(17,988	)		—			—			—			—
Subscriptions – Class C		1,768			3,603			79,175			15,268			79			138			13			5
Distributions reinvested – Class C		1,143			494			89			313			—			—			—	(c)		—	(c)
Net assets of shares issued in connection with Merger – Class C		—			—			—			—			—			—			—			—
Redemptions – Class C		(8,647	)		(23,948	)		(2,845	)		(4,725	)		—			(10	)		—			—
Net Increase/(Decrease) – Class C		(5,736	)		(19,851	)		76,419			10,856			79			128			13			5
Subscriptions – Class I		18,526			12,447			—			—			—			5			—			5
Distributions reinvested – Class I		494			141			—			—			—	(c)		—			—	(c)		—	(c)
Net assets of shares issued in connection with Merger – Class I		—			—			—			—			—			—			—			—
Redemptions – Class I		(8,175	)		(8,782	)		—			—			—			—			—			—
Net Increase/(Decrease) – Class I		10,845			3,806			—			—			—	(c)		5			—	(c)		5

See accompanying notes to financial statements.

95

Columbia Acorn Family of Funds

Statements of Changes in Net Assets, continued

	Columbia Acorn Fund						Columbia Acorn International						Columbia Acorn USA						Columbia Acorn International Select
Increase (Decrease) in Net Assets	(Unaudited) Six months ended June 30,			Year ended December 31,			(Unaudited) Six months ended June 30,			Year ended December 31,			(Unaudited) Six months ended June 30,			Year ended December 31,			(Unaudited) Six months ended June 30,			Year ended December 31,
(in thousands)	2012			2011			2012			2011 (a)			2012			2011			2012			2011
Subscriptions – Class R		—			—			356			370			—			—			—			—
Net assets of shares issued in connection with Merger – Class R		—			—			—			2,027			—			—			—			—
Redemptions – Class R		—			—			(1,617	)		(77	)		—			—			—			—
Net Increase/(Decrease) – Class R		—			—			(1,261	)		2,320			—			—			—			—
Subscriptions – Class R5		—			—			—	(c)		3			—			—			—			—
Distributions reinvested – Class R5		—			—			2			—			—			—			—			—
Net assets of shares issued in connection with Merger – Class R5		—			—			—			2,232			—			—			—			—
Redemptions – Class R5		—			—			(27	)		—	(c)		—			—			—			—
Net Increase/(Decrease) – Class R5		—			—			(25	)		2,235			—			—			—			—
Subscriptions – Class Z		958,888			2,172,346			681,137			965,616			109,255			349,841			19,696			45,936
Distributions reinvested – Class Z		133,961			471,639			19,181			91,324			2,158			7,534			524			5,069
Redemptions – Class Z		(1,325,932	)		(2,515,311	)		(458,986	)		(973,865	)		(204,681	)		(331,533	)		(34,101	)		(113,289	)
Net Increase/(Decrease) – Class Z		(233,083	)		128,674			241,332			83,075			(93,268	)		25,842			(13,881	)		(62,284	)
Net Increase/(Decrease) from Share Transactions		(476,953	)		(160,647	)		161,772			364,290			(124,636	)		(49,669	)		(19,858	)		(71,300	)
Increase from regulatory settlements (See Note 7)		—			—			108			108			—			—			—			—
Increase from contribution from affiliate (See Note 4)		—			—			—			—			—			—			—			—
Total Increase/(Decrease) in Net Assets		827,897			(1,762,137	)		609,614			(708,110	)		29,416			(140,101	)		11,751			(126,284	)
Net Assets:
Beginning of period		16,336,575			18,098,712			5,416,953			6,125,063			1,558,445			1,698,546			326,383			452,667
End of period	$	17,164,472		$	16,336,575		$	6,026,567		$	5,416,953		$	1,587,861		$	1,558,445		$	338,134		$	326,383
Undistributed (Overdistributed) Net Investment Income	$	(28,080	)	$	(32,074	)	$	(36,596	)	$	(60,514	)	$	(3,403	)	$	(167	)	$	(2,516	)	$	(5,294	)

(a)  Class R and Class R5 shares reflect activity for the period August 15, 2011 (commencement of operations) through December 31, 2011.

(b)  For the period from August 19, 2011 (commencement of operations) to December 31, 2011.

(c)  Rounds to less than $500.

See accompanying notes to financial statements.

96

	Columbia Acorn Select						Columbia Thermostat Fund						Columbia Acorn Emerging Markets Fund						Columbia Acorn European Fund
Increase (Decrease) in Net Assets	(Unaudited) Six months ended June 30,			Year ended December 31,			(Unaudited) Six months ended June 30,			Year ended December 31,			(Unaudited) Six months ended June 30,			Year ended December 31,			(Unaudited) Six months ended June 30,			Year ended December 31,
(in thousands)	2012			2011			2012			2011			2012			2011 (b)			2012			2011 (b)
Subscriptions – Class R		—			—			—			—			—			—			—			—
Net assets of shares issued in connection with Merger – Class R		—			—			—			—			—			—			—			—
Redemptions – Class R		—			—			—			—			—			—			—			—
Net Increase/(Decrease) – Class R		—			—			—			—			—			—			—			—
Subscriptions – Class R5		—			—			—			—			—			—			—			—
Distributions reinvested – Class R5		—			—			—			—			—			—			—			—
Net assets of shares issued in connection with Merger – Class R5		—			—			—			—			—			—			—			—
Redemptions – Class R5		—			—			—			—			—			—			—			—
Net Increase/(Decrease) – Class R5		—			—			—			—			—			—			—			—
Subscriptions – Class Z		57,480			177,362			120,997			42,102			1,290			2,949			195			1,589
Distributions reinvested – Class Z		11,596			17,488			116			1,165			2			—			3			13
Redemptions – Class Z		(283,273	)		(653,289	)		(39,753	)		(14,914	)		(1	)		—	(c)		—	(c)		—	(c)
Net Increase/(Decrease) – Class Z		(214,197	)		(458,439	)		81,360			28,353			1,291			2,949			198			1,602
Net Increase/(Decrease) from Share Transactions		(280,179	)		(636,183	)		237,562			55,458			2,335			3,420			245			1,777
Increase from regulatory settlements (See Note 7)		—			—			—			—			—			—			—			—
Increase from contribution from affiliate (See Note 4)		—			57			—			—			—			—			—			—
Total Increase/(Decrease) in Net Assets		(191,501	)		(992,234	)		250,444			58,332			2,543			3,229			427			1,679
Net Assets:
Beginning of period		1,290,621			2,282,855			189,607			131,275			3,229			—			1,679			—
End of period	$	1,099,120		$	1,290,621		$	440,051		$	189,607		$	5,772		$	3,229		$	2,106		$	1,679
Undistributed (Overdistributed) Net Investment Income	$	(2,288	)	$	(324	)	$	2,831		$	471		$	10		$	(1	)	$	23		$	—	(c)

See accompanying notes to financial statements.

97

Columbia Acorn Family of Funds

Statements of Changes in Net Assets, continued

	Columbia Acorn Fund						Columbia Acorn International						Columbia Acorn USA						Columbia Acorn International Select
Changes in Shares of Beneficial Interest:	(Unaudited) Six months ended June 30,			Year ended December 31,			(Unaudited) Six months ended June 30,			Year ended December 31,			(Unaudited) Six months ended June 30,			Year ended December 31,			(Unaudited) Six months ended June 30,			Year ended December 31,
(in thousands)	2012			2011			2012			2011 (a)			2012			2011			2012			2011
Subscriptions – Class A		9,628			30,309			2,671			7,713			391			1,507			274			666
Shares issued in reinvestment and capital gains – Class A		1,388			4,849			40			463			9			38			9			78
Shares issued in connection with merger – Class A		—			—			—			5,467			—			—			—			—
Less shares redeemed – Class A		(18,258	)		(37,725	)		(4,553	)		(6,592	)		(1,318	)		(2,879	)		(454	)		(980	)
Net Increase/(Decrease) – Class A		(7,242	)		(2,567	)		(1,842	)		7,051			(918	)		(1,334	)		(171	)		(236	)
Shares issued in reinvestment and capital gains – Class B (d)		25			185			—			14			—	(c)		1			—	(c)		2
Shares issued in connection with merger – Class B		—			—			—			343			—			—			—			—
Less shares redeemed – Class B		(1,030	)		(8,046	)		(151	)		(353	)		(32	)		(267	)		(23	)		(39	)
Net Increase/(Decrease) – Class B		(1,005	)		(7,861	)		(151	)		4			(32	)		(266	)		(23	)		(37	)
Subscriptions – Class C		1,516			3,779			134			519			34			90			14			36
Shares issued in reinvestment and capital gains – Class C		325			1,086			—			46			2			8			1			8
Shares issued in connection with merger – Class C		—			—			—			703			—			—			—			—
Less shares redeemed – Class C		(2,746	)		(5,913	)		(484	)		(1,110	)		(107	)		(231	)		(52	)		(115	)
Net Increase/(Decrease) – Class C		(905	)		(1,048	)		(350	)		158			(71	)		(133	)		(37	)		(71	)
Subscriptions – Class I		901			639			1,013			764			70			371			—			—
Shares issued in reinvestment and capital gains – Class I		15			25			11			17			—	(c)		1			—			—
Shares issued in connection with merger – Class I		—			—			—			4,062			—			—			—			—
Less shares redeemed – Class I		(413	)		(454	)		(797	)		(5,004	)		(147	)		(1,289	)		—			—
Net Increase/(Decrease) – Class I		503			210			227			(161	)		(77	)		(917	)		—			—
Subscriptions – Class R		—			—			10			10			—			—			—			—
Shares issued in connection with merger – Class R		—			—			—			54			—			—			—			—
Less shares redeemed – Class R		—			—			(46	)		(2	)		—			—			—			—
Net Increase/(Decrease) – Class R		—			—			(36	)		62			—			—			—			—
Subscriptions – Class R5		—			—			—	(c)		—	(c)		—			—			—			—
Shares issued in reinvestment and capital gains – Class R5		—			—			—	(c)		—			—			—			—			—
Shares issued in connection with merger – Class R5		—			—			—			59			—			—			—			—
Less shares redeemed – Class R5		—			—			—	(c)		—			—			—			—			—
Net Increase – Class R5		—			—			—	(c)		59			—			—			—			—
Subscriptions – Class Z		31,901			72,817			18,269			24,482			3,627			12,164			743			1,655
Shares issued in reinvestment and capital gains – Class Z		4,605			16,442			535			2,222			75			274			20			192
Less shares redeemed – Class Z		(43,613	)		(85,040	)		(12,206	)		(25,537	)		(6,966	)		(11,564	)		(1,298	)		(4,157	)
Net Increase/(Decrease) – Class Z		(7,107	)		4,219			6,598			1,167			(3,264	)		874			(535	)		(2,310	)
Net Increase/(Decrease) in Shares of Beneficial Interest		(15,756	)		(7,047	)		4,446			8,340			(4,362	)		(1,776	)		(766	)		(2,654	)

(a)  Class R and Class R5 shares reflect activity for the period August 15, 2011 (commencement of operations) through December 31, 2011.

(b)  For the period from August 19, 2011 (commencement of operations) to December 31, 2011.

(c)  Rounds to less than 500 shares.

(d)  Presentation for fiscal year 2011 has been changed to conform to that of the current year.

See accompanying notes to financial statements.

98

	Columbia Acorn Select						Columbia Thermostat Fund						Columbia Acorn Emerging Markets Fund						Columbia Acorn European Fund
Changes in Shares of Beneficial Interest:	(Unaudited) Six months ended June 30,			Year ended December 31,			(Unaudited) Six months ended June 30,			Year ended December 31,			(Unaudited) Six months ended June 30,			Year ended December 31,			(Unaudited) Six months ended June 30,			Year ended December 31,
(in thousands)	2012			2011			2012			2011			2012			2011 (b)			2012			2011 (b)
Subscriptions – Class A		1,056			2,804			7,563			3,467			97			37			6			16
Shares issued in reinvestment and capital gains – Class A		256			242			13			109			—			—			—	(c)		—	(c)
Shares issued in connection with merger – Class A		—			—			—			—			—			—			—			—
Less shares redeemed – Class A		(3,581	)		(8,092	)		(1,260	)		(898	)		(8	)		(1	)		(3	)		—
Net Increase/(Decrease) – Class A		(2,269	)		(5,046	)		6,316			2,678			89			36			3			16
Shares issued in reinvestment and capital gains – Class B (d)		14			19			1			30			—			—			—			—
Shares issued in connection with merger – Class B		—			—			—			—			—			—			—			—
Less shares redeemed – Class B		(551	)		(1,569	)		(453	)		(1,427	)		—			—			—			—
Net Increase/(Decrease) – Class B		(537	)		(1,550	)		(452	)		(1,397	)		—			—			—			—
Subscriptions – Class C		75			145			5,788			1,196			7			15			1			1
Shares issued in reinvestment and capital gains – Class C		52			21			7			24			—			—			—	(c)		—	(c)
Shares issued in connection with merger – Class C		—			—			—			—			—			—			—			—
Less shares redeemed – Class C		(365	)		(1,011	)		(210	)		(368	)		—			(1	)		—			—
Net Increase/(Decrease) – Class C		(238	)		(845	)		5,585			852			7			14			1			1
Subscriptions – Class I		708			520			—			—			—			1			—			1
Shares issued in reinvestment and capital gains – Class I		20			5			—			—			—			—			—	(c)		—	(c)
Shares issued in connection with merger – Class I		—			—			—			—			—			—			—			—
Less shares redeemed – Class I		(319	)		(335	)		—			—			—			—			—			—
Net Increase/(Decrease) – Class I		409			190			—			—			—			1			—	(c)		1
Subscriptions – Class R		—			—			—			—			—			—			—			—
Shares issued in connection with merger – Class R		—			—			—			—			—			—			—			—
Less shares redeemed – Class R		—			—			—			—			—			—			—			—
Net Increase/(Decrease) – Class R		—			—			—			—			—			—			—			—
Subscriptions – Class R5		—			—			—			—			—			—			—			—
Shares issued in reinvestment and capital gains – Class R5		—			—			—			—			—			—			—			—
Shares issued in connection with merger – Class R5		—			—			—			—			—			—			—			—
Less shares redeemed – Class R5		—			—			—			—			—			—			—			—
Net Increase – Class R5		—			—			—			—			—			—			—			—
Subscriptions – Class Z		2,182			6,576			8,991			3,338			122			298			17			159
Shares issued in reinvestment and capital gains – Class Z		467			654			9			92			—	(c)		—			—	(c)		2
Less shares redeemed – Class Z		(10,647	)		(25,141	)		(2,944	)		(1,192	)		—	(c)		—	(c)		—	(c)		—	(c)
Net Increase/(Decrease) – Class Z		(7,998	)		(17,911	)		6,056			2,238			122			298			17			161
Net Increase/(Decrease) in Shares of Beneficial Interest		(10,633	)		(25,162	)		17,505			4,371			218			349			21			179

See accompanying notes to financial statements.

99

Columbia Acorn Family of Funds

Financial Highlights

Columbia Acorn Fund

Class A Shares	(Unaudited) Six months ended June 30,			Year ended December 31,
Selected data for a share outstanding throughout each period	2012			2011			2010			2009			2008			2007
Net Asset Value, Beginning of Period	$	26.63		$	29.24		$	23.98		$	17.22		$	28.87		$	29.02
Income from Investment Operations
Net investment income/(loss) (a)		(0.02	)		(0.10	)		(0.06	)		(0.02	)		(0.01	)		0.05	(b)
Net realized and unrealized gain/(loss)		2.44			(1.30	)		6.18			6.78			(10.98	)		2.13
Total from Investment Operations		2.42			(1.40	)		6.12			6.76			(10.99	)		2.18
Less Distributions to Shareholders
From net investment income		—			(0.02	)		(0.02	)		—			—			(0.03	)
From net realized gains		(0.36	)		(1.19	)		(0.84	)		—			(0.66	)		(2.30	)
Total Distributions to Shareholders		(0.36	)		(1.21	)		(0.86	)		—			(0.66	)		(2.33	)
Increase from regulatory settlements		—			—			0.00	(c)		0.00	(c)		—			—
Net Asset Value, End of Period	$	28.69		$	26.63		$	29.24		$	23.98		$	17.22		$	28.87
Total Return (d)		9.11	%(e)		(4.91	)%		25.61	%		39.26	%		(38.72	)%		7.39	%(f)(g)
Ratios to Average Net Assets/Supplemental Data
Net expenses		1.05	%(h)		1.06	%(i)		1.07	%(i)		1.07	%(i)		1.05	%(i)		1.02	%(i)
Net investment income/(loss)		(0.14	)%(h)		(0.33	)%(i)		(0.22	)%(i)		(0.12	)%(i)		(0.04	)%(i)		0.17	%(i)
Waiver/Reimbursement		—	%		—	%		—	%		—	%		—	%		0.01	%
Portfolio turnover rate		8	%(e)		18	%		28	%		27	%		21	%		20	%
Net assets at end of period (000s)	$	3,289,689		$	3,246,833		$	3,639,788		$	2,937,761		$	2,221,100		$	4,300,920

(a)  Per share data was calculated using the average shares outstanding during the period.

(b)  Net investment income per share includes special dividends. The effect of these dividends amounted to $0.03 per share.

(c)  Rounds to less than $0.01 per share.

(d)  Total return at net asset value assuming all distributions reinvested and no initial sales charge or contingent deferred sales charge.

(e)  Not annualized.

(f)  Had the Investment Manager and/or Transfer Agent not waived fees and/or reimbursed a portion of expenses, total return would have been reduced.

(g)  Total return includes a voluntary reimbursement by the Advisor for a realized investment loss due to a trading error. This reimbursement increased total return and net asset value per share by less than 0.01% and less than $0.01, respectively.

(h)  Annualized.

(i)  The benefits derived from custody fees paid indirectly had an impact of less than 0.01%.

Columbia Acorn Fund

Class B Shares	(Unaudited) Six months ended June 30,			Year ended December 31,
Selected data for a share outstanding throughout each period	2012			2011			2010			2009			2008			2007
Net Asset Value, Beginning of Period	$	24.53		$	27.14		$	22.43		$	16.21		$	27.39		$	27.78
Income from Investment Operations
Net investment loss (a)		(0.10	)		(0.27	)		(0.21	)		(0.14	)		(0.15	)		(0.11	)(b)
Net realized and unrealized gain/(loss)		2.25			(1.15	)		5.76			6.36			(10.37	)		2.02
Total from Investment Operations		2.15			(1.42	)		5.55			6.22			(10.52	)		1.91
Less Distributions to Shareholders
From net realized gains		(0.36	)		(1.19	)		(0.84	)		—			(0.66	)		(2.30	)
Total Distributions to Shareholders		(0.36	)		(1.19	)		(0.84	)		—			(0.66	)		(2.30	)
Increase from regulatory settlements		—			—			0.00	(c)		0.00	(c)		—			—
Net Asset Value, End of Period	$	26.32		$	24.53		$	27.14		$	22.43		$	16.21		$	27.39
Total Return (d)		8.78	%(e)		(5.34	)%		24.81	%		38.37	%		(39.11	)%		6.76	%(f)(g)
Ratios to Average Net Assets/Supplemental Data
Net expenses		1.65	%(h)		1.67	%(i)		1.69	%(i)		1.74	%(i)		1.65	%(i)		1.59	%(i)
Net investment loss		(0.76	)%(h)		(0.98	)%(i)		(0.88	)%(i)		(0.77	)%(i)		(0.64	)%(i)		(0.39	)%(i)
Waiver/Reimbursement		—	%		—	%		—	%		—	%		—	%		0.01	%
Portfolio turnover rate		8	%(e)		18	%		28	%		27	%		21	%		20	%
Net assets at end of period (000s)	$	45,604		$	67,153		$	287,650		$	525,072		$	581,587		$	1,270,292

(a)  Per share data was calculated using the average shares outstanding during the period.

(b)  Net investment income per share includes special dividends. The effect of these dividends amounted to $0.03 per share.

(c)  Rounds to less than $0.01 per share.

(d)  Total return at net asset value assuming all distributions reinvested and no contingent deferred sales charge.

(e)  Not annualized.

(f)  Had the Investment Manager and/or Transfer Agent not waived fees and/or reimbursed a portion of expenses, total return would have been reduced.

(g)  Total return includes a voluntary reimbursement by the Advisor for a realized investment loss due to a trading error. This reimbursement increased total return and net asset value per share by less than 0.01% and less than $0.01, respectively.

(h)  Annualized.

(i)  The benefits derived from custody fees paid indirectly had an impact of less than 0.01%.

See accompanying notes to financial statements.

100

Columbia Acorn Fund

Class C Shares	(Unaudited) Six months ended June 30,			Year ended December 31,
Selected data for a share outstanding throughout each period	2012			2011			2010			2009			2008			2007
Net Asset Value, Beginning of Period	$	24.18		$	26.85		$	22.23		$	16.09		$	27.25		$	27.70
Income from Investment Operations
Net investment loss (a)		(0.12	)		(0.29	)		(0.24	)		(0.17	)		(0.19	)		(0.18	)(b)
Net realized and unrealized gain/(loss)		2.22			(1.19	)		5.70			6.31			(10.31	)		2.03
Total from Investment Operations		2.10			(1.48	)		5.46			6.14			(10.50	)		1.85
Less Distributions to Shareholders
From net realized gains		(0.36	)		(1.19	)		(0.84	)		—			(0.66	)		(2.30	)
Total Distributions to Shareholders		(0.36	)		(1.19	)		(0.84	)		—			(0.66	)		(2.30	)
Increase from regulatory settlements		—			—			0.00	(c)		0.00	(c)		—			—
Net Asset Value, End of Period	$	25.92		$	24.18		$	26.85		$	22.23		$	16.09		$	27.25
Total Return (d)		8.70	%(e)		(5.63	)%		24.63	%		38.16	%		(39.23	)%		6.56	%(f)(g)
Ratios to Average Net Assets/Supplemental Data
Net expenses		1.80	%(h)		1.82	%(i)		1.85	%(i)		1.89	%(i)		1.83	%(i)		1.79	%(i)
Net investment loss		(0.89	)%(h)		(1.10	)%(i)		(1.00	)%(i)		(0.93	)%(i)		(0.82	)%(i)		(0.60	)%(i)
Waiver/Reimbursement		—	%		—	%		—	%		—	%		—	%		0.00	%(j)
Portfolio turnover rate		8	%(e)		18	%		28	%		27	%		21	%		20	%
Net assets at end of period (000s)	$	749,753		$	721,446		$	829,181		$	736,818		$	622,665		$	1,312,243

(a)  Per share data was calculated using the average shares outstanding during the period.

(b)  Net investment income per share includes special dividends. The effect of these dividends amounted to $0.03 per share.

(c)  Rounds to less than $0.01 per share.

(d)  Total return at net asset value assuming all distributions reinvested and no contingent deferred sales charge.

(e)  Not annualized.

(f)  Had the Investment Manager and/or Transfer Agent not waived fees and/or reimbursed a portion of expenses, total return would have been reduced.

(g)  Total return includes a voluntary reimbursement by the Advisor for a realized investment loss due to a trading error. This reimbursement increased total return and net asset value per share by less than 0.01% and less than $0.01, respectively.

(h)  Annualized.

(i)  The benefits derived from custody fees paid indirectly had an impact of less than 0.01%.

(j)  Rounds to less than 0.01%.

Columbia Acorn Fund

Class I Shares	(Unaudited) Six months ended June 30,			Year ended December 31,
Selected data for a share outstanding throughout each period	2012			2011			2010 (a)
Net Asset Value, Beginning of Period	$	27.57		$	30.19		$	26.80
Income from Investment Operations
Net investment income/(loss) (b)		0.04			0.01			(0.01	)
Net realized and unrealized gain/(loss)		2.51			(1.35	)		4.26
Total from Investment Operations		2.55			(1.34	)		4.25
Less Distributions to Shareholders
From net investment income		—			(0.09	)		(0.02	)
From net realized gains		(0.36	)		(1.19	)		(0.84	)
Total Distributions to Shareholders		(0.36	)		(1.28	)		(0.86	)
Net Asset Value, End of Period	$	29.76		$	27.57		$	30.19
Total Return (c)		9.27	%(d)		(4.57	)%		15.94	%(d)
Ratios to Average Net Assets/Supplemental Data
Net expenses		0.72	%(e)		0.72	%(f)		0.71	%(e)(f)
Net investment income/(loss)		0.24	%(e)		0.02	%(f)		(0.13	)%(e)(f)
Portfolio turnover rate		8	%(d)		18	%		28	%(d)
Net assets at end of period (000s)	$	32,680		$	16,397		$	11,627

(a)  Class I shares commenced operations on September 27, 2010. Per share data and total return reflect activity from that date.

(b)  Per share data was calculated using the average shares outstanding during the period.

(c)  Total return at net asset value assuming all distributions reinvested.

(d)  Not annualized.

(e)  Annualized.

(f)  The benefits derived from custody fees paid indirectly had an impact of less than 0.01%.

See accompanying notes to financial statements.

101

Columbia Acorn Family of Funds

Financial Highlights, continued

Columbia Acorn International

Class A Shares	(Unaudited) Six months ended June 30,			Year ended December 31,
Selected data for a share outstanding throughout each period	2012			2011			2010			2009			2008			2007
Net Asset Value, Beginning of Period	$	34.15		$	40.87		$	34.13		$	23.03		$	43.42		$	40.07
Income from Investment Operations
Net investment income (a)		0.27			0.32			0.22			0.23			0.47			0.27
Net realized and unrealized gain/(loss)		2.65			(6.02	)		7.21			11.27			(20.20	)		6.52
Reimbursement from affiliate		—			0.00	(b)		—			—			—			—
Total from Investment Operations		2.92			(5.70	)		7.43			11.50			(19.73	)		6.79
Less Distributions to Shareholders
From net investment income		(0.06	)		(1.02	)		(0.69	)		(0.41	)		(0.06	)		(0.08	)
From net realized gains		—			—			—			—			(0.60	)		(3.36	)
Total Distributions to Shareholders		(0.06	)		(1.02	)		(0.69	)		(0.41	)		(0.66	)		(3.44	)
Redemption fees added to paid in capital (a)		—			—			0.00	(b)		0.00	(b)		0.00	(b)		0.00	(b)
Increase from regulatory settlements		0.00	(b)		0.00	(b)		0.00	(b)		0.01			—			—
Net Asset Value, End of Period	$	37.01		$	34.15		$	40.87		$	34.13		$	23.03		$	43.42
Total Return (c)		8.56	%(d)		(14.37	)%(e)(f)		22.23	%		50.40	%		(46.09	)%		16.90	%(e)
Ratios to Average Net Assets/Supplemental Data
Net expenses		1.24	%(g)		1.30	%(h)		1.35	%(h)		1.36	%(h)		1.31	%(h)		1.23	%(h)
Net investment income		1.44	%(g)		0.84	%(h)		0.62	%(h)		0.85	%(h)		1.36	%(h)		0.60	%(h)
Waiver/Reimbursement		0.04	%(g)		0.02	%		—	%		—	%		—	%		0.00	%(i)
Portfolio turnover rate		18	%(d)		32	%		25	%		31	%		38	%		28	%
Net assets at end of period (000s)	$	926,998		$	918,112		$	810,603		$	578,599		$	366,820		$	622,901

(a)  Per share data was calculated using the average shares outstanding during the period.

(b)  Rounds to less than $0.01 per share.

(c)  Total return at net asset value assuming all distributions reinvested and no initial sales charge or contingent deferred sales charge.

(d)  Not annualized.

(e)  Had the Investment Manager and/or Transfer Agent not waived fees and/or reimbursed a portion of expenses, total return would have been reduced.

(f)  During the year ended December 31, 2011, Columbia Management reimbursed the Fund for a loss on a trading error. Had the Fund not received this reimbursement total return would have been lower by less than 0.01%.

(g)  Annualized.

(h)  The benefits derived from custody fees paid indirectly had an impact of less than 0.01%.

(i)  Rounds to less than 0.01%.

Columbia Acorn International

Class B Shares	(Unaudited) Six months ended June 30,			Year ended December 31,
Selected data for a share outstanding throughout each period	2012			2011			2010			2009			2008			2007
Net Asset Value, Beginning of Period	$	33.17		$	39.96		$	33.22		$	22.41		$	42.46		$	39.39
Income from Investment Operations
Net investment income (a)		0.12			0.06			0.03			0.08			0.27			0.04
Net realized and unrealized gain/(loss)		2.59			(5.85	)		7.02			10.92			(19.72	)		6.39
Increase from payments by affiliate		—			0.00	(b)		—			—			—			—
Total from Investment Operations		2.71			(5.79	)		7.05			11.00			(19.45	)		6.43
Less Distributions to Shareholders
From net investment income		—			(1.00	)		(0.31	)		(0.20	)		—			(0.00	)(b)
From net realized gains		—			—			—			—			(0.60	)		(3.36	)
Total Distributions to Shareholders		—			(1.00	)		(0.31	)		(0.20	)		(0.60	)		(3.36	)
Redemption fees added to paid in capital (a)		—			—			0.00	(b)		0.00	(b)		0.00	(b)		0.00	(b)
Increase from regulatory settlements		0.00	(b)		0.00	(b)		0.00	(b)		0.01			—			—
Net Asset Value, End of Period	$	35.88		$	33.17		$	39.96		$	33.22		$	22.41		$	42.46
Total Return (c)		8.17	%(d)		(14.92	)%(e)(f)		21.49	%		49.36	%		(46.41	)%		16.25	%(e)
Ratios to Average Net Assets/Supplemental Data
Net expenses		1.99	%(g)		1.96	%(h)		1.96	%(h)		2.03	%(h)		1.90	%(h)		1.81	%(h)
Net investment income		0.64	%(g)		0.15	%(h)		0.08	%(h)		0.29	%(h)		0.77	%(h)		0.08	%(h)
Waiver/Reimbursement		0.03	%(g)		0.02	%		—	%		—	%		—	%		0.01	%
Portfolio turnover rate		18	%(d)		32	%		25	%		31	%		38	%		28	%
Net assets at end of period (000s)	$	21,112		$	24,510		$	29,368		$	38,835		$	39,153		$	103,631

(a)  Per share data was calculated using the average shares outstanding during the period.

(b)  Rounds to less than $0.01 per share.

(c)  Total return at net asset value assuming all distributions reinvested and no contingent deferred sales charge.

(d)  Not annualized.

(e)  Had the Investment Manager and/or Transfer Agent not waived fees and/or reimbursed a portion of expenses, total return would have been reduced.

(f)  During the year ended December 31, 2011, Columbia Management reimbursed the Fund for a loss on a trading error. Had the Fund not received this reimbursement total return would have been lower by less than 0.01%.

(g)  Annualized.

(h)  The benefits derived from custody fees paid indirectly had an impact of less than 0.01%.

See accompanying notes to financial statements.

102

Columbia Acorn International

Class C Shares	(Unaudited) Six months ended June 30,			Year ended December 31,
Selected data for a share outstanding throughout each period	2012			2011			2010			2009			2008			2007
Net Asset Value, Beginning of Period	$	33.03		$	39.79		$	33.08		$	22.30		$	42.32		$	39.35
Income from Investment Operations
Net investment income/(loss) (a)		0.12			0.04			(0.05	)		0.02			0.21			(0.06	)
Net realized and unrealized gain/(loss)		2.58			(5.86	)		7.03			10.89			(19.63	)		6.39
Increase from payments by affiliate		—			0.00	(b)		—			—			—			—
Total from Investment Operations		2.70			(5.82	)		6.98			10.91			(19.42	)		6.33
Less Distributions to Shareholders
From net investment income		—			(0.94	)		(0.27	)		(0.14	)		—			(0.00	)(b)
From net realized gains		—			—			—			—			(0.60	)		(3.36	)
Total Distributions to Shareholders		—			(0.94	)		(0.27	)		(0.14	)		(0.60	)		(3.36	)
Redemption fees added to paid in capital (a)		—			—			0.00	(b)		0.00	(b)		0.00	(b)		0.00	(b)
Increase from regulatory settlements		0.00	(b)		0.00	(b)		0.00	(b)		0.01			—			—
Net Asset Value, End of Period	$	35.73		$	33.03		$	39.79		$	33.08		$	22.30		$	42.32
Total Return (c)		8.17	%(d)		(15.02	)%(e)(f)		21.34	%		49.12	%		(46.50	)%		16.01	%(e)
Ratios to Average Net Assets/Supplemental Data
Net expenses		1.99	%(g)		2.06	%(h)		2.11	%(h)		2.17	%(h)		2.08	%(h)		1.99	%(h)
Net investment income/(loss)		0.69	%(g)		0.10	%(h)		(0.13	)%(h)		0.07	%(h)		0.60	%(h)		(0.14	)%(h)
Waiver/Reimbursement		0.02	%(g)		0.01	%		—	%		—	%		—	%		0.00	%(i)
Portfolio turnover rate		18	%(d)		32	%		25	%		31	%		38	%		28	%
Net assets at end of period (000s)	$	92,746		$	97,328		$	110,931		$	85,625		$	62,906		$	153,416

(a)  Per share data was calculated using the average shares outstanding during the period.

(b)  Rounds to less than $0.01 per share.

(c)  Total return at net asset value assuming all distributions reinvested and no contingent deferred sales charge.

(d)  Not annualized.

(e)  Had the Investment Manager and/or Transfer Agent not waived fees and/or reimbursed a portion of expenses, total return would have been reduced.

(f)  During the year ended December 31, 2011, Columbia Management reimbursed the Fund for a loss on a trading error. Had the Fund not received this reimbursement total return would have been lower by less than 0.01%.

(g)  Annualized.

(h)  The benefits derived from custody fees paid indirectly had an impact of less than 0.01%.

(i)  Rounds to less than 0.01%.

Columbia Acorn International

Class I Shares	(Unaudited) Six months ended June 30,			Year ended December 31,
Selected data for a share outstanding throughout each period	2012			2011			2010 (a)
Net Asset Value, Beginning of Period	$	34.33		$	40.92		$	37.69
Income from Investment Operations
Net investment income (b)		0.34			0.37			0.08
Net realized and unrealized gain/(loss)		2.67			(5.94	)		3.49
Increase from payments by affiliate		—			0.00	(c)		—
Total from Investment Operations		3.01			(5.57	)		3.57
Less Distributions to Shareholders
From net investment income		(0.21	)		(1.02	)		(0.34	)
Total Distributions to Shareholders		(0.21	)		(1.02	)		(0.34	)
Redemption fees added to paid in capital (b)		—			—			0.00	(c)
Increase from regulatory settlements		0.00	(c)		0.00	(c)		—
Net Asset Value, End of Period	$	37.13		$	34.33		$	40.92
Total Return (d)		8.79	%(e)		(14.02	)%(f)		9.50	%(e)
Ratios to Average Net Assets/Supplemental Data
Net expenses		0.87	%(g)		0.91	%(h)		0.94	%(h)
Net investment income		1.82	%(g)		0.99	%(h)		0.77	%(h)
Portfolio turnover rate		18	%(e)		32	%		25	%(e)
Net assets at end of period (000s)	$	62,855		$	50,335		$	66,581

(a)  Class I shares commenced operations on September 27, 2010. Per share data and total return reflect activity from that date.

(b)  Per share data was calculated using the average shares outstanding during the period.

(c)  Rounds to less than $0.01 per share.

(d)  Total return at net asset value assuming all distributions reinvested.

(e)  Not annualized.

(f)  During the year ended December 31, 2011, Columbia Management reimbursed the Fund for a loss on a trading error. Had the Fund not received this reimbursement total return would have been lower by less than 0.01%.

(g)  Annualized.

(h)  The benefits derived from custody fees paid indirectly had an impact of less than 0.01%.

See accompanying notes to financial statements.

103

Columbia Acorn Family of Funds

Financial Highlights, continued

Columbia Acorn International

Class R Shares	(Unaudited) Six months ended June 30,			Year ended December 31,
Selected data for a share outstanding throughout each period	2012			2011 (a)
Net Asset Value, Beginning of Period	$	34.11		$	40.11
Income from Investment Operations
Net investment income (b)		0.19			(0.00	)(c)
Net realized and unrealized gain (loss)		2.67			(6.00	)
Increase from payments by affiliate		—			0.00	(c)
Total from Investment Operations		2.86			(6.00	)
Increase from regulatory settlements		0.00	(c)		0.00	(c)
Net Asset Value, End of Period	$	36.97		$	34.11
Total Return (d)(e)		8.38	%		(14.96	)%
Ratios to Average Net Assets/Supplemental Data
Net expenses (f)		1.47	%		1.59	%(g)
Net investment income/(loss) (f)		1.01	%		(0.02	)%(g)
Portfolio turnover rate (e)		18	%		32	%
Net assets at end of period (000s)	$	961		$	2,130

(a)  Class R shares commenced operations on August 15, 2011. Per share data and total return reflect activity from that date.

(b)  Per share data was calculated using the average shares outstanding during the period.

(c)  Rounds to less than $0.01 per share.

(d)  Total return at net asset value assuming all distributions reinvested and no initial sales charge or contingent deferred sales charge.

(e)  Not annualized.

(f)  Annualized.

(g)  The benefits derived from custody fees paid indirectly had an impact of less than 0.01%.

Columbia Acorn International

Class R5 Shares	(Unaudited) Six months ended June 30,			Year ended December 31,
Selected data for a share outstanding throughout each period	2012			2011 (a)
Net Asset Value, Beginning of Period	$	34.31		$	40.24
Income from Investment Operations
Net investment income (b)		0.34			0.09
Net realized and unrealized gain/(loss)		2.66			(6.02	)
Increase from payments by affiliate		—			0.00	(c)
Total from Investment Operations		3.00			(5.93	)
Less Distributions to Shareholders
From net investment income		(0.21	)		—
Total Distributions to Shareholders		(0.21	)		—
Increase from regulatory settlements		0.00	(c)		0.00	(c)
Net Asset Value, End of Period	$	37.10		$	34.31
Total Return (d)(e)		8.77	%		(14.74	)%
Ratios to Average Net Assets/Supplemental Data
Net expenses (f)		0.88	%		0.91	%(g)
Net investment income (f)		1.82	%		0.65	%(g)
Portfolio turnover rate (e)		18	%		32	%
Net assets at end of period (000s)	$	2,179		$	2,038

(a)  Class R5 shares commenced operations on August 15, 2011. Per share data and total return reflect activity from that date.

(b)  Per share data was calculated using the average shares outstanding during the period.

(c)  Rounds to less than $0.01 per share.

(d)  Total return at net asset value assuming all distributions reinvested and no initial sales charge or contingent deferred sales charge.

(e)  Not annualized.

(f)  Annualized.

(g)  The benefits derived from custody fees paid indirectly had an impact of less than 0.01%.

See accompanying notes to financial statements.

104

Columbia Acorn USA

Class A Shares	(Unaudited) Six months ended June 30,			Year ended December 31,
Selected data for a share outstanding throughout each period	2012			2011			2010			2009			2008			2007
Net Asset Value, Beginning of Period	$	25.94		$	27.54		$	22.43		$	15.90		$	27.23		$	28.02
Income from Investment Operations
Net investment loss (a)		(0.09	)		(0.22	)		(0.15	)		(0.11	)		(0.14	)		(0.09	)(b)
Net realized and unrealized gain/(loss)		2.72			(1.21	)		5.26			6.64			(10.23	)		1.01
Total from Investment Operations		2.63			(1.43	)		5.11			6.53			(10.37	)		0.92
Less Distributions to Shareholders
From net realized gains		(0.05	)		(0.17	)		—			—			(0.96	)		(1.71	)
Total Distributions to Shareholders		(0.05	)		(0.17	)		—			—			(0.96	)		(1.71	)
Increase from regulatory settlements		—			—			—			0.00	(c)		—			—
Net Asset Value, End of Period	$	28.52		$	25.94		$	27.54		$	22.43		$	15.90		$	27.23
Total Return (d)		10.15	%(e)		(5.21	)%		22.78	%		41.07	%		(39.38	)%		3.18	%(f)(g)
Ratios to Average Net Assets/Supplemental Data
Net expenses		1.31	%(h)		1.30	%(i)		1.30	%(i)		1.32	%(i)		1.29	%(i)		1.25	%(i)
Net investment loss		(0.61	)%(h)		(0.78	)%(i)		(0.64	)%(i)		(0.64	)%(i)		(0.60	)%(i)		(0.29	)%(i)
Waiver/Reimbursement		—	%		—	%		—	%		—	%		—	%		0.00	%(j)
Portfolio turnover rate		8	%(e)		20	%		32	%		28	%		23	%		21	%
Net assets at end of period (000s)	$	157,525		$	167,038		$	214,097		$	178,605		$	136,597		$	245,085

(a)  Per share data was calculated using the average shares outstanding during the period.

(b)  Net investment income per share includes special dividends. The effect of these dividends amounted to $0.09 per share.

(c)  Rounds to less than $0.01 per share.

(d)  Total return at net asset value assuming all distributions reinvested and no initial sales charge or contingent deferred sales charge.

(e)  Not annualized.

(f)  Had the Investment Manager and/or Transfer Agent not waived fees and/or reimbursed a portion of expenses, total return would have been reduced.

(g)  Total return includes a voluntary reimbursement by the Advisor for a realized investment loss due to a trading error. This reimbursement increased total return and net asset value per share by less than 0.01% and less than $0.01, respectively.

(h)  Annualized.

(i)  The benefits derived from custody fees paid indirectly had an impact of less than 0.01%.

(j)  Rounds to less than 0.01%.

Columbia Acorn USA

Class B Shares	(Unaudited) Six months ended June 30,			Year ended December 31,
Selected data for a share outstanding throughout each period	2012			2011			2010			2009			2008			2007
Net Asset Value, Beginning of Period	$	23.98		$	25.60		$	20.99		$	14.98		$	25.87		$	26.87
Income from Investment Operations
Net investment loss (a)		(0.17	)		(0.37	)		(0.30	)		(0.22	)		(0.27	)		(0.25	)(b)
Net realized and unrealized gain/(loss)		2.51			(1.08	)		4.91			6.23			(9.66	)		0.96
Total from Investment Operations		2.34			(1.45	)		4.61			6.01			(9.93	)		0.71
Less Distributions to Shareholders
From net realized gains		(0.05	)		(0.17	)		—			—			(0.96	)		(1.71	)
Total Distributions to Shareholders		(0.05	)		(0.17	)		—			—			(0.96	)		(1.71	)
Increase from regulatory settlements		—			—			—			0.00	(c)		—			—
Net Asset Value, End of Period	$	26.27		$	23.98		$	25.60		$	20.99		$	14.98		$	25.87
Total Return (d)		9.77	%(e)		(5.68	)%		21.96	%		40.12	%		(39.75	)%		2.53	%(f)(g)
Ratios to Average Net Assets/Supplemental Data
Net expenses		2.01	%(h)		1.92	%(i)		1.98	%(i)		2.02	%(i)		1.92	%(i)		1.85	%(i)
Net investment loss		(1.32	)%(h)		(1.42	)%(i)		(1.37	)%(i)		(1.33	)%(i)		(1.24	)%(i)		(0.87	)%(i)
Waiver/Reimbursement		—	%		—	%		—	%		—	%		—	%		0.01	%
Portfolio turnover rate		8	%(e)		20	%		32	%		28	%		23	%		21	%
Net assets at end of period (000s)	$	1,627		$	2,253		$	9,222		$	20,903		$	23,633		$	53,820

(a)  Per share data was calculated using the average shares outstanding during the period.

(b)  Net investment income per share includes special dividends. The effect of these dividends amounted to $0.09 per share.

(c)  Rounds to less than $0.01 per share.

(d)  Total return at net asset value assuming all distributions reinvested and no contingent deferred sales charge.

(e)  Not annualized.

(f)  Had the Investment Manager and/or Transfer Agent not waived fees and/or reimbursed a portion of expenses, total return would have been reduced.

(g)  Total return includes a voluntary reimbursement by the Advisor for a realized investment loss due to a trading error. This reimbursement increased total return and net asset value per share by less than 0.01% and less than $0.01, respectively.

(h)  Annualized.

(i)  The benefits derived from custody fees paid indirectly had an impact of less than 0.01%.

See accompanying notes to financial statements.

105

Columbia Acorn Family of Funds

Financial Highlights, continued

Columbia Acorn USA

Class C Shares	(Unaudited) Six months ended June 30,			Year ended December 31,
Selected data for a share outstanding throughout each period	2012			2011			2010			2009			2008			2007
Net Asset Value, Beginning of Period	$	23.72		$	25.39		$	20.84		$	14.89		$	25.77		$	26.81
Income from Investment Operations
Net investment loss (a)		(0.18	)		(0.39	)		(0.31	)		(0.24	)		(0.30	)		(0.30	)(b)
Net realized and unrealized gain/(loss)		2.50			(1.11	)		4.86			6.19			(9.62	)		0.97
Total from Investment Operations		2.32			(1.50	)		4.55			5.95			(9.92	)		0.67
Less Distributions to Shareholders
From net realized gains		(0.05	)		(0.17	)		—			—			(0.96	)		(1.71	)
Total Distributions to Shareholders		(0.05	)		(0.17	)		—			—			(0.96	)		(1.71	)
Increase from regulatory settlements		—			—			—			0.00	(c)		—			—
Net Asset Value, End of Period	$	25.99		$	23.72		$	25.39		$	20.84		$	14.89		$	25.77
Total Return (d)		9.79	%(e)		(5.92	)%		21.83	%		39.96	%		(39.87	)%		2.39	%(f)(g)
Ratios to Average Net Assets/Supplemental Data
Net expenses		2.05	%(h)		2.05	%(i)		2.08	%(i)		2.13	%(i)		2.08	%(i)		2.03	%(i)
Net investment loss		(1.35	)%(h)		(1.53	)%(i)		(1.41	)%(i)		(1.45	)%(i)		(1.39	)%(i)		(1.07	)%(i)
Waiver/Reimbursement		—	%		—	%		—	%		—	%		—	%		0.00	%(j)
Portfolio turnover rate		8	%(e)		20	%		32	%		28	%		23	%		21	%
Net assets at end of period (000s)	$	31,666		$	30,584		$	36,101		$	32,508		$	25,899		$	50,743

(a)  Per share data was calculated using the average shares outstanding during the period.

(b)  Net investment income per share includes special dividends. The effect of these dividends amounted to $0.09 per share.

(c)  Rounds to less than $0.01 per share.

(d)  Total return at net asset value assuming all distributions reinvested and no contingent deferred sales charge.

(e)  Not annualized.

(f)  Had the Investment Manager and/or Transfer Agent not waived fees and/or reimbursed a portion of expenses, total return would have been reduced.

(g)  Total return includes a voluntary reimbursement by the Advisor for a realized investment loss due to a trading error. This reimbursement increased total return and net asset value per share by less than 0.01% and less than $0.01, respectively.

(h)  Annualized.

(i)  The benefits derived from custody fees paid indirectly had an impact of less than 0.01%.

(j)  Rounds to less than 0.01%.

Columbia Acorn USA

Class I Shares	(Unaudited) Six months ended June 30,			Year ended December 31,
Selected data for a share outstanding throughout each period	2012			2011			2010 (a)
Net Asset Value, Beginning of Period	$	27.00		$	28.56		$	24.24
Income from Investment Operations
Net investment loss (b)		(0.04	)		(0.14	)		(0.03	)
Net realized and unrealized gain/(loss)		2.84			(1.25	)		4.35
Total from Investment Operations		2.80			(1.39	)		4.32
Less Distributions to Shareholders
From net realized gains		(0.05	)		(0.17	)		—
Total Distributions to Shareholders		(0.05	)		(0.17	)		—
Net Asset Value, End of Period	$	29.75		$	27.00		$	28.56
Total Return (c)		10.38	%(d)		(4.88	)%		17.82	%(d)
Ratios to Average Net Assets/Supplemental Data
Net expenses		0.96	%(e)		0.94	%(f)		0.94	%(e)(f)
Net investment loss		(0.28	)%(e)		(0.47	)%(f)		(0.35	)%(e)(f)
Portfolio turnover rate		8	%(d)		20	%		32	%(d)
Net assets at end of period (000s)	$	618		$	2,635		$	28,993

(a)  Class I shares commenced operations on September 27, 2010. Per share data and total return reflect activity from that date.

(b)  Per share data was calculated using the average shares outstanding during the period.

(c)  Total return at net asset value assuming all distributions reinvested.

(d)  Not annualized.

(e)  Annualized.

(f)  The benefits derived from custody fees paid indirectly had an impact of less than 0.01%.

See accompanying notes to financial statements.

106

Columbia Acorn International Select

Class A Shares	(Unaudited) Six months ended June 30,			Year ended December 31,
Selected data for a share outstanding throughout each period	2012			2011			2010			2009			2008			2007
Net Asset Value, Beginning of Period	$	24.26		$	28.01		$	23.39		$	17.99		$	31.74		$	27.68
Income from Investment Operations
Net investment income (a)		0.18			0.18			0.08			0.10			0.20			0.04	(b)
Net realized and unrealized gain/(loss)		2.30			(2.95	)		4.84			5.43			(13.41	)		5.91
Total from Investment Operations		2.48			(2.77	)		4.92			5.53			(13.21	)		5.95
Less Distributions to Shareholders
From net investment income		—			(0.59	)		(0.30	)		(0.15	)		—			(0.12	)
From net realized gains		(0.12	)		(0.39	)		—			—			(0.54	)		(1.77	)
Total Distributions to Shareholders		(0.12	)		(0.98	)		(0.30	)		(0.15	)		(0.54	)		(1.89	)
Redemption fees added to paid in capital (a)		—			—			0.00	(c)		0.00	(c)		0.00	(c)		0.00	(c)
Increase from regulatory settlements		—			—			0.00	(c)		0.02			—			—
Net Asset Value, End of Period	$	26.62		$	24.26		$	28.01		$	23.39		$	17.99		$	31.74
Total Return (d)		10.23	%(e)		(10.11	)%		21.41	%		31.01	%		(42.30	)%		21.50	%(f)
Ratios to Average Net Assets/Supplemental Data
Net expenses		1.50	%(g)		1.51	%(h)		1.56	%(h)		1.56	%(h)		1.54	%(h)		1.49	%(h)
Net investment income		1.42	%(g)		0.66	%(h)		0.33	%(h)		0.53	%(h)		0.78	%(h)		0.11	%(h)
Waiver/Reimbursement		—	%		—	%		—	%		—	%		—	%		0.00	%(i)
Portfolio turnover rate		29	%(e)		44	%		42	%		56	%		68	%		57	%
Net assets at end of period (000s)	$	57,282		$	56,350		$	71,668		$	64,664		$	46,522		$	48,538

(a)  Per share data was calculated using the average shares outstanding during the period.

(b)  Net investment income per share includes special dividends. The effect of these dividends amounted to $0.07 per share.

(c)  Rounds to less than $0.01 per share.

(d)  Total return at net asset value assuming all distributions reinvested and no initial sales charge or contingent deferred sales charge.

(e)  Not annualized.

(f)  Had the Investment Manager and/or Transfer Agent not waived fees and/or reimbursed a portion of expenses, total return would have been reduced.

(g)  Annualized.

(h)  The benefits derived from custody fees paid indirectly had an impact of less than 0.01%.

(i)  Rounds to less than 0.01%.

Columbia Acorn International Select

Class B Shares	(Unaudited) Six months ended June 30,			Year ended December 31,
Selected data for a share outstanding throughout each period	2012			2011			2010			2009			2008			2007
Net Asset Value, Beginning of Period	$	23.27		$	26.72		$	22.34		$	17.16		$	30.50		$	26.73
Income from Investment Operations
Net investment income/(loss) (a)		0.10			0.01			(0.06	)		(0.01	)		0.04			(0.13	)(b)
Net realized and unrealized gain/(loss)		2.20			(2.82	)		4.62			5.17			(12.84	)		5.67
Total from Investment Operations		2.30			(2.81	)		4.56			5.16			(12.80	)		5.54
Less Distributions to Shareholders
From net investment income		—			(0.25	)		(0.18	)		—			—			—
From net realized gains		(0.12	)		(0.39	)		—			—			(0.54	)		(1.77	)
Total Distributions to Shareholders		(0.12	)		(0.64	)		(0.18	)		—			(0.54	)		(1.77	)
Redemption fees added to paid in capital (a)		—			—			0.00	(c)		0.00	(c)		0.00	(c)		0.00	(c)
Increase from regulatory settlements		—			—			0.00	(c)		0.02			—			—
Net Asset Value, End of Period	$	25.45		$	23.27		$	26.72		$	22.34		$	17.16		$	30.50
Total Return (d)		9.89	%(e)		(10.64	)%		20.63	%(f)		30.19	%(f)		(42.68	)%		20.69	%(f)
Ratios to Average Net Assets/Supplemental Data
Net expenses		2.11	%(g)		2.14	%(h)		2.20	%(h)		2.20	%(h)		2.17	%(h)		2.10	%(h)
Net investment income/(loss)		0.77	%(g)		0.04	%(h)		(0.27	)%(h)		(0.05	)%(h)		0.16	%(h)		(0.45	)%(h)
Waiver/Reimbursement		—	%		—	%		0.04	%		0.12	%		—	%		0.01	%
Portfolio turnover rate		29	%(e)		44	%		42	%		56	%		68	%		57	%
Net assets at end of period (000s)	$	1,364		$	1,774		$	3,030		$	3,887		$	4,444		$	11,941

(a)  Per share data was calculated using the average shares outstanding during the period.

(b)  Net investment income per share includes special dividends. The effect of these dividends amounted to $0.07 per share.

(c)  Rounds to less than $0.01 per share.

(d)  Total return at net asset value assuming all distributions reinvested and no contingent deferred sales charge.

(e)  Not annualized.

(f)  Had the Investment Manager and/or Transfer Agent not waived fees and/or reimbursed a portion of expenses, total return would have been reduced.

(g)  Annualized.

(h)  The benefits derived from custody fees paid indirectly had an impact of less than 0.01%.

See accompanying notes to financial statements.

107

Columbia Acorn Family of Funds

Financial Highlights, continued

Columbia Acorn International Select

Class C Shares	(Unaudited) Six months ended June 30,			Year ended December 31,
Selected data for a share outstanding throughout each period	2012			2011			2010			2009			2008			2007
Net Asset Value, Beginning of Period	$	23.17		$	26.58		$	22.21		$	17.08		$	30.42		$	26.70
Income from Investment Operations
Net investment income/(loss) (a)		0.08			(0.04	)		(0.10	)		(0.06	)		0.00	(b)		(0.20	)(c)
Net realized and unrealized gain/(loss)		2.19			(2.81	)		4.60			5.17			(12.80	)		5.69
Total from Investment Operations		2.27			(2.85	)		4.50			5.11			(12.80	)		5.49
Less Distributions to Shareholders
From net investment income		—			(0.17	)		(0.13	)		—			—			—
From net realized gains		(0.12	)		(0.39	)		—			—			(0.54	)		(1.77	)
Total Distributions to Shareholders		(0.12	)		(0.56	)		(0.13	)		—			(0.54	)		(1.77	)
Redemption fees added to paid in capital (a)		—			—			0.00	(b)		0.00	(b)		0.00	(b)		0.00	(b)
Increase from regulatory settlements		—			—			0.00	(b)		0.02			—			—
Net Asset Value, End of Period	$	25.32		$	23.17		$	26.58		$	22.21		$	17.08		$	30.42
Total Return (d)		9.81	%(e)		(10.81	)%		20.45	%		30.04	%		(42.79	)%		20.53	%(f)
Ratios to Average Net Assets/Supplemental Data
Net expenses		2.29	%(g)		2.31	%(h)		2.36	%(h)		2.42	%(h)		2.34	%(h)		2.29	%(h)
Net investment income/(loss)		0.62	%(g)		(0.14	)%(h)		(0.45	)%(h)		(0.30	)%(h)		0.01	%(h)		(0.68	)%(h)
Waiver/Reimbursement		—	%		—	%		—	%		—	%		—	%		0.01	%
Portfolio turnover rate		29	%(e)		44	%		42	%		56	%		68	%		57	%
Net assets at end of period (000s)	$	8,585		$	8,704		$	11,885		$	11,096		$	9,747		$	13,023

(a)  Per share data was calculated using the average shares outstanding during the period.

(b)  Rounds to less than $0.01 per share.

(c)  Net investment income per share includes special dividends. The effect of these dividends amounted to $0.07 per share.

(d)  Total return at net asset value assuming all distributions reinvested and no contingent deferred sales charge.

(e)  Not annualized.

(f)  Had the Investment Manager and/or Transfer Agent not waived fees and/or reimbursed a portion of expenses, total return would have been reduced.

(g)  Annualized.

(h)  The benefits derived from custody fees paid indirectly had an impact of less than 0.01%.

Columbia Acorn International Select

Class I Shares	(Unaudited) Six months ended June 30,			Year ended December 31,
Selected data for a share outstanding throughout each period	2012			2011			2010 (a)
Net Asset Value, Beginning of Period	$	24.45		$	28.33		$	26.11
Income from Investment Operations
Net investment income (b)		0.23			0.31			0.03
Net realized and unrealized gain/(loss)		2.32			(2.97	)		2.19
Total from Investment Operations		2.55			(2.66	)		2.22
Less Distributions to Shareholders
From net investment income		—			(0.83	)		—
From net realized gains		(0.12	)		(0.39	)		—
Total Distributions to Shareholders		(0.12	)		(1.22	)		—
Net Asset Value, End of Period	$	26.88		$	24.45		$	28.33
Total Return (c)		10.44	%(d)		(9.68	)%		8.50	%(d)
Ratios to Average Net Assets/Supplemental Data
Net expenses		1.14	%(e)		1.04	%(f)		1.14	%(e)(f)
Net investment income		1.78	%(e)		1.12	%(f)		0.44	%(e)(f)
Portfolio turnover rate		29	%(d)		44	%		42	%(d)
Net assets at end of period (000s)	$	3		$	2		$	3

(a)  Class I shares commenced operations on September 27, 2010. Per share data and total return reflect activity from that date.

(b)  Per share data was calculated using the average shares outstanding during the period.

(c)  Total return at net asset value assuming all distributions reinvested and no contingent deferred sales charge.

(d)  Not annualized.

(e)  Annualized.

(f)  The benefits derived from custody fees paid indirectly had an impact of less than 0.01%.

See accompanying notes to financial statements.

108

Columbia Acorn Select

Class A Shares	(Unaudited) Six months ended June 30,			Year ended December 31,
Selected data for a share outstanding throughout each period	2012			2011			2010			2009			2008			2007
Net Asset Value, Beginning of Period	$	22.95		$	27.94		$	22.81		$	13.77		$	27.89		$	26.18
Income from Investment Operations
Net investment loss (a)		(0.06	)		(0.15	)		(0.18	)		(0.14	)		(0.18	)		(0.15	)
Net realized and unrealized gain/(loss)		1.81			(4.46	)		5.31			9.18			(13.25	)		2.50
Total from Investment Operations		1.75			(4.61	)		5.13			9.04			(13.43	)		2.35
Less Distributions to Shareholders
From net investment income		—			(0.38	)		—			—			—			—
From net realized gains		(0.53	)		—			—			—			(0.69	)		(0.64	)
Total Distributions to Shareholders		(0.53	)		(0.38	)		—			—			(0.69	)		(0.64	)
Net Asset Value, End of Period	$	24.17		$	22.95		$	27.94		$	22.81		$	13.77		$	27.89
Total Return (b)		7.64	%(c)		(16.65	)%		22.49	%		65.65	%		(49.31	)%(d)		8.92	%(e)
Ratios to Average Net Assets/Supplemental Data
Net expenses before interest expense		1.32	%(f)		1.28	%(g)		1.28	%(g)		1.30	%(g)		1.24	%(g)		1.19	%(g)
Interest expense		0.00	%(f)(h)		—	%		—	%		—	%		—	%		—	%
Net expenses		1.32	%(f)		1.28	%(g)		1.28	%(g)		1.30	%(g)		1.24	%(g)		1.19	%(g)
Net investment loss		(0.45	)%(f)		(0.57	)%(g)		(0.73	)%(g)		(0.78	)%(g)		(0.80	)%(g)		(0.52	)%(g)
Waiver/Reimbursement		—	%		—	%		—	%		—	%		—	%		0.00	%(h)
Portfolio turnover rate		8	%(c)		21	%		28	%		19	%		28	%		14	%
Net assets at end of period (000s)	$	303,485		$	340,325		$	555,263		$	522,443		$	395,794		$	1,117,941

(a)  Per share data was calculated using the average shares outstanding during the period.

(b)  Total return at net asset value assuming all distributions reinvested and no initial sales charge or contingent deferred sales charge.

(c)  Not annualized.

(d)  Total return includes a voluntary reimbursement by the Advisor for a realized investment loss due to a trading error. This reimbursement increased total return and net asset value per share by less than 0.01% and less than $0.01, respectively.

(e)  Had the Investment Manager and/or Transfer Agent not waived fees and/or reimbursed a portion of expenses, total return would have been reduced.

(f)  Annualized.

(g)  The benefits derived from custody fees paid indirectly had an impact of less than 0.01%.

(h)  Rounds to less than 0.01%.

Columbia Acorn Select

Class B Shares	(Unaudited) Six months ended June 30,			Year ended December 31,
Selected data for a share outstanding throughout each period	2012			2011			2010			2009			2008			2007
Net Asset Value, Beginning of Period	$	21.40		$	26.06		$	21.41		$	13.02		$	26.57		$	25.13
Income from Investment Operations
Net investment loss (a)		(0.13	)		(0.30	)		(0.31	)		(0.24	)		(0.31	)		(0.31	)
Net realized and unrealized gain/(loss)		1.69			(4.13	)		4.96			8.63			(12.55	)		2.39
Total from Investment Operations		1.56			(4.43	)		4.65			8.39			(12.86	)		2.08
Less Distributions to Shareholders
From net investment income		—			(0.23	)		—			—			—			—
From net realized gains		(0.53	)		—			—			—			(0.69	)		(0.64	)
Total Distributions to Shareholders		(0.53	)		(0.23	)		—			—			(0.69	)		(0.64	)
Net Asset Value, End of Period	$	22.43		$	21.40		$	26.06		$	21.41		$	13.02		$	26.57
Total Return (b)		7.30	%(c)		(17.11	)%		21.72	%		64.44	%		(49.62	)%(d)		8.22	%(e)
Ratios to Average Net Assets/Supplemental Data
Net expenses before interest expense		1.90	%(f)		1.88	%(g)		1.92	%(g)		2.01	%(g)		1.87	%(g)		1.79	%(g)
Interest expense		0.00	%(f)(h)		—	%		—	%		—	%		—	%		—	%
Net expenses		1.90	%(f)		1.88	%(g)		1.92	%(g)		2.01	%(g)		1.87	%(g)		1.79	%(g)
Net investment loss		(1.08	)%(f)		(1.21	)%(g)		(1.39	)%(g)		(1.49	)%(g)		(1.43	)%(g)		(1.12	)%(g)
Waiver/Reimbursement		—	%		—	%		—	%		—	%		—	%		0.01	%
Portfolio turnover rate		8	%(c)		21	%		28	%		19	%		28	%		14	%
Net assets at end of period (000s)	$	15,343		$	26,126		$	72,203		$	88,004		$	73,152		$	199,182

(a)  Per share data was calculated using the average shares outstanding during the period.

(b)  Total return at net asset value assuming all distributions reinvested and no contingent deferred sales charge.

(c)  Not annualized.

(d)  Total return includes a voluntary reimbursement by the Advisor for a realized investment loss due to a trading error. This reimbursement increased total return and net asset value per share by less than 0.01% and less than $0.01, respectively.

(e)  Had the Investment Manager and/or Transfer Agent not waived fees and/or reimbursed a portion of expenses, total return would have been reduced.

(f)  Annualized.

(g)  The benefits derived from custody fees paid indirectly had an impact of less than 0.01%.

(h)  Rounds to less than 0.01%.

See accompanying notes to financial statements.

109

Columbia Acorn Family of Funds

Financial Highlights, continued

Columbia Acorn Select

Class C Shares	(Unaudited) Six months ended June 30,			Year ended December 31,
Selected data for a share outstanding throughout each period	2012			2011			2010			2009			2008			2007
Net Asset Value, Beginning of Period	$	21.20		$	25.83		$	21.25		$	12.94		$	26.46		$	25.07
Income from Investment Operations
Net investment loss (a)		(0.14	)		(0.32	)		(0.34	)		(0.26	)		(0.34	)		(0.36	)
Net realized and unrealized gain/(loss)		1.67			(4.12	)		4.92			8.57			(12.49	)		2.39
Total from Investment Operations		1.53			(4.44	)		4.58			8.31			(12.83	)		2.03
Less Distributions to Shareholders
From net investment income		—			(0.19	)		—			—			—			—
From net realized gains		(0.53	)		—			—			—			(0.69	)		(0.64	)
Total Distributions to Shareholders		(0.53	)		(0.19	)		—			—			(0.69	)		(0.64	)
Net Asset Value, End of Period	$	22.20		$	21.20		$	25.83		$	21.25		$	12.94		$	26.46
Total Return (b)		7.23	%(c)		(17.27	)%		21.55	%		64.22	%		(49.71	)%(d)		8.04	%(e)
Ratios to Average Net Assets/Supplemental Data
Net expenses before interest expense		2.07	%(f)		2.05	%(g)		2.07	%(g)		2.14	%(g)		2.04	%(g)		1.98	%(g)
Interest expense		0.00	%(f)(h)		—	%		—	%		—	%		—	%		—	%
Net expenses		2.07	%(f)		2.05	%(g)		2.07	%(g)		2.14	%(g)		2.04	%(g)		1.98	%(g)
Net investment loss		(1.19	)%(f)		(1.34	)%(g)		(1.52	)%(g)		(1.62	)%(g)		(1.60	)%(g)		(1.31	)%(g)
Waiver/Reimbursement		—	%		—	%		—	%		—	%		—	%		0.00	%(h)
Portfolio turnover rate		8	%(c)		21	%		28	%		19	%		28	%		14	%
Net assets at end of period (000s)	$	60,556		$	62,887		$	98,445		$	93,121		$	70,962		$	197,100

(a)  Per share data was calculated using the average shares outstanding during the period.

(b)  Total return at net asset value assuming all distributions reinvested and no contingent deferred sales charge.

(c)  Not annualized.

(d)  Total return includes a voluntary reimbursement by the Advisor for a realized investment loss due to a trading error. This reimbursement increased total return and net asset value per share by less than 0.01% and less than $0.01, respectively.

(e)  Had the Investment Manager and/or Transfer Agent not waived fees and/or reimbursed a portion of expenses, total return would have been reduced.

(f)  Annualized.

(g)  The benefits derived from custody fees paid indirectly had an impact of less than 0.01%.

(h)  Rounds to less than 0.01%.

Columbia Acorn Select

Class I Shares	(Unaudited) Six months ended June 30,			Year ended December 31,
Selected data for a share outstanding throughout each period	2012			2011			2010 (a)
Net Asset Value, Beginning of Period	$	23.65		$	28.74		$	24.74
Income from Investment Operations
Net investment income/(loss) (b)		0.00	(c)		(0.03	)		0.01
Net realized and unrealized gain/(loss)		1.84			(4.59	)		3.99
Total from Investment Operations		1.84			(4.62	)		4.00
Less Distributions to Shareholders
From net investment income		—			(0.47	)		—
From net realized gains		(0.53	)		—			—
Total Distributions to Shareholders		(0.53	)		(0.47	)		—
Net Asset Value, End of Period	$	24.96		$	23.65		$	28.74
Total Return (d)		7.79	%(e)		(16.25	)%		16.17	%(e)
Ratios to Average Net Assets/Supplemental Data
Net expenses before interest expense		0.97	%(f)		0.92	%(g)		0.91	%(f)(g)
Interest expense		0.00	%(f)(h)		—	%		—	%
Net expenses		0.97	%(f)		0.92	%(g)		0.91	%(f)(g)
Net investment income/(loss)		0.03	%(f)		(0.12	)%(g)		0.18	%(f)(g)
Portfolio turnover rate		8	%(e)		21	%		28	%(e)
Net assets at end of period (000s)	$	21,778		$	10,944		$	7,832

(a)  Class I shares commenced operations on September 27, 2010. Per share data and total return reflect activity from that date.

(b)  Per share data was calculated using the average shares outstanding during the period.

(c)  Rounds to less than $0.01 per share.

(d)  Total return at net asset value assuming all distributions reinvested.

(e)  Not annualized.

(f)  Annualized.

(g)  The benefits derived from custody fees paid indirectly had an impact of less than 0.01%.

(h)  Rounds to less than 0.01%.

See accompanying notes to financial statements.

110

Columbia Thermostat Fund

Class A Shares	(Unaudited) Six months ended June 30,			Year ended December 31,
Selected data for a share outstanding throughout each period	2012			2011			2010			2009			2008			2007
Net Asset Value, Beginning of Period	$	12.82		$	12.58		$	10.90		$	8.26		$	12.31		$	12.59
Income from Investment Operations
Net investment income (a)		0.13			0.28			0.19			0.11			0.22			0.49
Net realized and unrealized gain/(loss)		0.72			0.30			1.67			2.53			(3.98	)		0.53
Total from Investment Operations		0.85			0.58			1.86			2.64			(3.76	)		1.02
Less Distributions to Shareholders
From net investment income		(0.02	)		(0.34	)		(0.18	)		(0.00	)(b)		(0.22	)		(0.51	)
From net realized gains		—			—			—			—			(0.07	)		(0.79	)
Total Distributions to Shareholders		(0.02	)		(0.34	)		(0.18	)		(0.00	)(b)		(0.29	)		(1.30	)
Net Asset Value, End of Period	$	13.65		$	12.82		$	12.58		$	10.90		$	8.26		$	12.31
Total Return (c)(d)		6.61	%(e)		4.62	%		17.28	%		31.98	%		(30.67	)%		8.19	%
Ratios to Average Net Assets/Supplemental Data
Net expenses (f)		0.50	%(g)		0.50	%(h)		0.50	%(h)		0.50	%(h)		0.50	%(h)		0.50	%(h)
Net investment income		1.94	%(g)		2.17	%(h)		1.64	%(h)		1.17	%(h)		1.99	%(h)		3.75	%(h)
Waiver/Reimbursement		0.09	%(g)		0.17	%		0.22	%		0.28	%		0.18	%		0.18	%
Portfolio turnover rate		47	%(e)		130	%		118	%		17	%		130	%		128	%
Net assets at end of period (000s)	$	171,091		$	79,744		$	44,527		$	42,976		$	41,032		$	53,246

(a)  Per share data was calculated using the average shares outstanding during the period.

(b)  Rounds to less than $0.01 per share.

(c)  Total return at net asset value assuming all distributions reinvested and no initial sales charge or contingent deferred sales charge.

(d)  Had the Investment Manager and/or Transfer Agent not waived fees and/or reimbursed a portion of expenses, total return would have been reduced.

(e)  Not annualized.

(f)  In addition to the fees and expenses which the Fund bears directly, the Fund indirectly bears a pro rata share of the fees and expenses of the affiliated funds in which it invests. Such indirect expenses are not included in the reported expense ratios.

(g)  Annualized.

(h)  The benefits derived from custody fees paid indirectly had an impact of less than 0.01%.

Columbia Thermostat Fund

Class B Shares	(Unaudited) Six months ended June 30,			Year ended December 31,
Selected data for a share outstanding throughout each period	2012			2011			2010			2009			2008			2007
Net Asset Value, Beginning of Period	$	12.91		$	12.64		$	10.93		$	8.32		$	12.38		$	12.62
Income from Investment Operations
Net investment income (a)		0.09			0.15			0.13			0.06			0.16			0.42
Net realized and unrealized gain/(loss)		0.73			0.38			1.67			2.55			(4.00	)		0.54
Total from Investment Operations		0.82			0.53			1.80			2.61			(3.84	)		0.96
Less Distributions to Shareholders
From net investment income		(0.02	)		(0.26	)		(0.09	)		—			(0.15	)		(0.41	)
From net realized gains		—			—			—			—			(0.07	)		(0.79	)
Total Distributions to Shareholders		(0.02	)		(0.26	)		(0.09	)		—			(0.22	)		(1.20	)
Net Asset Value, End of Period	$	13.71		$	12.91		$	12.64		$	10.93		$	8.32		$	12.38
Total Return (b)(c)		6.33	%(d)		4.19	%		16.64	%		31.37	%		(31.10	)%		7.71	%
Ratios to Average Net Assets/Supplemental Data
Net expenses (e)		1.00	%(f)		1.00	%(g)		1.00	%(g)		1.00	%(g)		1.00	%(g)		1.00	%(g)
Net investment income		1.31	%(f)		1.18	%(g)		1.10	%(g)		0.64	%(g)		1.45	%(g)		3.25	%(g)
Waiver/Reimbursement		0.17	%(f)		0.23	%		0.28	%		0.32	%		0.20	%		0.19	%
Portfolio turnover rate		47	%(d)		130	%		118	%		17	%		130	%		128	%
Net assets at end of period (000s)	$	5,833		$	11,318		$	28,752		$	32,758		$	36,673		$	67,709

(a)  Per share data was calculated using the average shares outstanding during the period.

(b)  Total return at net asset value assuming all distributions reinvested and no contingent deferred sales charge.

(c)  Had the Investment Manager and/or Transfer Agent not waived fees and/or reimbursed a portion of expenses, total return would have been reduced.

(d)  Not annualized.

(e)  In addition to the fees and expenses which the Fund bears directly, the Fund indirectly bears a pro rata share of the fees and expenses of the affiliated funds in which it invests. Such indirect expenses are not included in the reported expense ratios.

(f)  Annualized.

(g)  The benefits derived from custody fees paid indirectly had an impact of less than 0.01%.

See accompanying notes to financial statements.

111

Columbia Acorn Family of Funds

Financial Highlights, continued

Columbia Thermostat Fund

Class C Shares	(Unaudited) Six months ended June 30,			Year ended December 31,
Selected data for a share outstanding throughout each period	2012			2011			2010			2009			2008			2007
Net Asset Value, Beginning of Period	$	12.91		$	12.62		$	10.91		$	8.33		$	12.37		$	12.62
Income from Investment Operations
Net investment income (a)		0.08			0.18			0.10			0.03			0.13			0.39
Net realized and unrealized gain/(loss)		0.72			0.31			1.68			2.55			(3.97	)		0.53
Total from Investment Operations		0.80			0.49			1.78			2.58			(3.84	)		0.92
Less Distributions to Shareholders
From net investment income		(0.02	)		(0.20	)		(0.07	)		—			(0.13	)		(0.38	)
From net realized gains		—			—			—			—			(0.07	)		(0.79	)
Total Distributions to Shareholders		(0.02	)		(0.20	)		(0.07	)		—			(0.20	)		(1.17	)
Net Asset Value, End of Period	$	13.69		$	12.91		$	12.62		$	10.91		$	8.33		$	12.37
Total Return (b)(c)		6.18	%(d)		3.87	%		16.43	%		30.97	%		(31.20	)%		7.36	%
Ratios to Average Net Assets/Supplemental Data
Net expenses (e)		1.25	%(f)		1.25	%(g)		1.25	%(g)		1.25	%(g)		1.25	%(g)		1.25	%(g)
Net investment income		1.22	%(f)		1.40	%(g)		0.88	%(g)		0.39	%(g)		1.23	%(g)		3.02	%(g)
Waiver/Reimbursement		0.10	%(f)		0.18	%		0.24	%		0.30	%		0.20	%		0.19	%
Portfolio turnover rate		47	%(d)		130	%		118	%		17	%		130	%		128	%
Net assets at end of period (000s)	$	111,865		$	33,378		$	21,866		$	21,090		$	24,383		$	26,908

(a)  Per share data was calculated using the average shares outstanding during the period.

(b)  Total return at net asset value assuming all distributions reinvested and no contingent deferred sales charge.

(c)  Had the Investment Manager and/or Transfer Agent not waived fees and/or reimbursed a portion of expenses, total return would have been reduced.

(d)  Not annualized.

(e)  In addition to the fees and expenses which the Fund bears directly, the Fund indirectly bears a pro rata share of the fees and expenses of the affiliated funds in which it invests. Such indirect expenses are not included in the reported expense ratios.

(f)  Annualized.

(g)  The benefits derived from custody fees paid indirectly had an impact of less than 0.01%.

Columbia Acorn Emerging Markets Fund

Class A Shares	(Unaudited) Six months ended June 30,			Year ended December 31,
Selected data for a share outstanding throughout each period	2012			2011 (a)
Net Asset Value, Beginning of Period	$	9.26		$	10.00
Income from Investment Operations
Net investment income (b)		0.03			(0.00	)(c)
Net realized and unrealized gain/(loss)		0.86			(0.74	)
Total from Investment Operations		0.89			(0.74	)
Net Asset Value, End of Period	$	10.15		$	9.26
Total Return (d)(e)(f)		9.61	%		(7.40	)%
Ratios to Average Net Assets/Supplemental Data
Net expenses (g)		1.79	%		1.85	%
Net investment income/(loss) (g)		0.53	%		(0.01	)%
Waiver/Reimbursement (g)		6.25	%		18.28	%
Portfolio turnover rate (f)		15	%		9	%
Net assets at end of period (000s)	$	1,274		$	332

(a)  Class A shares commenced operations on August 19, 2011. Per share data and total return reflect activity from that date.

(b)  Per share data was calculated using the average shares outstanding during the period.

(c)  Rounds to less than $0.01 per share.

(d)  Total return at net asset value assuming all distributions reinvested and no initial sales charge or contingent deferred sales charge.

(e)  Had the Investment Manager and/or Transfer Agent not waived fees and/or reimbursed a portion of expenses, total return would have been reduced.

(f)  Not annualized.

(g)  Annualized.

See accompanying notes to financial statements.

112

Columbia Acorn Emerging Markets Fund

Class C Shares	(Unaudited) Six months ended June 30,			Year ended December 31,
Selected data for a share outstanding throughout each period	2012			2011 (a)
Net Asset Value, Beginning of Period	$	9.24		$	10.00
Income from Investment Operations
Net investment income/(loss) (b)		(0.03	)		(0.02	)
Net realized and unrealized gain/(loss)		0.89			(0.74	)
Total from Investment Operations		0.86			(0.76	)
Net Asset Value, End of Period	$	10.10		$	9.24
Total Return (c)(d)(e)		9.31	%		(7.60	)%
Ratios to Average Net Assets/Supplemental Data
Net expenses (f)		2.55	%		2.60	%
Net investment income/(loss) (f)		(0.52	)%		(0.68	)%
Waiver/Reimbursement (f)		5.95	%		22.46	%
Portfolio turnover rate (e)		15	%		9	%
Net assets at end of period (000s)	$	216		$	127

(a)  Class C shares commenced operations on August 19, 2011. Per share data and total return reflect activity from that date.

(b)  Per share data was calculated using the average shares outstanding during the period.

(c)  Total return at net asset value assuming all distributions reinvested and no contingent deferred sales charge.

(d)  Had the Investment Manager and/or Transfer Agent not waived fees and/or reimbursed a portion of expenses, total return would have been reduced.

(e)  Not annualized.

(f)  Annualized.

Columbia Acorn Emerging Markets Fund

Class I Shares	(Unaudited) Six months ended June 30,			Year ended December 31,
Selected data for a share outstanding throughout each period	2012			2011 (a)
Net Asset Value, Beginning of Period	$	9.29		$	10.00
Income from Investment Operations
Net investment income (b)		0.02			0.01
Net realized and unrealized gain/(loss)		0.89			(0.72	)
Total from Investment Operations		0.91			(0.71	)
Less Distributions to Shareholders
From net investment income		(0.01	)		—
Total Distributions to Shareholders		(0.01	)		—
Net Asset Value, End of Period	$	10.19		$	9.29
Total Return (c)(d)(e)		9.76	%		(7.10	)%
Ratios to Average Net Assets/Supplemental Data
Net expenses (f)		1.41	%		1.41	%
Net investment income (f)		0.47	%		0.17	%
Waiver/Reimbursement (f)		5.83	%		17.90	%
Portfolio turnover rate (e)		15	%		9	%
Net assets at end of period (000s)	$	5		$	5

(a)  Class I shares commenced operations on August 19, 2011. Per share data and total return reflect activity from that date.

(b)  Per share data was calculated using the average shares outstanding during the period.

(c)  Total return at net asset value assuming all distributions reinvested and no contingent deferred sales charge.

(d)  Had the Investment Manager and/or Transfer Agent not waived fees and/or reimbursed a portion of expenses, total return would have been reduced.

(e)  Not annualized.

(f)  Annualized.

See accompanying notes to financial statements.

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Columbia Acorn Family of Funds

Financial Highlights, continued

Columbia Acorn European Fund

Class A Shares	(Unaudited) Six months ended June 30,			Year ended December 31,
Selected data for a share outstanding throughout each period	2012			2011 (a)
Net Asset Value, Beginning of Period	$	9.43		$	10.00
Income from Investment Operations
Net investment income/(loss) (b)		0.12			(0.03	)
Net realized and unrealized gain/(loss)		0.97			(0.46	)
Total from Investment Operations		1.09			(0.49	)
Less Distributions to Shareholders
From net investment income		(0.01	)		(0.06	)
From net realized gains		(0.01	)		(0.02	)
Total Distributions to Shareholders		(0.02	)		(0.08	)
Net Asset Value, End of Period	$	10.50		$	9.43
Total Return (c)(d)(e)		11.53	%		(4.97	)%
Ratios to Average Net Assets/Supplemental Data
Net expenses (f)		1.60	%		1.75	%
Net investment income/(loss) (f)		2.27	%		(0.84	)%
Waiver/Reimbursement (f)		12.28	%		31.84	%
Portfolio turnover rate (e)		18	%		17	%
Net assets at end of period (000s)	$	203		$	154

(a)  Class A shares commenced operations on August 19, 2011. Per share data and total return reflect activity from that date.

(b)  Per share data was calculated using the average shares outstanding during the period.

(c)  Total return at net asset value assuming all distributions reinvested.

(d)  Had the Investment Manager and/or Transfer Agent not waived fees and/or reimbursed a portion of expenses, total return would have been reduced.

(e)  Not annualized.

(f)  Annualized.

Columbia Acorn European Fund

Class C Shares	(Unaudited) Six months ended June 30,			Year ended December 31,
Selected data for a share outstanding throughout each period	2012			2011 (a)
Net Asset Value, Beginning of Period	$	9.44		$	10.00
Income from Investment Operations
Net investment income/(loss) (b)		0.08			(0.06	)
Net realized and unrealized gain/(loss)		0.96			(0.45	)
Total from Investment Operations		1.04			(0.51	)
Less Distributions to Shareholders
From net investment income		(0.01	)		(0.03	)
From net realized gains		(0.01	)		(0.02	)
Total Distributions to Shareholders		(0.02	)		(0.05	)
Net Asset Value, End of Period	$	10.46		$	9.44
Total Return (c)(d)(e)		10.99	%		(5.14	)%
Ratios to Average Net Assets/Supplemental Data
Net expenses (f)		2.39	%		2.50	%
Net investment income/(loss) (f)		1.48	%		(1.66	)%
Waiver/Reimbursement (f)		12.53	%		33.29	%
Portfolio turnover rate (e)		18	%		17	%
Net assets at end of period (000s)	$	18		$	5

(a)  Class C shares commenced operations on August 19, 2011. Per share data and total return reflect activity from that date.

(b)  Per share data was calculated using the average shares outstanding during the period.

(c)  Total return at net asset value assuming all distributions reinvested.

(d)  Had the Investment Manager and/or Transfer Agent not waived fees and/or reimbursed a portion of expenses, total return would have been reduced.

(e)  Not annualized.

(f)  Annualized.

See accompanying notes to financial statements.

114

Columbia Acorn European Fund

Class I Shares	(Unaudited) Six months ended June 30,			Year ended December 31,
Selected data for a share outstanding throughout each period	2012			2011 (a)
Net Asset Value, Beginning of Period	$	9.43		$	10.00
Income from Investment Operations
Net investment income/(loss) (b)		0.14			(0.02	)
Net realized and unrealized gain/(loss)		0.96			(0.46	)
Total from Investment Operations		1.10			(0.48	)
Less Distributions to Shareholders
From net investment income		(0.01	)		(0.07	)
From net realized gains		(0.01	)		(0.02	)
Total Distributions to Shareholders		(0.02	)		(0.09	)
Net Asset Value, End of Period	$	10.51		$	9.43
Total Return (c)(d)(e)		11.64	%		(4.81	)%
Ratios to Average Net Assets/Supplemental Data
Net expenses (f)		1.31	%		1.31	%
Net investment income/(loss) (f)		2.69	%		(0.47	)%
Waiver/Reimbursement (f)		12.17	%		28.69	%
Portfolio turnover rate (e)		18	%		17	%
Net assets at end of period (000s)	$	5		$	5

(a)  Class I shares commenced operations on August 19, 2011. Per share data and total return reflect activity from that date.

(b)  Per share data was calculated using the average shares outstanding during the period.

(c)  Total return at net asset value assuming all distributions reinvested.

(d)  Had the Investment Manager and/or Transfer Agent not waived fees and/or reimbursed a portion of expenses, total return would have been reduced.

(e)  Not annualized.

(f)  Annualized.

See accompanying notes to financial statements.

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Columbia Acorn Family of Funds

Notes to Financial Statements (Unaudited)

1.  Nature of Operations

Columbia Acorn Fund, Columbia Acorn International, Columbia Acorn USA, Columbia Acorn International Select, Columbia Acorn Select, Columbia Thermostat Fund, Columbia Acorn Emerging Markets Fund and Columbia Acorn European Fund (the Funds) are each a series of Columbia Acorn Trust (the Trust). The Trust is registered under the Investment Company Act of 1940, as amended (the 1940 Act), as an open-end management investment company organized as a Massachusetts business trust. The investment objective of each Fund is to seek long-term capital appreciation.

Columbia Thermostat Fund pursues its investment objective by investing in shares of other mutual funds. As a "fund of funds" under normal circumstances, the Fund allocates at least 95% of its net assets among a selected group of affiliated stock and bond mutual funds (underlying portfolio funds) according to the current level of the Standard & Poor's (S&P) 500 Index in relation to predetermined ranges set by Columbia Wanger Asset Management, LLC (the Investment Manager). The Fund may invest up to 5% of its net assets plus any cash received that day in cash, repurchase agreements, high quality short-term paper and government securities.

Each Fund may issue an unlimited number of shares. Columbia Acorn Fund, Columbia Acorn USA, Columbia Acorn International Select and Columbia Acorn Select each currently offers Class A, Class B, Class C, Class I and Class Z shares. Columbia Acorn International currently offers Class A, Class B, Class C, Class I, Class R, Class R5 and Class Z shares. Columbia Acorn Emerging Markets Fund and Columbia Acorn European Fund each currently offers Class A, Class C, Class I and Class Z shares. Columbia Thermostat Fund currently offers Class A, Class B, Class C and Class Z shares. Effective February 29, 2008, the Funds generally no longer accept investments by new or existing investors in the Fund's Class B shares, except in connection with the reinvestment of any dividend and/or capital gain distributions in Class B shares of the Funds and exchanges by existing Class B shareholders of certain other funds within the Columbia Family of Funds.

Class A shares are sold with a front-end sales charge. Class A shares bought without an initial sales charge in accounts aggregating $1 million to $50 million at the time of purchase are subject to a 1.00% contingent deferred sales charge (CDSC) if the shares are redeemed within 18 months of purchase.

Class B shares are subject to CDSC if redeemed within six years of purchase. Class B shares will convert to Class A shares automatically eight years after purchase.

Class C shares are offered at net asset value but are subject to a CDSC on redemptions made within one year after purchase.

Class I, Class R and Class R5 shares are offered at net asset value. There are certain restrictions on who may purchase Class I, Class R and Class R5 shares.

Class Z shares are offered at net asset value. There are certain restrictions on who may purchase Class Z shares. Generally, Class Z shares of a Fund may be exchanged for shares of another fund distributed by Columbia Management Distributors, Inc. at no additional charge.

The financial highlights for the Fund's Class Z shares are presented in a separate semiannual report.

Investment income, realized and unrealized gains and losses, and certain fund-level expenses are allocated pro rata on the basis of the relative net assets of all classes, except that each class bears certain expenses specific to that class such as distribution services, transfer agent fees, and certain other class specific expenses. Differences in class expenses may result in payment of different dividend distributions for each class. All of the Funds' share classes have equal rights with respect to voting, subject to Fund or class specific matters.

2.  Significant Accounting Policies

The preparation of financial statements in accordance with accounting principles generally accepted in the United States of America (GAAP) requires management to make certain estimates and assumptions that affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenue and expenses during the reporting period. Actual results could differ from those estimates.

>Security valuation

Securities of the Funds are valued at market value or, if a market quotation for a security is not readily available or is deemed not to be reliable because of events or circumstances that have occurred between the market quotation and the time as of which the security is to be valued, the security is valued at a fair value determined in good faith under consistently applied procedures established by the Board of Trustees. With respect to Columbia Thermostat Fund, investments in portfolio funds are valued at their net asset values as reported by the portfolio funds. A security traded on a securities exchange or in an over-the-counter market in which transaction prices are reported is valued at the last sales price at the time of valuation. A security traded principally on NASDAQ is valued at the

116

NASDAQ official closing price. Mutual Funds and Exchange Traded Funds are valued at their closing net asset value as reported to NASDAQ.

Short-term investments maturing in 60 days or less are valued at amortized cost, which approximates market value.

Forward foreign currency exchange contracts are marked-to-market based upon foreign currency exchange rates provided by a pricing service.

A security for which a market quotation is not readily available and any other assets are valued at their fair value determined in good faith under consistently applied procedures established by the Board of Trustees. The Trust has retained an independent statistical fair value pricing service that employs a systematic methodology to assist in the fair valuation process for securities principally traded in a foreign market in order to adjust for possible changes in value that may occur between the close of the foreign exchange and the time as of which the securities are to be valued. If a security is valued at fair value, that value may be different from the last quoted market price for the security. A security for which there is no reported sale on the valuation date is valued at the mean of the latest bid and ask quotations.

>Foreign currency translations

Values of investments denominated in foreign currencies are converted into U.S. dollars using the New York spot market rate of exchange at the time of valuation. Purchases and sales of investments and dividend and interest income are translated into U.S. dollars using the spot market rate of exchange prevailing on the respective dates of such transactions. The gain or loss resulting from changes in foreign exchange rates is included with net realized and unrealized gain or loss from investments, as appropriate.

>Repurchase agreements

Each Fund may engage in repurchase agreement transactions. Each Fund, through its custodian, receives delivery of underlying securities collateralizing repurchase agreements. The counterparty is required to maintain collateral that is at all times at least equal to the repurchase price including interest. In the event of default or bankruptcy by the counterparty to the agreement, realization and/or retention of the collateral may be subject to legal proceedings.

>Restricted securities

Restricted securities are securities that may only be resold upon registration under federal securities laws or in transactions exempt from registration. In some cases, the issuer of restricted securities has agreed to register such securities for resale at the issuer's expense either upon demand by the Fund or in connection with another registered offering of the securities. Many restricted securities may be resold in the secondary market in transactions exempt from registration. Such restricted securities may be determined to be liquid under criteria established by the Board of Trustees.

>Derivative instruments

Columbia Acorn International and Columbia Acorn International Select invest in certain derivative instruments as detailed below to meet their investment objectives. Derivatives are instruments whose values depend on, or are derived from, in whole or in part, the value of one or more other assets, such as securities, currencies, commodities or indices. Derivative instruments may be used to maintain cash reserves while maintaining exposure to certain other assets, to offset anticipated declines in values of investments, to facilitate trading, to reduce transaction costs and to pursue higher investment returns. The Funds may also use derivative instruments to mitigate certain investment risks, such as foreign currency exchange rate risk, interest rate risk and credit risk. Derivatives may involve various risks, including the potential inability of the counterparty to fulfill its obligation under the terms of the contract, the potential for an illiquid secondary market and the potential for market movements which may expose the Funds to gains or losses in excess of the amount shown in the Statements of Assets and Liabilities.

>Forward foreign currency exchange contracts

Forward foreign currency exchange contracts are agreements between two parties to buy and sell a currency at a set price on a future date. These contracts are intended to be used to minimize the exposure to foreign exchange rate fluctuations during the period between the trade and settlement dates of the contracts. Columbia Acorn International and Columbia Acorn International Select utilize forward foreign currency exchange contracts to hedge the currency exposure associated with some or all of the Fund's securities or to hedge out of a currency that is off benchmark.

The values of forward foreign currency exchange contracts fluctuate with changes in foreign currency exchange rates. Each Fund will record a realized gain or loss when the forward foreign currency exchange contract is closed.

The use of forward foreign currency exchange contracts does not eliminate fluctuations in the prices of the Funds' portfolio securities. The risks of forward foreign currency exchange contracts include movement in the values of the foreign currencies relative to the U.S. dollar (or other foreign currencies) and

117

Columbia Acorn Family of Funds

Notes to Financial Statements (Unaudited), continued

the possibility that counterparties will not complete their contractual obligations, which may be in excess of the amount reflected, if any, in the Statements of Assets and Liabilities.

>Effects of derivative transactions in the financial statements

The following tables are intended to provide additional information about the effect of derivatives on the financial statements of Columbia Acorn International and Columbia Acorn International Select including: the fair value of derivatives by risk category and the location of those fair values in the Statements of Assets and Liabilities; the impact of derivative transactions on the Funds' operations over the period including realized gains or losses and unrealized gains or losses. The derivative schedules following the Statements of Investments present additional information regarding derivative instruments outstanding at the end of the period, if any.

During the six months ended June 30, 2012, Columbia Acorn International entered into three forward foreign currency exchange contracts.

The effect of derivative instruments on Columbia Acorn International's Statement of Operations for the six months ended June 30, 2012, was as follows:

Amount of Realized Gain (Loss) and Change in Unrealized
Appreciation (Depreciation)
on Derivatives Recognized in Income

	Risk Exposure Category	Realized Gain (Loss)		Change in Unrealized Appreciation (Depreciation)
(in thousands)
Forward foreign currency exchange contracts	Foreign Exchange Rate Risk	$	5,423	$	(4,539	)

During the six months ended June 30, 2012, Columbia Acorn International Select entered into 12 forward foreign currency exchange contracts.

The following table is a summary of the value of Columbia Acorn International Select's derivative instruments as of June 30, 2012.

Liability Derivatives

Risk Exposure Category	Statement of Assets and Liabilities Location	Fair Value
(in thousands)
Foreign exchange contracts	Unrealized depreciation on forward foreign currency exchange contracts		$(932)

The effect of derivative instruments on Columbia Acorn International Select's Statement of Operations for the six months ended June 30, 2012, was as follows:

Amount of Realized Gain (Loss) and Change in Unrealized
Appreciation (Depreciation)
on Derivatives Recognized in Income

	Risk Exposure Category	Realized Gain (Loss)		Change in Unrealized Appreciation (Depreciation)
(in thousands)
Forward foreign currency exchange contracts	Foreign Exchange Rate Risk	$	210	$	16

>Security transactions and investment income

Security transactions, investment income and shareholder fund transactions are accounted for on the trade date (date the order to buy or sell is executed) and dividend income and realized gain distributions from other funds are recorded on the ex-dividend date, except that certain dividends from foreign securities are recorded as soon as the information is available to the Funds. Interest income is recorded on the accrual basis and includes amortization of discounts on debt obligations when required for federal income tax purposes. Realized gains and losses from security transactions are recorded on an identified cost basis.

Awards, if any, from class action litigation related to securities owned may be recorded as a reduction of cost of those securities. If the applicable securities are no longer owned, the proceeds are recorded as realized gains.

The Funds estimate the tax character of distributions from real estate investment trusts (REITs). Distributions received in excess of income are recorded as a reduction of the cost of the related investments. If the applicable securities are no longer owned, any distributions received in excess of income are recorded as realized gains.

>Fund share valuation

Fund shares are sold and redeemed on a daily basis at net asset value, subject to any applicable sales charge. Net asset value per share is determined daily as of the close of trading on the New York Stock Exchange (NYSE) on each day the NYSE is open for trading. Generally, income, expenses and realized and unrealized gain/(losses) of a Fund are allocated to each class proportionately on a daily basis for purposes of determining the net asset value of each class. The Rule 12b-1 distribution and service fees and transfer agent fees are charged to each specific class as expenses are incurred.

118

Redemption fees are accounted for as an addition to paid in capital for purposes of determining the net asset value of each class.

>Securities lending

Each Fund, except Columbia Thermostat Fund, may lend securities up to one-third of the value of its total assets to certain approved brokers, dealers and other financial institutions to earn additional income. The Fund retains the benefits of owning the securities, including receipt of dividends or interest generated by the security. Each Fund also receives a fee for the loan. Each Fund has the ability to recall the loans at any time and could do so in order to vote proxies or to sell the loaned securities. Each loan is collateralized by cash that exceeds the value of the securities on loan. The market value of the loaned securities is determined daily at the close of business of each Fund and any additional required collateral is delivered to each Fund on the next business day. Each Fund has elected to invest the cash collateral in the Dreyfus Government Cash Management Fund, and the income earned is paid to each Fund, net of any fees remitted to Goldman Sachs Agency Lending, the lending agent, and net of any borrower rebates. The Investment Manager does not retain any fees earned by the lending program. Generally, in the event of borrower default, a Fund has the right to use the collateral to offset any losses incurred. In the event a Fund is delayed or prevented from exercising its right to dispose of the collateral, there may be a potential loss to the Fund. Some of these losses may be indemnified by the lending agent. Each Fund bears the risk of loss with respect to the investment of collateral.

The net securities lending income earned as of June 30, 2012, by each Fund is included in the Statements of Operations.

>Federal income taxes

It is each Fund's policy to comply with the provisions of the Internal Revenue Code available to regulated investment companies and, in the manner provided therein, distribute substantially all their taxable income, as well as any net realized gain on sales of investments and foreign currency transactions reportable for federal income tax purposes. Columbia Thermostat Fund distributes all of its taxable income, as well as any net realized gain on sales of portfolio fund shares and any distributions of net realized gains received by the Fund from its portfolio funds, reportable for federal income tax purposes. Accordingly, the Funds paid no federal income taxes and no federal income tax provision was required.

>Foreign capital gains taxes

Realized gains in certain countries may be subject to foreign taxes at the fund level. The Funds accrue for such foreign taxes on net realized and unrealized gains at the appropriate rate for each jurisdiction. The amount, if any, is disclosed as a liability on the Statements of Assets and Liabilities.

>Distributions to shareholders

Distributions to shareholders are recorded on the ex-dividend date.

>Indemnification

In the normal course of business, the Trust on behalf of the Funds enters into contracts that contain a variety of representations and warranties and that provide general indemnities. A Fund's maximum exposure under these arrangements is unknown, as this would involve future claims against the Fund. Also, under the Trust's organizational documents, the trustees and officers of the Trust are indemnified against certain liabilities that may arise out of their duties to the Trust. However, based on experience, the Funds expect the risk of loss due to these warranties and indemnities to be remote.

>Recent Accounting Pronouncement

Disclosures about Offsetting Assets and Liabilities

In December 2011, the Financial Accounting Standards Board (FASB) issued ASU No. 2011-11, Disclosures about Offsetting Assets and Liabilities. The objective of the FASB is to enhance current disclosure requirements on offsetting of certain assets and liabilities and to enable financial statement users to compare financial statements prepared under GAAP and International Financial Reporting Standards.

Specifically, ASU No. 2011-11 requires an entity to disclose both gross and net information for derivatives and other financial instruments that are subject to a master netting arrangement or similar agreement. The standard requires disclosure of collateral received in connection with the master netting agreements or similar agreements. The effective date of ASU No. 2011-11 is for interim and annual periods beginning on or after January 1, 2013. At this time, management is evaluating the implications of this guidance and the impact it will have on the financial statement amounts and footnote disclosures, if any.

3.  Federal Tax Information

The timing and character of income and capital gain distributions are determined in accordance with income tax regulations, which may differ from GAAP. Reclassifications are made to the Funds' capital accounts for permanent tax

119

Columbia Acorn Family of Funds

Notes to Financial Statements (Unaudited), continued

differences to reflect income and gains available for distribution (or available capital loss carryforwards) under income tax regulations.

The following capital loss carryforward, determined as of December 31, 2011, may be available to reduce taxable income arising from future net realized gains on investments, if any, to the extent permitted by the Internal Revenue Code:

	Year of Expiration
Fund	2015		2016		2017		2018		Unlimited		Total
( in thousands)
Columbia Acorn International	$	15,640	$	82,683	$	189,008	$	—	$	—	$	287,331
Columbia Thermostat Fund		—		—		17,733		2,955		—		20,688
Columbia Acorn Emerging Markets Fund		—		—		—		—		11		11

Unlimited capital loss carryforwards are required to be utilized prior to any capital losses which carry an expiration date. As a result of this ordering rule, capital loss carryforwards which carry an expiration date may be more likely to expire unused.

Columbia Acorn International acquired capital loss carryforwards in connection with the merger with RiverSource Partners International Select Growth Fund and RiverSource Partners International Small Cap Fund of $121,174,098 and $73,618,287, respectively (Note 8). In addition to the acquired capital loss carryforwards, the Fund also acquired unrealized capital gains as a result of the merger. The yearly utilization of the acquired capital loss carryforwards may be limited by the Internal Revenue Code. Any capital loss carryforwards acquired as part of a merger that are permanently lost due to the provisions under the Internal Revenue Code are included as being expired.

Under current tax rules, regulated investment companies can elect to treat certain late-year ordinary losses incurred and post-October capital losses (capital losses realized after October 31) as arising on the first day of the following taxable year. At December 31, 2011, the Funds elected to treat the following late year ordinary losses and post-October capital losses as arising on January 1, 2012:

Fund	Late year ordinary losses		Post-October capital losses
(in thousands)
Columbia Acorn Fund	$	9,350	$	50,163
Columbia Acorn International		—		12,775
Columbia Acorn USA		—		3,057
Columbia Acorn International Select		2,622		3,120
Columbia Acorn Select		107		3,172
Columbia Acorn Emerging Markets Fund		—		42
Columbia Acorn European Fund		2		7

Management of the Funds has concluded that there are no significant uncertain tax positions that would require recognition in the financial statements. However, management's conclusion may be subject to review and adjustment at a later date based on factors including, but not limited to, new tax laws, regulations, and administrative interpretations (including relevant court decisions). Generally, the Funds' federal tax returns for the prior three fiscal years remain subject to examination by the Internal Revenue Service.

4.  Transactions With Affiliates

Columbia Wanger Asset Management, LLC (CWAM) is a wholly-owned subsidiary of Columbia Management Investment Advisers, LLC (Columbia Management), which is a wholly-owned subsidiary of Ameriprise Financial, Inc. (Ameriprise Financial). CWAM furnishes continuing investment supervision to the Funds and is responsible for the overall management of the Funds' business affairs.

CWAM receives a monthly advisory fee based on each Fund's average daily net assets at the following annual rates:

Columbia Acorn Fund

Average Daily Net Assets	Annual Fee Rate
Up to $700 million		0.74	%
$700 million to $2 billion		0.69	%
$2 billion to $6 billion		0.64	%
$6 billion and over		0.63	%

Columbia Acorn International

Average Daily Net Assets	Annual Fee Rate
Up to $100 million		1.19	%
$100 million to $500 million		0.94	%
$500 million and over		0.74	%

Columbia Acorn USA

Average Daily Net Assets	Annual Fee Rate
Up to $200 million		0.94	%
$200 million to $500 million		0.89	%
$500 million to $2 billion		0.84	%
$2 billion to $3 billion		0.80	%
$3 billion and over		0.70	%

Columbia Acorn International Select

Average Daily Net Assets		Annual Fee Rate
	Up to $500 million		0.94	%
	$500 million and over		0.90	%

Columbia Acorn Select

Average Daily Net Assets	Annual Fee Rate
Up to $700 million		0.85	%
$700 million to $2 billion		0.80	%
$2 billion to $3 billion		0.75	%
$3 billion and over		0.70	%

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Columbia Thermostat Fund

	Annual Fee Rate
All Average Daily Net Assets		0.10	%

Columbia Acorn Emerging Markets Fund

Average Daily Net Assets	Annual Fee Rate
Up to $100 million		1.25	%
$100 million to $500 million		1.00	%
$500 million and over		0.80	%

Columbia Acorn European Fund

Average Daily Net Assets	Annual Fee Rate
Up to $100 million		1.19	%
$100 million to $500 million		0.94	%
$500 million and over		0.74	%

For the six months ended June 30, 2012, the annualized effective investment advisory fee rate were as follows:

Fund
Columbia Acorn Fund	0.64	%
Columbia Acorn International	0.76	%
Columbia Acorn USA	0.86	%
Columbia Acorn International Select	0.94	%
Columbia Acorn Select	0.83	%
Columbia Thermostat Fund	0.10	%
Columbia Acorn Emerging Markets Fund	1.25	%
Columbia Acorn European Fund	1.19	%

>Expense Limit

CWAM has voluntarily agreed to reimburse the ordinary operating expenses (exclusive of brokerage commissions, interest, taxes and extraordinary expenses, but inclusive of custodial charges relating to overdrafts, if any) after giving effect to any balance credits from the Funds' custodian, exceeding annually each class' average daily net assets as follows:

Fund	Class A			Class B			Class C			Class I
Columbia Acorn International Select		1.70	%		2.20	%		2.45	%		1.28	%
Columbia Acorn Select		1.60	%		2.10	%		2.35	%		1.25	%

This arrangement may be modified or terminated by either the Funds or CWAM on 30 days notice.

CWAM has contractually agreed to waive fees and/or reimburse expenses of Columbia Thermostat Fund through April 30, 2013 so that the ordinary operating expenses (exclusive of distribution and service fees, interest and fees on borrowings, and expenses associated with the Fund's investment in other investment companies, but including custodian charges relating to overdrafts, if any) do not exceed the annual rate of 0.25% of the Fund's average daily net assets.

There is no guarantee that this arrangement will continue after April 30, 2013.

CWAM has contractually agreed to waive fees and/or reimburse expenses of Columbia Acorn Emerging Markets Fund and Columbia Acorn European Fund through April 30, 2013, so that the ordinary operating expenses (exclusive of interest and fees on borrowings, and expenses associated with each Fund's investment in other investment companies, but including custodian charges relating to overdrafts, if any), do not exceed the following annual rates based on each class' average daily net assets:

Fund	Class A			Class C			Class I
Columbia Acorn Emerging Markets Fund		1.85	%		2.60	%		1.41	%
Columbia Acorn European Fund		1.75	%		2.50	%		1.31	%

There is no guarantee that these arrangements will continue after April 30, 2013.

CWAM may recoup any fees waived and/or expenses reimbursed with respect to any share class of Columbia Acorn Emerging Markets Fund and Columbia Acorn European Fund for a one-year period following the date of such fee waiver and/or reimbursement if such recovery does not cause the Funds' ordinary operating expenses (excluding interest and fees on borrowings and expenses associated with the Funds' investment in other investment companies, if any) to exceed the annual expense limitations above, or to exceed such annual expense limitations as may be in place at the time of the recoupment, whichever is less.

Effective August 15, 2011, CWAM and its affiliates have contractually agreed to waive a portion of total annual Fund operating expenses incurred by Class A shares, Class B shares and Class C shares of Columbia Acorn International such that the Fund's total annual Fund operating expenses will be reduced by 0.04%, 0.03% and 0.02% for Class A, Class B and Class C shares of the Fund, respectively, through August 14, 2013. There is no guarantee that this arrangement will continue thereafter.

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Columbia Acorn Family of Funds

Notes to Financial Statements (Unaudited), continued

Expenses reimbursed by CWAM and its affiliates for the six months ended June 30, 2012, were as follows:

Fund	Expenses Reimbursed
(in thousands)
Columbia Acorn International Select	$	206
Columbia Thermostat Fund		127
Columbia Acorn Emerging Markets Fund		149
Columbia Acorn European Fund		118

CWAM provides administrative services and receives an administration fee from the Funds at the following annual rates:

Columbia Acorn Trust

Aggregate Average Daily Net Assets of the Trust	Annual Fee Rate
Up to $8 billion		0.050	%
$8 billion to $16 billion		0.040	%
$16 billion to $35 billion		0.030	%
$35 billion to $45 billion		0.025	%
$45 billion and over		0.015	%

For the six months ended June 30, 2012, the annualized effective administration fee rate was 0.04% of each Fund's average daily net assets. CWAM has delegated to Columbia Management responsibility to provide certain sub-administrative services to the Funds.

Columbia Management Investment Distributors, Inc. (CMID), a wholly owned subsidiary of Ameriprise Financial, is the distributor of the Funds.

Each Fund has adopted a Rule 12b-1 (distribution and service) plan which requires it to pay CMID a monthly service fee equal to 0.25% annually of the average daily net assets attributable to Class A, Class B and Class C shares and a monthly distribution fee equal to 0.50%, 0.75% and 0.50%, annually, of the average daily net assets attributable to Class B, Class C and Class R shares, respectively. CMID receives no compensation with respect to Class R5 and Class Z shares.

Columbia Management Investment Services Corp. (CMIS), a wholly owned subsidiary of Ameriprise Financial, is the transfer agent of the Funds. Effective May 1, 2012, CMIS receives monthly account-based service fees based on the number of open Fund accounts. CMIS is also reimbursed by the Funds for the fees and expenses that it pays retirement plan sponsors, defined contribution plans and 529 Plans (the Plans) or other financial intermediaries that maintain omnibus accounts with the Funds and provide record keeping services to shareholders invested through the Plans. Such fees are calculated as a percentage of the average aggregate value of each Fund's shares maintained by a Plan. CMIS is also reimbursed for the fees and expenses that it pays each fund supermarket, broker-dealer firm or other financial intermediary that maintains an omnibus accounts with a Fund. Such fees are based on the number of sub-accounts comprising the omnibus position. Each Fund paid CMIS a monthly fee at the annual rate of $17.00 per open account prior to May 1, 2012, and $20.00 per open account thereafter.

The Transfer Agent also receives compensation from fees for various shareholder services and reimbursements for certain out-of-pocket fees. Class I shares do not pay transfer agent fees.

For the six months ended June 30, 2012, the Funds' annualized effective transfer agent fee rates as a percentage of average daily net assets of each class were as follows:

Fund	Class A			Class B			Class C			Class R			Class R5
Columbia Acorn Fund		0.09	%		0.18	%		0.09	%		—			—
Columbia Acorn International		0.16	%		0.40	%		0.14	%		0.11	%		0.02	%
Columbia Acorn USA		0.10	%		0.30	%		0.09	%		—			—
Columbia Acorn International Select		0.13	%		0.24	%		0.17	%		—			—
Columbia Acorn Select		0.11	%		0.20	%		0.11	%		—			—
Columbia Thermostat Fund		0.09	%		0.18	%		0.09	%		—			—
Columbia Acorn Emerging Markets Fund		0.13	%		—			0.14	%		—			—
Columbia Acorn European Fund		0.04	%		—			0.08	%		—			—

In connection with the acquisition that closed August 15, 2011, Columbia Acorn International assumed the assets and obligations of RiverSource Partners International Small Cap Fund and RiverSource Partners International Select Growth Fund (See Note 8), which together with certain other associated investment companies, have severally, but not jointly, guaranteed the performance and observance of all the terms and conditions of a lease (including the payment of rent (the Guaranty)) entered into by Seligman Data Corp. (SDC), the former transfer agent of Seligman Global Smaller Companies Fund and Seligman International Growth Fund, which were acquired by RiverSource Partners International Small Cap Fund

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and RiverSource Partners International Select Growth Fund, respectively, in previous years. The lease and the Guaranty expire in January 2019. At June 30, 2012, Columbia Acorn International's total potential future obligation over the life of the Guaranty is $131,390. The liability remaining at June 30, 2012, for non-recurring charges associated with the lease amounted to $75,951 and is included within payable for other liabilities in the Statements of Assets and Liabilities.

Certain officers and trustees of the Trust are also officers of CWAM. The Trust makes no direct payments to its officers and trustees who are affiliated with CWAM.

The Board of Trustees has appointed a Chief Compliance Officer of the Trust in accordance with federal securities regulations. The Funds, along with other affiliated funds, pay their pro-rata share of the expenses associated with the Office of the Chief Compliance Officer. These expenses are disclosed separately as "Chief compliance officer expenses" in the Statements of Operations.

The Trust offers a deferred compensation plan for its independent trustees. Under that plan, a trustee may elect to defer all or a portion of his or her compensation. Amounts deferred are retained by the Trust and may represent an unfunded obligation of the Trust. The value of amounts deferred is determined by reference to the change in value of Class Z shares of one or more series of the Trust or a money market fund as specified by the trustee. Benefits under the deferred compensation plan are payable in accordance with the plan.

Organizational expenses for Columbia Acorn Emerging Markets Fund and Columbia Acorn European Fund consist of offering costs which were incurred prior to the initial public offering of shares of the Funds and include, among other things, state registration filing fees and printing costs. The offering costs were paid by CWAM as incurred. The Funds have capitalized these offering costs and are amortizing them to expense over a period of 12 months from the commencement of the initial public offering of shares. The Funds reimburse CWAM during the 12 month period on a monthly basis an amount equal to the offering amortized to expense by each Fund during that month.

An affiliated person of a Fund may include any company in which a Fund owns five percent or more of its outstanding voting shares. On June 30, 2012, Columbia Acorn Fund, Columbia Acorn International, Columbia Acorn USA, Columbia Acorn Select and Columbia Thermostat Fund each held five percent or more of the outstanding voting securities of one or more companies. Details of investments in those affiliated companies are presented on pages 39, 51, 60, 72 and 76, respectively.

For the six months ended June 30, 2012, the Funds engaged in purchase and sales transactions with funds that have a common investment adviser (or affiliated investment advisers), common directors/trustees, and/or common officers. Those transactions complied with Rule 17a-7 under the Investment Company Act of 1940 and were as follows:

	Purchases		Sales
(in thousands)
Columbia Acorn Fund	$	800	$	—
Columbia Acorn International		1,450		—
Columbia Acorn Select		—		1,446
Columbia Acorn Emerging Markets Fund		12		—

During the year ended December 31, 2011, Columbia Management reimbursed Columbia Acorn International $174,055 for a loss on a trading error.

During the year ended December 31, 2011, Columbia Acorn Select Class Z shares received a payment of $56,666 from Columbia Management as a reimbursement for certain shareholder transactions processed at an incorrect price. The payment has been included in "Increase from contribution from affiliate" on the Statements of Changes in Net Assets.

5.  Borrowing Arrangements

The Trust participates in a $150 million credit facility, along with another Trust managed by CWAM, which was entered into to facilitate portfolio liquidity. Under the facility, as in effect for the six months ended June 30, 2012, interest is charged to each participating fund based on its borrowings at a rate per annum equal to the higher of Federal Funds Rate or Overnight LIBOR plus 1.25%. In addition, a commitment fee of 0.10% per annum of the unutilized line of credit is accrued and apportioned among the participating funds based on their relative net assets. The commitment fee is included in "Other expenses" in the Statements of Operations. The Trust expects to renew this line of credit for one year durations annually in July at then current market rates and terms.

Except for Columbia Acorn Select, no Fund had borrowings during the six months ended June 30, 2012. For Columbia Acorn Select, the average daily loan balance outstanding on days when borrowing existed was $8,500,000 at a weighted average interest rate of 1.49%.

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Columbia Acorn Family of Funds

Notes to Financial Statements (Unaudited), continued

6.  Investment Transactions

The aggregate cost of purchases and proceeds from sales, other than short-term obligations, for the six months ended June 30, 2012, were:

Fund	Purchases		Proceeds from Sales
(in thousands)
Columbia Acorn Fund	$	1,335,545	$	2,296,276
Columbia Acorn International		1,052,221		1,021,815
Columbia Acorn USA		129,533		261,587
Columbia Acorn International Select		93,008		111,597
Columbia Acorn Select		99,446		423,716
Columbia Thermostat Fund		382,471		144,148
Columbia Acorn Emerging Markets Fund		3,240		715
Columbia Acorn European Fund		503		331

7. Regulatory Settlements with Third Parties

During the six months ended June 30, 2012, Columbia Acorn International received payments of $107,802 resulting from certain regulatory settlements with third parties in which the Fund had participated. The payments have been included in "Increase from regulatory settlements" in the Statements of Changes in Net Assets.

During the year ended December 31, 2011, Columbia Acorn International received payments of $107,617 resulting from certain regulatory settlements with third parties in which the Fund had participated. The payments have been included in "Increase from regulatory settlements" in the Statements of Changes in Net Assets.

8.  Fund Merger

On August 15, 2011, Columbia Acorn International acquired the assets and assumed the identified liabilities of RiverSource Partners International Select Growth Fund and RiverSource Partners International Small Cap Fund, both series of RiverSource International Managers Series, Inc., which were sub-advised by CWAM. The reorganization was completed after shareholders approved the plan on May 11, 2011. The purpose of the transaction was to combine funds managed by CWAM with comparable investment objectives and strategies.

The aggregate net assets of Columbia Acorn International immediately before the acquisitions were $5,887,634,436 and the combined net assets immediately after the acquisitions were $6,287,891,195.

The merger was accomplished by a tax-free exchange of 48,230,699 shares of RiverSource Partners International Select Growth Fund valued at $311,482,971 (including $29,840,736 of unrealized appreciation) and 15,801,504 shares of RiverSource Partners International Small Cap Fund valued at $88,773,788 (including $6,322,097 of unrealized appreciation).

In exchange for RiverSource Partners International Select Growth Fund and RiverSource Partners International Small Cap Fund shares, Columbia Acorn International issued the following number of shares:

	RiverSource Partners International Select Growth Fund		RiverSource Partners International Small Cap Fund
Class A		3,800,227		1,666,707
Class B		267,259		75,499
Class C		183,761		518,779
Class I		4,010,380		51,634
Class R		35,341		48,348
Class R5		5,711		23,983

For financial reporting purposes, net assets received and shares issued by Columbia Acorn International were recorded at fair value; however, RiverSource Partners International Select Growth Fund and RiverSource Partners International Small Cap Fund's cost of investments was carried forward.

The financial statements reflect the operations of Columbia Acorn International for the period prior to the merger and the combined fund for the period subsequent to the merger. Because the combined investment portfolios have been managed as a single integrated portfolio since the merger was completed, it is not practicable to separate the amounts of revenue and earnings of RiverSource Partners International Select Growth Fund and RiverSource Partners International Small Cap Fund that have been included in the combined Fund's Statement of Operations since the merger was completed.

Assuming the merger had been completed on January 1, 2011, Columbia Acorn International's pro-forma net investment income, net gain on investments, net change in unrealized depreciation and net increase in net assets from operations for the year ended December 31, 2011, would have been approximately $76.7 million, $260.0 million, $(1,274.8) million and $(938.1) million, respectively.

9.  Shareholder Concentration

At June 30, 2012, the table below details the affiliated and significant unaffiliated shareholder account ownership of outstanding shares of each Fund. The Funds have no knowledge about whether any portion of those shares was owned

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beneficially. Subscription and redemption activity of these accounts may have a significant effect on the operations of the Funds.

Fund	Number of unaffiliated accounts		Percentage of shares outstanding held – unaffiliated			Percentage of shares outstanding held – affiliated
Columbia Acorn Fund		1		11.1	%		—
Columbia Acorn International		3		38.7	%		—
Columbia Acorn USA		3		51.7	%		—
Columbia International Select		1		43.6	%		—
Columbia Acorn Select		2		26.5	%		—
Columbia Thermostat Fund		2		38.2	%		—
Columbia Acorn Emerging Markets Fund		1		17.4	%		29.7	%
Columbia Acorn European Fund		1		18.0	%		53.7	%

10.  Subsequent Events

Management has evaluated the events and transactions that have occurred through the date the financial statements were issued and noted no items requiring adjustment of the financial statements or additional disclosure.

11.  Information Regarding Pending and Settled Legal Proceedings

Ameriprise Financial and certain of its affiliates have historically been involved in a number of legal, arbitration and regulatory proceedings, including routine litigation, class actions, and governmental actions, concerning matters arising in connection with the conduct of their business activities. Ameriprise Financial believes that the Funds are not currently the subject of, and that neither Ameriprise Financial nor any of its affiliates are the subject of, any pending legal, arbitration or regulatory proceedings that are likely to have a material adverse effect on the Funds or the ability of Ameriprise Financial or its affiliates to perform under their contracts with the Funds. Ameriprise Financial is required to make 10-Q, 10-K and, as necessary, 8-K filings with the Securities and Exchange Commission on legal and regulatory matters that relate to Ameriprise Financial and its affiliates. Copies of these filings may be obtained by accessing the SEC website at www.sec.gov.

There can be no assurance that these matters, or the adverse publicity associated with them, will not result in increased fund redemptions, reduced sale of fund shares or other adverse consequences to the Funds. Further, although we believe proceedings are not likely to have a material adverse effect on the Funds or the ability of Ameriprise Financial or its affiliates to perform under their contracts with the Funds, these proceedings are subject to uncertainties and, as such, we are unable to estimate the possible loss or range of loss that may result. An adverse outcome in one or more of these proceedings could result in adverse judgments, settlements, fines, penalties or other relief that could have a material adverse effect on the consolidated financial condition or results of operations of Ameriprise Financial.

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Board Approval of the Advisory Agreement

Columbia Acorn Trust (the "Trust") has an investment advisory agreement (the "Advisory Agreement") with Columbia Wanger Asset Management, LLC ("Columbia WAM") under which Columbia WAM manages the Columbia Acorn Funds (each, a "Fund", and together, the "Funds"). More than 75% of the trustees of the Trust (the "Trustees") are persons who have no direct or indirect interest in the Advisory Agreement and are not "interested persons" (as defined in the Investment Company Act of 1940, as amended (the "1940 Act")) of the Trust (the "Independent Trustees"). The Trustees oversee the management of each Fund and, as required by law, determine at least annually whether to continue the Advisory Agreement for each Fund.

The Contract Committee (the "Committee") of the Board of Trustees (the "Board"), which is comprised solely of Independent Trustees, makes recommendations to the Board regarding any proposed continuation of the Advisory Agreement. After the Committee has made its recommendations, the full Board determines whether to approve continuation of the Advisory Agreement. The Board also considers matters bearing on the Advisory Agreement at its various meetings throughout the year, meets at least quarterly with Columbia WAM's portfolio managers and receives monthly reports from Columbia WAM on the performance of the Funds.

In connection with their most recent consideration of the Advisory Agreement for each Fund, the Committee and all Trustees received and reviewed a substantial amount of information provided by Columbia WAM, Columbia Management Investment Advisers, LLC ("Columbia Management") and Ameriprise Financial, Inc. ("Ameriprise") in response to written requests from the Independent Trustees and their independent legal counsel. Throughout the process, the Trustees had numerous opportunities to ask questions of and request additional materials from Columbia WAM, Columbia Management and Ameriprise.

During each meeting at which the Committee or the Independent Trustees considered the Advisory Agreement, they met in executive session with their independent legal counsel. The Committee also met with representatives of Columbia WAM, Columbia Management and Ameriprise on several occasions. In all, the Committee convened formally on six separate occasions to consider the continuation of the Advisory Agreement. The Board and/or some or all of the Independent Trustees met on other occasions to receive the Committee's status reports, receive presentations from Columbia WAM, Columbia Management and Ameriprise representatives, and to discuss outstanding issues. In addition, the Investment Performance Analysis Committee of the Board, also comprised exclusively of Independent Trustees, reviewed the performance of the Funds and presented its findings to the Board and the Committee throughout the year. The Compliance Committee of the Board also provided information to the Committee with respect to relevant matters.

The Trustees reviewed the Advisory Agreement, as well as certain information obtained through Columbia WAM's, Columbia Management's and Ameriprise's responses to independent legal counsel's questionnaires. In addition, the Trustees reviewed the Management Fee Evaluation dated June 2012 (the "Fee Evaluation") prepared by the Trust's chief compliance officer, senior vice president and general counsel, at the request of the Board.

The materials reviewed by the Committee and the Trustees included, among other items, (i) information on the investment performance of each Fund and of independently selected peer groups of funds and of the Funds' performance benchmarks over various time periods, (ii) information on each Fund's advisory fees and other expenses, including information comparing the Fund's fees and expenses to those of peer groups of funds and information about any applicable expense limitations and fee breakpoints, (iii) data on sales and redemptions of Fund shares, and (iv) information on the profitability to Columbia WAM and Ameriprise, as well as potential "fall-out" or ancillary benefits that Columbia WAM and its affiliates may receive as a result of their relationships with the Funds. The Trustees also considered other information such as (i) Columbia WAM's financial condition, (ii) each Fund's investment objective and strategy, (iii) the size, education and experience of Columbia WAM's investment staff and its use of technology, external research and trading cost measurement tools, (iv) the portfolio manager compensation framework, (v) the allocation of the Funds' brokerage, and the use of "soft" commission dollars to pay for research products and services, (vi) Columbia WAM's risk management program, and (vii) the resources devoted to, and the record of compliance with, the Funds' investment policies and restrictions, policies on personal securities transactions and other compliance policies.

At a meeting held on June 6, 2012, upon recommendations of the Committee, the Board of Trustees unanimously approved the continuation of the Advisory Agreement.

126

In considering the continuation of the Advisory Agreement, the Trustees reviewed and analyzed various factors that they determined were relevant, none of which by itself was considered dispositive. The material factors and conclusions that formed the basis for the Trustees' determination to approve the continuation of the Advisory Agreement are discussed below.

Nature, quality and extent of services. The Trustees reviewed the nature, quality and extent of the services provided by Columbia WAM and its affiliates to the Funds under the Advisory Agreement, taking into account the investment objective and strategy of each Fund and knowledge gained from meetings with management, which were held on at least a quarterly basis. In addition, the Trustees reviewed the available resources and key personnel of Columbia WAM and its affiliates, especially those providing investment management services to the Funds. The Trustees also considered other services provided to the Funds by Columbia WAM and its affiliates, including: managing the execution of portfolio transactions and selecting broker-dealers for those transactions; monitoring adherence to the Funds' investment restrictions; producing shareholder reports; providing support services for the Board and committees of the Board; managing the Funds' securities lending program; communicating with shareholders; serving as the Funds' administrator; and overseeing the activities of the Funds' other service providers, including monitoring for compliance with various policies and procedures as well as applicable securities laws and regulations.

The Trustees concluded that the nature, quality and extent of the services provided by Columbia WAM and its affiliates to each Fund under the Advisory Agreement were appropriate for the Funds and that the Funds were likely to benefit from the continued provision of those services by Columbia WAM. They also concluded that Columbia WAM currently had sufficient personnel, with appropriate education and experience, to serve the Funds effectively, and that the firm had demonstrated its continuing ability to attract and retain well-qualified personnel. In addition, they took note of the quality of Columbia WAM's compliance record.

Performance of the Funds. The Trustees received and considered detailed performance information at various meetings of the Board, the Committee and the Investment Performance Analysis Committee of the Board throughout the year. They reviewed information comparing each Fund's performance with that of its benchmark(s) and with the performance of comparable funds and peer groups as identified by Lipper Inc. ("Lipper") and Morningstar, Inc. ("Morningstar"). The Trustees evaluated the performance of the Funds over various time periods, including over the one-, three- and five-year periods ending December 31, 2011. The Trustees also considered peer performance rankings for similar time periods although they focused more on the five-year period, or the since inception periods in the case of the two newer Funds, Columbia Acorn Emerging Markets Fund and Columbia Acorn European Fund.

The Trustees noted that Columbia Acorn International and Columbia Acorn International Select had delivered excellent results over the past five years, and had done so while exposing investors to less risk than competing funds, according to Morningstar. They also considered that Columbia Acorn Emerging Markets Fund and Columbia Acorn European Fund had delivered excellent returns since inception versus their respective Morningstar peer groups, although their returns were below median compared to their respective Lipper peer groups. The Trustees considered that these newer Funds had operated for less than one year and that the Funds had relatively few peers in their peer groups compared to peer groups for other Funds.

The Trustees considered that the domestic Funds have had mixed results. Columbia Acorn Fund underperformed its peers over the five-year period, ending December 31, 2011, but the Fund beat its benchmark during the same period. Columbia Acorn Fund underperformed its peer groups for the one- and three-year periods as well, and outperformed its benchmark for the three-year but not the one-year period. The Trustees considered, however, that Morningstar and Lipper ranked Columbia Acorn Fund as the best-performing fund over the past ten years. Columbia Acorn Select underperformed its peers and benchmark over the five-year period ending December 31, 2011 and exposed investors to more risk versus its peers. The Trustees considered that Columbia Acorn Select had performed better over the three-year period, but that its one-year returns were well below the peer group median and benchmark. Columbia Acorn USA's returns were behind its peer group median over the five-year period ending December 31, 2011, though it outperformed its benchmark for the same period. The Trustees noted that the Fund also had underperformed its peers for the one- and three-year periods but had outperformed its benchmark for the same periods. Over the ten-year period, Columbia Acorn USA ranked above

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Board Approval of the Advisory Agreement, continued

median according to Morningstar and Lipper. The Fund also exposed shareholders to more risk than its peers. Columbia Thermostat Fund outperformed its stated benchmark, a 50/50 blend of the Fund's primary equity and debt benchmarks, over the three- and five-year periods ending December 31, 2011, and enjoyed strong rankings from Morningstar and Lipper versus its peer groups over these periods.

The Trustees concluded that Fund performance was satisfactory with respect to the international Funds and Columbia Thermostat Fund. The Trustees determined that performance with respect to Columbia Acorn Select, in particular, and with respect to Columbia Acorn Fund and Columbia Acorn USA needed to be improved, although performance of these three Funds had been ahead of their benchmarks at the time of the June 6th Board meeting. The Trustees concluded, however, that Columbia WAM had taken and continued to take a number of corrective steps to improve performance of the underperforming domestic Funds, that Columbia WAM had reported that these steps were being successfully implemented, and that the Investment Performance Analysis Committee of the Board was monitoring these Funds' performance closely. In addition the Trustees considered that the Chief Investment Officer (the "CIO") of Columbia WAM had reported to them at numerous committee and Board meetings on the corrective steps being taken to improve performance, and committee representatives met separately with the CIO on multiple occasions to discuss the underperforming Funds.

The Trustees concluded that, although past performance is not necessarily indicative of future results, the strong overall longer-term performance record of the international Funds, Columbia Acorn Fund and Columbia Thermostat Fund, and the steps taken by Columbia WAM to correct performance in the underperforming domestic Funds, were an important factor in their evaluation of the quality of services provided by Columbia WAM under the Advisory Agreement for these Funds.

Costs of Services and Profits Realized by Columbia WAM. At various Committee and Board meetings, the Trustees examined detailed information on the fees and expenses of each Fund in comparison to information for comparable funds provided by Lipper and Morningstar. The Trustees reviewed data from Lipper and Morningstar and noted that in general the Funds' total net operating expenses were equal to or below their Morningstar median peer group rankings, except that Columbia Acorn USA, Columbia Acorn European Fund, and Columbia Acorn Select had total net operating expenses above their Morningstar peer group medians. All of the Funds' total net operating expenses, however, were below their Lipper peer group medians.

The actual advisory fees paid by Columbia Acorn Fund, Columbia Acorn International and Columbia Thermostat Fund were lower than both their Morningstar and Lipper peer groups; the actual advisory fees paid by Columbia Acorn Select and Columbia Acorn USA were higher than the median advisory fee of the Funds' Lipper and Morningstar peer groups; the actual advisory fees paid by Columbia Acorn Emerging Markets Fund and Columbia Acorn European Fund were higher than the median advisory fees paid by the Funds' Morningstar peer groups but not their Lipper peer groups; and the actual advisory fee paid by Columbia Acorn International Select was higher than the median advisory fee of the Fund's Lipper peer group, but not of its Morningstar peer group.

The Trustees also reviewed the advisory fee rates charged by Columbia WAM for managing other investment companies (including the Columbia Wanger Funds), sub-advised funds and other institutional separate accounts, as detailed in materials provided to the Committee by Columbia WAM and in the Fee Evaluation. The Trustees noted that the Funds' advisory fees were generally comparable to the Columbia Wanger Funds' advisory fees at the same asset levels. The Trustees also examined Columbia WAM's institutional separate account fees for various investment strategies; in some cases those fees were higher than the advisory fees charged to the Funds, and in a few instances the fees were lower. The Trustees noted that Columbia WAM performs significant additional services for the Funds that it does not provide to sub-advised funds or non-mutual fund clients, including administrative services, oversight of the Funds' other service providers, Trustee support, regulatory compliance and numerous other services, and that, in servicing the Funds, Columbia WAM assumes many legal and business risks that it does not assume in servicing many of its non-fund clients.

The Trustees concluded that the rates of advisory fees payable to Columbia WAM were reasonable in relation to the nature and quality of the services to be provided. The Trustees also concluded that the Funds' overall expense ratios were reasonable, considering the quality of the services provided by Columbia WAM and its affiliates and the investment performance of the Funds, taking into account Columbia WAM's continuing steps to improve performance of the underperforming domestic Funds.

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The Trustees reviewed the analysis of the historic profitability of Columbia WAM in serving as each Fund's investment adviser and of Columbia WAM and its affiliates in their relationships with each Fund. The Committee and Trustees met with representatives from Ameriprise to discuss its methodologies for calculating profitability and allocating costs. They considered that Ameriprise calculated profitability and allocated costs on a contract-by-contract and fund-by-fund basis. The Trustees also considered the methodology used by Columbia WAM and Ameriprise in determining compensation payable to portfolio managers and the competitive market for investment management talent. The Trustees were also provided with profitability information from Lipper, which compared Columbia WAM's profitability to other similar investment advisers in the mutual fund industry. The Trustees concluded that Columbia WAM's and its affiliates' profits were within a reasonable range of those of competitors with similar business models. The Trustees discussed, however, that profitability comparisons among fund managers may not always be meaningful due to the lack of consistency in data, small number of publicly-owned managers, and the fact that profitability of any investment manager is affected by numerous factors, including its particular organizational structure, the types of funds and other accounts managed, other lines of business, expense allocation methodology, capital structure and cost of capital.

Economies of Scale. At various Committee and Board meetings and other informal meetings, the Trustees considered information about the extent to which Columbia WAM realizes economies of scale in connection with an increase in Fund assets. The Trustees also discussed the potential for Fund sales growth. The Trustees noted that the advisory fee schedule for each Fund, other than Columbia Thermostat Fund, includes breakpoints in the rate of fees at various asset levels. The Trustees concluded that the fee structure of each Fund was reflective of a sharing between Columbia WAM and the Funds of economies of scale.

Other Benefits to Columbia WAM. The Trustees also reviewed benefits that accrue to Columbia WAM and its affiliates from their relationships with the Funds, based upon information provided to them by Ameriprise and as outlined in the Fee Evaluation. They noted that the Funds' transfer agency services are performed by Columbia Management Investment Services Corp., an affiliate of Ameriprise, which receives compensation from the Funds for its services provided. They considered that an affiliate of Ameriprise, Columbia Management Investment Distributors, Inc. ("CMID"), serves as the Funds' distributor under a distribution agreement, and that it receives fees under the Trust's Rule 12b-1 Plan, most of which CMID pays to broker-dealers. In addition, Columbia Management provides sub-administration services to the Funds. The Committee received information regarding the profitability of each Fund agreement with Columbia WAM affiliates. The Committee and the Board also reviewed information about and discussed the capabilities of each affiliated entity in performing its duties.

The Trustees considered other ways that the Funds and Columbia WAM may potentially benefit from their relationship with each other. For example, the Trustees considered Columbia WAM's use of commissions paid by each Fund on its portfolio brokerage transactions to obtain research products and services benefiting the Funds and/or other clients of Columbia WAM. The Committee reviewed Columbia WAM's annual "soft dollar" report and met with representatives from Columbia WAM to review Columbia WAM's soft dollar spending. The Committee also considered that the Compliance Committee of the Board regularly reviewed third-party prepared reports that evaluated the quality of Columbia WAM's execution of the Funds' portfolio transactions. The Trustees noted that these reports showed that Columbia WAM's execution capabilities were generally better than industry peers. The Trustees determined that Columbia WAM's use of the Funds' "soft" commission dollars to obtain research products and services was consistent with current regulatory requirements and guidance. They also concluded that Columbia WAM benefits from the receipt of proprietary research products and services acquired through commissions paid on portfolio transactions of the Funds, and that the Funds benefit from Columbia WAM's receipt of those products and services as well as research products and services acquired through commissions paid by other clients of Columbia WAM.

After full consideration of the above factors, as well as other factors that were instructive in evaluating the Advisory Agreement, the Trustees, including the Independent Trustees, concluded that the continuation of the Advisory Agreement was in the best interest of each Fund. On June 6, 2012, the Trustees approved continuation of the Advisory Agreement through July 31, 2013.

129

Columbia Acorn Family of Funds

Second Quarter Class A, B, C, I, R and R5 Expense Information (Unaudited)

Columbia Acorn Fund	Class A			Class B*			Class C			Class I
Management Fees		0.64	%		0.64	%		0.64	%		0.64	%
Distribution and Services (12b-1) Fees		0.25	%		0.75	%		1.00	%		0.00	%
Other Expenses		0.16	%		0.26	%		0.16	%		0.08	%
Net Expense Ratio		1.05	%		1.65	%		1.80	%		0.72	%
Columbia Acorn International	Class A			Class B*			Class C			Class I			Class R			Class R5
Management Fees		0.76	%		0.76	%		0.76	%		0.76	%		0.76	%		0.76	%
Distribution and Services (12b-1) Fees		0.25	%		0.75	%		1.00	%		0.00	%		0.50	%		0.00	%
Other Expenses		0.23	%		0.48	%		0.23	%		0.11	%		0.21	%		0.12	%
Net Expense Ratio		1.24	%		1.99	%		1.99	%		0.87	%		1.47	%		0.88	%
Columbia Acorn USA	Class A			Class B*			Class C			Class I
Management Fees		0.86	%		0.86	%		0.86	%		0.86	%
Distribution and Services (12b-1) Fees		0.25	%		0.75	%		1.00	%		0.00	%
Other Expenses		0.20	%		0.40	%		0.19	%		0.10	%
Net Expense Ratio		1.31	%		2.01	%		2.05	%		0.96	%
Columbia Acorn International Select	Class A			Class B*			Class C			Class I
Management Fees		0.94	%		0.94	%		0.94	%		0.94	%
Distribution and Services (12b-1) Fees		0.25	%		0.75	%		1.00	%		0.00	%
Other Expenses		0.31	%		0.42	%		0.35	%		0.20	%
Net Expense Ratio		1.50	%		2.11	%		2.29	%		1.14	%
Columbia Acorn Select	Class A			Class B*			Class C			Class I
Management Fees		0.83	%		0.83	%		0.83	%		0.83	%
Distribution and Services (12b-1) Fees		0.25	%		0.75	%		1.00	%		0.00	%
Other Expenses		0.24	%		0.32	%		0.24	%		0.14	%
Net Expense Ratio		1.32	%		1.90	%		2.07	%		0.97	%
Columbia Thermostat Fund	Class A			Class B*			Class C
Management Fees		0.10	%		0.10	%		0.10	%
Distribution and Services (12b-1) Fees		0.25	%		0.75	%		1.00	%
Other Expenses**		0.15	%		0.15	%		0.15	%
Net Expense Ratio**		0.50	%		1.00	%		1.25	%
Columbia Acorn Emerging Markets Fund	Class A						Class C			Class I
Management Fees		1.25	%					1.25	%		1.25	%
Distribution and Services (12b-1) Fees		0.25	%					1.00	%		0.00	%
Other Expenses		0.29	%					0.30	%		0.16	%
Net Expense Ratio		1.79	%					2.55	%		1.41	%
Columbia Acorn European Fund	Class A						Class C			Class I
Management Fees		1.19	%					1.19	%		1.19	%
Distribution and Services (12b-1) Fees		0.25	%					1.00	%		0.00	%
Other Expenses		0.16	%					0.20	%		0.12	%
Net Expense Ratio		1.60	%					2.39	%		1.31	%

    See the Funds' prospectuses for information on minimum initial investment amounts and other details of buying, selling and exchanging shares of the Funds.

    Fees and expenses are for the six months ended June 30, 2012. The fees and expenses of Columbia Acorn Select and Columbia Acorn International Select include the effect of the voluntary undertaking by Columbia Wanger Asset Management, LLC (CWAM) to waive fees and/or reimburse the Funds for any ordinary operating expenses (exclusive of brokerage commissions, interest, taxes and extraordinary expenses, but inclusive of custodian charges relating to overdrafts, if any), after giving effect to any balance credits from the Funds' custodian, in excess of the following annual rates:

Fund	Class A			Class B			Class C			Class I
Columbia Acorn International Select		1.70	%		2.20	%		2.45	%		1.30	%
Columbia Acorn Select		1.60	%		2.10	%		2.35	%		1.25	%

    These arrangements may be modified or terminated by either the Funds or CWAM upon 30 days notice.

Columbia Thermostat Fund's fees and expenses include the effect of CWAM's contractual undertaking to waive fees and/or reimburse the Fund for any ordinary operating expenses (exclusive of distribution and service fees, interest and fees on borrowings and expenses associated with the Fund's investments in other investment companies, but including custodian charges relating to overdrafts, if any), after giving effect to any balance credits from the Fund's custodian, in excess of the annual rate of 0.25% of the average daily net assets. Columbia Thermostat Fund's waiver/reimbursement arrangement is contractual through April 30, 2013. There is no guarantee that this arrangement will continue thereafter.

    The fees and expenses of Columbia Acorn Emerging Markets Fund and Columbia Acorn European Fund also include the effect of fee waivers/reimbursement. CWAM has contractually undertaken to waive fees and/or reimburse Columbia Acorn Emerging Markets Fund so that the Fund's ordinary operating expenses (excluding interest and fees on borrowings and expenses associated with the Fund's investment in other investment companies, if any) do not exceed the annual rates of 1.85%, 2.60% and 1.41% of the Fund's average daily net assets attributable to Class A, Class C and Class I shares, respectively, through April 30, 2013. There is no guarantee that this arrangement will continue thereafter. CWAM has contractually undertaken to waive fees and/or reimburse Columbia Acorn European Fund so that the Fund's ordinary operating expenses (excluding interest and fees on borrowings and expenses associated with the Fund's investment in other investment companies, if any) do not exceed the annual rates of 1.75%, 2.50% and 1.31% of the Fund's average daily net assets attributable to Class A, Class C and Class I shares, respectively, through April 30, 2013. There is no guarantee that this arrangement will continue thereafter.

Columbia Acorn International's fees and expenses include the effect of the contractual undertaking by CWAM and its affiliates, effective August 15, 2011, to waive a portion of total annual Fund operating expenses incurred by Class A, Class B and Class C shares of Columbia Acorn International such that the Fund's total annual Fund operating expenses will be reduced by 0.04%, 0.03% and 0.02% for Class A, Class B and Class C shares of the Fund, respectively, through August 14, 2013. There is no guarantee that this arrangement will continue thereafter.

  *  The Funds generally no longer accept investments by new or existing investors in Class B shares, except in connection with the reinvestment of any dividend and/or capital gain distributions in Class B shares of the Funds and exchanges by existing Class B shareholders of certain other funds within the Columbia Family of Funds.

  **  Does not include estimated fees and expenses of 0.61% incurred by the Fund from the underlying portfolio funds in which it invests.

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133

Columbia Acorn Family of Funds

Trustees

Laura M. Born

Chair of the Board

Steven N. Kaplan

Vice Chair of the Board

Michelle L. Collins

Maureen M. Culhane

Margaret M. Eisen

John C. Heaton

Charles P. McQuaid

David J. Rudis

David B. Small

Ralph Wanger (Trustee Emeritus)

Officers

Charles P. McQuaid

President

Ben Andrews

Vice President

Robert A. Chalupnik

Vice President

Michael G. Clarke

Assistant Treasurer

Joseph F. DiMaria

Assistant Treasurer

P. Zachary Egan

Vice President

Fritz Kaegi

Vice President

John M. Kunka

Assistant Treasurer

Stephen Kusmierczak

Vice President

Joseph C. LaPalm

Vice President

Bruce H. Lauer

Vice President, Secretary and Treasurer

Louis J. Mendes III

Vice President

Robert A. Mohn

Vice President

Christopher J. Olson

Vice President

Christopher O. Petersen

Assistant Secretary

Scott R. Plummer

Assistant Secretary

Andreas Waldburg-Wolfegg

Vice President

Linda K. Roth-Wiszowaty

Assistant Secretary

Robert P. Scales

Chief Compliance Officer, Chief Legal Officer,
Senior Vice President and General Counsel

Investment Manager

Columbia Wanger Asset Management, LLC
227 West Monroe Street, Suite 3000
Chicago, Illinois 60606

1-800-922-6769

Distributor

Columbia Management Investment Distributors, Inc.
225 Franklin Street
Boston, Massachusetts 02110

Transfer Agent, Dividend Disbursing Agent

Columbia Management Investment Services Corp.
P. O. Box 8081
Boston, Massachusetts 02266-8081

1-800-345-6611

Legal Counsel to the Funds

Perkins Coie LLP
Washington, DC

Legal Counsel to the Independent Trustees

Drinker Biddle & Reath LLP
Philadelphia, Pennsylvania

Independent Registered Public Accounting Firm

PricewaterhouseCoopers LLP
Chicago, Illinois

This report, including the schedules of investments, is submitted for the general information of the shareholders of Columbia Acorn Trust.

A description of the policies and procedures that the Funds use to determine how to vote proxies and a copy of the Funds' voting record are available (i) without charge, upon request, by calling 800-922-6769 and (ii) on the Securities and Exchange Commission's website at www.sec.gov. Information regarding how the Funds voted proxies relating to portfolio securities during the 12-month period ended June 30, is available from the SEC's website. Information regarding how the Funds voted proxies relating to portfolio securities is also available at www.columbiamanagement.com under "About Us." From there, click on "Disclosures."

The Funds file a complete schedule of portfolio holdings with the SEC for the first and third quarters of each fiscal year on Form N-Q. The Funds' Form N-Q is available on the SEC's website at www.sec.gov and may be reviewed and copied at the SEC's Public Reference Room in Washington, D.C. Information on the operation of the Public Reference Room may be obtained by calling 1-800-SEC-0330. The Funds' complete portfolio holdings are disclosed at www.columbiamanagement.com approximately 30 to 40 days after each month-end.

Investors should consider the investment objectives, risks, charges and expenses of a mutual fund carefully before investing. For a free prospectus, which contains this and other important information about the funds, visit www.columbiamanagement.com. Read the prospectus carefully before investing.

Columbia Acorn Funds are distributed by Columbia Management Investment Distributors, Inc., member FINRA and managed by Columbia Wanger Asset Management, LLC.

Find out what's new – visit our web site at:

www.columbiamanagement.com

Our e-mail address is:

ServiceInquiries@ColumbiaManagement.com

Shareholders should not include personal information such as account numbers, Social Security numbers or taxpayer identification numbers in e-mail. We are unable to accept account transactions sent via e-mail.

134

This document contains Global Industry Classification Standard data. The Global Industry Classification Standard ("GICS") was developed by and is the exclusive property and a service mark of MSCI Inc. ("MSCI") and Standard & Poor's Financial Services LLC ("S&P") and is licensed for use by Columbia Wanger Asset Management, LLC. Neither MSCI, S&P, nor any other party involved in making or compiling the GICS or any GICS classifications makes any express or implied warranties or representations with respect to such standard or classification (or the results to be obtained by the use thereof), and all such parties hereby expressly disclaim all warranties of originality, accuracy, completeness, merchantability and fitness for a particular purpose with respect to any of such standard or classification. Without limiting any of the foregoing, in no event shall MSCI, S&P, any of their affiliates or any third party involved in making or compiling the GICS or any GICS classifications have any liability for any direct, indirect, special, punitive, consequential or any other damages (including lost profits) even if notified of the possibility of such damages.

Columbia Management^®

Columbia Acorn Family of Funds
Class A, B, C, I, R and R5 Shares

Semiannual Report, June 30, 2012

For More Information

You'll find more information about the Columbia Acorn Family of Funds in the documents described below. Contact Columbia Funds as follows to obtain these documents free of charge:

By Mail:  Columbia Funds
c/o Columbia Management Investment Services Corp.
P.O. Box 8081
Boston, MA 02266-8081

By Telephone: 800.345.6611

Online: www.columbiamanagement.com

Shareholder Communications with the Board

The Funds' Board of Trustees has adopted procedures by which shareholders may communicate with the Board. Shareholders who wish to communicate with the Board should send their written communications to the Board by mail, c/o Columbia Wanger Asset Management, LLC, 227 West Monroe Street, Suite 3000, Chicago, Illinois 60606, Attention: Secretary. Shareholder communications must (i) be in writing, (ii) identify the Columbia Acorn Fund to which the communication relates and (iii) state the particular class of shares and number of shares held by the communicating shareholder.

Prospectuses and the Statement of Additional Information (SAI)

The prospectuses and the SAI provide more detailed information about the Funds and their policies. The SAI is legally part of each prospectus (it's incorporated by reference). A copy of each has been filed with the SEC.

Information Provided by the SEC

You can review and copy information about the Funds (including their prospectuses, the SAI and shareholder reports) at the SEC's Public Reference Room in Washington, DC. To find out more about the operation of the Public Reference Room, call the SEC at 202.551.8090. Reports and other information about the Fund are also available in the EDGAR Database on the SEC's website at http://www.sec.gov, or you can receive copies of this information, for a fee, by electronic request at the following e-mail address: publicinfo@sec.gov. You can also obtain copies of this information by writing the Public Reference Section, Securities and Exchange Commission, Washington, DC 20549-0102.

The investment company registration number of Columbia Acorn Trust, of which each of these Funds is a series, is 811-01829.

© 2012 Columbia Management Investment Advisers, LLC. All rights reserved.

225 Franklin Street, Boston, MA 02110

800.345.6611 www.columbiamanagement.com

C-1454 D (8/12) 142923

Item 2. Code of Ethics.

Not applicable for semiannual reports.

Item 3. Audit Committee Financial Expert.

Not applicable for semiannual reports.

Item 4. Principal Accountant Fees and Services.

Not applicable for semiannual reports.

Item 5. Audit Committee of Listed Registrants.

Not applicable.

Item 6. Investments

(a)The registrant’s “Schedule I — Investments in securities of unaffiliated issuers” (as set forth in 17 CFR 210.12-12) is included in Item 1 of this Form N-CSR.

(b)Not applicable.

Item 7. Disclosure of Proxy Voting Policies and Procedures for Closed-End Management Investment Companies.

Not applicable.

Item 8. Portfolio Managers of Closed-End Management Investment Companies.

Not applicable.

Item 9. Purchases of Equity Securities by Closed-End Management Investment Company and Affiliated Purchasers.

Not applicable.

Item 10. Submission of Matters to a Vote of Security Holders.

There were no material changes to the procedures by which shareholders may recommend nominees to the registrant’s board of directors.

Item 11. Controls and Procedures.

(a)The registrant’s principal executive officer and principal financial officers, based on their evaluation of the registrant’s disclosure controls and procedures as of a date within 90 days of the filing of this report, have concluded that such controls and procedures are adequately designed to ensure that material information required to be disclosed by the registrant in Form N-CSR is accumulated and communicated to the registrant’s management, including the principal executive officer and principal financial officer, or persons performing similar functions, as appropriate to allow timely decisions regarding required disclosure.

(b)There was no change in the registrant’s internal control over financial reporting that occurred during the registrant’s second fiscal quarter of the period covered by this report that has materially affected, or is reasonably likely to materially affect, the registrant’s internal control over financial reporting.

Item 12. Exhibits.

(a)(1) Code of ethics required to be disclosed under Item 2 of Form N-CSR: Not applicable for semiannual reports.

(a)(2) Certifications pursuant to Rule 30a-2(a) under the Investment Company Act of 1940 (17 CFR 270.30a-2(a)) attached hereto as Exhibit 99.CERT.

(a)(3) Not applicable.

(b) Certification pursuant to Rule 30a-2(b) under the Investment Company Act of 1940 (17 CFR 270.30a-2(b)) attached hereto as Exhibit 99.906CERT.

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934 and the Investment Company Act of 1940, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.

(registrant)	Columbia Acorn Trust
By (Signature and Title)	/s/ Charles P. McQuaid
	Charles P. McQuaid, President
Date	August 21, 2012

Pursuant to the requirements of the Securities Exchange Act of 1934 and the Investment Company Act of 1940, this report has been signed below by the following persons on behalf of the registrant and in the capacities and on the dates indicated.

By (Signature and Title)	/s/ Charles P. McQuaid
	Charles P. McQuaid, President
Date	August 21, 2012
By (Signature and Title)	/s/ Bruce H. Lauer
	Bruce H. Lauer, Treasurer
Date	August 21, 2012

EX-99.CERT

Exhibit 99.CERT

I, Charles P. McQuaid, certify that:

1.I have reviewed this report on Form N-CSR of Columbia Acorn Trust;

2.Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to the period covered by this report;

3.Based on my knowledge, the financial statements, and other financial information included in this report, fairly present in all material respects the financial condition, results of operations, changes in net assets, and cash flows (if the financial statements are required to include a statement of cash flows) of the registrant as of, and for, the periods presented in this report;

4.The registrant’s other certifying officers and I are responsible for establishing and maintaining disclosure controls and procedures (as defined in Rule 30a-3(c) under the Investment Company Act of 1940) and internal control over financial reporting (as defined in Rule 30a-3(d) under the Investment Company Act of 1940) for the registrant and have:

(a)designed such disclosure controls and procedures, or caused such disclosure controls and procedures to be designed under our supervision, to ensure that material information relating to the registrant, including its consolidated subsidiaries, is made known to us by others within those entities, particularly during the period in which this report is being prepared;

(b)designed such internal control over financial reporting, or caused such internal control over financial reporting to be designed under our supervision, to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with generally accepted accounting principles;

(c)evaluated the effectiveness of the registrant’s disclosure controls and procedures and presented in this report our conclusions about the effectiveness of the disclosure controls and procedures, as of a date within 90 days prior to the filing date of this report based on such evaluation; and

(d)disclosed in this report any change in the registrant’s internal control over financial reporting that occurred during the registrant’s second fiscal quarter of the period covered by this report that has materially affected, or is reasonably likely to materially affect, the registrant’s internal control over financial reporting; and

5.The registrant’s other certifying officers and I have disclosed to the registrant’s auditors and the audit committee of the registrant’s board of directors (or persons performing the equivalent functions):

(a)all significant deficiencies and material weaknesses in the design or operation of internal control over financial reporting which are reasonably likely to adversely affect the registrant’s ability to record, process, summarize, and report financial information; and

(b)any fraud, whether or not material, that involves management or other employees who have a significant role in the registrant’s internal control over financial reporting.

Date:     August 21, 2012	/s/ Charles P. McQuaid
	Charles P. McQuaid, President

I, Bruce H. Lauer, certify that:

1.I have reviewed this report on Form N-CSR of Columbia Acorn Trust;

2.Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to the period covered by this report;

3.Based on my knowledge, the financial statements, and other financial information included in this report, fairly present in all material respects the financial condition, results of operations, changes in net assets, and cash flows (if the financial statements are required to include a statement of cash flows) of the registrant as of, and for, the periods presented in this report;

4.The registrant’s other certifying officers and I are responsible for establishing and maintaining disclosure controls and procedures (as defined in Rule 30a-3(c) under the Investment Company Act of 1940) and internal control over financial reporting (as defined in Rule 30a-3(d) under the Investment Company Act of 1940) for the registrant and have:

(a)designed such disclosure controls and procedures, or caused such disclosure controls and procedures to be designed under our supervision, to ensure that material information relating to the registrant, including its consolidated subsidiaries, is made known to us by others within those entities, particularly during the period in which this report is being prepared;

(b)designed such internal control over financial reporting, or caused such internal control over financial reporting to be designed under our supervision, to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with generally accepted accounting principles;

(c)evaluated the effectiveness of the registrant’s disclosure controls and procedures and presented in this report our conclusions about the effectiveness of the disclosure controls and procedures, as of a date within 90 days prior to the filing date of this report based on such evaluation; and

(d)disclosed in this report any change in the registrant’s internal control over financial reporting that occurred during the registrant’s second fiscal quarter of the period covered by this report that has materially affected, or is reasonably likely to materially affect, the registrant’s internal control over financial reporting; and

5.The registrant’s other certifying officers and I have disclosed to the registrant’s auditors and the audit committee of the registrant’s board of directors (or persons performing the equivalent functions):

(a)all significant deficiencies and material weaknesses in the design or operation of internal control over financial reporting which are reasonably likely to adversely affect the registrant’s ability to record, process, summarize, and report financial information; and

(b)any fraud, whether or not material, that involves management or other employees who have a significant role in the registrant’s internal control over financial reporting.

Date:     August 21, 2012	/s/ Bruce H. Lauer
	Bruce H. Lauer, Treasurer

EX-99.906CERT

Exhibit 99.906CERT

CERTIFICATION PURSUANT TO SECTION 906 OF

THE SARBANES-OXLEY ACT OF 2002

In connection with the Certified Shareholder Report of Columbia Acorn Trust (the “Trust”) on Form N-CSR for the period ending June 30, 2012, as filed with the Securities and Exchange Commission on the date hereof (“the Report”), the undersigned hereby certifies that, to his knowledge:

1.The Report fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934; and

2.The information contained in the Report fairly presents, in all material respects, the financial condition and results of operations of the Trust.

Date: August 21, 2012	/s/ Charles P. McQuaid
	Charles P. McQuaid, President
Date: August 21, 2012	/s/ Bruce H. Lauer
	Bruce H. Lauer, Treasurer

A signed original of this written statement required by Section 906 of the Sarbanes-Oxley Act of 2002 has been provided to the Registrant and will be retained by the Registrant and furnished to the Securities and Exchange Commission (the “Commission”) or its staff upon request.

This certification is being furnished to the Commission solely pursuant to 18 U.S.C. §1350 and is not being filed as part of the Form N-CSR with the Commission.