N-CSR

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:		December 31, 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.

Q4 2012

Columbia Acorn Family of Funds

Class A, B, C, I, R, R4, R5, Y and Z Shares

Managed by Columbia Wanger Asset Management, LLC

Annual Report

December 31, 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

Net Asset Value Per Share as of 12/31/12

	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	$	29.36	$	40.79	$	28.21	$	25.61	$	24.72	$	14.29	$	12.04	$	11.76
Class B	$	26.80	$	39.67	$	25.81	$	24.40	$	22.75	$	14.39		NA		NA
Class C	$	26.34	$	39.50	$	25.49	$	24.28	$	22.48	$	14.39	$	12.01	$	11.73
Class I	$	30.47	$	40.86	$	29.47	$	25.85	$	25.63		NA	$	12.08	$	11.75
Class R		NA	$	40.79		NA		NA		NA		NA		NA		NA
Class R4	$	30.90	$	41.08	$	29.92	$	25.99	$	25.92	$	14.19	$	12.14		NA
Class R5	$	30.88	$	40.81	$	29.90	$	25.98	$	25.93	$	14.19	$	12.14	$	11.86
Class Y	$	30.90	$	41.08	$	29.93	$	25.98	$	25.98	$	14.18		NA		NA
Class Z	$	30.45	$	40.84	$	29.45	$	25.86	$	25.57	$	14.13	$	12.07	$	11.76

The views expressed in the "Squirrel Chatter II" 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.

Letter to Shareholders from the
Columbia Acorn Board of Trustees

Dear Shareholder,

In 2012, the domestic equity market suffered its sixth consecutive year of outflows. According to Morningstar, U.S. stock funds experienced outflows of $105 billion while taxable bond funds enjoyed inflows of $266 billion in 2012. Even as investors pulled out of equities, however, the Russell 2500 Index, the primary benchmark for Columbia Acorn Fund, gained 17.88% and the S&P 500 Index gained 16.00% for the year.

The Columbia Acorn Funds are not immune to the sometimes sudden reversals in investor attitudes toward equity markets. Our flagship fund, Columbia Acorn Fund, essentially matched its benchmark in 2012 but nonetheless had redemptions of approximately 10% of its average assets over the year. These redemptions are modest in comparison to the approximately 60% of U.S. equity funds that experienced redemptions in 2012, as reported by Morningstar, with an average outflow of 22% of assets. However, redemptions have not altered the Funds' commitment to their guiding principles. What this means is that your portfolio managers continue to apply the "growth at reasonable price" discipline that has been the hallmark of the Funds, and that they continue to invest and hold stocks that they believe will provide investment returns over the long term.

In addition, the portfolio turnover rate for Columbia Acorn Fund last year was only 16%, in keeping with its historically low rate. The turnover rate reflects the velocity with which the portfolio manager is buying and selling securities. A high percentage, for example 100%, suggests that many of a fund's holdings are being sold and new ones bought during the year. A low turnover rate also minimizes commission costs. Although a low turnover rate alone does not result in fund outperformance, it reflects an important element of investment process and, in fact, Columbia Acorn Fund has delivered outstanding long-term performance. According to Morningstar, Columbia Acorn Fund's annualized return for the past 15 years trumps 93% of its U.S. mid-cap growth category peers and tops its benchmark by nearly 3%,¹ an extraordinary accomplishment.

Investors did not abandon all equities: sentiment favored international equities, which Morningstar reports

enjoyed inflows of $20 billion across the industry. In keeping with this trend, our international funds collectively experienced net inflows. They have performed well too, with Columbia Acorn International and Columbia Acorn International Select outperforming their benchmarks in 2012. Launched in August 2011, Columbia Acorn Emerging Markets Fund and Columbia Acorn European Fund have had promising starts. Both enjoyed modest inflows during 2012 and both delivered impressive annual results. Columbia Acorn Emerging Markets Fund returned 31.35%, well ahead of its benchmark, while Columbia Acorn European Fund delivered a strong absolute return, up 25.66%, though it lagged its benchmark, which increased 28.24%.

The investment results from 2012 suggest that investors may benefit from a focus on the long term and by resisting dramatic swings in sentiment. The Board of Trustees remains confident in the established philosophy and management principles that guide the Funds. Thank you for your continued investment in the Funds.

Laura M. Born
Independent Chair of the Board of Trustees
Columbia Acorn Trust

Fund performance data cited is for Class Z shares. Past performance does not guarantee future results. For more detailed performance comparisons, including standard performance data for the Columbia Acorn Funds, please see Pages 2 and 3 of this report.

Information concerning investment flows provided above is derived from Morningstar Direct. ©2013 Morningstar, Inc. All rights reserved. Morningstar is an independent provider of financial information. 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.

¹ According to Morningstar, Columbia Acorn Fund Class Z ranked 14 of 198 U.S. mid-cap growth equity funds for the 15-year period ended December 31, 2012. Morningstar percentile rankings are based on the average annual total returns of the funds in the category for the period stated and do not include any sales charges or redemption fees, but do include 12b-1 fees and the reinvestment of dividends and capital gains distributions. The highest (or most favorable) percentile rank is 1 and the lowest (or least favorable) percentile rank is 100. Rankings for each share class will vary due to different expenses. Columbia Acorn Fund Class Z gained 10.21% for the 15-year period, compared to a 7.43% return for the Russell 2500 Index, its primary benchmark.

Columbia Acorn Family of Funds

Table of Contents

Descriptions of Indexes	1
Share Class Performance	2
Fund Performance vs. Benchmarks	3
2012 Year-End Distributions	4
Squirrel Chatter II: Photovoltaic Energy	6
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	75
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	114
Report of Independent Registered Public Accounting Firm	125
Federal Income Tax Information	126
Board of Trustees and Management	127
Expense Information	130

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; 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 Mid-Cap Core Funds Index, 30 largest mid-cap core funds; 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.

1

Columbia Acorn Family of Funds

Share Class Performance Average Annual Total Returns through 12/31/12

	Class A						Class B						Class C						Class I			Class R			Class R4			Class R5			Class Y			Class Z
	Without Sales Charge			With Sales Charge			Without Sales Charge			With Sales Charge			Without Sales Charge			With Sales Charge
Columbia Acorn Fund
1 year		17.62	%		10.87	%		16.98	%		11.98	%		16.77	%		15.77	%		18.02	%		NA			17.93	%		17.95	%		17.96	%		17.93	%
5 years		3.69	%		2.47	%		3.09	%		2.75	%		2.89	%		2.89	%		4.03	%		NA			4.00	%		4.00	%		4.00	%		4.00	%
10 years		11.25	%		10.59	%		10.57	%		10.57	%		10.41	%		10.41	%		11.64	%		NA			11.62	%		11.62	%		11.62	%		11.62	%
Columbia Acorn International
1 year		21.21	%		14.25	%		20.33	%		15.33	%		20.31	%		19.31	%		21.69	%		20.83	%		21.57	%		21.61	%		21.58	%		21.60	%
5 years		0.57	%		-0.62	%		-0.09	%		-0.47	%		-0.21	%		-0.21	%		0.96	%		0.30	%		0.93	%		0.92	%		0.93	%		0.93	%
10 years		14.01	%		13.34	%		13.26	%		13.26	%		13.16	%		13.16	%		14.46	%		13.72	%		14.44	%		14.43	%		14.44	%		14.44	%
Columbia Acorn USA
1 year		18.67	%		11.86	%		17.87	%		12.87	%		17.82	%		16.82	%		19.10	%		NA			18.97	%		18.97	%		18.97	%		18.98	%
5 years		3.39	%		2.17	%		2.74	%		2.38	%		2.59	%		2.59	%		3.71	%		NA			3.67	%		3.67	%		3.67	%		3.67	%
10 years		10.05	%		9.39	%		9.33	%		9.33	%		9.22	%		9.22	%		10.42	%		NA			10.40	%		10.40	%		10.40	%		10.40	%
Columbia Acorn International Select
1 year		22.05	%		15.03	%		21.29	%		16.29	%		21.10	%		20.10	%		22.48	%		NA			22.38	%		22.39	%		22.40	%		22.42	%
5 years		0.14	%		-1.04	%		-0.49	%		-0.82	%		-0.65	%		-0.65	%		0.53	%		NA			0.50	%		0.50	%		0.50	%		0.50	%
10 years		12.88	%		12.22	%		12.15	%		12.15	%		12.01	%		12.01	%		13.28	%		NA			13.26	%		13.27	%		13.27	%		13.27	%
Columbia Acorn Select
1 year		16.87	%		10.15	%		16.11	%		11.11	%		15.93	%		14.93	%		17.26	%		NA			17.11	%		17.15	%		17.14	%		17.15	%
5 years		0.04	%		-1.14	%		-0.60	%		-0.95	%		-0.76	%		-0.76	%		0.39	%		NA			0.32	%		0.33	%		0.33	%		0.33	%
10 years		8.28	%		7.64	%		7.57	%		7.57	%		7.44	%		7.44	%		8.65	%		NA			8.61	%		8.62	%		8.62	%		8.62	%
Columbia Thermostat Fund
1 year		13.34	%		6.84	%		12.78	%		7.78	%		12.52	%		11.52	%		NA			NA			13.68	%		13.66	%		13.63	%		13.69	%
5 years		4.94	%		3.70	%		4.41	%		4.07	%		4.16	%		4.16	%		NA			NA			5.19	%		5.19	%		5.18	%		5.19	%
10 years		7.61	%		6.97	%		7.03	%		7.03	%		6.82	%		6.82	%		NA			NA			7.89	%		7.89	%		7.89	%		7.89	%
Columbia Acorn Emerging Markets Fund
1 year		30.86	%		23.40	%		NA			NA			29.98	%		28.98	%		31.39	%		NA			30.97	%		31.05	%		NA			31.35	%
Life of Fund		15.05	%		10.19	%		NA			NA			14.31	%		14.31	%		15.66	%		NA			15.12	%		15.17	%		NA			15.55	%
Columbia Acorn European Fund
1 year		25.46	%		18.19	%		NA			NA			24.46	%		23.46	%		25.71	%		NA			NA			25.46	%		NA			25.66	%
Life of Fund		13.70	%		8.89	%		NA			NA			12.89	%		12.89	%		14.00	%		NA			NA			13.70	%		NA			14.00	%

Returns for Class A shares are shown with and without the maximum initial sales charge of 5.75%. Returns for Class B shares are shown with and without the applicable contingent deferred sales charge (CDSC) of 5.00% in the first year, declining to 1.00% in the sixth year and eliminated thereafter. Returns for Class C shares are shown with and without the maximum CDSC of 1.00% for the first year after purchase. The Funds' other classes are not subject to sales charges and have limited eligibility. Please see the Funds' prospectuses for details. Performance for different share classes will vary based on differences in sales charges and certain fees associated with each class.

All results shown assume reinvestment of distributions during the period. Returns do not reflect the deduction of taxes that a shareholder may pay on Fund distributions or on the redemption of Fund shares. Performance results may reflect the effect of 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 see Page 130 of this report for information on fee waiver and expense reimbursement arrangements in place for Columbia Acorn International, Columbia Thermostat Fund, Columbia Acorn Emerging Markets Fund and Columbia Acorn European Fund.

The performance information shown represents past performance and is not a guarantee of future results. The investment return and principal value of your 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. You may obtain performance information current to the most recent month-end by contacting your financial intermediary, visiting columbiamanagement.com or calling 800.922.6769.

The returns shown include the returns of each Fund's Class Z shares, each Fund's oldest share class, in cases where the inception date of the Fund is earlier than the inception date of the particular share class or where a period shown dates to before the inception date of the 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.

Continued on Page 3.

2

Fund Performance vs. Benchmarks Class Z Average Annual Total Returns through 12/31/12

Class Z Shares	4th quarter*			1 year			5 years			10 years			Life of Fund
Columbia Acorn Fund (ACRNX) (6/10/70)		3.01	%		17.93	%		4.00	%		11.62	%		14.58	%
Russell 2500 Index		3.10	%		17.88	%		4.34	%		10.49	%		NA
S&P 500 Index**		-0.38	%		16.00	%		1.66	%		7.10	%		10.56	%
Russell 2000 Index		1.85	%		16.35	%		3.56	%		9.72	%		NA
Lipper Mid-Cap Growth Funds Index		0.80	%		13.36	%		1.49	%		9.40	%		NA
Columbia Acorn International (ACINX) (9/23/92)		4.23	%		21.60	%		0.93	%		14.44	%		11.14	%
S&P Global Ex-U.S. Between $500M and $5B Index		5.66	%		19.17	%		-0.04	%		13.92	%		8.43	%
S&P Global Ex-U.S. SmallCap Index		5.82	%		20.35	%		-0.78	%		13.20	%		7.72	%
MSCI EAFE Index (Net)		6.57	%		17.32	%		-3.69	%		8.21	%		5.77	%
Lipper International Small/Mid Growth Funds Index		5.19	%		23.38	%		-0.05	%		13.19	%		NA
Columbia Acorn USA (AUSAX) (9/4/96)		3.17	%		18.98	%		3.67	%		10.40	%		10.05	%
Russell 2000 Index		1.85	%		16.35	%		3.56	%		9.72	%		7.31	%
Lipper Small-Cap Growth Funds Index		0.12	%		14.95	%		2.09	%		8.56	%		5.78	%
Columbia Acorn International Select (ACFFX) (11/23/98)		-1.49	%		22.42	%		0.50	%		13.27	%		9.58	%
S&P Developed Ex-U.S. Between $2B and $10B Index		5.35	%		16.78	%		-1.86	%		11.17	%		7.17	%
MSCI EAFE Index (Net)		6.57	%		17.32	%		-3.69	%		8.21	%		3.61	%
Lipper International Small/Mid Growth Funds Index		5.19	%		23.38	%		-0.05	%		13.19	%		10.10	%
Columbia Acorn Select (ACTWX) (11/23/98)		2.04	%		17.15	%		0.33	%		8.62	%		9.33	%
S&P MidCap 400 Index		3.61	%		17.88	%		5.15	%		10.53	%		9.21	%
S&P 500 Index**		-0.38	%		16.00	%		1.66	%		7.10	%		3.33	%
Lipper Mid-Cap Core Funds Index		3.28	%		16.27	%		3.11	%		9.27	%		7.70	%
Columbia Thermostat Fund (COTZX) (9/25/02)		1.52	%		13.69	%		5.19	%		7.89	%		8.10	%
S&P 500 Index		-0.38	%		16.00	%		1.66	%		7.10	%		7.71	%
Barclays U.S. Aggregate Bond Index		0.22	%		4.22	%		5.95	%		5.18	%		5.22	%
Lipper Flexible Portfolio Funds Index		1.54	%		13.34	%		2.72	%		7.31	%		7.70	%
50/50 Blended Benchmark		-0.07	%		10.13	%		4.26	%		6.44	%		6.78	%
Columbia Acorn Emerging Markets Fund (CEFZX) (8/19/11)		9.08	%		31.35	%		—			—			15.55	%
S&P Emerging Markets Between $500M and $5B Index		7.07	%		25.71	%		—			—			6.34	%
MSCI Emerging Markets Small Cap Index		5.10	%		22.22	%		—			—			1.36	%
Lipper Emerging Markets Index		6.28	%		20.08	%		—			—			8.55	%
Columbia Acorn European Fund (CAEZX) (8/19/11)		5.08	%		25.66	%		—			—			14.00	%
S&P Europe Between $500M and $5B Index		8.01	%		28.24	%		—			—			13.57	%
HSBC Smaller European Companies Index		8.53	%		25.89	%		—			—			9.96	%
Lipper European Region Index		7.17	%		22.07	%		—			—			14.62	%

The inception dates for Class A, B and C shares (if offered) are as follows: Columbia Acorn Fund, Columbia Acorn International, Columbia Acorn USA, Columbia Acorn International Select and Columbia Acorn Select, 10/16/00; Columbia Thermostat Fund, 3/3/03; Columbia Acorn Emerging Markets Fund and Columbia Acorn European Fund, 8/19/11. The inception dates for Class I Shares are as follows: Columbia Acorn Fund, Columbia Acorn International, Columbia Acorn USA, Columbia Acorn International Select and Columbia Acorn Select, 9/27/10; Columbia Acorn Emerging Markets Fund and Columbia Acorn European Fund, 8/19/11. The inception date for Class R Shares for Columbia Acorn International is 8/15/11. The inception date for Class R4, R5 and Y shares (if offered) is as follows: Columbia Acorn Fund, Columbia Acorn USA, Columbia Acorn International Select, Columbia Acorn Select, Columbia Thermostat Fund, Columbia Acorn Emerging Markets Fund and Columbia Acorn European Fund, 11/8/12. The inception date for Class R5 shares of Columbia Acorn International is 8/15/11. The inception date for Class R4 and Class Y shares of Columbia Acorn International is 11/8/12. The inception date for Class Z shares is as follows: Columbia Acorn Fund, 6/10/70; Columbia Acorn International, 9/23/92; Columbia Acorn USA, 9/4/96; Columbia Acorn International Select and Columbia Acorn Select, 11/23/98; Columbia Thermostat Fund, 9/25/02; Columbia Acorn Emerging Markets Fund and Columbia Acorn European Fund, 8/19/11.

*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.

Please see Page 1 for a description of the indexes listed above.

3

Columbia Acorn Family of Funds

2012 Year-End Distributions

The following table details the year-end distributions for the Columbia Acorn Family of Funds. For all Funds except for Columbia Thermostat Fund, the record date was December 5, 2012, and the ex-dividend and payable date was December 6, 2012. For Columbia Thermostat Fund, the record date was December 20, 2012, and the ex-dividend and payable date was December 21, 2012. Additionally, Columbia Acorn International and Columbia Acorn USA paid additional dividends with a record date of December 26, 2012, and an ex-dividend and payable date of December 27, 2012. In the chart below, the ordinary income shown is the sum of these two distributions.

	Short-term Capital Gains		Long-term Capital Gains		Ordinary Income		Reinvestment Price
Columbia Acorn Fund
Class A		None	$	1.46206	$	0.06234	$	28.54
Class B		None	$	1.46206		None	$	26.05
Class C		None	$	1.46206		None	$	25.61
Class I		None	$	1.46206	$	0.16459	$	29.61
Class R4		None	$	1.46206	$	0.11346	$	30.03
Class R5		None	$	1.46206	$	0.13752	$	30.00
Class Y		None	$	1.46206	$	0.15256	$	30.03
Class Z		None	$	1.46206	$	0.14955	$	29.59
Columbia Acorn International
Class A		None		None	$	0.52359	$	40.08/$40.57	*
Class B		None		None	$	0.24101	$	39.00/$39.46	*
Class C		None		None	$	0.23337	$	38.83/$39.30	*
Class I		None		None	$	0.66106	$	40.13/$40.64	*
Class R		None		None	$	0.41667	$	40.08/$40.57	*
Class R4		None		None	$	0.59232	$	40.36/$40.86	*
Class R5		None		None	$	0.65724	$	40.09/$40.59	*
Class Y		None		None	$	0.63815	$	40.35/$40.86	*
Class Z		None		None	$	0.64197	$	40.11/$40.62	*
Columbia Acorn USA
Class A		None	$	2.31906	$	0.11399	$	27.32/$27.86	*
Class B		None	$	2.31906		None	$	24.94
Class C		None	$	2.31906		None	$	24.63
Class I		None	$	2.31906	$	0.22168	$	28.53/$29.11	*
Class R4		None	$	2.31906	$	0.15886	$	28.97/$29.55	*
Class R5		None	$	2.31906	$	0.17681	$	28.94/$29.53	*
Class Y		None	$	2.31906	$	0.19177	$	28.98/$29.56	*
Class Z		None	$	2.31906	$	0.18878	$	28.52/$29.09	*

*  The first price is the reinvestment price on 12/6/12. The second price is the reinvestment price on 12/27/12.

4

	Short-term Capital Gains		Long-term Capital Gains		Ordinary Income		Reinvestment Price
Columbia Acorn International Select
Class A		None	$	2.09423	$	1.74324	$	25.44
Class B		None	$	2.09423	$	1.57167	$	24.25
Class C		None	$	2.09423	$	1.52739	$	24.13
Class I		None	$	2.09423	$	1.84009	$	25.67
Class R4		None	$	2.09423	$	1.78751	$	25.81
Class R5		None	$	2.09423	$	1.79858	$	25.80
Class Y		None	$	2.09423	$	1.81242	$	25.80
Class Z		None	$	2.09423	$	1.82625	$	25.68
Columbia Acorn Select
Class A		None	$	1.50555		None	$	24.44
Class B		None	$	1.50555		None	$	22.51
Class C		None	$	1.50555		None	$	22.24
Class I		None	$	1.50555		None	$	25.34
Class R4		None	$	1.50555		None	$	25.63
Class R5		None	$	1.50555		None	$	25.63
Class Y		None	$	1.50555		None	$	25.68
Class Z		None	$	1.50555		None	$	25.28
Columbia Thermostat Fund
Class A		None		None	$	0.22082	$	14.29
Class B		None		None	$	0.15159	$	14.39
Class C		None		None	$	0.11698	$	14.39
Class R4		None		None	$	0.25543	$	14.18
Class R5		None		None	$	0.25266	$	14.18
Class Y		None		None	$	0.25958	$	14.18
Class Z		None		None	$	0.25543	$	14.12
Columbia Acorn Emerging Markets Fund
Class A		None		None	$	0.07638	$	11.79
Class C		None		None		None		NA
Class I		None		None	$	0.11580	$	11.82
Class R4		None		None	$	0.10301	$	11.89
Class R5		None		None	$	0.11047	$	11.88
Class Z		None		None	$	0.11154	$	11.81
Columbia Acorn European Fund
Class A		None		None	$	0.05024	$	11.39
Class C		None		None		None		NA
Class I		None		None	$	0.08251	$	11.39
Class R5		None		None	$	0.07713	$	11.49
Class Z		None		None	$	0.08035	$	11.39

5

Squirrel Chatter II: Photovoltaic Electricity

When the sun is directly overhead on a clear day, it casts about 1,000 watts of energy per square meter. Across the earth, in about one hour the sun provides as much energy as mankind uses from all sources during an entire year.

Photovoltaic (PV) energy, electricity generated directly from sunlight, was discovered in 1839 by Edmund Becquerel. In 1873, Willoughby Smith observed that selenium became conductive when exposed to light.¹ Selenium photovoltaic cells, which convert sunlight directly into electricity, were first made in the 1870s and were later used as light meters for photography.² But selenium cells converted at best 1% of sun power into electricity and were expensive, so their uses were limited.³

In the 1950s, Bell Laboratories began developing silicon photovoltaic cells, and succeeded in creating cells capable of converting 6% of solar power into energy. Cells were combined together into PV modules, and were originally used to recharge batteries that powered remote transmitters. PV modules using more expensive and efficient gallium arsenide were also invented, and almost immediately began to be used in space. The Vanguard I satellite in 1958 had solar capacity well under a watt.⁴ Capacity on satellites grew rapidly, to 1962's Telstar at 14 watts, to the early 1970's Skylab at 16,000 watts, and to today's International Space Station at more than 100,000 watts.⁵

In 1960, silicon solar modules were handmade and cost about $1,000 per peak watt.⁶ The cost of modules has declined in accordance with learning curve theory. For each doubling of cumulative production, prices generally dropped about 20% through the year 2000. The price fell to about $300 per peak watt in 1970, and then to about $3.50 in 2000.⁷ Module costs fell as sunlight conversion efficiency was enhanced, materials requirements were reduced and manufacturing processes were mechanized and streamlined. Other costs of PV systems, including electronics, cabling, racks, mounting hardware and installation expenses, have also been dropping, but not as quickly.

As prices fell, mass market applications developed. In the 1980s, PV systems were most often used to provide power to areas without electrical infrastructure to run irrigation pumps, illuminate schools and refrigerate medicine, for example.⁸ In the 1990s, PV systems began to be connected to electric grids in the developed world in order to utilize essentially pollution-free energy.⁹ Governments created incentives for installing and producing PV electricity in order to reduce carbon dioxide emissions and slow global warming.

In 2000, Germany passed legislation that guarantees high, 20-year payments to producers for PV-produced electricity. Payment rates on new projects decline along with the costs of photovoltaic systems. Utilities in Germany currently pay about $0.35 per kilowatt hour (kWh) for home roof-top produced PV electricity.¹⁰ As of the end of 2011, Germany was the world leader in PV energy investment with 24.8 billion peak watts of installed PV capacity, about 35% of the world total.¹¹ Italy, which also adopted high payments for PV electricity, was second, at about 17% of world PV capacity.¹² The United States, in comparison, accounted for only 5% of installed worldwide PV capacity.

As a result of the incentives in Germany and Italy, demand for photovoltaic systems surged. A shortage of polysilicon, the primary raw material for silicon solar cells, also developed. Module prices were stuck between $3 and $4 from 2000 until the second half of 2008, and profits boomed for both solar module and polysilicon makers. Manufacturing capacity consequently jumped, boosted at first by attractive profits and then by Chinese efforts to dominate world PV module production. Module prices then fell to $2 in 2009¹³ and collapsed to as low as $0.70 by September 2012, when global manufacturing capacity equaled nearly double worldwide demand.¹⁴ Extremely competitive pricing, plus the lack of apparent technology or cost advantages, have caused losses, an industry shakeout, and poor stock performance for PV module producers.

According to the World Research Institute, by 2011 the average installed price for complete photovoltaic systems fell to $4.75 per peak watt of energy generated.

6

Meanwhile, the price of utility-generated electricity has been rising. According to the U.S. Energy Information Administration, the average residential electricity price in the United States rose from $0.02 per kWh in 1970 to $0.08 in the year 2000 and $0.12 in 2011. The falling price of PV systems and the rising price of electricity have made PV electricity more competitive.

In the United States, 44 states have adopted net metering policies. These policies make it possible for consumers to buy PV systems, produce their own PV electricity by day and provide what they don't use into the electric grid. By night, they get electricity from the grid. Consumers are generally billed for the net amount they use. Given that solar electric production varies by hour of the day and cloud cover, and utilities need reliable supplies, utility obligations to purchase such power are capped state by state. PV electricity production, however, tends to match peak load needs, so utilities are generally buying what would otherwise be expensive peak-load power and selling cheaper off-peak power to owners of PV systems at average retail rates.

PV electricity is now competitive in areas with high electric rates, especially in places with lots of sunshine. Household electricity rates vary tremendously by location. As examples, Honolulu rates recently hit $0.34 per kWh, and the New York City area, $0.20. Worldwide electric rates vary tremendously as well, with Denmark at nearly $0.40 and Italy at about $0.30 per kWh. These prices contrast to electric rates ranging from $0.05 to $0.10 per kWh in some energy-rich states and countries.¹⁵

Peak sunshine varies by location; solar modules in Honolulu receive an average of 5.7 hours of peak sunshine per day, so each peak watt of installed solar module would generate about 1.87 kWh yearly.¹⁶ Assuming that a PV system costs $4.75 per peak watt installed, it would pay for itself in about 7.5 years based on Honolulu's electricity rates. Utilizing the current 30% federal tax credit reduces the payback period to 5.2 years.¹⁷ After the PV system pays for itself, it should provide more than 20 years of nearly free energy to its owner, as modules are designed to last 30 years, though electronics associated with them will likely need to be replaced once or twice during that period.

Honolulu is an extreme example in the United States because of its high electricity costs and its abundant sunshine. Tucson receives even more sunshine, but with approximately $0.10 kWh power prices, PV systems there have after-tax credit paybacks of nearly 16 years. New York receives about one-third less sunshine than Tucson, but due to its higher power rates, PV systems there have about 11 year paybacks.¹⁸

As of early 2012, 30 states had renewable portfolio standards, which mandate certain percentages of electricity production to be from renewable sources such as PV. Solar renewable energy credits and tax credits have also incentivized purchases of PV systems in many of those states.¹⁹ As a result, large, non-residential PV installations jumped, and recently accounted for 84% of nationwide PV capacity.²⁰ Total new installations in the United States surged over 15-fold from 2007 to 2012, to about 3.2 billion peak watts.²¹

Although PV installations in the United States are rising sharply, relatively low net metered electricity prices in most of the United States makes PV electricity less competitive compared to high payment rates in other countries. Abundant and cheap shale natural gas in the United States will likely keep domestic electric rates low. With these factors in mind, despite tax incentives and renewable portfolio standards, the United States seems unlikely to become the world leader in PV electricity production.

Photovoltaic electricity production is instead more economically attractive in areas with high electricity costs. PV electricity should displace a lot of the 5% of worldwide electricity that is generated by burning costly petroleum. Also, the World Bank estimates that 1.4 billion people do not have access to electricity, and is funding billions of dollars to provide electricity to them.²² PV electricity seems like a good choice to provide power to third world locations currently lacking electricity.

Usage of photovoltaic electricity is growing rapidly from a very low base. Worldwide PV power production jumped about 86% in 2012, but accounted for just 0.25% of electric power.²³ As photovoltaic costs continue to drop, fossil fuel prices rise, and concerns about carbon emissions grow, PV seems poised to achieve substantially

7

greater shares of electricity production, helping to change the world in a favorable way.

Charles P. McQuaid

President and Chief Investment Officer
Columbia Wanger Asset Management, LLC

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 here are those of the author 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  Dunlop, James P., Photovoltaic Systems, Second Edition, (Orland Park, Illinois, American Technical Publishers, Inc., 2010), p. 5.

²  Lynn, Paul A., Electricity from Sunlight, An Introduction to Photovoltaics, (West Sussex, United Kingdom, John Wiley & Sons, Ltd, 2010), p. 13.

³  Dunlop, James P., op. cit., p. 6.

⁴  Ibid., p. 7.

⁵  Lynn, Paul A., op. cit., p. 14 and p. 168.

⁶  Dunlop, James P., op. cit., p. 7. Peak watts are the amount of electricity produced by photovoltaic modules when the sun is directly overhead and unobstructed.

⁷  Lynn, Paul A., op. cit., p. 14-16.

⁸  Dunlop, James P., op. cit., p. 7.

⁹  Lynn, Paul A., op. cit., p. 19.

¹⁰  German Feed-in Tariffs 2012, posted on the German Energy Blog. http://www.germanenergyblog.de/?page_id=8617. Accessed January 21, 2013.

¹¹  Barua, Priya and Tawney, Letha and Weischer, Lutz, "Delivering on the Clean Energy Economy: The Role of Policy in Developing Successful Domestic Solar and Wind Industries," a Working Paper published by the World Resources Institute, November 2012, p. 16, http://www.wri.org/publication/delivering-on-the-clean-energy-economy. Accessed February 4, 2013.

¹²  Kaften, Cheryl, "IEA: Renewables to Rival Coal by 2035," PV Magazine.com, November 14, 2012, http://www.pv-magazine.com/news/details/beitrag/iea--renewables-to-rival-coal-by-2035_100009194/#axzz2JxkjpuqF. Accessed January 18, 2013.

¹³  Bazilian, Morgan, et al., "Reconsidering the Economics of Photovoltaic Power," a Working Paper published May 17, 2012, p. 3, http://www.ourenergypolicy.org/wp-content/uploads/2012/05/BNEF_re_considering_the_economics_of_photovoltaic_power.pdf. Accessed February 4, 2013.

¹⁴  "U.S. Solar Market Insight Report, Q3 2012, Executive Summary," Copyright 2012, SEIA (Solar Energy Industries Association)/GTM Research, p. 11, http://www.seia.org/research-resources/us-solar-market-insight. Accessed February 4, 2013.

¹⁵  U.S. Energy Information Administration website, http://www.eia.gov/electricity/state/. Accessed January 7, 2013.

¹⁶  Assumes 10% electricity loss from line losses and conversion from direct current to alternating current.

¹⁷  $4.75 average included commercial systems; residential system costs averaged $5.21 per watt, as stated in the "U.S. Solar Market Insight Report, Q3 2012, Executive Summary," p. 10. See footnote 14.

¹⁸  Paybacks calculated by author utilizing recently published electric rates as mentioned in essay, hours of peak sunshine per Dunlop book, 10% line and conversion losses, and the current 30% federal tax credit. Readers are advised to update data and do own calculations prior to purchasing PV systems.

¹⁹  U.S. Energy Information Administration website, http://www.eia.gov/todayinenergy/detail.cfm?id=4850. Accessed February 4, 2013.

²⁰  Sherwood, Larry, "U.S. Solar Market Trends 2011," IREC (Interstate Renewable Energy Council, Inc.), August 2012, p. 7, http://www.irecusa.org/wp-content/uploads/IRECSolarMarketTrends-2012-Web-8-28-12.pdf. Accessed February 4, 2013.

²¹  "U.S. Solar Market Insight Report," op. cit., p. 2.

²²  The world bank website, http://web.worldbank.org/WBSITE/EXTERNAL/TOPICS/EXTENERGY2/0,,contentMDK:22855502~pagePK:210058~piPK:210062~theSitePK:4114200,00.html. Accessed February 4, 2013.

²³  Carr, Geoffrey, "Science and Technology: Sunny Uplands," The Economist, November 13, 2012, 2:22, http://www.economist.com/news/21566414-alternative-energy-will-no-longer-be-alternative-sunny-uplands. Accessed February 4, 2013.

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, R4, R5, Y and 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.

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.

July 1, 2012 – December 31, 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		1,078.00		1,019.86		5.62		5.46		1.07
Class B		1,000.00		1,000.00		1,075.40		1,017.03		8.55		8.31		1.63
Class C		1,000.00		1,000.00		1,074.20		1,016.17		9.44		9.17		1.80
Class I		1,000.00		1,000.00		1,080.10		1,021.63		3.79		3.68		0.72
Class R4*		1,000.00		1,000.00		1,063.10		1,020.93		1.26		4.39		0.86
Class R5*		1,000.00		1,000.00		1,063.30		1,021.18		1.19		4.14		0.81
Class Y*		1,000.00		1,000.00		1,063.40		1,021.48		1.10		3.83		0.75
Class Z		1,000.00		1,000.00		1,079.60		1,021.28		4.15		4.04		0.79

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		1,116.50		1,019.01		6.63		6.33		1.24
Class B		1,000.00		1,000.00		1,112.50		1,015.47		10.36		9.88		1.94
Class C		1,000.00		1,000.00		1,112.20		1,015.16		10.68		10.19		2.00
Class I		1,000.00		1,000.00		1,118.60		1,020.83		4.71		4.49		0.88
Class R		1,000.00		1,000.00		1,114.80		1,017.54		8.18		7.80		1.53
Class R4*		1,000.00		1,000.00		1,045.70		1,020.12		1.48		5.21		1.02
Class R5		1,000.00		1,000.00		1,118.00		1,020.72		4.82		4.60		0.90
Class Y*		1,000.00		1,000.00		1,045.90		1,020.72		1.31		4.60		0.90
Class Z		1,000.00		1,000.00		1,118.40		1,020.52		5.03		4.80		0.94
Columbia Acorn USA
Class A		1,000.00		1,000.00		1,077.40		1,018.60		6.93		6.73		1.32
Class B		1,000.00		1,000.00		1,073.80		1,015.37		10.27		9.98		1.96
Class C		1,000.00		1,000.00		1,073.10		1,014.91		10.74		10.44		2.05
Class I		1,000.00		1,000.00		1,079.00		1,020.57		4.89		4.75		0.93
Class R4*		1,000.00		1,000.00		1,080.60		1,019.51		1.68		5.82		1.14
Class R5*		1,000.00		1,000.00		1,080.60		1,019.61		1.66		5.72		1.12
Class Y*		1,000.00		1,000.00		1,080.70		1,020.02		1.54		5.31		1.04
Class Z		1,000.00		1,000.00		1,078.20		1,019.66		5.83		5.67		1.11
Columbia Acorn International Select
Class A		1,000.00		1,000.00		1,107.20		1,017.84		7.83		7.50		1.47
Class B		1,000.00		1,000.00		1,103.70		1,014.71		11.11		10.64		2.09
Class C		1,000.00		1,000.00		1,102.80		1,013.85		12.01		11.50		2.26
Class I		1,000.00		1,000.00		1,109.10		1,019.51		6.08		5.82		1.14
Class R4*		1,000.00		1,000.00		997.30		1,018.70		1.84		6.63		1.30
Class R5*		1,000.00		1,000.00		997.30		1,018.80		1.82		6.53		1.28
Class Y*		1,000.00		1,000.00		997.50		1,019.21		1.70		6.12		1.20
Class Z		1,000.00		1,000.00		1,108.90		1,019.21		6.40		6.12		1.20
Columbia Acorn Select
Class A		1,000.00		1,000.00		1,085.80		1,018.70		6.85		6.63		1.30
Class B		1,000.00		1,000.00		1,082.10		1,015.62		10.05		9.73		1.91
Class C		1,000.00		1,000.00		1,081.20		1,014.86		10.84		10.49		2.06
Class I		1,000.00		1,000.00		1,087.90		1,020.47		5.01		4.85		0.95
Class R4*		1,000.00		1,000.00		1,059.20		1,019.92		1.55		5.41		1.06
Class R5*		1,000.00		1,000.00		1,059.60		1,020.27		1.45		5.05		0.99
Class Y*		1,000.00		1,000.00		1,059.40		1,020.62		1.35		4.70		0.92
Class Z		1,000.00		1,000.00		1,087.20		1,020.02		5.49		5.31		1.04

10

	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 Emerging Markets Fund
Class A		1,000.00		1,000.00		1,193.90		1,016.33		9.81		9.02		1.77
Class C		1,000.00		1,000.00		1,189.10		1,012.33		14.16		13.02		2.56
Class I		1,000.00		1,000.00		1,197.10		1,018.15		7.83		7.19		1.41
Class R4*		1,000.00		1,000.00		1,070.40		1,017.49		2.26		7.85		1.54
Class R5*		1,000.00		1,000.00		1,071.10		1,017.89		2.15		7.45		1.46
Class Z		1,000.00		1,000.00		1,195.70		1,017.84		8.16		7.50		1.47
Columbia Acorn European Fund
Class A		1,000.00		1,000.00		1,124.90		1,017.08		8.70		8.26		1.62
Class C		1,000.00		1,000.00		1,121.40		1,013.65		12.33		11.71		2.30
Class I		1,000.00		1,000.00		1,126.10		1,018.65		7.04		6.68		1.31
Class R5*		1,000.00		1,000.00		1,067.00		1,018.40		2.00		6.94		1.36
Class Z		1,000.00		1,000.00		1,125.80		1,018.50		7.20		6.84		1.34

Fund of Funds—Columbia Thermostat Fund

July 1, 2012 – December 31, 2012

	Account value at the beginning of the period ($)				Account value at the end of the period ($)				Expenses paid during the period ($)				Fund's annualized expense ratio (%)		Effective expenses paid during the period ($)				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		1,063.10		1,022.75		2.61		2.56		0.50		5.74		5.62		1.10
Class B		1,000.00		1,000.00		1,060.70		1,020.22		5.21		5.11		1.00		8.33		8.17		1.60
Class C		1,000.00		1,000.00		1,059.70		1,018.95		6.51		6.38		1.25		9.63		9.44		1.85
Class R4*		1,000.00		1,000.00		1,026.00		1,024.01		0.36		1.28		0.25		1.22		4.35		0.85
Class R5*		1,000.00		1,000.00		1,025.80		1,023.91		0.39		1.38		0.27		1.25		4.45		0.87
Class Y*		1,000.00		1,000.00		1,025.50		1,024.16		0.32		1.13		0.22		1.18		4.19		0.82
Class Z		1,000.00		1,000.00		1,064.80		1,024.01		1.30		1.28		0.25		4.44		4.35		0.85

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.

Except with respect to Columbia Thermostat Fund, expenses do not include any fees and expenses incurred indirectly by a 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 manager and/or certain of its affiliates not waived/reimbursed certain fees and expenses for Columbia Acorn International, Columbia Thermostat Fund, Columbia Acorn Emerging Markets Fund and Columbia Acorn European Fund, account value at the end of the period would have been reduced.

*  For the period from November 8, 2012 (commencement of operations) through December 31, 2012.

11

Columbia Acorn Fund

In a Nutshell

Charles P. McQuaid Lead Portfolio Manager	Robert A. Mohn 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 most recent month-end performance updates.

Including a 3.01% gain in the fourth quarter, Columbia Acorn Fund (Class Z shares) rose 17.93% in 2012. Both gains about matched the Fund's primary benchmark, the Russell 2500 Index, and were moderately ahead of the Lipper Mid-Cap Growth Index and the large-cap S&P 500 Index.

The technology hardware group did well during both periods. Fiber optic laser equipment provider IPG Photonics lit up performance, rising 17% in the quarter and nearly doubling for the year. Earnings beat expectations and fears of a slowdown did not materialize. Swedish measurement equipment and software company Hexagon rose 18% in the quarter and jumped over 70% during the year on fine earnings and margin gains. Trimble Navigation, a producer of global positioning equipment for engineering and agriculture, grew 25% in the quarter and 38% in the year, also on excellent earnings and margin gains. Electronics connector maker Amphenol rose 10% in the quarter and 44% in the year, as it won additional business and grew nicely.

Communications stocks also performed well. Tower companies were the highest performers. Both SBA Communications and Crown Castle International rose 13% in the quarter; SBA edged out Crown for the year with a 65% rise versus 61%. Both companies are benefiting from buildouts of new generation cellular technology, as well as reportedly improved outlooks for some of its cell phone provider customers. Voice and data provider tw telecom rose 31% in 2012 on continued growth and consolidation within the industry.

Consumer discretionary stocks rounded out the winner's circle. Premium active apparel retailer lululemon athletica jumped 64% during the year as it proved the naysayers wrong. It was the Fund's largest dollar winner. Ryman Hospitality Properties, formerly Gaylord Entertainment, rose 19% in the quarter and surged 95% in the year on its conversion to real estate investment trust status. PVH, the owner of most of the Calvin Klein brand, agreed to buy Warnaco Group, the owner of Calvin Klein underwear and international rights. Warnaco rose 38% in the quarter and 43% during the year. However, Deckers Outdoor, the wholesaler of UGG fashion footwear, had a disappointing year due to higher costs and unfavorable weather. Its stock stumbled 47% during the year.

Health care stocks were generally disappointing. During the quarter, Auxilium Pharmaceuticals fell 24% on increased competition and Isis Pharmaceuticals fell 33% on poor drug development. During the year, health care information technology provider Quality Systems fell 52% on disappointing earnings. Chelsea Therapeutics International plunged 86%, and Anthera Pharmaceuticals 86%, both on poor drug development results. On the bright side, BioMarin Pharmaceutical rose 43% for the year as it made progress developing orphan drugs. Alexion Pharmaceuticals appreciated 30% on continued earnings growth, though it did fall 19% in the quarter. We opted to sell the Fund's positions in Isis Pharmaceuticals and Anthera Pharmaceuticals.

Columbia Acorn Fund's international stocks fell 0.16% in the quarter and were up only 13.73% in the year.* While Hexagon, as mentioned above, performed well, Canadian mining company Kirkland Lake Gold dropped 61% and Mongolian copper miner Turquoise Hill Resources fell 53% during the year. Foreign stocks accounted for 8.3% of the Fund's assets at year end, down from 9.2% at the beginning of year and 8.7% at the beginning of the quarter.

Stocks did quite well in 2012 despite mediocre economic growth. Small and mid caps were helped by takeovers. Seventeen takeovers of Columbia Acorn Fund portfolio companies were announced during the year. Given low interest rates on bonds and inflated prices of some real assets, such as precious metals and farmland, we believe stocks may continue to do relatively well in 2013. In the current environment, the takeover trend could also persist, further benefiting small and mid caps.

*  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, operational and settlement risks 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.

Fund Positions in Mentioned Holdings

As a percentage of net assets, as of 12/31/12

Crown Castle International	1.7	%
lululemon athletica	1.6
tw telecom	1.4
SBA Communications	1.4
Amphenol	1.3
IPG Photonics	1.1
PVH	1.1
BioMarin Pharmaceutical	1.0
Ryman Hospitality Properties	1.0
Hexagon	0.8
Trimble Navigation	0.7
Alexion Pharmaceuticals	0.4
Warnaco Group	0.3
Deckers Outdoor	0.2
Auxilium Pharmaceuticals	0.2
Quality Systems	0.1
Kirkland Lake Gold	0.1
Turquoise Hill Resources	0.1
Chelsea Therapeutics International	0.0	*

*Rounds to less than 0.1%.

12

Columbia Acorn Fund

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 performance data current to the most recent month-end. Market indexes are unmanaged; their results do not reflect the effect of expenses or sales charges. Securities in the Fund may not match those in an index.

Average Annual Total Returns for period ended December 31, 2012

	4th quarter			1 year			5 years			10 years			Life of Fund
Class Z (06/10/70 inception)		3.01	%		17.93	%		4.00	%		11.62	%		14.58	%
Class A (10/16/00 inception)
without sales charge		2.92			17.62			3.69			11.25			14.20
with sales charge		-2.99			10.87			2.47			10.59			14.04
Russell 2500 Index*		3.10			17.88			4.34			10.49			NA

Results for other share classes can be found on Page 2.

*The Fund's primary benchmark. Please see Page 1 for index definitions.

All results shown assume reinvestment of distributions. The Fund's Class Z share annual operating expense ratio, as stated in the May 1, 2012, prospectus, is 0.77% and the Class A share expense ratio is 1.11%. Class Z shares are sold at NAV, have limited eligibility and the investment minimum requirement may vary. Only eligible investors may purchase Class Z shares of the Fund, directly or by exchange. Please see the Fund's prospectuses for eligibility and other details. Returns for Class A shares are shown with and without the maximum initial sales charge of 5.75%. The returns shown for periods prior to the inception of the 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.

Portfolio Diversification

as a percentage of net assets, as of 12/31/12

Top 10 Holdings

as a percentage of net assets, as of 12/31/12

1.	Ametek Aerospace/Industrial Instruments	2.2	%
2.	Mettler-Toledo International Laboratory Equipment	1.8	%
3.	Crown Castle International Communications Towers	1.7	%
4.	lululemon athletica Premium Active Apparel Retailer	1.6	%
5.	Donaldson Industrial Air Filtration	1.6	%
6.	tw telecom Fiber Optic Telephone/Data Services	1.4	%
7.	SBA Communications Communications Towers	1.4	%
8.	Amphenol Electronic Connectors	1.3	%
9.	FMC Technologies Oil & Gas Well Head Manufacturer	1.1	%
10.	Nordson Dispensing Systems for Adhesives & Coatings	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 Shares

June 10, 1970 (Fund inception) through December 31, 2012

The chart shows the change in value of a hypothetical $10,000 investment in Class Z shares of the Fund during the stated time period, and does not reflect the deduction of taxes that a shareholder may pay on Fund distributions or on the redemption of Fund shares. 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.

Total Net Assets of the Fund: $17.5 billion

13

Columbia Acorn International

In a Nutshell

P. Zachary Egan Co-Portfolio Manager	Louis J. Mendes III 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 most recent month-end performance updates.

Columbia Acorn International (Class Z shares) returned 4.23% in the fourth quarter, 1.43% behind the 5.66% return of its primary benchmark, the S&P Global Ex-U.S. between $500M and $5B Index. For 2012, the Fund's annual return was 21.60%, 2.43% ahead of its benchmark, up 19.17%. International small-cap stocks outperformed larger caps as measured by the large-cap developed market MSCI EAFE Index, which rose 17.32% during the year.

Recall that in 2011, fears of a renewed global recession dragged down equity markets just about everywhere, with those in Europe, Asia excluding Japan, and Latin America particularly hard hit. Early concerns over inflation in China, India and Brazil abated as 2011 progressed. They were replaced that year by the far greater concerns of a renewed credit crunch triggered by potential European debt defaults and even the possible demise of the European single currency. In 2012, concerns over the eurozone abated, and market participants preoccupied themselves with the scarcity of growth and the real risk of a prolonged deflation, despite the best efforts of many governments to keep the liquidity spigot open via low interest rates and deficit spending. The result was a bifurcated market where conservative, high-yielding assets in mature markets (for example, real estate investment trusts or REITs) and high-growth assets in the few remaining growth markets around (especially emerging markets) rallied, while global cyclicals, particularly commodities, generally rose only modestly.

This is evidenced in the Fund by the fact that nine of the top 15 performers were emerging market companies with returns ranging from 75% to 160%. Asian gaming stocks continued to move higher with Cambodia-based Nagacorp rising 160% and Macau-based Melco Crown Entertainment appreciating over 75%. We expect rising regional wealth and increased opportunities and desire for leisure travel to continue to drive growth in this sector. In India, rising affluence within a sizable and expanding middle class continued to drive expectations for consumer stocks higher. United Breweries, India's leading brewer, for example, was up 137% in the year. In Indonesia, continued penetration of cellular phones increased the demand for requisite cellular tower infrastructure, propelling Tower Bersama Infrastructure up over 128%. In South Africa, wealth effects across the population helped drive earnings for fund management company Coronation Fund Managers, sending the stock up 77% in the year.

The strong performance in many high-growth emerging market companies contrasts sharply with comparatively weak economic trends in developed markets and the inability of most western governments to confront fiscal imbalances with solutions rather than rhetoric and continued large deficits.

The concerns of a "fiscal cliff" in the United States and little growth in Japan and Europe continued to weigh heavily on commodity-related stocks. In particular, Japan continued to suffer the consequences of deflation and economic stagnation, accounting for eight of the 15 worst performers in the Fund. Japanese consumer and Internet stocks suffered with online apparel retailer Start Today down nearly 60% on weak earnings, social networker Gree down 25% on lower expectations, and Sanrio, owner of the "Hello Kitty" brand, down over 23%. We sold the Fund's position in Gree.

As we enter 2013, the outlook appears more positive than one year ago. Elections in the United States and changes in leadership in China have taken place without hanging chads or revolution. European policymakers are regarded as more credible on the common currency than was previously the case. Even Japan has embarked on a more aggressive reflationary stance to end over 20 years of deflation. Emerging markets appear stable and poised for continued economic growth that is well above global averages. Unfortunately, after a strong performance in 2012, equity markets may no longer appear as attractive as they did one year ago, and have been invigorated by nominal interest rates at record lows in many countries. We believe that for equities to continue to perform, they will need to demonstrate solid ongoing growth in quality earnings, as this is what present valuations appear to discount. As always, we will continue to work hard to identify investments in dynamic, emerging growth companies for shareholders, while remaining attentive to the downside risks.

International investing involves special risks, including foreign taxation, currency risks, risks associated with possible differences in financial standards, operational and settlement risks 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.

Fund's Positions in Mentioned Holdings

As a percentage of net assets, as of 12/31/12

Melco Crown Entertainment	1.6	%
Coronation Fund Managers	0.8
United Breweries	0.6
Nagacorp	0.5
Tower Bersama Infrastructure	0.5
Sanrio	0.5
Start Today	0.4

14

Columbia Acorn International

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 performance data current to the most recent month-end. Market indexes are unmanaged; their results do not reflect the effect of expenses or sales charges. Securities in the Fund may not match those in an index.

Average Annual Total Returns for period ended December 31, 2012

	4th quarter			1 year			5 years			10 years			Life of Fund
Class Z (9/23/92 inception)		4.23	%		21.60	%		0.93	%		14.44	%		11.14	%
Class A (10/16/00 inception)
without sales charge		4.14			21.21			0.57			14.01			10.71
with sales charge		-1.85			14.25			-0.62			13.34			10.39
S&P Global Ex-U.S. Between $500M and $5B*		5.66			19.17			-0.04			13.92			8.43

Results for other share classes can be found on Page 2.

*The Fund's primary benchmark. Please see Page 1 for index definitions.

All results shown assume reinvestment of distributions. The Fund's Class Z share annual operating expense ratio, as stated in the May 1, 2012, prospectus, is 0.98% and the Class A share expense ratio is 1.35%. Class Z shares are sold at NAV, have limited eligibility and the investment minimum requirement may vary. Only eligible investors may purchase Class Z shares of the Fund, directly or by exchange. Please see the Fund's prospectuses for eligibility and other details. Returns for Class A shares are shown with and without the maximum initial sales charge of 5.75%. The returns shown for periods prior to the inception of the 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.

Portfolio Diversification

as a percentage of net assets, as of 12/31/12

Top 10 Holdings

as a percentage of net assets, as of 12/31/12

1.	Melco Crown Entertainment (Hong Kong) Macau Casino Operator	1.6	%
2.	Far EasTone Telecom (Taiwan) Taiwan's Third Largest Mobile Operator	1.5	%
3.	Hexagon (Sweden) Design, Measurement & Visualization Software & Equipment	1.5	%
4.	Eurofins Scientific (France) Food, Pharmaceuticals & Materials Screening & Testing	1.3	%
5.	Naspers (South Africa) Media in Africa, China, Russia & Other Emerging Markets	1.1	%
6.	Grupo Aeroportuario del Sureste (Mexico) Mexican Airport Operator	1.0	%
7.	Localiza Rent A Car (Brazil) Car Rental	1.0	%
8.	Gemalto (France) Digital Security Solutions	1.0	%
9.	Partners Group (Switzerland) Private Markets Asset Management	1.0	%
10.	Taiwan Mobile (Taiwan) Taiwan's Second Largest Mobile Operator	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 Shares

September 23, 1992 (Fund inception) through December 31, 2012

This chart shows the change in value of a hypothetical $10,000 investment in Class Z shares of the Fund during the stated time period, and does not reflect the deduction of taxes that a shareholder may pay on Fund distributions or on the redemption of Fund shares.

Total Net Assets of the Fund: $6.7 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.

Columbia Acorn USA (Class Z shares) ended the fourth quarter of 2012 up 3.17%, outperforming the 1.85% gain of its primary benchmark, the Russell 2000 Index. For the annual period, the Fund also topped the benchmark with an 18.98% gain versus a 16.35% return for the Russell 2000 Index.

The top contributor to performance in the fourth quarter came from teen apparel retailer Abercrombie & Fitch, up 42% on improved U.S. earnings results, a reduction in excess inventory and a large share buy-back executed in the quarter. Global branded apparel manufacturer Warnaco Group also had a strong quarter, gaining 38% after announcing that it was to be acquired by PVH Corp. The Fund also profited from the other side of the deal table, as casino operator Pinnacle Entertainment gained 29% in the quarter on news it would acquire Ameristar Casinos.

Car rental company Avis Budget Group was up 29% in the fourth quarter and ended the year up 85%, benefiting from high fleet utilization and what we believe could be a new trend of positive rental car pricing in the industry. IPG Photonics rose 17% in the fourth quarter and was up 99% for the year. Revenue growth was strong as IPG's fiber laser technology continued to gain acceptance across a wide range of new applications. Convention hotel operator Ryman Hospitality Properties issued a large special dividend in advance of its conversion to a real estate investment trust. The stock rose 19% in the fourth quarter and was up 95% for the year.

The top contributor to Fund performance for the year was premium active apparel retailer lululemon atheletica, up 63% as growing brand awareness continued to fuel earnings growth. Industrial companies Nordson and Ametek had annual gains of 55% and 34%, respectively. Nordson's dispensing systems for adhesives and coatings are in high demand from a wide spectrum of product manufacturers, including, of particular note, smartphone and tablet producers. Ametek, a maker of aerospace and industrial instruments, continued to take market share, which propelled earnings nearly 20% higher year-to-date through September.

Several technology stocks detracted from Fund performance. Micros Systems, a developer of information systems used by the hospitality industry, fell 14% in the quarter and 9% for the year. Data integration software developer Informatica was off 13% for the quarter and 18% for the year. Both fell on disappointing sales results. Atmel, a manufacturer of microcontrollers, ended the year on a strong note with a fourth quarter gain of 25%, but it was not enough to offset earlier losses. For the year, Atmel's stock was down 19%, beset by declining revenues and a lost contract bid.

Biotechnology stocks also marred performance. In the fourth quarter, Isis Pharmaceuticals, Auxilium Pharmaceuticals and ARIAD Pharmaceuticals had losses ranging from 21% to 34%. Isis and ARIAD both had drugs that were approved by the FDA, but Isis received negative callouts from the FDA panel and ARIAD was required to add a warning label to its product. We sold the Fund's position in Isis. Sales of Auxilium's drug came in short of expectations. For the annual period, Chelsea Therapeutics International fell 85% as data presented to the FDA failed to warrant a reversal of a prior rejection of Chelsea's drug for hypo-tension.

On the first trading day of the New Year, small-cap stock indexes hit all-time record highs to very little fanfare. It's as though we're stuck in a stealth bull market that few feel comfortable acknowledging. Traumatized by the market's plunge four long years ago, investors have in general remained suspicious and skeptical about stocks (with the notable exception of their crush on Apple). We believe this is not at all a bad thing, for bull markets typically keep grinding higher until sometime after the crowd's skepticism twists into enthusiasm, and we hope the current one will do the same.

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.

Fund's Positions in Mentioned Holdings

As a percentage of net assets, as of 12/31/12

Nordson	2.9	%
Ametek	2.5
lululemon atheletica	2.5
Ryman Hospitality Properties	2.4
IPG Photonics	2.2
Informatica	1.7
Micros Systems	1.7
Avis Budget Group	1.6
Abercrombie & Fitch	1.4
Pinnacle Entertainment	0.7
ARIAD Pharmaceuticals	0.6
Atmel	0.5
Auxilium Pharmaceuticals	0.1
Chelsea Therapeutics International	0.0	*

* Rounds to less than 0.1%.

16

Columbia Acorn USA

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 performance data current to the most recent month-end. Market indexes are unmanaged; their results do not reflect the effect of expenses or sales charges. Securities in the Fund may not match those in an index.

Average Annual Total Returns for period ended December 31, 2012

	4th quarter			1 year			5 years			10 years			Life of Fund
Class Z (9/4/96 inception)		3.17	%		18.98	%		3.67	%		10.40	%		10.05	%
Class A (10/16/00 inception)
without sales charge		3.11			18.67			3.39			10.05			9.67
with sales charge		-2.82			11.86			2.17			9.39			9.27
Russell 2000 Index*		1.85			16.35			3.56			9.72			7.31

Results for other share classes can be found on Page 2.

*The Fund's primary benchmark. Please see Page 1 for index definitions.

All results shown assume reinvestment of distributions. The Fund's Class Z share annual operating expense ratio, as stated in the May 1, 2012, prospectus, is 1.05% and the Class A share expense ratio is 1.33%. Class Z shares are sold at NAV, have limited eligibility and the investment minimum requirement may vary. Only eligible investors may purchase Class Z shares of the Fund, directly or by exchange. Please see the Fund's prospectuses for eligibility and other details. Returns for Class A shares are shown with and without the maximum initial sales charge of 5.75%. The returns shown for periods prior to the inception of the 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.

Portfolio Diversification

as a percentage of net assets, as of 12/31/12

Top 10 Holdings

as a percentage of net assets, as of 12/31/12

1.	Nordson Dispensing Systems for Adhesives & Coatings	2.9	%
2.	Ametek Aerospace/Industrial Instruments	2.5	%
3.	lululemon athletica Premium Active Apparel Retailer	2.5	%
4.	Ryman Hospitality Properties Convention Hotels	2.4	%
5.	tw telecom Fiber Optic Telephone/Data Services	2.3	%
6.	IPG Photonics Fiber Lasers	2.2	%
7.	Mettler-Toledo International Laboratory Equipment	2.2	%
8.	Extra Space Storage Self Storage Facilities	2.1	%
9.	Atwood Oceanics Offshore Drilling Contractor	2.1	%
10.	ESCO Technologies Automatic Electric Meter Readers	2.0	%

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 USA Class Z Shares

September 4, 1996 (Fund inception) through December 31, 2012

This chart shows the change in value of a hypothetical $10,000 investment in Class Z shares of the Fund during the stated time period, and does not reflect the deduction of taxes that a shareholder may pay on Fund distributions or on the redemption of Fund shares.

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.

Columbia Acorn International Select (Class Z shares) ended the fourth quarter of 2012 down 1.49%, underperforming the 5.35% gain of its primary benchmark, the S&P Developed Ex-U.S. Between $2B and $10B Index. Even with the lag in the fourth quarter, the Fund's annual gain remained well ahead of its benchmark, up 22.42% versus the benchmark's 16.78% return. As I have mentioned in previous reports, Columbia Acorn International Select is managed with a preference for quality, high cash flow and dividend yield, strong balance sheet, and less cyclical businesses. This style generally does well in more difficult or lower growth periods but can lag when the market takes a euphoric turn either due to unexpectedly loose monetary policy or strong economic growth. The fourth quarter was certainly one of those times. Investors globally became more optimistic about economic growth as the market felt the effect of significant monetary stimulus in the United States and Japan. As a result, investors switched their attention to more cyclical companies, an area where the Fund is significantly underweight. In addition, the Fund's hedge in gold and silver mining stocks, which were very successful in the third quarter, reversed their gains.

Jupiter Telecommunications, the largest cable service provider in Japan, was the top contributor to Fund performance in the fourth quarter, up 28%, and its stock was up nearly 30% for the year. We opted to sell the Fund's position as the gain was driven by the decision of the two largest shareholders to purchase the company and take it private. Far EasTone Telecom, a Taiwanese mobile device operator, had a 3% gain in the fourth quarter and was up 41% for the annual period. The company continued to benefit from growing smartphone sales and data usage. Hexagon, a Swedish software developer, gained 18% in the quarter and ended the year up 70% thanks to its continued investment in higher quality and automated manufacturing. German online payment processor Wirecard's 7% fourth quarter gain added to the stock's 54% annual return. Stock gains were driven by a continuation of strong online payment growth as consumers became more comfortable doing business over the Internet.

Singaporean industrial property landlords Ascendas REIT, Mapletree Industrial Trust and Mapletree Logistics Trust ended the year with annual gains ranging from 44% to 53%. In the fourth quarter, Mapletree Logistics Trust gained 5%, Ascendas REIT rose 1% and Mapletree Industrial Trust fell 1%. While these stocks cooled at year end due to investor preference for more cyclical stocks, the strong economic outlook for Singapore and the real estate investment trust's (REIT) high dividend yields drove interest in these stocks throughout the year.

The Fund's largest detractor from performance was Japanese online apparel retailer Start Today, off 35% in the quarter and 40% for the year. The stock fell on a slowdown in revenue growth. Adcock Ingram Holdings was also down for both the quarter and annual periods, off 15% and 19%, respectively. This South African manufacturer of pharmaceuticals and medical supplies suffered from increasing price competition and we elected to sell the stock out of the portfolio.

The Fund saw a reversal in the performance of its mining stocks in the fourth quarter. Allied Nevada Gold and Alamos Gold were added to the Fund in the quarter, but ended the period down 23% and 13%, respectively. Canada-listed Goldcorp fell 20% and China's Zhaojin Mining Industry was down 12%. For the year, Goldcorp and Zhaojin were up only slightly. We opted to sell the Fund's position in Zhaojin and reallocate the funds to better quality ideas.

We believe that the main question going into 2013 is the sustainability of the current rally. Have we sufficiently solved many of our economic and financial problems? Is it enough to get the global economy back on the track of sustainable growth? While I remain skeptical, these are questions that bear further serious consideration and I will continue to reassess the Fund's current positioning to determine whether or not changes to the portfolio are warranted.

International investing involves special risks, including foreign taxation, currency risks, risks associated with possible differences in financial standards, operational and settlement risks 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.

Fund's Positions in Mentioned Holdings

As a percentage of net assets, as of 12/31/12

Far EasTone Telecom	7.5	%
Ascendas REIT	6.8
Goldcorp	4.8
Mapletree Industrial Trust	4.7
Mapletree Logistics Trust	3.5
Alamos Gold	3.0
Wirecard	2.3
Allied Nevada Gold	2.2
Start Today	2.1
Hexagon	1.3

18

Columbia Acorn International Select

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 performance data current to the most recent month-end. Market indexes are unmanaged; their results do not reflect the effect of expenses or sales charges. Securities in the Fund may not match those in an index.

Average Annual Total Returns for period ended December 31, 2012

	4th quarter			1 year			5 years			10 years			Life of Fund
Class Z (11/23/98 inception)		-1.49	%		22.42	%		0.50	%		13.27	%		9.58	%
Class A (10/16/00 inception)
without sales charge		-1.56			22.05			0.14			12.88			9.21
with sales charge		-7.23			15.03			-1.04			12.22			8.76
S&P Developed Ex-U.S. Between $2B and $10B Index*		5.35			16.78			-1.86			11.17			7.17

Results for other share classes can be found on Page 2.

*The Fund's primary benchmark. Please see Page 1 for index definitions.

All results shown assume reinvestment of distributions. The Fund's Class Z share annual operating expense ratio, as stated in the May 1, 2012, prospectus, is 1.25% and the Class A share expense ratio is 1.62%. Class Z shares are sold at NAV, have limited eligibility and the investment minimum requirement may vary. Only eligible investors may purchase Class Z shares of the Fund, directly or by exchange. Please see the Fund's prospectuses for eligibility and other details. Returns for Class A shares are shown with and without the maximum initial sales charge of 5.75%. The returns shown for periods prior to the inception of the 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.

Portfolio Diversification

as a percentage of net assets, as of 12/31/12

Top 10 Holdings

as a percentage of net assets, as of 12/31/12

1.	Far EasTone Telecom (Taiwan) Taiwan's Third Largest Mobile Operator	7.5	%
2.	Ascendas REIT (Singapore) Industrial Property Landlord	6.8	%
3.	Fresnillo (Mexico) Silver & Metal Byproduct Mining in Mexico	6.0	%
4.	Goldcorp (Canada) Gold Mining	4.8	%
5.	Mapletree Industrial Trust (Singapore) Industrial Property Landlord	4.7	%
6.	Taiwan Mobile (Taiwan) Taiwan's Second Largest Mobile Operator	4.7	%
7.	Challenger Financial (Australia) Largest Annuity Provider	4.1	%
8.	Seven Bank (Japan) ATM Processing Services	3.8	%
9.	Mapletree Logistics Trust (Singapore) Industrial Property Landlord	3.5	%
10.	Commonwealth Property Office Fund (Australia) Australia Prime Office REIT	3.4	%

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 Shares

November 23, 1998 (Fund inception) through December 31, 2012

This chart shows the change in value of a hypothetical $10,000 investment in Class Z shares of the Fund during the stated time period, and does not reflect the deduction of taxes that a shareholder may pay on Fund distributions or on the redemption of Fund shares.

Total Net Assets of the Fund: $380.4 million

19

Columbia Acorn Select

In a Nutshell

Ben Andrews Lead Portfolio Manager	Robert A. Chalupnik 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 most recent month-end performance updates.

Columbia Acorn Select (Class Z shares) gained 2.04% in the fourth quarter of 2012, underperforming the S&P MidCap 400 Index, the Fund's primary benchmark, which was up 3.61%. The large-cap S&P 500 Index lost 0.38% in the fourth quarter. For the year, Columbia Acorn Select was up 17.15%, the S&P Midcap 400 Index gained 17.88%, and the S&P 500 Index was up 16.00%.

We've mentioned previously the repositioning of the Fund into more core growth companies. We believe this repositioning contributed to the solid returns that we experienced this year, as most of the Fund's core growth stocks outperformed its riskier opportunistic holdings (which usually have turnaround characteristics). Though such opportunistic holdings cost the Fund some performance in 2012, we still believe in using this strategy within the Fund, but to a lesser degree. When the Fund makes investments in opportunistic stocks, we have typically sought to purchase the stocks at historic low valuations, such as on a multiple of revenue or cash on their balance sheet. If the turnaround took longer than we anticipated or if we were wrong and it never happened, the already low valuation could serve to lower the risk that the Fund would experience a substantial principal loss from the investment. We believe the risk of principal loss has increased, however, since the end of 2009, as the economy has grown slowly and money flows into the equity market have been continuously negative. In particular, with money continuing to flow out of stocks, we have seen valuation compression in the Fund's opportunistic stocks in cases where we believe the market was less certain of their future turnaround. As a result, we lost capital in opportunistic stocks where our analysis or timing was incorrect. Therefore, it is particularly crucial that we are correct in our analysis and timing before making an investment in an opportunistic stock in today's market environment.

Co-portfolio manager Rob Chalupnik has played a key role in the repositioning of the Fund into more core growth names. Two stocks that Rob selected for the Fund's portfolio were top contributors to performance for the year. Ryman Hospitality Properties and Ametek combined added over 3.5% of portfolio annual performance. Ryman Hospitality Properties, formerly Gaylord Entertainment, runs convention hotel properties and was up 95% in the year as travel picked up in the United States and as a result of its conversion to a real estate investment trust. Ametek, a global manufacturer of aerospace and industrial instruments, gained market share in a soft economy and added over 1.5% to portfolio performance for the year with its 34% gain.

Financials were also a strong driver of portfolio performance in 2012. Discover Financial Services, which offers the Discover Card, and CNO Financial Group, a provider of life, long-term care and medical supplemental insurance, were up 62% and 49%, respectively, for the year and added over 5% of portfolio performance.

Energy stocks detracted from the Fund's annual performance, with six energy names costing the Fund 3.3% of performance for the year. Colombian oil exploration companies Canacol and Houston American Energy, down 58% and 98%, respectively, cost the Fund roughly 2%. Both had disappointing exploration results. Houston American Energy drilled three wells in Colombia and all three were dry holes, leaving the company low on funds and with a questionable future. We opted to sell the Fund's position in the stock.

During the fourth quarter, we purchased Airgas, the United States' largest distributor of industrial, medical, and specialty gases. We also added Choice Hotels, owner of the Comfort Inn, Clarion, and Quality Inn hotel brands, among others, to the portfolio.

We sold out of business software company Concur Technologies. Though its sales have been growing, we felt its valuation was high and that operating margins may compress, leaving the company with flat year-over-year earnings. We also exited luxury goods retailer Tiffany & Co. as we believe its near-term sales growth data is murky and that we can find other ideas with more top-line visibility. We swapped out of Expeditors International of Washington in favor of Forward Air, a provider of time-definite surface transportation and logistics to the North American air freight market. We believe domestic transportation is growing faster than trans-Pacific (which Expeditors International caters to), and domestic is not suffering from the overcapacity that exists in ocean freight (which is one of Expeditors International's strong suits). In addition, Forward Air is increasing its pickup and delivery business of goods it handles.

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 investing involves special risks, including foreign taxation, currency risks, risks associated with possible differences in financial standards, operational and settlement risks 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.

Fund's Positions in Mentioned Holdings

As a percentage of net assets, as of 12/31/12

Ametek	6.0	%
Discover Financial Services	5.6
CNO Financial Group	5.4
Ryman Hospitality Properties	4.1
Canacol	1.0
Airgas	0.7
Forward Air	0.4
Choice Hotels	0.3

20

Columbia Acorn Select

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 performance data current to the most recent month-end. Market indexes are unmanaged; their results do not reflect the effect of expenses or sales charges. Securities in the Fund may not match those in an index.

Average Annual Total Returns for period ended December 31, 2012

	4th quarter			1 year			5 years			10 years			Life of Fund
Class Z (11/23/98 inception)		2.04	%		17.15	%		0.33	%		8.62	%		9.33	%
Class A (10/16/00 inception)
without sales charge		1.99			16.87			0.04			8.28			8.98
with sales charge		-3.87			10.15			-1.14			7.64			8.52
S&P MidCap 400 Index*		3.61			17.88			5.15			10.53			9.21

Results for other share classes can be found on Page 2.

*The Fund's primary benchmark. Please see Page 1 for index definitions.

All results shown assume reinvestment of distributions. The Fund's Class Z share annual operating expense ratio, as stated in the May 1, 2012, prospectus, is 1.00% and the Class A share expense ratio is 1.35%. Class Z shares are sold at NAV, have limited eligibility and the investment minimum requirement may vary. Only eligible investors may purchase Class Z shares of the Fund, directly or by exchange. Please see the Fund's prospectuses for eligibility and other details. Returns for Class A shares are shown with and without the maximum initial sales charge of 5.75%. The returns shown for periods prior to the inception of the 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.

Portfolio Diversification

as a percentage of net assets, as of 12/31/12

Top 10 Holdings

as a percentage of net assets, as of 12/31/12

1.	Ametek Aerospace/Industrial Instruments	6.0	%
2.	Discover Financial Services Credit Card Company	5.6	%
3.	CNO Financial Group Life, Long-term Care & Medical Supplement Insurance	5.4	%
4.	Hertz Largest US Rental Car Operator	5.0	%
5.	Crown Castle International Communications Towers	4.2	%
6.	Ryman Hospitality Properties Convention Hotels	4.1	%
7.	Donaldson Industrial Air Filtration	3.6	%
8.	Amphenol Electronic Connectors	3.4	%
9.	WNS (India) Offshore BPO (Business Process Outsourcing) Services	3.3	%
10.	SBA Communications Communications Towers	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 Select Class Z Shares

November 23, 1998 (Fund inception) through December 31, 2012

This chart shows the change in value of a hypothetical $10,000 investment in Class Z shares of the Fund during the stated time period, and does not reflect the deduction of taxes that a shareholder may pay on Fund distributions or on the redemption of Fund shares.

Total Net Assets of the Fund: $965.6 million

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 (Class Z shares) ended the fourth quarter up 1.52%. This compares to a 0.38% drop of the Fund's primary equity benchmark, the S&P 500 Index, and a 0.22% gain of its primary debt benchmark, the Barclays U.S. Aggregate Bond Index. Weighted returns for the equity and income portions of the Fund were up 1.09% and 1.60%, respectively. The equity portion's tilt toward international and small- and mid-caps helped that portion to beat the S&P 500 Index, and the bond portion's tilt toward higher yields contributed to its outperformance of the bond index.

For the year, the Fund was up 13.69%, the S&P 500 Index gained 16.00% and the Barclays U.S. Aggregate Bond Index rose 4.22%. The equity portion of the Fund had a 17.14% weighted average gain with top underlying fund performance coming from Columbia Acorn International, up 21.69% (Class I shares). On the income side of the Fund, the annual weighted average gain was 8.59% with the higher yielding Columbia Income Opportunities Fund's 14.55% gain contributing heavily to that number.

The Fund hit three reallocation triggers during the fourth quarter, increasing stock exposure in October and November and reducing it in December. At the end of the period, the Fund had a 45% weighting in its underlying stock funds and a 55% weighting in its bond funds.

As a result of the periodic review of underlying funds called for by Columbia Thermostat Fund's prospectus, effective December 10, 2012, the following changes were made to the Fund's fixed income allocation:

•  The weighting of Columbia Intermediate Bond Fund was reduced from 50% to 30%.

•  Columbia Short Term Bond Fund, which provides exposure to the shorter duration investment-grade debt style, was added to the Fund's portfolio with a weighting of 40%.

•  Columbia U.S. Treasury Index Fund was removed from the portfolio.

These changes were driven by a concern over the possibility of rising interest rates in the future, given the current low rate environment, expansionary monetary policy and government budget deficits. The average duration of the bond funds within Columbia Thermostat

Fund was reduced as a result of these changes, lowering the Fund's interest rate risk.

Results of the Funds Owned in Columbia Thermostat Fund

as of December 31, 2012

Stock Funds

Fund	Weightings in category			4th quarter			1 year
Columbia Acorn International, Class I		20	%		4.25	%		21.69	%
Columbia Dividend Income Fund, Class I		20	%		-1.37	%		11.30	%
Columbia Acorn Fund, Class I		15	%		3.03	%		18.02	%
Columbia Select Large Cap Growth Fund, Class I		10	%		-0.92	%		15.51	%
Columbia Acorn Select, Class I		10	%		2.08	%		17.26	%
Columbia Contrarian Core Fund, Class I		15	%		0.51	%		18.92	%
Columbia Large Cap Enhanced Core Fund, Class I		10	%		-1.28	%		16.17	%
Weighted Average Equity Gain		100	%		1.09	%		17.14	%

Bond Funds

Fund	Weightings in category			4th quarter			1 year
Columbia Short Term Bond Fund, Class I*		40	%		0.33	%		2.99	%
Columbia Intermediate Bond Fund, Class I		30	%		1.06	%		7.57	%
Columbia Income Opportunities Fund, Class I		30	%		3.27	%		14.55	%
Weighted Average Income Gain		100	%		1.60	%		8.59	%

*Replaced Columbia U.S. Treasury Index Fund effective December 10, 2012. Weighted average income returns through year-end reflect linked returns between the previous Fund holding and Columbia Short Term Bond Fund.

Columbia Thermostat Fund Rebalancing in the Fourth Quarter

October 15, 2012	45% stocks, 55% bonds
November 8, 2012	50% stocks, 50% bonds
December 10, 2012	45% stocks, 55% bonds

The value of an investment in the Fund is based primarily on the performance of the underlying funds in which its invests. The Fund is subject to the risk that the investment manager's decisions regarding asset classes and underlying funds will not anticipate market trends successfully, resulting in a failure to preserve capital or lower total return.

The Fund's investments in the underlying funds may also present certain risks, including the following. Investments made by underlying funds in foreign securities, particularly those in emerging markets countries, are subject to special risks, including but not limited to a greater degree of social, political and economic volatility than is associated with domestic investments, as well as the risks associated with any differences in financial standards, including foreign taxation. Investments by the underlying funds in small- and mid-cap companies, as well as in restricted securities, pose special risks, including potential illiquidity and price volatility. Underlying funds that concentrate their investments in a single industry sector, such as technology or healthcare, are subject to the risk that companies in the same sector may be similarly affected by economic or market downturns. Risks associated with investments in bond funds include credit risk, interest rate risk, and prepayment and extension risk. Debt securities with the lowest investment grade ratings and unrated securities of comparable quality are more speculative than securities with higher ratings and may experience greater price fluctuations. These securities also tend to be more sensitive to credit risk than higher-rated securities. This is not an offer of the shares of any other mutual fund mentioned herein.

22

Columbia Thermostat Fund

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 performance data current to the most recent month-end. Market indexes are unmanaged; their results do not reflect the effect of expenses or sales charges. Securities in the Fund may not match those in an index.

Average Annual Total Returns for period ended December 31, 2012

	4th quarter			1 year			5 years			10 years			Life of Fund
Class Z (9/25/02 inception)		1.52	%		13.69	%		5.19	%		7.89	%		8.10	%
Class A (3/3/03 inception)
without sales charge		1.47			13.34			4.94			7.61			7.82
with sales charge		-4.35			6.84			3.70			6.97			7.20
S&P 500 Index*		-0.38			16.00			1.66			7.10			7.71
Barclays U.S. Aggregate   Bond Index*		0.22			4.22			5.95			5.18			5.22

Results for other share classes can be found on Page 2.

*The Fund's primary stock and bond benchmarks, respectively. Please see Page 1 for index definitions.

All results shown assume reinvestment of distributions. The Fund's Class Z share annual operating expense ratio, as stated in the May 1, 2012, prospectus, is 0.90% and the Class A share expense ratio is 1.15%. Class Z shares are sold at NAV, have limited eligibility and the investment minimum requirement may vary. Only eligible investors may purchase Class Z shares of the Fund, directly or by exchange. Please see the Fund's prospectuses for eligibility and other details. Returns for Class A shares are shown with and without the maximum initial sales charge of 5.75%. The returns shown for periods prior to the inception of the 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.

Asset Allocation

as a percentage of net assets, as of 12/31/12

Portfolio Weightings

as a percentage of assets in each investment category, as of 12/31/12

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 Acorn Select, Class I	10	%
Columbia Large Cap Enhanced Core Fund, Class I	10	%
Columbia Select Large Cap Growth Fund, Class I	10	%

Bond Mutual Funds

Columbia Short Term Bond Fund, Class I	40	%*
Columbia Intermediate Bond Fund, Class I	30	%
Columbia Income Opportunities Fund, Class I	30	%

*Replaced Columbia U.S. Treasury Index Fund effective December 10, 2012.

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

September 25, 2002 (Fund inception) through December 31, 2012

This chart shows the change in value of a hypothetical $10,000 investment in Class Z shares of the Fund during the stated time period, and does not reflect the deduction of taxes that a shareholder may pay on Fund distributions or on the redemption of Fund shares.

Total Net Assets of the Fund: $874.6 million

23

Columbia Acorn Emerging Markets Fund

In a Nutshell

Fritz Kaegi Lead Portfolio Manager	Stephen Kusmierczak Lead Portfolio Manager
P. Zachary Egan Co-Portfolio Manager	Louis J. Mendes III 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 most recent month-end performance updates.

Columbia Acorn Emerging Markets Fund (Class Z shares) gained 9.08% in the fourth quarter of 2012, outperforming the 7.07% increase in the Fund's primary benchmark, the S&P Emerging Markets Between $500M and $5B Index. For the year, the Fund returned 31.35%, substantially beating the benchmark result of 25.71%. Since inception in August 2011, the Fund's 15.55% annualized advance was more than double the benchmark gain of 6.34%.

Emerging markets' equity returns were up solidly in 2012, and admittedly we have been somewhat surprised by the Fund's strong outperformance in these markets. Our strategy has been to position the Fund conservatively, with the expectation that performance might lag the benchmark in strongly rising markets. The Fund did decline less than the benchmark during the negative second quarter of 2012, so the limited record so far is that the Fund has outperformed in both falling and rising markets.

Energy companies Americas Petrogas and Madalena Ventures were the best performers in the fourth quarter, up 60% and 54%, respectively. Both companies announced successful new well developments, while sentiment towards their key market, Argentina, improved somewhat. Yet for the year, Madalena Ventures was down 65% as Argentina's nationalization of another energy company crushed industry valuations and made it the worst performing holding in 2012. Two consumer staples companies contributed strongly in the fourth quarter. A new idea in the second quarter, Petra Foods jumped 42% following the announcement that Barry Callebaut was buying its cocoa business at a large premium. United Breweries, an Indian brewer, gained 38% in the quarter after its inclusion in the MSCI India Index. The stock rose 135% in 2012 on solid earnings gains, making it the Fund's second best performer for the year. German automotive paint equipment manufacturer Dürr, with a strong position in emerging markets, advanced 36% in the fourth quarter and 113% for the year on consistent revenue and margin growth.

The biggest decliner in the fourth quarter was Arcos Dorados, the largest McDonald's franchise operator in Latin America. Its shares dropped 22% following weak growth in its key Brazilian operations. Taiwanese Internet retailer PC Home fell 18% in the quarter as low utilization in its new warehouse depressed operating margins. NetEase.com, a Chinese online gaming company, experienced a sharp slowdown in revenues during the second and third quarters, and the stock declined 18% on

the news in the fourth quarter. We opted to exit the name. Leading Taiwanese battery pack manufacturer Simplo Technology slid 16% on continued weakness in the PC and notebook markets.

When we introduced Columbia Acorn Emerging Markets Fund in 2011, we believed that the rising consumer class was one of the key themes recommending investing in emerging markets. Through a thoroughly bottom-up process, the Fund's positioning reflects this conviction. The Fund's sizeable overweight in consumer discretionary and staples has widened in 2012 from 28% to roughly 40% of the portfolio. This group also includes four of the Fund's top 10 contributors. On balance, our Columbia Wanger Asset Management analysts appear to have rightly sized their best ideas, meaning that five of the Fund's largest holdings were top 10 performers for the year. An example is Cambodian casino operator Nagacorp, which was the Fund's largest contributor in 2012, up 159%, and also its third largest position.

While the opportunities in many emerging markets' consumer retail stocks are less attractive after big gains, our analysts continue to identify new ideas that should benefit from supportive trends like urbanization, better education, productivity increases following new infrastructure investment, and the emergence of a sizeable middle class.

International investing involves special risks, including foreign taxation, currency risks, risks associated with possible differences in financial standards, operational and settlement risks 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.

Fund's Positions in Mentioned Holdings

As a percentage of net assets, as of 12/31/12

Nagacorp	2.8	%
United Breweries	2.1
PC Home	2.0
Arcos Dorados	1.1
Petra Foods	1.1
Americas Petrogas	1.0
Dürr	0.9
Simplo Technology	0.8
Madalena Ventures	0.4

24

Columbia Acorn Emerging Markets Fund

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 performance data current to the most recent month-end. Market indexes are unmanaged; their results do not reflect the effect of expenses or sales charges. Securities in the Fund may not match those in an index.

Average Annual Total Returns for period ended December 31, 2012

	4th quarter			1 year			Life of Fund
Class Z (8/19/11 inception)		9.08	%		31.35	%		15.55	%
Class A (8/19/11 inception)
without sales charge		8.88			30.86			15.05
with sales charge		2.61			23.40			10.19
S&P Emerging Markets Between $500M and $5B Index*		7.07			25.71			6.34

Results for other share classes can be found on Page 2.

*The Fund's primary benchmark. Please see Page 1 for index definitions.

All results shown assume reinvestment of distributions. The Fund's Class Z share annual operating expense ratio, as stated in the May 1, 2012, prospectus, is 1.60% and the Class A share expense ratio is 1.85%. Class Z shares are sold at NAV, have limited eligibility and the investment minimum requirement may vary. Only eligible investors may purchase Class Z shares of the Fund, directly or by exchange. Please see the Fund's prospectuses for eligibility and other details. Returns for Class A shares are shown with and without the maximum initial sales charge of 5.75%. For purposes of the Fund's principal investment strategies, CWAM generally determines which countries are emerging market countries by reference to the countries included in the S&P Emerging Markets Broad Market Index.

Portfolio Diversification

as a percentage of net assets, as of 12/31/12

Top 10 Holdings

as a percentage of net assets, as of 12/31/12

1.	Far EasTone Telecom (Taiwan) Taiwan's Third Largest Mobile Operator	3.3	%
2.	Tower Bersama Infrastructure (Indonesia) Communications Towers	3.0	%
3.	Nagacorp (Cambodia) Casino/Entertainment Complex in Cambodia	2.8	%
4.	Halyk Savings Bank of Kazakhstan (Kazakhstan) Largest Retail Bank & Insurer in Kazakhstan	2.7	%
5.	Ace Indonesia (Indonesia) Home Improvement Retailer	2.5	%
6.	Hexagon (Sweden) Design, Measurement & Visualization Software & Equipment	2.5	%
7.	Coronation Fund Managers (South Africa) South African Fund Manager	2.4	%
8.	Archipelago Resources (Indonesia) Gold Mining Projects in Indonesia, Vietnam & the Philippines	2.4	%
9.	Dufry Group (Switzerland) Operates Airport Duty Free & Duty Paid Shops	2.3	%
10.	Melco International (Hong Kong) Macau Casino Operator	2.2	%

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 Emerging Markets Fund Class Z Shares

August 19, 2011 (Fund inception) through December 31, 2012

This chart shows the change in value of a hypothetical $10,000 investment in Class Z shares of the Fund during the stated time period, and does not reflect the deduction of taxes that a shareholder may pay on Fund distributions or on the redemption of Fund shares.

Total Net Assets of the Fund: $10.5 million

25

Columbia Acorn European Fund

In a Nutshell

Andreas Waldburg-Wolfegg Lead Portfolio Manager	Stephen Kusmierczak 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.

For 2012, Columbia Acorn European Fund (Class Z shares) returned 25.66% versus its primary benchmark, the S&P Europe Between $500M and $5B Index, up 28.24%. Following strong outperformance in the first half of the year, the Fund lagged the benchmark in the second half. For the fourth quarter, the Fund posted a 5.08% gain while its benchmark rose 8.01%.

Several of the Fund's strongest contributors to annual performance were Eurofins Scientific, Gemalto, GlobeOp Financial Services and Wirecard. French testing company Eurofins Scientific, up 126% for the year, reported strong improvements in operating margins following the consolidation and restructuring of smaller, less efficient laboratories. French digital security solutions provider Gemalto, up 86%, is reaping the benefits of investing heavily in a new product line-up for mobile telephones, secure transactions and access control. Wirecard, up 54%, is a German online payment processor and risk manager. The company consistently reported good operating statistics throughout the year. Finally GlobeOp Financial Services, a U.K. hedge fund administrator, became the object of a takeover battle early in the year, providing the Fund with a 60% gain before its first quarter exit from the portfolio.

The main detractors from performance for the year were Velti, a U.S.-based provider of mobile marketing software, Alliance Grain Traders, a Canada-listed processor of lentils and peas (pulses) with more than half of its sales in Turkey, and CIR, an Italian holding company.

We had bought Velti to diversify our bet on mobile marketing in Europe, where Velti had 60% of its sales. However, the company was unable to get its considerable working capital issues under control and, in the third quarter of 2012, sold a large portion of its European activities to local management. Our investment case, which was premised on the business both remaining mainly European and controlling its working capital, was disproven and we sold the position. The stock had a fourth quarter decline of 57% and was off 48% for the year.

Alliance Grain Traders was off 34% for the year with 9% of the decline coming in the fourth quarter. The company's Middle Eastern clients suffered from a liquidity squeeze in the wake of political turmoil and devaluing currencies in the first quarter. The situation and the stock remained volatile for the rest of the year. With its short-term outlook unclear, this kind of volatility will persist, yet management has delivered on its promises in this tough environment, and we believe the long-term outlook for pulses as a cheap source of protein and fiber remains very strong.

CIR, the holding company of the de Benedetti family, has been suffering from a difficult operating environment in Italian electricity generation and there seems to be no catalyst in sight for either its electricity generation arm or for its health care arm. Its shares fell 7% in the fourth quarter and were down 32% for the year.

Velti and Alliance Grain Traders were significant detractors from performance in the fourth quarter as was FX Energy, an oil and gas exploration company operating in Poland and the United States. The company reported cautious updates for two of its core wells in Poland, depressing the share price more than 40% from the date of the announcement in early October to the end of November. Given the number of projects in Poland that the company is active in and the size of the opportunity, we believe the investment still has long-term value.

Major contributors in the fourth quarter were, again, Eurofins Scientific, up 14%, followed by German automotive plant engineer Dürr, up 34% on consistent revenue and margin growth. German automotive engineer Bertrandt was also strong in the quarter, gaining 36%.

International investing involves special risks, including foreign taxation, currency risks, risks associated with possible differences in financial standards, operational and settlement risks 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.

Fund's Positions in Mentioned Holdings

As a percentage of net assets, as of 12/31/12

Eurofins Scientific	2.8	%
Gemalto	2.5
Wirecard	2.2
Alliance Grain Traders	1.3
Bertrandt	1.3
Dürr	1.0
FX Energy	0.5
CIR	0.2

26

Columbia Acorn European Fund

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 performance data current to the most recent month-end. Market indexes are unmanaged; their results do not reflect the effect of expenses or sales charges. Securities in the Fund may not match those in an index.

Average Annual Total Returns for period ended December 31, 2012

	4th quarter			1 year			Life of Fund
Class Z (8/19/11 inception)		5.08	%		25.66	%		14.00	%
Class A (8/19/11 inception)
without sales charge		4.99			25.46			13.70
with sales charge		-1.07			18.19			8.89
S&P Europe Between $500M and $5B Index*		8.01			28.24			13.57

Results for other share classes can be found on Page 2.

*The Fund's primary benchmark. Please see Page 1 for index definitions.

All results shown assume reinvestment of distributions. The Fund's Class Z share annual operating expense ratio, as stated in the May 1, 2012, prospectus, is 1.50% and the Class A share expense ratio is 1.75%. Class Z shares are sold at NAV, have limited eligibility and the investment minimum requirement may vary. Only eligible investors may purchase Class Z shares of the Fund, directly or by exchange. Please see the Fund's prospectuses for eligibility and other details. Returns for Class A shares are shown with and without the maximum initial sales charge of 5.75%.

Portfolio Diversification

as a percentage of net assets, as of 12/31/12

Top 10 Holdings

as a percentage of net assets, as of 12/31/12

1.	Eurofins Scientific (France) Food, Pharmaceuticals & Materials Screening & Testing	2.8	%
2.	Geberit (Switzerland) Plumbing Supplies	2.8	%
3.	1000 Interactive Advertising and Marketingmercis (France)	2.7	%
4.	Partners Group (Switzerland) Private Markets Asset Management	2.7	%
5.	Hexagon (Sweden) Design, Measurement & Visualization Software & Equipment	2.6	%
6.	Dufry Group (Switzerland) Operates Airport Duty Free & Duty Paid Shops	2.6	%
7.	Gemalto (France) Digital Security Solutions	2.5	%
8.	Archipelago Resources (Indonesia) Gold Mining Projects in Indonesia, Vietnam & the Philippines	2.5	%
9.	Charles Taylor (United Kingdom) Insurance Services	2.3	%
10.	Aalberts Industries (Netherlands) Flow Control & Heat Treatment	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 Shares

August 19, 2011 (Fund inception) through December 31, 2012

This chart shows the change in value of a hypothetical $10,000 investment in Class Z shares of the Fund during the stated time period, and does not reflect the deduction of taxes that a shareholder may pay on Fund distributions or on the redemption of Fund shares.

Total Net Assets of the Fund: $3.2 million

27

Columbia Acorn Fund

Major Portfolio Changes in the Fourth Quarter (Unaudited)

	Number of Shares
	9/30/12		12/31/12
Purchases
Information
Bazaarvoice		141,923		1,700,000
Blackbaud		368,889		900,000
Cree		560,000		720,000
Exa		102,593		872,060
iGATE		3,400,000		3,700,000
InContact		2,110,000		2,200,000
Liquidity Services		100,000		250,000
Monolithic Power Systems		1,165,000		1,415,000
Navigant Consulting		3,500,000		3,704,600
RealPage		0		1,219,511
Rogers		0		35,816
Semtech		0		650,000
Solera Holdings		55,000		155,000
Windstream		0		2,000,000
Industrial Goods & Services
Aalberts Industries  (Netherlands)		2,472,255		2,695,419
Airgas		0		294,180
Albemarle		1,580,000		1,730,000
Ashland		800,000		1,100,000
Forward Air		1,400,000		1,500,000
Imtech (Netherlands)		1,300,000		1,948,368
Insperity		1,546,000		1,800,000
Moog		3,000,000		3,230,000
Polyone		0		1,200,000
Polypore International		1,557,553		1,600,000
Thermon		0		1,065,000
WESCO International		157,843		1,200,000
Consumer Goods & Services
American Eagle Outfitters		1,575,000		1,925,000
B&G Foods		0		700,000
Boulder Brands Inc		0		1,675,000
Casey's General Stores		0		500,000
Choice Hotels		1,100,000		1,337,338
DeVry		600,000		1,300,000
Domino's Pizza		0		370,000
Fossil		527,845		822,845
Lifetime Fitness		2,190,000		2,280,000
Massmart Holdings (South Africa)		388,220		852,000
Pier 1 Imports		6,600,000		7,185,000
Ryman Hospitality Properties		3,850,000		4,520,690
ULTA		0		640,000
Williams-Sonoma		415,000		1,375,000

	Number of Shares
	9/30/12		12/31/12
Finance
Associated Banc-Corp		6,956,800		7,756,800
Brown & Brown		900,000		1,500,000
CAI International		1,123,400		1,397,834
Oriental Financial Group		0		500,000
SEI Investments		6,654,000		7,100,000
Selective Insurance Group		2,050,000		2,625,000
The Hanover Insurance Group		1,120,000		1,400,000
Tower Group		2,764,000		3,300,000
Health Care
DENTSPLY International		1,550,000		1,950,000
Orthofix International		570,000		725,000
PerkinElmer Inc.		950,000		1,475,000
Sarepta Therapeutics		0		955,000
Seattle Genetics		6,153,000		6,550,000
Synageva Biopharma		735,000		1,165,000
Ultragenyx		0		3,610,890
Other Industries
EdR		3,000,000		5,744,300
Hudson Pacific Properties		0		544,330
Kirby		350,000		602,000
Kite Realty Group		3,500,000		4,000,000
Mapletree Commercial Trust  (Singapore)		8,845,000		10,000,000
Pepco Holdings		0		2,200,000
Post Properties		975,000		1,435,000
Summit Hotel Properties		2,476,000		2,850,000
Terreno Realty		0		358,151
Energy & Minerals
Alamos Gold (Canada)		0		1,600,000
Allied Nevada Gold		0		1,150,000
Chart Industries		0		226,889
Dresser-Rand Group		0		400,000
Gulfmark Offshore		0		150,000
Kirkland Lake Gold (Canada)		1,400,000		1,900,000
Regis Resources (Australia)		217,283		1,282,902

See accompanying notes to financial statements.

28

	Number of Shares
	9/30/12		12/31/12
Sales
Information
Ansys		2,550,000		2,350,000
Ariba		300,000		0
Atmel		11,562,000		7,976,000
Concur Technologies		1,400,000		1,130,000
Crown Castle International		4,465,000		4,200,000
Discovery Series C		900,000		720,000
Eloqua		130,881		0
Equinix		450,000		300,000
IXYS		1,900,000		850,000
Kenexa		925,000		0
Lamar Advertising		1,700,000		1,200,000
NetEase.com - ADR (China)		222,400		0
Quality Systems		2,350,000		1,500,000
SABA		2,000,000		148,664
Stratasys		480,000		310,000
Syntel		680,000		616,029
WMS Industries		1,530,000		600,000
Industrial Goods & Services
Albany International		600,000		0
Clarcor		2,213,551		1,750,000
Clean Harbors		560,000		400,000
Expeditors International of Washington		2,900,000		2,600,000
FMC Corporation		1,520,000		1,050,000
Fortune Brands Home & Security		1,350,000		1,050,000
GrafTech International		2,221,812		0
Novozymes (Denmark)		1,525,000		1,000,000
Oshkosh Corporation		2,675,000		2,400,000
Pall		1,800,000		1,660,000
Pentair		1,250,000		0
WABCO Holdings		950,000		750,000
Consumer Goods & Services
Abercrombie & Fitch		2,601,000		2,431,000
Annie's		45,500		0
Cheesecake Factory		450,000		370,000
Coach		2,100,000		1,500,000
Deckers Outdoor		1,310,000		1,060,000
Expedia		1,225,000		1,100,000
Jarden		1,500,000		595,000
lululemon athletica		4,505,000		3,761,540
Monster Beverage		1,700,000		600,000
Olam International (Singapore)		32,000,000		20,000,000
Saks		4,425,000		4,100,000
Skullcandy		1,290,000		975,386
Teavana		971,500		0
The Fresh Market		66,000		0
True Religion Apparel		182,866		0
Warnaco Group		1,460,000		762,000

	Number of Shares
	9/30/12		12/31/12
Finance
Eaton Vance		4,036,000		3,052,000
Willis Group		832,000		0
Health Care
Adcock Ingram Holdings (South Africa)		2,606,333		0
Alexion Pharmaceuticals		1,215,000		800,000
Auxilium Pharmaceuticals		3,250,000		2,202,196
BioMarin Pharmaceutical		3,875,000		3,617,000
Hill-Rom Holdings		925,000		0
Horizon Pharma		1,095,000		0
Isis Pharmaceuticals		3,430,000		0
Patterson Companies		2,126,000		1,676,000
Other Industries
Allete		500,000		0
Associated Estates Realty		3,700,000		3,000,000
Dupont Fabros Technology		3,700,000		3,625,000
Heartland Express		2,400,000		1,773,000
Kilroy Realty		770,000		0
Wisconsin Energy		1,660,000		700,000
Energy & Minerals
Approach Resources		200,000		0
Black Diamond Group (Canada)		893,600		847,600
Celtic Exploration (Canada)		718,000		0
Denbury Resources		2,700,000		1,477,000
FMC Technologies		5,150,000		4,635,000
Horizon North Logistics (Canada)		2,890,900		2,631,339
Hornbeck Offshore		884,000		499,000
Kodiak Oil and Gas		1,100,000		0
Oil States International		513,000		191,000
Pacific Rubiales Energy (Colombia)		3,500,000		2,700,000
Rosetta Resources		974,000		722,000
ShawCor (Canada)		1,670,000		1,334,000
SM Energy		703,000		590,000
Tullow Oil (United Kingdom)		1,050,000		850,000
Vopak (Netherlands)		218,000		0

See accompanying notes to financial statements.

29

Columbia Acorn Fund

Statement of Investments, December 31, 2012

Number of Shares			Value
			Equities: 97.7%
Information 26.7%
		> Business Software 5.9%
	2,350,000	Ansys (a)	$	158,249,000
		Simulation Software for Engineers & Designers
	5,000,000	Informatica (a)		151,600,000
		Enterprise Data Integration Software
	5,450,000	Hexagon (Sweden)		137,820,900
		Design, Measurement & Visualization Software & Equipment
	2,700,000	Micros Systems (a)		114,588,000
		Information Systems for Hotels, Restaurants & Retailers
	1,130,000	Concur Technologies (a)		76,297,600
		Web Enabled Cost & Expense Management Software
	700,000	NetSuite (a)		47,110,000
		End-to-end IT Systems Solutions Delivered Over the Web
	900,000	Tyler Technologies (a)		43,596,000
		Financial, Tax, Court & Document Management Systems for Local Governments
	700,000	Red Hat (a)		37,072,000
		Maintenance & Support for Opensource Operating System & Middleware
	900,000	SPS Commerce (a)(b)		33,543,000
		Supply Chain Management Software Delivered via the Web
	1,450,000	TIBCO (a)		31,914,500
		Datacenter Software
	750,000	Jack Henry & Associates		29,445,000
		IT Systems & Outsourced IT Solutions for Financial Institutions
	1,219,511	RealPage (a)		26,304,852
		Software for Managing Rental Properties Delivered Via the Web
	1,500,000	Quality Systems		26,040,000
		IT Systems for Medical Groups & Ambulatory Care Centers
	900,000	Blackbaud		20,547,000
		Software & Services for Non-profits
	1,200,000	Constant Contact (a)		17,052,000
		Email & Other Marketing Campaign Management Systems Delivered Over Web
	1,700,000	Bazaarvoice (a)(c)		15,895,000
		Platform for Managing Consumer Interaction Via the Web
	500,000	DemandWare (a)		13,660,000
		eCommerce Website Solutions for Retailers & Apparel Manufacturers
	2,700,000	Velti (a)(c)		12,150,000
		Mobile Marketing Software Platform
	2,200,000	InContact (a)		11,396,000
		Call Center Systems Delivered Via the Web & Telco Services
	872,060	Exa (a)(b)		8,485,144
		Simulation Software
	155,000	Solera Holdings		8,287,850
		Software for Automotive Insurance Claims Processing

Number of Shares			Value
	900,000	Active Network (a)	$	4,419,000
		Web-delivered Software Solutions for Managing Events & Activities
	148,664	SABA (a)		1,299,323
		Learning Management Systems
				1,026,772,169
		> Instrumentation 3.5%
	1,600,000	Mettler-Toledo International (a)(b)		309,280,000
		Laboratory Equipment
	2,780,000	IPG Photonics (b)(c)		185,287,000
		Fiber Lasers
	2,035,000	Trimble Navigation (a)		121,652,300
		GPS-based Instruments
				616,219,300
		> Mobile Communications 3.1%
	4,200,000	Crown Castle International (a)		303,072,000
		Communications Towers
	3,400,000	SBA Communications (a)		241,468,000
		Communications Towers
	1,200,000	Globalstar (a)(c)		366,000
		Satellite Mobile Voice & Data Carrier
				544,906,000
		> Computer Hardware & Related Equipment 2.7%
	3,415,000	Amphenol		220,950,500
		Electronic Connectors
	4,550,000	II-VI (a)(b)		83,128,500
		Laser Optics & Specialty Materials
	1,365,000	Zebra Technologies (a)		53,617,200
		Bar Code Printers
	900,000	Netgear (a)		35,478,000
		Networking Products for Small Business & Home
	800,000	Nice Systems - ADR (Israel) (a)		26,784,000
		Audio & Video Recording Solutions
	310,000	Stratasys (a)(c)		24,846,500
		Rapid Prototyping Systems
	250,000	Gemalto (France)		22,566,209
		Digital Security Solutions
	35,816	Rogers (a)		1,778,623
		Printed Circuit Materials & High-performance Foams
				469,149,532
		> Semiconductors & Related Equipment 2.2%
	7,932,000	ON Semiconductor (a)		55,920,600
		Mixed Signal & Power Management Semiconductors
	7,976,000	Atmel (a)		52,242,800
		Microcontrollers, Radio Frequency & Memory Semiconductors
	5,000,000	Entegris (a)		45,900,000
		Semiconductor Materials Management Products
	2,160,000	Microsemi (a)		45,446,400
		Analog/Mixed Signal Semiconductors
	1,415,000	Monolithic Power Systems		31,526,200
		High Performance Analog & Mixed Signal Integrated Circuits

See accompanying notes to financial statements.

30

Number of Shares			Value
		> Semiconductors & Related Equipment—continued
	420,000	Littelfuse	$	25,918,200
		Little Fuses
	400,000	Hittite Microwave (a)		24,840,000
		Radio Frequency, Microwave & Millimeterwave Semiconductors
	720,000	Cree (a)(c)		24,465,600
		LED Lighting, Components & Chips
	615,000	Ultratech (a)		22,939,500
		Semiconductor Equipment
	650,000	Semtech (a)		18,817,500
		Analog Semiconductors
	1,765,000	Pericom Semiconductor (a)(b)		14,172,950
		Interface Integrated Circuits & Frequency Control Products
	2,290,000	TriQuint Semiconductor (a)		11,083,600
		Radio Frequency Semiconductors
	850,000	IXYS		7,769,000
		Power Semiconductors
				381,042,350
		> Telephone & Data Services 1.9%
	9,500,000	tw telecom (a)(b)		241,965,000
		Fiber Optic Telephone/Data Services
	2,200,000	Cogent Communications		49,808,000
		Internet Data Pipelines
	2,000,000	Windstream (c)		16,560,000
		Business & Rural Telecom Services
	1,500,000	General Communications (a)		14,385,000
		Commercial Communications & Consumer CATV, Web & Phone in Alaska
	1,900,000	Boingo Wireless (a)(b)(c)		14,345,000
		Wholesale & Retail WiFi Networks
				337,063,000
		> Computer Services 1.3%
	3,700,000	iGATE (a)(b)		58,349,000
		IT & Business Process Outsourcing Services
	1,618,000	ExlService Holdings (a)(b)		42,877,000
		Business Process Outsourcing
	2,125,000	Virtusa (a)(b)		34,913,750
		Offshore IT Outsourcing
	616,029	Syntel		33,012,994
		Offshore IT Services
	1,705,000	Genpact		26,427,500
		Business Process Outsourcing
	3,849,207	Hackett Group (b)		16,474,606
		IT Integration & Best Practice Research
	1,491,353	WNS - ADR (India) (a)		15,539,898
		Offshore BPO (Business Process Outsourcing) Services
				227,594,748
		> Gaming Equipment & Services 1.0%
	3,725,000	Bally Technologies (a)(b)		166,544,750
		Slot Machines & Software
	600,000	WMS Industries (a)		10,500,000
		Slot Machine Provider
				177,044,750

Number of Shares			Value
		> Internet Related 0.8%
	300,000	Equinix (a)	$	61,860,000
		Network Neutral Data Centers
	1,325,000	TripAdvisor (a)		55,597,000
		Online Travel Research
	727,000	Yandex (Russia) (a)		15,681,390
		Search Engine for Russian & Turkish Languages
	900,000	Angie's List (a)(c)		10,791,000
		Consumer Subscription & Internet Advertising
	86,700	Trulia (a)(c)		1,408,008
		Real Estate Broker Subscription & Advertising
				145,337,398
		> Business Information & Marketing Services 0.8%
	1,900,000	Verisk Analytics (a)		96,900,000
		Risk & Decision Analytics
	3,704,600	Navigant Consulting (a)(b)		41,343,336
		Financial Consulting Firm
	505,000	RPX (a)		4,565,200
		Patent Aggregation & Defensive Patent Consulting
				142,808,536
		> Telecommunications Equipment 0.7%
	640,000	F5 Networks (a)		62,176,000
		Internet Traffic Management Equipment
	1,730,000	Ixia (a)		29,375,400
		Telecom Network Test Equipment
	1,675,000	Finisar (a)		27,302,500
		Optical Subsystems & Components
	1,925,000	Infinera (a)(c)		11,184,250
		Optical Networking Equipment
				130,038,150
		> Financial Processors 0.7%
	1,700,000	Global Payments		77,010,000
		Credit Card Processor
	5,000,000	Singapore Exchange (Singapore)		29,055,467
		Singapore Equity & Derivatives Market Operator
	250,000	Liquidity Services (a)		10,215,000
		E-Auctions for Surplus & Salvage Goods
				116,280,467
		> CATV 0.7%
	800,000	Liberty Global Series A (a)		50,392,000
		Cable TV Franchises Outside the US
	720,000	Discovery Series C (a)		42,120,000
		Cable TV Programming
	18,000	Jupiter Telecommunications (Japan)		22,418,191
		Largest Cable Service Provider in Japan
				114,930,191
		> Electronics Distribution 0.6%
	3,125,000	Avnet (a)		95,656,250
		Electronic Components Distribution
				95,656,250

See accompanying notes to financial statements.

31

Columbia Acorn Fund

Statement of Investments, continued

Number of Shares			Value
		> Contract Manufacturing 0.4%
	3,800,000	Sanmina-SCI (a)	$	42,066,000
		Electronic Manufacturing Services
	960,000	Plexus (a)		24,768,000
		Electronic Manufacturing Services
				66,834,000
		> Advertising 0.3%
	1,200,000	Lamar Advertising (a)		46,500,000
		Outdoor Advertising
				46,500,000
		> Entertainment Programming 0.1%
	1,100,000	IMAX (Canada) (a)(c)		24,728,000
		IMAX Movies, Theatre Equipment & Theatre Joint Ventures
				24,728,000
		> TV Broadcasting —%
	2,500,000	Entravision Communications		4,150,000
		Spanish Language TV & Radio Stations
	1,750,000	Gray Television (a)		3,850,000
		Mid-market Affiliated TV Stations
				8,000,000
		> Consumer Software —%
	273,500	Carbonite (a)(c)		2,529,875
		Online Data Storage
				2,529,875
Information: Total				4,673,434,716
Industrial Goods & Services 20.6%
		> Machinery 11.6%
	10,125,000	Ametek		380,396,250
		Aerospace/Industrial Instruments
	8,400,000	Donaldson (b)		275,856,000
		Industrial Air Filtration
	3,125,000	Nordson		197,250,000
		Dispensing Systems for Adhesives & Coatings
	3,725,000	Kennametal		149,000,000
		Consumable Cutting Tools
	3,230,000	Moog (a)(b)		132,526,900
		Motion Control Products for Aerospace, Defense & Industrial Markets
	1,660,000	Pall		100,031,600
		Life Science, Water & Industrial Filtration
	3,063,000	HEICO (b)		97,954,740
		FAA Approved Aircraft Replacement Parts
	2,725,000	Generac		93,494,750
		Standby Power Generators
	1,750,000	Clarcor		83,615,000
		Mobile Equipment & Industrial Filters
	2,200,000	ESCO Technologies (b)		82,302,000
		Automatic Electric Meter Readers
	1,600,000	Polypore International (a)(c)		74,400,000
		Battery Separators & Filtration Media
	2,400,000	Oshkosh Corporation (a)		71,160,000
		Specialty Truck Manufacturer

Number of Shares			Value
	1,610,000	Toro	$	69,197,800
		Turf Maintenance Equipment
	435,000	Valmont Industries		59,399,250
		Center Pivot Irrigation Systems & Utility Poles
	600,000	Wabtec		52,524,000
		Freight & Transit Component Supplier
	750,000	WABCO Holdings (a)		48,892,500
		Truck & Bus Component Supplier
	170,000	Middleby (a)		21,795,700
		Manufacturer of Cooking Equipment
	400,000	Neopost (France) (c)		21,212,712
		Postage Meter Machines
	10,000,000	Marel (Iceland)		11,025,103
		Largest Manufacturer of Poultry & Fish Processing Equipment
	1,000,000	Spartan Motors		4,930,000
		Specialty Truck & Chassis Manufacturer
				2,026,964,305
		> Industrial Materials & Specialty Chemicals 2.5%
	1,730,000	Albemarle		107,467,600
		Specialty Chemicals for Refineries, Plastics, Pharma, Food
	1,100,000	Ashland		88,451,000
		Diversified Chemicals Company
	1,050,000	FMC Corporation		61,446,000
		Niche Specialty Chemicals
	1,880,000	Drew Industries (b)		60,630,000
		RV & Manufactured Home Components
	673,000	Sociedad Quimica y Minera de Chile - ADR (Chile)		38,791,720
		Producer of Specialty Fertilizers, Lithium & Iodine
	1,000,000	Novozymes (Denmark)		28,386,637
		Industrial Enzymes
	1,200,000	Polyone		24,504,000
		Intermediate Stage Chemicals Producer
	2,218,700	Kansai Paint (Japan)		23,910,669
		Paint Producer in Japan, India, China & Southeast Asia
	200,000	Silgan Holdings		8,318,000
		Metal & Plastic Packaging
				441,905,626
		> Other Industrial Services 1.8%
	2,600,000	Expeditors International of Washington		102,830,000
		International Freight Forwarder
	2,700,000	LKQ (a)		56,970,000
		Alternative Auto Parts Distribution
	1,500,000	Forward Air (b)		52,515,000
		Freight Transportation Between Airports
	1,948,368	Imtech (Netherlands)		45,254,792
		Technical Installation & Maintenance
	1,600,000	Mobile Mini (a)		33,328,000
		Portable Storage Units Leasing
	1,512,352	Acorn Energy (b)(c)		11,811,469
		Frac Well Exploration/Monitoring Device, Sonar Security, Electric Grid Monitoring

See accompanying notes to financial statements.

32

Number of Shares			Value
		> Other Industrial Services—continued
	500,000	UTI Worldwide	$	6,700,000
		Freight Forwarding & Logistics
				309,409,261
		> Construction 1.5%
	2,850,000	Chicago Bridge & Iron		132,097,500
		Engineering & Construction for Liquefied Natural Gas & Petrochemicals
	72,000	NVR (a)		66,240,000
		DC Homebuilder
	1,050,000	Fortune Brands Home & Security (a)		30,681,000
		Home Building Supplies & Small Locks
	1,800,000	Mills Estruturas e Servicos de Engenharia (Brazil)		29,890,110
		Civil Engineering & Construction
				258,908,610
		> Electrical Components 1.0%
	1,765,000	Acuity Brands		119,543,450
		Commercial Lighting Fixtures
	1,065,000	Thermon (a)		23,994,450
		Global Engineered Thermal Solutions
	1,500,000	Ushio (Japan)		16,448,568
		Industrial Light Sources
	351,000	Saft (France)		8,260,374
		Niche Battery Manufacturer
				168,246,842
		> Outsourcing Services 0.8%
	2,800,000	Quanta Services (a)		76,412,000
		Electrical & Telecom Construction Services
	1,800,000	Insperity (b)		58,608,000
		Professional Employer Organization
	600,000	GP Strategies (a)		12,390,000
		Outsourced Training Services
				147,410,000
		> Industrial Distribution 0.6%
	1,200,000	WESCO International (a)		80,916,000
		Industrial Distribution
	294,180	Airgas		26,855,692
		Industrial Gas Distributor
				107,771,692
		> Waste Management 0.5%
	2,050,000	Waste Connections		69,269,500
		Solid Waste Management
	400,000	Clean Harbors (a)		22,004,000
		Hazardous Waste Services & Disposal
				91,273,500
		> Conglomerates 0.3%
	2,695,419	Aalberts Industries (Netherlands)		56,431,490
		Flow Control & Heat Treatment
				56,431,490
Industrial Goods & Services: Total				3,608,321,326

Number of Shares			Value
Consumer Goods & Services 17.5%
		> Retail 5.7%
	3,761,540	lululemon athletica (a)	$	286,742,194
		Premium Active Apparel Retailer
	7,185,000	Pier 1 Imports (b)		143,700,000
		Home Furnishing Retailer
	2,431,000	Abercrombie & Fitch		116,615,070
		Teen Apparel Retailer
	2,835,000	Shutterfly (a)(b)		84,681,450
		Internet Photo-centric Retailer
	822,845	Fossil (a)		76,606,870
		Watch Designer & Retailer
	640,000	ULTA		62,886,400
		Specialty Beauty Product Retailer
	1,375,000	Williams-Sonoma		60,183,750
		Home Goods & Furnishing Retailer
	4,100,000	Saks (a)(c)		43,091,000
		Luxury Department Store Retailer
	1,925,000	American Eagle Outfitters		39,481,750
		Teen Apparel Retailer
	525,000	DSW		34,487,250
		Branded Footwear Retailer
	500,000	Casey's General Stores		26,550,000
		Owner/Operator of Convenience Stores
	852,000	Massmart Holdings (South Africa)		19,317,084
		General Merchandise, Food & Home Improvement Stores; Wal-Mart Subsidiary
	1,371,366	Gaiam (a)(b)		4,333,517
		Healthy Living Catalogs & E-Commerce, Non-theatrical Media
				998,676,335
		> Travel 3.3%
	4,520,690	Ryman Hospitality Properties (b)(c)		173,865,737
		Convention Hotels
	4,400,000	Avis Budget Group (a)		87,208,000
		Second Largest Car Rental Company
	1,430,000	Vail Resorts		77,348,700
		Ski Resort Operator & Developer
	1,100,000	Expedia		67,595,000
		Online Travel Services Company
	3,750,000	Hertz (a)		61,012,500
		Largest US Rental Car Operator
	1,337,338	Choice Hotels		44,961,304
		Franchisor of Budget Hotel Brands
	2,000,000	Localiza Rent A Car (Brazil)		36,630,037
		Car Rental
	1,600,000	HomeAway (a)(c)		35,200,000
		Vacation Rental Online Marketplace
				583,821,278
		> Apparel 2.2%
	1,660,000	PVH		184,276,600
		Apparel Wholesaler & Retailer
	1,500,000	Coach		83,265,000
		Designer & Retailer of Branded Leather Accessories
	762,000	Warnaco Group (a)		54,536,340
		Global Branded Apparel Manufacturer

See accompanying notes to financial statements.

33

Columbia Acorn Fund

Statement of Investments, continued

Number of Shares			Value
		> Apparel—continued
	1,060,000	Deckers Outdoor (a)(c)	$	42,686,200
		Fashion Footwear Wholesaler
	600,000	Steven Madden (a)		25,362,000
		Wholesaler/Retailer of Fashion Footwear
				390,126,140
		> Consumer Goods Distribution 1.0%
	2,015,000	Pool		85,274,800
		Distributor of Swimming Pool Supplies & Equipment
	2,305,000	GNC Holdings		76,710,400
		Specialty Retailer of Health & Wellness Products
	625,000	United Stationers		19,368,750
		Wholesale Distributor of Business Products
				181,353,950
		> Casinos & Gaming 1.0%
	3,950,000	Pinnacle Entertainment (a)(b)		62,528,500
		Regional Casino Operator
	3,000,000	Melco Crown Entertainment - ADR (Hong Kong) (a)		50,520,000
		Macau Casino Operator
	850,000	Penn National Gaming (a)		41,743,500
		Regional Casino Operator
	12,000,000	MGM China Holdings (Hong Kong)		22,102,000
		Macau Casino Operator
				176,894,000
		> Other Consumer Services 0.9%
	2,280,000	Lifetime Fitness (a)(b)		112,198,800
		Sport & Fitness Club Operator
	17,000,000	Lifestyle International (Hong Kong)		42,052,554
		Mid- to High-end Department Store Operator in Hong Kong & China
	1,062,500	Move (a)		8,064,375
		Real Estate Internet Websites
	450,000	IFM Investments (Century 21 China RE) - ADR (China) (a)		823,500
		Provide Real Estate Services in China
				163,139,229
		> Furniture & Textiles 0.9%
	4,200,000	Knoll (b)		64,512,000
		Office Furniture
	2,250,000	Herman Miller		48,195,000
		Office Furniture
	2,325,000	Interface		37,386,000
		Modular Carpet
	215,000	Caesarstone (Israel) (a)		3,472,250
		Quartz Countertops
				153,565,250
		> Food & Beverage 0.7%
	600,000	Monster Beverage (a)		31,728,000
		Alternative Beverages
	20,000,000	Olam International (Singapore) (c)		25,690,573
	6,260,000	Olam International - Rights (Singapore) (a)(d)		1,482,136
		Agriculture Supply Chain Manager
	1,675,000	Boulder Brands Inc (a)		21,607,500
		Healthy Food Products

Number of Shares			Value
	1,800,000	Arcos Dorados (Brazil) (c)	$	21,528,000
		McDonald's Master Franchise for Latin America
	700,000	B&G Foods		19,817,000
		Acquiror of Small Food Brands
	1,665,270	GLG Life Tech (Canada) (a)(b)(d)		434,636
		Produces an All-natural Sweetener Extracted from the Stevia Plant
				122,287,845
		> Restaurants 0.5%
	2,000,000	AFC Enterprises (a)(b)		52,260,000
		Popeye's Restaurants
	370,000	Domino's Pizza		16,113,500
		Franchisor of Pizza Restaurants
	370,000	Cheesecake Factory		12,106,400
		Casual Dining Restaurants
	675,000	Bravo Brio Restaurant Group (a)		9,065,250
		Upscale Casual Italian Restaurants
				89,545,150
		> Other Durable Goods 0.5%
	595,000	Jarden		30,761,500
		Branded Household Products
	850,000	Tesla Motors (a)(c)		28,789,500
		Design, Manufacture & Sell High Performance Electric Vehicles
	460,000	Cavco Industries (a)(b)		22,990,800
		Manufactured Homes
				82,541,800
		> Educational Services 0.3%
	1,300,000	DeVry		30,849,000
		Postsecondary Degree Services
	800,000	New Oriental Education & Technology - ADR (China) (c)		15,544,000
		Education Service Provider
	500,000	ITT Educational Services (a)(c)		8,655,000
		Postsecondary Degree Services
	2,000,000	Voyager Learning - Contingent Value Rights (a)(d)(e)		220,000
		Education Services for the K-12 Market
				55,268,000
		> Nondurables 0.3%
	1,600,000	Helen of Troy (a)(b)		53,424,000
		Personal Care, Housewares, Healthcare & Home Environment Products
				53,424,000
		> Other Entertainment 0.1%
	265,000	CTS Eventim (Germany)		9,337,630
		Event Ticket Sales
				9,337,630
		> Leisure Products 0.1%
	975,386	Skullcandy (a)(c)		7,598,257
		Lifestyle Branded Headphones
				7,598,257
Consumer Goods & Services: Total				3,067,578,864

See accompanying notes to financial statements.

34

Number of Shares			Value
Finance 11.2%
		> Banks 4.3%
	2,638,000	BOK Financial	$	143,665,480
		Tulsa-based S.W. Bank
	7,756,800	Associated Banc-Corp		101,769,216
		Midwest Bank
	2,337,313	Hancock Holding		74,186,315
		Gulf Coast Bank
	1,348,000	City National		66,752,960
		Bank & Asset Manager
	2,860,000	MB Financial (b)		56,485,000
		Chicago Bank
	985,000	SVB Financial Group (a)		55,130,450
		Bank to Venture Capitalists
	5,323,500	Valley National Bancorp (c)		49,508,550
		New Jersey/New York Bank
	3,000,000	CVB Financial		31,200,000
		Inland Empire Business Bank
	2,200,000	TCF Financial		26,730,000
		Great Lakes Bank
	1,350,000	TriCo Bancshares (b)		22,612,500
		California Central Valley Bank
	1,162,000	Sandy Spring Bancorp		22,566,040
		Baltimore, D.C. Bank
	550,000	Wintrust Financial		20,185,000
		Chicago & Milwaukee Full Service Bank
	4,299,507	First Busey		19,992,707
		Illinois Bank
	2,500,000	First Commonwealth		17,050,000
		Western Pennsylvania Bank
	705,072	Eagle Bancorp (a)		14,080,288
		Metro D.C. Bank
	811,295	Hudson Valley		12,631,863
		Metro New York City Bank
	2,136,500	TrustCo Bank		11,280,720
		New York State Bank
	500,000	Oriental Financial Group (c)		6,675,000
		Puerto Rican Bank
				752,502,089
		> Insurance 2.5%
	8,900,000	CNO Financial Group		83,037,000
		Life, Long-term Care & Medical Supplement Insurance
	833,000	Allied World Holdings		65,640,400
		Commerical Lines Insurance/Reinsurance
	3,300,000	Tower Group (b)		58,641,000
		Commercial & Personal Lines Insurance
	1,400,000	The Hanover Insurance Group		54,236,000
		Commercial & Personal Lines Insurance
	2,625,000	Selective Insurance Group		50,583,750
		Commercial & Personal Lines Insurance
	1,100,000	HCC Insurance Holdings		40,931,000
		Specialty Insurance
	1,500,000	Brown & Brown		38,190,000
		Insurance Broker
	250,000	Enstar Group (a)		27,995,000
		Insurance/Reinsurance & Related Services

Number of Shares			Value
	925,000	Kemper	$	27,287,500
		Multi Line Insurance
				446,541,650
		> Finance Companies 1.7%
	1,285,000	World Acceptance (a)(b)		95,809,600
		Personal Loans
	2,150,000	McGrath Rentcorp (b)		62,393,000
		Temporary Space & IT Rentals
	3,400,000	H & E Equipment Services (b)		51,238,000
		Heavy Equipment Leasing
	1,397,834	CAI International (a)(b)		30,682,456
		International Container Leasing
	1,091,000	Marlin Business Services (b)		21,885,460
		Small Equipment Leasing
	450,000	Onex Capital (Canada)		18,941,892
		Private Equity
	228,500	Textainer Group Holdings		7,188,610
		Top International Container Leasor
	291,231	Regional Management (a)(c)		4,819,873
		Consumer Loans
				292,958,891
		> Brokerage & Money Management 1.5%
	7,100,000	SEI Investments		165,714,000
		Mutual Fund Administration & Investment Management
	3,052,000	Eaton Vance		97,206,200
		Specialty Mutual Funds
	1,000,000	Artio Global Investors		1,900,000
		International Asset Manager
				264,820,200
		> Credit Cards 0.6%
	550,000	Alliance Data Systems (a)		79,618,000
		Diversified Credit Card Provider
	350,000	Wright Express (a)		26,379,500
		Pay Card Processor
				105,997,500
		> Diversified Financial Companies 0.4%
	2,820,000	Leucadia National		67,087,800
		Holding Company
				67,087,800
		> Savings & Loans 0.2%
	400,000	Financial Engines (a)		11,100,000
		Asset Management for 401k Plans
	470,000	ViewPoint Financial		9,841,800
		Texas Thrift
	1,010,000	Provident New York Bancorp		9,403,100
		New York State Thrift
	452,146	Simplicity Bancorp (b)		6,759,583
		Los Angeles Savings & Loan
	65,991	Berkshire Hills Bancorp		1,574,545
		Northeast Thrift
				38,679,028
Finance: Total				1,968,587,158

See accompanying notes to financial statements.

35

Columbia Acorn Fund

Statement of Investments, continued

Number of Shares			Value
Health Care 8.6%
		> Biotechnology & Drug Delivery 4.4%
	3,617,000	BioMarin Pharmaceutical (a)	$	178,137,250
		Biotech Focused on Orphan Diseases
	6,550,000	Seattle Genetics (a)(b)(c)		151,960,000
		Antibody-based Therapies for Cancer
	800,000	Alexion Pharmaceuticals (a)		75,048,000
		Biotech Focused on Orphan Diseases
	3,600,000	ARIAD Pharmaceuticals (a)		69,048,000
		Biotech Focused on Cancer
	870,000	Onyx Pharmaceuticals (a)		65,711,100
		Commercial-stage Biotech Focused on Cancer
	6,000,000	NPS Pharmaceuticals (a)(b)		54,600,000
		Orphan Drugs & Healthy Royalties
	1,165,000	Synageva Biopharma (a)		53,927,850
		Biotech Focused on Orphan Diseases
	2,202,196	Auxilium Pharmaceuticals (a)		40,806,692
		Biotech Focused on Niche Disease Areas
	955,000	Sarepta Therapeutics (a)(c)		24,639,000
		Biotech Focused On Rare Diseases
	2,025,000	InterMune (a)(c)		19,622,250
		Drugs for Pulmonary Fibrosis & Hepatitis C
	3,000,000	Raptor Pharmaceutical (a)(b)(c)		17,550,000
		Orphan Drug Company
	3,610,890	Ultragenyx (a)(d)(e)		9,999,999
		Biotech Focused On "Ultra-Orphan" Drugs
	4,949,000	Chelsea Therapeutics International (a)(b)(c)		3,761,240
		Biotech Focused on Rare Diseases
	359,944	MicroDose Therapeutx (a)(d)(e)		61,190
		Drug Inhaler Development
				764,872,571
		> Medical Supplies 2.3%
	4,970,000	Cepheid (a)(b)		168,035,700
		Molecular Diagnostics
	1,950,000	DENTSPLY International		77,239,500
		Leading Dental Supplies Manufacturer
	950,000	Henry Schein (a)		76,437,000
		Largest Distributor of Healthcare Products
	1,676,000	Patterson Companies		57,369,480
		Dental/Vet/Med Distributor
	375,000	Techne		25,627,500
		Cytokines, Antibodies & Other Reagents for Life Science
				404,709,180
		> Medical Equipment & Devices 1.1%
	1,024,683	Sirona Dental Systems (a)		66,051,066
		Manufacturer of Dental Equipment
	1,475,000	PerkinElmer Inc.		46,816,500
		Analytical Instruments for Life Sciences
	1,100,000	Haemonetics (a)		44,924,000
		Blood & Plasma Collection Equipment
	725,000	Orthofix International (a)		28,514,250
		Bone Fixation & Stimulation Devices
				186,305,816

Number of Shares			Value
		> Health Care Services 0.5%
	665,000	Mednax (a)	$	52,880,800
		Physician Management for Pediatric & Anesthesia Practices
	1,875,000	Health Management Associates (a)		17,475,000
		Non-urban Hospitals
	825,000	HealthSouth (a)		17,415,750
		Inpatient Rehabalitation Facilities
				87,771,550
		> Pharmaceuticals 0.3%
	4,000,000	Akorn (a)		53,440,000
		Develops, Manufactures & Sells Specialty Generic Drugs
	2,040,000	Alimera Sciences (a)(b)		3,202,800
		Ophthalmology-focused Pharmaceutical Company
				56,642,800
Health Care: Total				1,500,301,917
Other Industries 6.7%
		> Real Estate 4.5%
	3,625,000	Dupont Fabros Technology (b)		87,580,000
		Technology-focused Office Buildings
	750,000	Federal Realty		78,015,000
		Shopping Centers
	1,435,000	Post Properties		71,678,250
		Multifamily Properties
	1,850,000	Extra Space Storage		67,321,500
		Self Storage Facilities
	5,744,300	EdR (b)		61,119,352
		Student Housing
	720,000	Digital Realty Trust		48,880,800
		Technology-focused Office Buildings
	3,000,000	Associated Estates Realty (b)		48,360,000
		Multifamily Properties
	2,450,000	Biomed Realty Trust		47,358,500
		Life Science-focused Office Buildings
	50,000,000	Mapletree Logistics Trust (Singapore)		47,057,100
		Industrial Property Landlord
	22,000,000	Ascendas REIT (Singapore)		43,052,265
		Industrial Property Landlord
	1,300,000	St. Joe (a)(c)		30,004,000
		Florida Panhandle Landowner
	325,000	Jones Lang LaSalle		27,280,500
		Real Estate Services
	2,850,000	Summit Hotel Properties (b)		27,075,000
		Owner of Select Service Hotels
	3,750,000	DCT Industrial Trust		24,337,500
		Industrial Properties
	4,000,000	Kite Realty Group (b)		22,360,000
		Community Shopping Centers
	2,800	Orix JREIT (Japan)		13,809,474
		Diversified REIT
	544,330	Hudson Pacific Properties		11,463,590
		West Coast Office Buildings & Production Studios

See accompanying notes to financial statements.

36

Number of Shares			Value
		> Real Estate—continued
	10,000,000	Mapletree Industrial Trust (Singapore)	$	11,165,904
		Industrial Property Landlord
	10,000,000	Mapletree Commercial Trust (Singapore)		9,995,931
		Retail & Office Property Landlord
	358,151	Terreno Realty		5,529,851
		Industrial Properties
				783,444,517
		> Transportation 1.4%
	3,100,000	Rush Enterprises, Class A (a)(b)		64,077,000
	550,000	Rush Enterprises, Class B (a)(b)		9,520,500
		Truck Sales & Service
	1,155,000	JB Hunt Transport Services		68,965,050
		Truck & Intermodal Carrier
	602,000	Kirby (a)		37,257,780
		Largest Operator of US (Jones Act) Liquid Tank Barges
	627,000	World Fuel Services		25,813,590
		Global Fuel Broker
	1,773,000	Heartland Express		23,173,110
		Regional Trucker
	300,000	Genesee & Wyoming (a)		22,824,000
		Short-line Operator
				251,631,030
		> Regulated Utilities 0.8%
	2,000,000	Northeast Utilities		78,160,000
		Regulated Electric Utility
	2,200,000	Pepco Holdings (c)		43,142,000
		Regulated Utility
	700,000	Wisconsin Energy		25,795,000
		Wisconsin Utility
				147,097,000
Other Industries: Total				1,182,172,547
Energy & Minerals 6.4%
		> Oil Services 3.1%
	4,635,000	FMC Technologies (a)		198,517,050
		Oil & Gas Well Head Manufacturer
	2,114,000	Atwood Oceanics (a)		96,800,060
		Offshore Drilling Contractor
	1,031,106	Fugro (Netherlands)		61,183,604
		Subsea Oilfield Services
	1,334,000	ShawCor (Canada)		52,289,796
		Oil & Gas Pipeline Products
	400,000	Dresser-Rand Group (a)		22,456,000
		Manufactures & Services Compressors
	585,000	Rowan (a)		18,292,950
		Contract Offshore Driller
	2,631,339	Horizon North Logistics (Canada)		18,173,619
		Provides Diversified Oil Service Offering in Northern Canada
	499,000	Hornbeck Offshore (a)		17,135,660
		Supply Vessel Operator in US Gulf of Mexico

Number of Shares			Value
	847,600	Black Diamond Group (Canada)	$	17,084,930
		Provides Accommodations/ Equipment for Oil Sands Development
	226,889	Chart Industries (a)		15,126,690
		Manufacturer of Natural Gas Processing/Storage Equipment
	191,000	Oil States International (a)		13,664,140
		Diversified North American Oil Service Provider
	150,000	Gulfmark Offshore		5,167,500
		Operator of Offshore Supply Vessels
	4,025,000	Tuscany International Drilling (Colombia) (a)		930,683
		South America Based Drilling Rig Contractor
				536,822,682
		> Oil & Gas Producers 1.9%
	2,700,000	Pacific Rubiales Energy (Colombia) (c)		62,729,466
		Oil Production & Exploration in Colombia
	695,000	Range Resources		43,666,850
		Oil & Gas Producer
	722,000	Rosetta Resources (a)		32,749,920
		Oil & Gas Producer Exploring in South Texas & Montana
	590,000	SM Energy		30,803,900
		Oil & Gas Producer
	1,477,000	Denbury Resources (a)		23,927,400
		Oil Producer Using Carbon Dioxide Injection
	443,000	Cabot Oil and Gas		22,034,820
		Large Natural Gas Producer in Appalachia & Gulf Coast
	1,159,000	Laredo Petroleum (a)		21,047,440
		Permian Basin Oil Producer
	850,000	Tullow Oil (United Kingdom)		17,720,305
		Oil & Gas Producer
	361,000	Baytex (Canada) (c)		15,558,530
		Oil & Gas Producer in Canada
	340,000	PDC Energy (a)		11,291,400
		Oil & Gas Producer in US
	27,000,000	Shamaran Petroleum (Iraq) (a)		10,586,106
		Oil Exploration in Kurdistan
	25,000,000	Petroamerica Oil (Colombia) (a)(c)		8,796,622
		Oil Exploration & Production in Colombia
	750,000	Athabasca Oil Sands (Canada) (a)		7,879,260
		Oil Sands & Unconventional Oil Development
	37,500,000	Petromanas (Canada) (a)(b)		6,597,467
		Exploring for Oil in Albania
	1,198,100	Pan Orient (Canada) (a)		3,529,137
		Asian Oil & Gas Explorer
	493,000	Crew Energy (Canada) (a)		3,216,618
		Canadian Oil & Gas Producer
	26,000,000	Petrodorado Energy (Colombia) (a)(b)		3,136,624
		Oil & Gas Exploration & Production in Colombia, Peru & Paraguay

See accompanying notes to financial statements.

37

Columbia Acorn Fund

Statement of Investments, continued

Number of Shares			Value
		> Oil & Gas Producers—continued
	511,600	Canacol (Colombia) (a)	$	1,640,700
		Oil Producer in South America
	8,400,000	Canadian Overseas Petroleum (United Kingdom) (a)(e)		1,459,254
	4,200,000	Canadian Overseas Petroleum - Warrants (United Kingdom) (a)(d)(e)		65,109
		Oil & Gas Exploration/Production in the North Sea
	50,000,000	Gulf United Energy (Colombia) (a)(b)		390,000
		Prospecting for Oil Alongside Large Producers in Colombia
	4,110,000	Santa Maria Petroleum (Colombia) (a)(b)(e)		337,163
	890,000	Santa Maria Petroleum (Colombia) (a)(b)		76,053
		Explores for Oil & Gas in Latin America
	393,600	Houston American Energy (a)(c)		86,592
		Oil & Gas Exploration/ Production in Colombia
				329,326,736
		> Mining 1.3%
	387,000	Core Labs (Netherlands)		42,302,970
		Oil & Gas Reservoir Consulting
	1,000,000	Silver Wheaton (Canada)		36,080,000
		Silver Mining Royalty Company
	1,150,000	Allied Nevada Gold (a)		34,649,500
		Gold & Silver Mining
	1,600,000	Alamos Gold (Canada)		28,068,764
		Gold Mining
	4,432,000	Northam Platinum (South Africa)		20,060,723
		Platinum Mining in South Africa
	7,500,000	Duluth Metals (Canada) (a)(b)		18,623,706
	500,000	Duluth Exploration - Special Warrants (Canada) (a)(d)(e)		25,133
		Copper & Nickel Miner
	1,900,000	Kirkland Lake Gold (Canada) (a)		11,174,223
		Gold Mining
	1,150,000	Turquoise Hill Resources (Mongolia) (a)		8,786,569
		Copper Mine Project in Mongolia
	16,000,000	Mongolian Mining (Mongolia) (a)		7,929,331
		Coking Coal Mining in Mongolia
	2,050,000	Alexco Resource (a)		7,318,500
		Mining, Exploration & Environmental Services
	1,282,902	Regis Resources (Australia) (a)		6,884,619
		Gold Mining in Australia
	3,000,000	Kaminak Gold (a)(c)		4,976,375
		Exploration Stage Canadian Gold Miner
	800,000	Augusta Resource (a)(c)		1,960,000
		US Copper/Molybdenum

Number of Shares			Value
	4,000,000	Wolverine Minerals (Canada) (a)(b)(e)	$	135,116
		Gold Mining
				228,975,529
		> Agricultural Commodities 0.1%
	1,306,818	Union Agriculture Group (Uruguay) (a)(d)(e)		13,381,816
		Farmland Operator in Uruguay
				13,381,816
		> Alternative Energy —%
	2,000,000	GT Advanced Technologies (a)(c)		6,040,000
		Largest Manufacturer of Furnaces & Reactors to Produce & Cast Polysilicon
	1,210,300	Synthesis Energy Systems (China) (a)		1,295,021
		Owner/Operator of Gasification Plants
				7,335,021
Energy & Minerals: Total				1,115,841,784
Total Equities: 97.7% (Cost: $10,488,578,720)				17,116,238,312	(f)
Short-Term Investments: 2.3%
	280,000,000	J.P. Morgan U.S. Government Money Market Fund - Capital Shares (7 day yield of 0.01%)		280,000,000
	117,232,736	J.P. Morgan U.S. Government Money Market Fund - Agency Shares (7 day yield of 0.01%)		117,232,736
Total Short-Term Investments: 2.3% (Cost: $397,232,736)				397,232,736
Securities Lending Collateral 2.1%
	371,676,935	Dreyfus Government Cash Management Fund (7 day yield of 0.01%) (g)		371,676,935
Total Securities Lending Collateral: (Cost: $371,676,935)				371,676,935
Total Investments: 102.1% (Cost: $11,257,488,391)(h)				17,885,147,983
Obligation to Return Collateral for Securities Loaned: (2.1)%				(371,676,935	)
Cash and Other Assets Less Liabilities: 0.0%				10,394,863
Net Assets: 100.0%			$	17,523,865,911

ADR - American Depositary Receipts

REIT - Real Estate Investment Trust

(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

See accompanying notes to financial statements.

38

> Notes to Statement of Investments

these affiliated companies during the year ended December 31, 2012, are as follows:

Security	Balance of Shares Held 12/31/11		Purchases/ Additions		Sales/ Reductions		Balance of Shares Held 12/31/12		Value		Dividend
AboveNet (1)		1,400,000		-		1,400,000		-	$	-	$	-
Acorn Energy		1,500,000		12,352		-		1,512,352		11,811,469		210,184
AFC Enterprises		2,000,000		-		-		2,000,000		52,260,000		-
Alimera Sciences		2,040,000		-		-		2,040,000		3,202,800		-
Associated Estates Realty		3,700,000		-		700,000		3,000,000		48,360,000		2,568,931
Auxilium Pharmaceuticals (1)		3,033,715		216,285		1,047,804		2,202,196		40,806,692		-
Bally Technologies		3,725,000		-		-		3,725,000		166,544,750		-
Boingo Wireless		1,500,000		400,000		-		1,900,000		14,345,000		-
CAI International		1,123,400		274,434		-		1,397,834		30,682,456		-
Cavco Industries		460,000		-		-		460,000		22,990,800		-
Cepheid		3,200,000		1,770,000		-		4,970,000		168,035,700		-
Chelsea Therapeutics International		4,550,000		1,200,000		801,000		4,949,000		3,761,240		-
Cogent Communications (1)		2,520,000		-		320,000		2,200,000		49,808,000		462,000
Constant Contact (1)		2,350,000		-		1,150,000		1,200,000		17,052,000		-
Donaldson (2)		4,200,000		4,200,000		-		8,400,000		275,856,000		2,940,000
Drew Industries		1,500,000		380,000		-		1,880,000		60,630,000		3,760,000
Duluth Metals		7,500,000		-		-		7,500,000		18,623,706		-
Dupont Fabros Technology		3,350,000		765,000		490,000		3,625,000		87,580,000		2,295,710
EdR		3,000,000		2,744,300		-		5,744,300		61,119,352		1,120,000
eResearch Technology (1)		4,900,000		-		4,900,000		-		-		-
ESCO Technologies		2,200,000		-		-		2,200,000		82,302,000		704,000
Exa		-		872,060				872,060		8,485,144		-
ExlService Holdings		1,145,000		473,000		-		1,618,000		42,877,000		-
Forward Air		1,300,000		200,000		-		1,500,000		52,515,000		472,000
Gaiam		1,371,366		-		-		1,371,366		4,333,517		-
GLG Life Tech		1,750,000		-		84,730		1,665,270		434,636		-
Gulf United Energy		-		50,000,000		-		50,000,000		390,000		-
H & E Equipment Services		3,400,000		-		-		3,400,000		51,238,000		4,514,860
Hackett Group (3)		4,500,000		-		650,793		3,849,207		16,474,606		384,921
HEICO (2)		2,250,000		813,000		-		3,063,000		97,954,740		7,057,380
Helen of Troy		1,600,000		-		-		1,600,000		53,424,000		-
Horizon Pharma (1)		1,095,000		-		1,095,000		-		-		-
iGATE		3,400,000		300,000		-		3,700,000		58,349,000		-
II-VI		4,550,000		-		-		4,550,000		83,128,500		-
Insperity		1,210,000		590,000		-		1,800,000		58,608,000		2,681,215
Interline Brands (1)		2,600,000		-		2,600,000		-		-		-
IPG Photonics		2,780,000		-		-		2,780,000		185,287,000		1,807,000
IXYS (1)		1,900,000		-		1,050,000		850,000		7,769,000		49,409
Kenexa (1)		1,700,000		-		1,700,000		-		-		-
Kite Realty Group		3,500,000		500,000		-		4,000,000		22,360,000		840,000
Knoll		4,200,000		-		-		4,200,000		64,512,000		1,848,000
Lifetime Fitness		2,190,000		90,000		-		2,280,000		112,198,800		-
lululemon athletica (1)		5,740,000		-		1,978,460		3,761,540		286,742,194		-
Marlin Business Services		1,091,000		-		-		1,091,000		21,885,460		305,480
MB Financial		2,360,000		500,000		-		2,860,000		56,485,000		369,300
McGrath Rentcorp		2,150,000		-		-		2,150,000		62,393,000		2,010,250
Mettler-Toledo International		1,600,000		-		-		1,600,000		309,280,000		-
Micromet (1)		6,702,347		64,547		6,766,894		-		-		-
Moog		2,775,000		455,000		-		3,230,000		132,526,900		-
Navigant Consulting		2,800,000		904,600		-		3,704,600		41,343,336		-
NPS Pharmaceuticals		6,000,000		-		-		6,000,000		54,600,000		-
Pericom Semiconductor		1,765,000		-		-		1,765,000		14,172,950		-
Petroamerica Oil (1)		30,275,000		-		5,275,000		25,000,000		8,796,622		-
Petrodorado Energy		26,000,000		-		-		26,000,000		3,136,624		-
PetroMagdalena Energy (1)		7,582,928		-		7,582,928		-		-		-
Petromanas		37,500,000		-		-		37,500,000		6,597,467		-
Pier 1 Imports		5,600,000		1,585,000		-		7,185,000		143,700,000		752,000
Pinnacle Entertainment		3,950,000		-		-		3,950,000		62,528,500		-
Raptor Pharmaceutical		3,455,000		745,000		1,200,000		3,000,000		17,550,000		-
Rush Enterprises		3,350,000		300,000		-		3,650,000		73,597,500		-

See accompanying notes to financial statements.

39

Columbia Acorn Fund

Statement of Investments, continued

> Notes to Statement of Investments

Security	Balance of Shares Held 12/31/11		Purchases/ Additions		Sales/ Reductions		Balance of Shares Held 12/31/12		Value		Dividend
Ryman Hospitality Properties		3,850,000		670,690		-		4,520,690	$	173,865,737	$	24,418,477
Salem Communications (1)		1,527,700		-		1,527,700		-		-		-
Santa Maria Petroleum (2)		50,000,000		-		45,000,000		5,000,000		413,216		-
Seattle Genetics		6,153,000		397,000		-		6,550,000		151,960,000		-
Shutterfly		3,070,000		300,000		535,000		2,835,000		84,681,450		-
Simplicity Bancorp		452,146		-		-		452,146		6,759,583		135,644
SPS Commerce		900,000		-		-		900,000		33,543,000		-
Summit Hotel Properties		1,500,000		1,350,000		-		2,850,000		27,075,000		916,969
Tower Group		1,675,000		1,625,000		-		3,300,000		58,641,000		2,173,500
TriCo Bancshares		1,350,000		-		-		1,350,000		22,612,500		486,000
True Religion Apparel (1)		1,507,000		-		1,507,000		-		-		92,581
tw telecom		9,500,000		-		-		9,500,000		241,965,000		-
Tyler Technologies (1)		1,700,000		-		800,000		900,000		43,596,000		-
Virtusa		2,125,000		-		-		2,125,000		34,913,750		-
Warnaco Group (1)		2,190,000		-		1,428,000		762,000		54,536,340		-
Wolverine Minerals		4,000,000		-		-		4,000,000		135,116		-
World Acceptance		1,505,202		-		220,202		1,285,000		95,809,600		-
Total of Affiliated Transactions		349,894,804		74,697,268		91,810,511		332,781,561	$	4,461,953,753	$		65,375,811

(1) At December 31, 2012, the Fund owned less than five percent of the company's outstanding voting shares.

(2) Includes the effects of a stock split.

(3) Includes the effects of a corporate action.

  The aggregate cost and value of these companies at December 31, 2012, were $2,466,414,630 and $3,952,846,905, respectively. Investments in affiliated companies represented 22.56% of the Fund's total net assets at December 31, 2012.

(c)  All or a portion of this security was on loan at December 31, 2012. The total market value of securities on loan at December 31, 2012 was $368,048,192.

(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 December 31, 2012, the market value of these securities amounted to $25,684,780, which represented 0.15% 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	$	15,000,000	$	13,381,816
Ultragenyx	12/19/12		3,610,890		9,999,999		9,999,999
Canadian Overseas Petroleum	11/24/10		8,400,000		3,591,152		1,459,254
Santa Maria Petroleum	1/14/11		4,110,000		5,193,292		337,163
Voyager Learning - Contingent Value Rights	12/24/09		2,000,000		-		220,000
Wolverine Minerals	6/3/11		4,000,000		2,004,903		135,116
Canadian Overseas Petroleum - Warrants	11/24/10		4,200,000		525,688		65,109
MicroDose Therapeutx	11/24/00		359,944		2,004,000		61,190
Duluth Exploration - Special Warrants	8/19/11		500,000		-		25,133
				$	38,319,034	$	25,684,780

(f)  On December 31, 2012, the market value of foreign securities represented 8.30% of total net assets. The Fund's foreign portfolio was diversified as follows:

Country	Value		Percentage of Net Assets
Canada	$	262,540,827		1.50
Netherlands		205,172,856		1.17
Singapore		167,499,376		0.95
Sweden		137,820,900		0.79
Hong Kong		114,674,554		0.65
Brazil		88,048,147		0.50
Colombia		78,037,311		0.45
Japan		76,586,902		0.44
France		52,039,295		0.30
South Africa		39,377,807		0.22
Chile		38,791,720		0.22
Israel		30,256,250		0.17

Country	Value		Percentage of Net Assets
Denmark	$	28,386,637		0.16
United Kingdom		19,244,668		0.11
China		17,662,521		0.10
Mongolia		16,715,900		0.10
Russia		15,681,390		0.09
India		15,539,898		0.09
Uruguay		13,381,816		0.08
Iceland		11,025,103		0.06
Iraq		10,586,106		0.06
Germany		9,337,630		0.05
Australia		6,884,619		0.04
Total Foreign Portfolio	$	1,455,292,233		8.30

See accompanying notes to financial statements.

40

> Notes to Statement of Investments

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

(h)  At December 31, 2012, for federal income tax purposes, the cost of investments was $11,326,139,898 and net unrealized appreciation was $6,559,008,085 consisting of gross unrealized appreciation of $7,244,753,464 and gross unrealized depreciation of $685,745,379.

Fair Value Measurements

Various inputs are used in determining the value of the Fund's investments, following the input prioritization hierarchy established by accounting principles generally accepted in the United States of America (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, to review the appropriateness of the Trust's Portfolio Pricing Policy and the pricing procedures of the investment manager (the Policies), and to review the continuing appropriateness of the current value of any security subject to 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 December 31, 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	$	4,461,573,949	$	211,860,767	$	-	$	4,673,434,716
Industrial Goods & Services		3,397,390,981		210,930,345		-		3,608,321,326
Consumer Goods & Services		2,946,942,251		120,416,613		220,000		3,067,578,864
Finance		1,968,587,158		-		-		1,968,587,158
Health Care		1,490,240,728		-		10,061,189		1,500,301,917
Other Industries		1,057,091,873		125,080,674		-		1,182,172,547
Energy & Minerals		986,659,611		115,775,224		13,406,949		1,115,841,784
Total Equities		16,308,486,551		784,063,623		23,688,138		17,116,238,312
Total Short-Term Investments		397,232,736		-		-		397,232,736
Total Securities Lending Collateral		371,676,935		-		-		371,676,935
Total Investments	$	17,077,396,222	$	784,063,623	$	23,688,138	$	17,885,147,983

  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

See accompanying notes to financial statements.

41

Columbia Acorn Fund

Statement of Investments, continued

> Notes to Statement of Investments

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
$	-	$	1,575,000	$	1,575,000	$	-

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

  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.

See accompanying notes to financial statements.

42

Columbia Acorn International

Major Portfolio Changes in the Fourth Quarter (Unaudited)

	Number of Shares
	9/30/12		12/31/12
Purchases
Asia
> Japan
Benesse		0		453,000
Hamamatsu Photonics		423,900		609,900
Horiba		711,100		765,000
Itochu Techno-Science		249,100		406,000
Lifenet Insurance		813,400		1,575,000
Miraca Holdings		816,456		862,706
Nippon Paint		0		1,586,000
Rinnai		0		40,300
Shimano		0		64,400
> Taiwan
Chipbond		37,000		689,000
Far EasTone Telecom		36,606,000		39,592,000
Flexium Interconnect		0		5,891,000
Lung Yen		3,835,000		6,173,000
PC Home		3,000,141		3,101,000
Taiwan Mobile		16,410,000		17,000,000
> Hong Kong
Melco International		8,000,000		12,000,000
Vitasoy International		9,557,900		11,473,900
> Singapore
Mapletree Commercial Trust		39,467,000		40,000,000
> Korea
BS Financial Group		1,208,000		1,726,000
Hite Jinro		138,990		751,390
iMarketKorea		724,727		806,004
KCC		0		74,400
Lotte Chilsung Beverage		0		14,540
Nexen Tire		0		660,140
Paradise Co		0		567,986
Samsung Engineering		57,000		132,000
> India
Bharti Infratel		0		5,200,000
Bosch		0		60,000
TTK Prestige		63,000		95,000
Yes Bank		0		2,765,000
> Thailand
Samui Airport Property Fund		699,700		2,680,100
Siam Makro		0		1,343,600
Europe
> United Kingdom
Abcam		2,855,000		3,486,700
Elementis		4,999,847		6,960,000
Greggs		2,300,000		2,843,000
JLT Group		2,281,600		3,254,000
Spirax Sarco		655,000		819,974

	Number of Shares
	9/30/12		12/31/12
> Netherlands
Aalberts Industries		2,742,165		2,915,700
Imtech		1,515,723		2,114,073
> Germany
Pfeiffer Vacuum		130,050		200,000
> Switzerland
Dufry Group		375,000		408,000
Partners Group		260,000		282,000
Zehnder		330,000		380,000
> France
Norbert Dentressangle		285,704		308,400
> Italy
Geox		7,706,873		8,501,000
> Finland
Vacon		0		401,000
> Kazakhstan
Halyk Savings Bank of Kazakhstan - GDR		4,506,259		5,143,000
> Turkey
Bizim Toptan		0		543,494
Other Countries
> South Africa
Coronation Fund Managers		11,763,907		11,920,964
Massmart Holdings		1,574,575		2,230,504
> Australia
Challenger Financial		14,652,712		15,000,000
Commonwealth Property Office Fund		49,017,000		52,500,000
Regis Resources		311,805		1,840,985
SAI Global		3,338,561		5,640,000
> United States
Textainer Group Holdings		1,103,297		1,272,297
> New Zealand
Telecom NZ		3,598,749		10,879,000
Latin America
> Brazil
Arcos Dorados		1,730,000		1,800,000
Beadell Resources		0		17,793,303
> Chile
Viña Concha y Toro		10,115,274		12,956,011

See accompanying notes to financial statements.

43

Columbia Acorn International

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

			Number of Shares
			9/30/12		12/31/12
Sales
Asia
> Japan
Aeon Delight				1,221,938		964,000
Ain Pharmaciez				300,792		50,292
Disco				480,000		396,000
Miura				202,150		0
Park24				2,719,900		2,545,200
Torishima Pump Manufacturing				1,069,963		302,263
> Taiwan
Chroma Ate				11,794,000		10,520,000
Radiant Opto-Electronics				4,564,960		2,577,960
Simplo Technology				6,334,713		5,159,713
Tripod Technologies				8,012,470		5,625,135
> Hong Kong
AAC Technologies				10,038,000		8,518,000
> Singapore
Mapletree Industrial Trust				33,000,000		30,000,000
Olam International				25,000,000		15,000,000
> Korea
Grand Korea Leisure				852,150		0
> India
Jain Irrigation Systems				1,426,549		0
REI Agro				27,212,878		10,823,473
Shriram Transport Finance				1,550,000		0
> China
	51	job - ADR		427,814		328,779
NetEase.com - ADR				419,323		0
RexLot Holdings				260,000,000		200,000,000
Europe
> United Kingdom
Asos				646,000		485,000
Premier Oil				1,907,154		1,403,932
Rotork				517,000		63,577
> Netherlands
BinckBank				449,113		0
Koninklijke TenCate				821,137		0
Vopak				317,424		266,124

	Number of Shares
	9/30/12		12/31/12
> Germany
Dürr		440,000		285,000
> France
Compagnie Française de l'Afrique Occidentale		377,000		0
> Italy
CIR		7,248,893		4,842,819
Fiat		3,791,000		0
Tod's		224,200		168,200
> Denmark
Novozymes		1,648,800		1,049,800
> Finland
Stockmann		1,430,429		1,168,630
> Ireland
Paddy Power		74,637		0
Other Countries
> South Africa
Adcock Ingram Holdings		3,938,965		0
> Australia
UGL		3,973,200		3,557,000
> Canada
Black Diamond Group		770,576		709,576
Horizon North Logistics		2,096,514		1,921,379
ShawCor		1,212,597		1,084,597
> United States
BioMarin Pharmaceutical		1,044,000		928,000
FMC Technologies		669,213		601,213
> Senegal
Sonatel		31,200		0
Latin America
> Brazil
Mills Estruturas e Servicos de Engenharia		1,880,200		1,800,000
MRV Engenharia		3,577,000		0
> Colombia
Gulf United Energy		22,525,000		19,893,109

See accompanying notes to financial statements.

44

Columbia Acorn International

Statement of Investments, December 31, 2012

Number of Shares			Value
			Equities: 97.1%
Asia 44.5%
		> Japan 16.0%
	5,582,600	Kansai Paint	$	60,163,024
		Paint Producer in Japan, India, China & Southeast Asia
	21,500	Wacom (a)		56,604,038
		Computer Graphic Illustration Devices
	20,227,000	Seven Bank		53,354,600
		ATM Processing Services
	1,817,562	Glory		42,122,862
		Currency Handling Systems & Related Equipment
	1,582,200	Hoshizaki Electric		42,069,705
		Commercial Kitchen Equipment
	2,545,200	Park24		40,196,188
		Parking Lot Operator
	2,981,100	Kuraray		39,079,727
		Special Resin, Fine Chemical, Fibers & Textures
	7,780	Orix JREIT		38,370,609
		Diversified REIT
	30,500	Jupiter Telecommunications		37,986,380
		Largest Cable Service Provider in Japan
	862,706	Miraca Holdings		34,784,977
		Outsourced Lab Testing, Diagnostic Equipment & Reagents
	937,651	Kintetsu World Express		31,355,399
		Airfreight Logistics
	960,000	Sanrio (b)		30,627,735
		Character Goods & Licensing
	2,552,000	NGK Insulators		30,273,569
		Ceramic Products for Auto, Power & Electronics
	295,762	Nakanishi		29,464,651
		Dental Tools & Machinery
	2,892,724	Start Today (b)		26,778,607
		Online Japanese Apparel Retailer
	7,620	Kenedix Realty Investment		26,563,778
		Tokyo Mid-size Office REIT
	4,900	Mori Hills REIT Investment		26,299,325
		Tokyo Centric Diversified REIT
	2,380,000	Japan Airport Terminal		24,569,722
		Airport Terminal Operator at Haneda
	345,000	FP Corporation		22,951,390
		Disposable Food Trays & Containers
	1,613,429	Daiseki		22,315,284
		Waste Disposal & Recycling
	765,000	Horiba		22,187,152
		Test & Measurement Instruments
	609,900	Hamamatsu Photonics		22,175,238
		Optical Sensors for Medical & Industrial Applications
	838,000	Doshisha		21,948,807
		Wholesaler
	772,000	Misumi Group		21,098,587
		Industrial Components Distributor
	396,000	Disco		20,642,364
		Semiconductor Dicing & Grinding Equipment

Number of Shares			Value
	9,700	Advance Residence Investment	$	19,881,813
		Residential REIT
	790,000	Aeon Mall		19,434,841
		Suburban Shopping Mall Developer, Owner & Operator
	964,000	Aeon Delight		18,870,214
		Facility Maintenance & Management
	453,000	Benesse		18,852,223
		Education Service Provider
	1,885,600	Asahi Diamond Industrial		18,659,274
		Consumable Diamond Tools
	3,000	Global One Real Estate		17,876,022
		Office REIT
	1,233,080	Nihon Parkerizing		17,737,580
		Metal Surface Treatment Agents & Processing
	406,000	Itochu Techno-Science		16,718,418
		IT Network Equipment Sales & Services
	732,108	Icom		16,347,318
		Two Way Radio Communication Equipment
	1,940,200	Sintokogio		15,429,277
		Automated Casting Machines, Surface Treatment System & Consumables
	1,405,739	Ushio		15,414,929
		Industrial Light Sources
	672,000	Nabtesco		15,009,968
		Machinery Components
	1,586,000	Nippon Paint		13,641,864
		Paints for Automotive, Decorative & Industrial Usage
	1,575,000	Lifenet Insurance (b)(c)		13,483,021
		Online Life Insurance Company in Japan
	64,400	Shimano		4,123,731
		Bicycle Components & Fishing Tackle
	5,230	GLP J-REIT (c)		3,996,376
		Logistics REIT in Japan
	50,292	Ain Pharmaciez		2,751,043
		Dispensing Pharmacy/ Drugstore Operator
	40,300	Rinnai		2,738,139
		Gas Appliances for Household & Commercial Use
	302,263	Torishima Pump Manufacturing		2,434,562
		Industrial Pump for Power Generation & Water Supply Systems
	11,500	MonotaRO		370,509
		Online MRO Goods Distributor in Japan
				1,077,754,840
		> Taiwan 6.4%
	39,592,000	Far EasTone Telecom		101,093,360
		Taiwan's Third Largest Mobile Operator
	17,000,000	Taiwan Mobile		62,824,429
		Taiwan's Second Largest Mobile Operator

See accompanying notes to financial statements.

45

Columbia Acorn International

Statement of Investments, continued

Number of Shares			Value
		> Taiwan—continued
	20,120,000	CTCI Corp	$	39,971,832
		International Engineering Firm
	2,035,000	St. Shine Optical		31,124,567
		World's Leading Disposable Contact Lens Original Equipment Manufacturer
	6,607,000	Advantech		27,997,696
		Industrial PC & Components
	5,159,713	Simplo Technology		26,226,350
		Battery Packs for Notebook & Tablet PCs
	11,200,000	Taiwan Hon Chuan		24,644,221
		Beverage Packaging (Bottles, Caps, Labels) Manufacturer
	10,520,000	Chroma Ate		23,546,438
		Automatic Test Systems, Testing & Measurement Instruments
	5,891,000	Flexium Interconnect		20,876,932
		Flexible Printed Circuit for Mobile Electronics
	6,173,000	Lung Yen		19,968,575
		Funeral Services & Columbaria
	3,181,000	President Chain Store		17,067,196
		Taiwanese Convenience Chain Store Operator
	3,101,000	PC Home		14,473,838
		Taiwanese Internet Retail Company
	5,625,135	Tripod Technologies		12,161,109
		Printed Circuit Boards (PCB)
	2,577,960	Radiant Opto-Electronics		10,705,050
		LCD Back Light Units & Modules
	689,000	Chipbond		1,360,486
		Semiconductor Back-end Packaging Services
				434,042,079
		> Hong Kong 4.7%
	6,500,000	Melco Crown Entertainment - ADR (b)(c)		109,460,000
		Macau Casino Operator
	22,000,000	Lifestyle International		54,420,953
		Mid- to High-end Department Store Operator in Hong Kong & China
	15,625,000	L'Occitane International		49,997,402
		Skin Care & Cosmetics Producer
	8,518,000	AAC Technologies		30,203,290
		Miniature Acoustic Components
	30,000,000	Sa Sa International		24,911,234
		Cosmetics Retailer
	10,000,000	MGM China Holdings		18,418,333
		Macau Casino Operator
	12,000,000	Melco International		14,246,925
		Macau Casino Operator
	11,473,900	Vitasoy International		11,805,188
		Hong Kong Soy Food Brand
				313,463,325

Number of Shares			Value
		> Singapore 3.9%
	22,000,000	Ascendas REIT	$	43,052,265
		Industrial Property Landlord
	40,000,000	Mapletree Commercial Trust		39,983,726
		Retail & Office Property Landlord
	40,000,000	Mapletree Logistics Trust		37,645,680
		Industrial Property Landlord
	30,000,000	Mapletree Industrial Trust		33,497,712
		Industrial Property Landlord
	20,000,000	CDL Hospitality Trust		30,908,452
		Hotel Owner/Operator
	15,000,000	Goodpack Limited		22,697,675
		International Bulk Container Leasing
	15,000,000	Olam International (b)		19,267,930
	4,695,000	Olam International - Rights (c)(d)		1,111,602
		Agriculture Supply Chain Manager
	3,500,000	Singapore Exchange		20,338,826
		Singapore Equity & Derivatives Market Operator
	4,772,000	Petra Foods		13,461,904
		Cocoa Processor & Chocolate Manufacturer
				261,965,772
		> Korea 3.2%
	623,120	Woongjin Coway		25,347,945
		Household Appliance Rental Service Provider
	806,004	iMarketKorea		21,472,051
		Procurement, Distribution of MRO (Maintenance, Repair, Operations) Goods
	1,726,000	BS Financial Group		21,401,560
		Regional Bank in Busan (Korea's Second Largest City)
	751,390	Hite Jinro (c)		21,331,271
		Beer & Spirits Manufacturer
	74,400	KCC		20,792,755
		Paint & Housing Material Manufacturer
	14,540	Lotte Chilsung Beverage		20,582,981
		Beverages & Liquor Manufacturer
	132,000	Samsung Engineering		20,565,259
		Global Engineering, Procurement & Construction (EPC) Firm
	305,540	Kepco Plant Service & Engineering		17,435,434
		Power Plant & Grid Maintenance
	624,441	Handsome		17,228,710
		High-end Apparel Company
	182,000	Hana Tour Service		10,433,840
		Wholesale Package Tour Provider
	660,140	Nexen Tire		9,923,118
		Korean Tire Manufacturer
	567,986	Paradise Co		9,189,084
		Korean 'Foreigner Only' Casino Operator
				215,704,008

See accompanying notes to financial statements.

46

Number of Shares					Value
		> India 2.9%
	2,262,300	United Breweries			$	38,785,528
		India's Largest Brewer
	341,652	Asian Paints				27,828,983
		India's Largest Paint Company
	2,765,000	Yes Bank				23,549,408
		Commercial Banking in India
	8,945,000	Adani Ports & Special Economic Zone				22,228,970
		Indian West Coast Shipping Port
	13,195,000	Redington India				20,998,407
		Supply Chain Solutions for IT & Mobile Handsets in Emerging Markets
	5,200,000	Bharti Infratel (c)(e)				18,383,647
		Communication Towers
	545,000	Colgate Palmolive India				15,731,036
		Consumer Products in Oral Care
	60,000	Bosch				10,503,093
		Automotive Parts
	1,600,000	Titan Industries				8,386,444
		Jewlery, Watches, Eyeglasses
	95,000	TTK Prestige				5,902,783
		Branded Cooking Equipment
	1,650,000	SKIL Ports and Logistics (c)				2,827,761
		Indian Container Port Project
	10,823,473	REI Agro				2,113,728
		Basmati Rice Processing
						197,239,788
		> China 2.2%
	22,168,300	Digital China				38,335,261
		IT Distribution & Systems Integration Services
	24,290,000	Want Want				34,040,150
		Chinese Branded Consumer Food Company
	1,000,000	New Oriental Education & Technology - ADR (b)				19,430,000
		Education Service Provider
	328,779		51	job - ADR (c)		15,370,418
		Integrated Human Resource Services
	200,000,000	RexLot Holdings				15,343,762
		Lottery Equipment Supplier in China
	9,306,554	Zhaojin Mining Industry				14,895,917
		Gold Mining & Refining in China
	30,000,000	AMVIG Holdings				10,953,638
		Chinese Tobacco Packaging Material Supplier
						148,369,146
		> Indonesia 1.9%
	60,516,300	Tower Bersama Infrastructure (c)				35,822,064
		Communications Towers
	31,764,600	Archipelago Resources (a)(c)				30,960,001
		Gold Mining Projects in Indonesia, Vietnam & the Philippines
	250,000,000	Ace Indonesia				21,383,607
		Home Improvement Retailer
	40,047,000	MNC Skyvision (c)				9,972,794
		Largest Satellite Pay TV Operator in Indonesia

Number of Shares			Value
	4,326,000	Mayora Indah	$	9,010,277
		Consumer Branded Food Manufacturer
	38,065,000	Surya Citra Media		8,886,771
		Free to Air TV in Indonesia
	12,488,000	Mitra Adiperkasa		8,630,935
		Operator of Department Store & Specialty Retail Stores
	6,217,500	Southern Arc Minerals (a)(c)		1,593,910
		Gold & Copper Exploration in Indonesia
				126,260,359
		> Thailand 1.1%
	130,000,000	Home Product Center		54,052,147
		Home Improvement Retailer
	1,343,600	Siam Makro		19,651,046
		General Merchadise Wholesaler in Thailand
	2,680,100	Samui Airport Property Fund		1,471,908
		Thai Airport Operator
				75,175,101
		> Philippines 0.9%
	73,221,250	SM Prime Holdings		29,515,107
		Shopping Mall Operator
	19,454,700	Manila Water Company		15,194,696
		Water Utility Company in Philippines
	7,931,700	Int'l Container Terminal		14,329,326
		Container Handling Terminals & Port Management
				59,039,129
		> Mongolia 0.8%
	74,865,700	Mongolian Mining (c)		37,102,183
		Coking Coal Mining in Mongolia
	1,049,943	Turquoise Hill Resources (c)		8,022,084
	914,678	Turquoise Hill Resources (c)(f)		6,960,699
		Copper Mine Project in Mongolia
				52,084,966
		> Cambodia 0.5%
	60,000,000	Nagacorp		36,656,769
		Casino/Entertainment Complex in Cambodia
				36,656,769
Asia: Total				2,997,755,282
Europe 30.2%
		> United Kingdom 6.2%
	935,000	Intertek Group		47,494,916
		Testing, Inspection, Certification Services
	3,254,000	JLT Group		42,140,366
		International Business Insurance Broker
	8,785,000	BBA Aviation		32,058,608
		Aviation Support Services

See accompanying notes to financial statements.

47

Columbia Acorn International

Statement of Investments, continued

Number of Shares			Value
		> United Kingdom—continued
	3,789,000	Domino's Pizza UK & Ireland	$	30,930,846
		Pizza Delivery in UK, Ireland & Germany
	819,974	Spirax Sarco		30,702,717
		Steam Systems for Manufacturing & Process Industries
	6,960,000	Elementis		26,574,986
		Clay-based Additives
	2,321,211	WH Smith		25,404,201
		Newsprint, Books & General Stationery Retailer
	875,000	Aggreko		24,971,247
		Temporary Power & Temperature Control Services
	998,000	Rightmove		23,462,631
		Internet Real Estate Listings
	3,486,700	Abcam		21,820,443
		Online Sales of Antibodies
	485,000	Asos (c)		21,392,481
		Internet-based Retailer to Hipsters Up to Age 35
	2,843,000	Greggs		21,208,037
		Bakery
	1,761,742	Smith and Nephew		19,474,113
		Medical Equipment & Supplies
	1,773,408	Shaftesbury		16,313,883
		London Prime Retail REIT
	4,163,948	PureCircle (b)(c)		16,030,976
		Natural Sweeteners
	382,581	Tullow Oil		7,975,826
		Oil & Gas Producer
	1,403,932	Premier Oil (c)		7,768,633
		Oil & Gas Producer in Europe, Pakistan & Asia
	63,577	Rotork		2,653,925
		Valve Actuators for Oil & Water Pipelines
	2,272,000	Sterling Resources (b)(c)		1,713,079
		Oil & Gas Exploration - Europe
				420,091,914
		> Netherlands 4.0%
	2,915,700	Aalberts Industries		61,043,309
		Flow Control & Heat Treatment
	2,114,073	Imtech		49,103,626
		Technical Installation & Maintenance
	1,574,145	UNIT4 (a)		47,517,926
		Business Software Development
	1,252,514	Arcadis		29,738,991
		Engineering Consultants
	1,118,268	TKH Group		28,945,194
		Dutch Industrial Conglomerate
	368,000	Fugro		21,836,326
		Subsea Oilfield Services
	266,124	Vopak		18,811,675
		World's Largest Operator of Petroleum & Chemical Storage Terminals
	143,395	Core Labs		15,674,508
		Oil & Gas Reservoir Consulting
				272,671,555

Number of Shares			Value
		> Germany 3.8%
	2,000,000	Wirecard	$	49,374,898
		Online Payment Processing & Risk Management
	148,295	Rational		42,837,140
		Commercial Ovens
	1,050,000	NORMA Group		29,104,915
		Clamps for Automotive & Industrial Applications
	285,000	Dürr		25,538,317
		Automotive Plant Engineering & Associated Capital Equipment
	200,000	Pfeiffer Vacuum		24,372,438
		Vacuum Pumps
	1,865,000	TAG Immobilien (b)		23,373,920
		Owner of Residential Properties in Germany
	625,000	CTS Eventim		22,022,711
		Event Ticket Sales
	165,400	Bertrandt		16,606,222
		Outsourced Engineering
	333,000	Elringklinger		11,294,005
		Automobile Components
	338,886	Deutsche Beteiligungs		8,750,900
		Private Equity Investment Management
				253,275,466
		> Switzerland 3.7%
	282,000	Partners Group		65,192,651
		Private Markets Asset Management
	255,000	Geberit (c)		56,527,204
		Plumbing Supplies
	408,000	Dufry Group (c)		53,950,668
		Operates Airport Duty Free & Duty Paid Shops
	15,500	Sika		35,850,662
		Chemicals for Construction & Industrial Applications
	170,000	Kuehne & Nagel		20,495,059
		Freight Forwarding/Logistics
	380,000	Zehnder		18,375,117
		Radiators & Heat Recovery Ventilation Systems
				250,391,361
		> France 3.7%
	553,000	Eurofins Scientific		89,954,447
		Food, Pharmaceuticals & Materials Screening & Testing
	729,700	Gemalto		65,866,252
		Digital Security Solutions
	770,000	Neopost (b)		40,834,470
		Postage Meter Machines
	308,400	Norbert Dentressangle		23,793,407
		Leading European Logistics & Transport Group
	971,800	Saft		22,870,175
		Niche Battery Manufacturer
	1,831,204	Hi-Media (b)(c)		5,042,671
		Online Advertiser in Europe
				248,361,422

See accompanying notes to financial statements.

48

Number of Shares			Value
		> Sweden 2.5%
	3,957,522	Hexagon	$	100,078,760
		Design, Measurement & Visualization Software & Equipment
	4,150,024	Sweco (a)		46,585,386
		Engineering Consultants
	666,777	Unibet		21,346,699
		European Online Gaming Operator
				168,010,845
		> Italy 1.3%
	3,245,000	Pirelli (b)		37,387,904
		Global Tire Supplier
	8,501,000	Geox		24,672,810
		Apparel & Shoe Maker
	168,200	Tod's (b)		21,356,306
		Leather Shoes & Bags
	4,842,819	CIR		5,105,689
		Italian Holding Company
				88,522,709
		> Denmark 1.1%
	168,042	SimCorp		37,578,523
		Software for Investment Managers
	1,049,800	Novozymes		29,800,291
		Industrial Enzymes
	207,968	Solar		9,523,454
		Technical Wholesaler of Electrical, Plumbing & HVAC Equipment
				76,902,268
		> Finland 0.6%
	401,000	Vacon		21,277,871
		Leading Independent Manufacturer of Variable Speed Alternating Current Drives
	1,168,630	Stockmann		20,990,713
		Department Store & Fashion Retailer in Scandinavia & Russia
				42,268,584
		> Kazakhstan 0.6%
	5,143,000	Halyk Savings Bank of Kazakhstan - GDR (c)		42,172,600
		Largest Retail Bank & Insurer in Kazakhstan
				42,172,600
		> Norway 0.5%
	3,281,864	Atea		35,112,424
		Leading Nordic IT Hardware/ Software Reseller & Installation Company
				35,112,424
		> Iceland 0.5%
	28,312,499	Marel (g)		22,314,448
	7,670,000	Marel (g)		8,456,254
		Largest Manufacturer of Poultry & Fish Processing Equipment
				30,770,702

Number of Shares			Value
		> Czech Republic 0.4%
	130,682	Komercni Banka	$	27,625,776
		Leading Czech Universal Bank
				27,625,776
		> Belgium 0.4%
	438,880	EVS Broadcast Equipment		25,805,303
		Digital Live Mobile Production Software & Systems
				25,805,303
		> Russia 0.4%
	1,167,000	Yandex (c)		25,172,190
		Search Engine for Russian & Turkish Languages
				25,172,190
		> Portugal 0.4%
	8,635,000	Redes Energéticas Nacionais		23,422,428
		Portuguese Power Transmission & Gas Transportation
				23,422,428
		> Turkey 0.1%
	543,494	Bizim Toptan		8,492,943
		Cash & Carry Stores in Turkey
				8,492,943
Europe: Total				2,039,070,490
Other Countries 17.1%
		> South Africa 4.6%
	1,170,188	Naspers		75,583,404
		Media in Africa, China, Russia & Other Emerging Markets
	11,920,964	Coronation Fund Managers		55,812,561
		South African Fund Manager
	2,230,504	Massmart Holdings		50,571,401
		General Merchandise, Food & Home Improvement Stores; Wal-Mart Subsidiary
	19,098,300	Rand Merchant Insurance		46,833,805
		Directly Sold Property & Casualty Insurance; Holdings in Other Insurers
	2,644,083	Mr. Price		43,820,805
		South African Retailer of Apparel, Household & Sporting Goods
	8,679,940	Northam Platinum		39,288,328
		Platinum Mining in South Africa
				311,910,304
		> Australia 4.3%
	52,500,000	Commonwealth Property Office Fund		55,930,038
		Australia Prime Office REIT
	15,000,000	Challenger Financial		55,891,572
		Largest Annuity Provider
	498,560	Cochlear		41,330,407
		Cochlear Implants
	3,557,000	UGL		40,604,617
		Engineering & Facilities Management
	7,059,010	IAG		34,768,051
		General Insurance Provider

See accompanying notes to financial statements.

49

Columbia Acorn International

Statement of Investments, continued

Number of Shares			Value
		> Australia—continued
	2,500,000	Domino's Pizza Enterprises	$	27,403,603
		Domino's Pizza Operator in Australia/New Zealand & France/Benelux
	5,640,000	SAI Global		25,056,754
		Publishing, Certification, Compliance Services
	1,840,985	Regis Resources (c)		9,879,539
		Gold Mining in Australia
				290,864,581
		> Canada 4.1%
	1,403,772	CCL Industries		60,669,708
		Leading Global Label Manufacturer
	1,084,597	ShawCor		42,513,760
		Oil & Gas Pipeline Products
	3,047,000	CAE (b)		30,846,778
		Flight Simulator Equipment & Training Centers
	653,200	Onex Capital		27,495,208
		Private Equity
	582,942	AG Growth (b)		18,378,467
		Leading Manufacturer of Augers & Grain Handling Equipment
	709,576	Black Diamond Group		14,302,804
		Provides Accommodations/ Equipment for Oil Sands Development
	1,921,379	Horizon North Logistics		13,270,206
		Provides Diversified Oil Service Offering in Northern Canada
	984,500	Alliance Grain Traders (b)		12,926,078
		Global Leader in Pulse Processing & Distribution
	454,000	Celtic Exploration (c)		11,999,256
		Canadian Oil & Gas Producer
	263,857	Baytex (b)		11,371,820
		Oil & Gas Producer in Canada
	1,142,377	DeeThree Exploration (c)		7,476,500
	1,130,000	DeeThree Exploration (c)(h)		7,358,519
		Canadian Oil & Gas Producer
	1,611,000	Americas Petrogas (c)		4,858,751
		Oil & Gas Exploration in Argentina, Potash in Peru
	1,607,306	Pan Orient (c)		4,734,499
		Asian Oil & Gas Explorer
	450,000	Athabasca Oil Sands (c)		4,727,556
		Oil Sands & Unconventional Oil Development
	332,700	Crew Energy (c)		2,170,728
		Canadian Oil & Gas Producer
				275,100,638
		> United States 3.1%
	928,000	BioMarin Pharmaceutical (c)		45,704,000
		Biotech Focused on Orphan Diseases
	952,080	Atwood Oceanics (c)		43,595,743
		Offshore Drilling Contractor
	1,272,297	Textainer Group Holdings (b)		40,026,463
		Top International Container Leasor
	601,213	FMC Technologies (c)		25,749,953
		Oil & Gas Well Head Manufacturer

Number of Shares			Value
	428,228	World Fuel Services	$	17,630,147
		Global Fuel Broker
	548,900	Rowan (c)		17,164,103
		Contract Offshore Driller
	439,500	Hornbeck Offshore (c)		15,092,430
		Supply Vessel Operator in US Gulf of Mexico
				204,962,839
		> Israel 0.7%
	3,145,527	Israel Chemicals		37,882,033
		Producer of Potash, Phosphates, Bromine & Specialty Chemicals
	625,000	Caesarstone (c)		10,093,750
		Quartz Countertops
				47,975,783
		> New Zealand 0.3%
	10,879,000	Telecom NZ		20,591,900
		Primary Telecom Operator
				20,591,900
Other Countries: Total				1,151,406,045
Latin America 5.3%
		> Brazil 2.8%
	3,700,000	Localiza Rent A Car		67,765,568
		Car Rental
	1,800,000	Mills Estruturas e Servicos de Engenharia		29,890,110
		Civil Engineering & Construction
	1,200,000	Multiplus		27,967,765
		Loyalty Program Operator in Brazil
	5,000,000	Odontoprev		26,202,686
		Dental Insurance
	1,800,000	Arcos Dorados (b)		21,528,000
		McDonald's Master Franchise for Latin America
	17,793,303	Beadell Resources (c)		18,384,027
		Gold Mining in Brazil
				191,738,156
		> Mexico 1.5%
	600,000	Grupo Aeroportuario del Sureste - ADR		68,400,000
		Mexican Airport Operator
	11,945,000	Genomma Lab International (c)		24,543,698
		Develops, Markets & Distributes Consumer Products
	1,728,500	Herdez		5,314,018
		Processed Foods Producer & Distributor
				98,257,716
		> Guatemala 0.4%
	1,434,600	Tahoe Resources (c)		26,248,839
		Silver Project in Guatemala
				26,248,839
		> Chile 0.4%
	12,956,011	Viña Concha y Toro		25,237,904
		Global Branded Wine Manufacturer
				25,237,904

See accompanying notes to financial statements.

50

Number of Shares			Value
		> Uruguay 0.2%
	1,306,818	Union Agriculture Group (c)(d)(h)	$	13,381,816
		Farmland Operator in Uruguay
				13,381,816
		> Argentina —%
	7,425,000	Madalena Ventures (c)		2,873,856
		Oil & Gas Exploration in Argentina
				2,873,856
		> Colombia —%
	785,077	Canacol (c)		2,517,740
		Oil Producer in South America
	19,893,109	Gulf United Energy (c)		155,166
		Prospecting for Oil Alongside Large Producers in Colombia
				2,672,906
Latin America: Total				360,411,193
Total Equities: 97.1% (Cost: $4,951,432,379)				6,548,643,010	(i)
Short-Term Investments: 2.7%
	180,857,939	J.P. Morgan U.S. Government Money Market Fund - Capital Shares (7 day yield of 0.01%)		180,857,939
Total Short-Term Investments: 2.7% (Cost: $180,857,939)				180,857,939

Number of Shares			Value
Securities Lending Collateral 1.9%
	131,072,367	Dreyfus Government Cash Management Fund (7 day yield of 0.01%) (j)	$	131,072,367
Total Securities Lending Collateral: (Cost: $131,072,367)				131,072,367
Total Investments: 101.7% (Cost: $5,263,362,685)(k)				6,860,573,316
Obligation to Return Collateral for Securities Loaned: (1.9)%				(131,072,367	)
Cash and Other Assets Less Liabilities: 0.2%				14,296,657
Net Assets: 100.0%			$	6,743,797,606

ADR - American Depositary Receipts

GDR - Global Depositary Receipts

REIT - Real Estate Investment Trust

> Notes to Statement of Investments

(a)  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 year ended December 31, 2012, are as follows:

Security	Balance of Shares Held 12/31/11		Purchases/ Additions		Sales/ Reductions		Balance of Shares Held 12/31/12		Value		Dividend
Archipelago Resources		29,063,787		2,700,813		-		31,764,600	$	30,960,001	$	-
DeeThree Exploration (1)		4,061,377		-		1,789,000		2,272,377		14,835,019		-
Gulf United Energy (1)		22,525,000		-		2,631,891		19,893,109		155,166		-
Koninklijke TenCate (1)		1,371,573		53,685		1,425,258		-		-		1,476,185
Southern Arc Minerals		6,217,500		-		-		6,217,500		1,593,910		-
Sweco		4,150,024		-		-		4,150,024		46,585,386		1,845,111
UNIT4		1,591,702		-		17,557		1,574,145		47,517,926		796,615
United Drug (1)		9,074,112		-		9,074,112		-		-		196,099
Wacom		23,790		1,404		3,694		21,500		56,604,038		807,532
Workspace Group (1)		8,000,000		-		8,000,000		-		-		359,171
Total of Affiliated Transactions		86,078,865		2,755,902		22,941,512		65,893,255	$	198,251,446	$	5,480,713

(1) At December 31, 2012, the Fund owned less than five percent of the company's outstanding voting shares.

  The aggregate cost and value of these companies at December 31, 2012, was $112,040,756 and $183,261,261, respectively. Investments in affiliated companies represented 2.72% of the Fund's total net assets at December 31, 2012.

(b)  All or a portion of this security was on loan at December 31, 2012. The total market value of securities on loan at December 31, 2012 was $125,494,564.

(c)  Non-income producing security.

(d)  Illiquid security.

(e)  A portion of this security is to be delivered on a delayed basis.

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

See accompanying notes to financial statements.

51

Columbia Acorn International

Statement of Investments, continued

> Notes to Statement of Investments

(g)  The common stock equity holdings of Marel are stated separately on the Statements of Investments due to the application of the onshore or offshore foreign currency exchange rate. The appropriate exchange rate is applied to each purchased security lot based on the applicable registration obtained from Marel's regulatory governing body, the Icelandic Central Bank.

(h)  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 December 31, 2012, the market value of these securities amounted to $20,740,335, which represented 0.31% 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	$	15,000,000	$	13,381,816
DeeThree Exploration	9/7/10		1,130,000		2,950,812		7,358,519
				$	17,950,812	$	20,740,335

(i)  On December 31, 2012, the Fund's total investments were denominated in currencies as follows:

Currency	Value		Percentage of Net Assets
Japanese Yen	$	1,077,754,840		16.0
Euro		938,652,959		13.9
United States Dollar		553,873,590		8.2
British Pound		452,166,597		6.7
Taiwan Dollar		434,042,080		6.4
Hong Kong Dollar		391,331,005		5.8
Other currencies less than 5% of total net assets		2,700,821,939		40.1
Total Equities	$	6,548,643,010		97.1

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

(k)  At December 31, 2012, for federal income tax purposes, the cost of investments was $5,426,082,628 and net unrealized appreciation was $1,434,490,688 consisting of gross unrealized appreciation of $1,728,170,866 and gross unrealized depreciation of $293,680,178.

Fair Value Measurements

  Various inputs are used in determining the value of the Fund's investments, following the input prioritization hierarchy established by accounting principles generally accepted in the United States of America (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, to review the appropriateness of the Trust's Portfolio Pricing Policy and the pricing procedures of the investment manager (the Policies), and to review the continuing appropriateness of the current value of any security subject to 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.

52

> Notes to Statement of Investments

The following table summarizes the inputs used, as of December 31, 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	$	160,837,111	$	2,836,918,171	$	-	$	2,997,755,282
Europe		42,559,777		1,996,510,713		-		2,039,070,490
Other Countries		482,798,708		668,607,337		-		1,151,406,045
Latin America		328,645,350		18,384,027		13,381,816		360,411,193
Total Equities		1,014,840,946		5,520,420,248		13,381,816		6,548,643,010
Total Short-Term Investments		180,857,939		-		-		180,857,939
Total Securities Lending Collateral		131,072,367		-		-		131,072,367
Total Investments	$	1,326,771,252	$	5,520,420,248	$	13,381,816	$	6,860,573,316

  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
$	15,784,552	$	-	$	-	$	15,784,552

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

  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.

See accompanying notes to financial statements.

53

Columbia Acorn International

Portfolio Diversification

At December 31, 2012, the Fund's portfolio investments as a percentage of net assets were diversified as follows:

	Value		Percentage of Net Assets
> Industrial Goods & Services
Other Industrial Services	$	610,132,159		9.0
Machinery		391,421,832		5.8
Industrial Materials & Specialty Chemicals		379,195,160		5.6
Construction		146,954,404		2.2
Conglomerates		95,094,193		1.4
Electrical Components		89,836,544		1.3
Industrial Distribution		54,063,689		0.8
Outsourcing Services		34,041,656		0.5
		1,800,739,637		26.6
> Consumer Goods & Services
Retail		430,388,693		6.4
Food & Beverage		288,797,260		4.3
Casinos & Gaming		224,661,571		3.3
Nondurables		156,567,113		2.3
Other Consumer Services		115,107,890		1.7
Consumer Goods Distribution		80,070,730		1.2
Other Durable Goods		78,450,790		1.2
Travel		78,199,408		1.2
Apparel		62,892,232		0.9
Restaurants		58,334,450		0.9
Educational Services		38,282,223		0.6
Other Entertainment		22,022,712		0.3
Furniture & Textiles		10,093,750		0.1
		1,643,868,822		24.4
> Information
Computer Hardware & Related Equipment		255,569,089		3.8
Mobile Communications		234,470,818		3.5
Business Software		185,175,209		2.7
Internet Related		124,218,225		1.8
Financial Processors		69,713,724		1.0
Instrumentation		67,908,828		1.0
Computer Services		51,830,841		0.8
Semiconductors & Related Equipment		42,879,782		0.6
Electronics Distribution		38,335,261		0.6
CATV		37,986,380		0.6
Telephone & Data Services		20,591,900		0.3
Satellite Broadcasting & Services		9,972,794		0.2
TV Broadcasting		8,886,770		0.1
Advertising		5,042,671		0.1
		1,152,582,292		17.1

	Value			Percentage of Net Assets
> Other Industries
Real Estate	$	443,208,704			6.6
Transportation		135,865,184			2.0
Regulated Utilities		38,617,124			0.6
		617,691,012			9.2
> Finance
Insurance		219,319,501			3.3
Banks		168,103,945			2.5
Brokerage & Money Management		129,756,113			1.9
Finance Companies		67,521,672			1.0
		584,701,231			8.7
> Energy & Minerals
Mining		209,010,035			3.1
Oil Services		193,525,324			2.9
Oil & Gas Producers		77,701,929			1.1
Agricultural Commodities		26,307,895			0.4
Oil Refining, Marketing & Distribution		18,811,675			0.3
		525,356,858			7.8
> Health Care
Medical Equipment & Devices		90,269,171			1.3
Medical Supplies		52,945,010			0.8
Biotechnology & Drug Delivery		45,704,000			0.7
Health Care Services		34,784,977			0.5
		223,703,158			3.3
Total Equities:		6,548,643,010			97.1
Short-Term Investments:		180,857,939			2.7
Securities Lending Collateral:		131,072,367			1.9
Total Investments:		6,860,573,316			101.7
Obligation to Return Collateral for Securities Loaned:		(131,072,367	)		(1.9	)
Cash and Other Assets Less Liabilities:		14,296,657			0.2
Net Assets:	$	6,743,797,606			100.0

See accompanying notes to financial statements.

54

Columbia Acorn USA Fund

Major Portfolio Changes in the Fourth Quarter (Unaudited)

	Number of Shares
	9/30/12		12/31/12
Purchases
Information
Exa		31,804		270,337
Liquidity Services		0		81,000
RealPage		0		125,442
Semtech		0		130,000
Industrial Goods & Services
Dorman Products		0		97,000
Drew Industries		496,000		539,000
Forward Air		109,000		207,000
Generac		155,000		183,963
Polyone		0		180,000
Thermon		0		260,000
Consumer Goods & Services
Boulder Brands Inc		0		149,000
Casey's General Stores		0		63,000
Choice Hotels		75,000		173,000
Ryman Hospitality Properties		849,700		997,722
Finance
CAI International		415,208		542,055
SEI Investments		0		139,000
Health Care
Sarepta Therapeutics		0		179,000
Techne		53,000		96,000
Other Industries
EdR		783,000		1,084,800
Energy & Minerals
Chart Industries		0		27,050

	Number of Shares
	9/30/12		12/31/12
Sales
Information
Ansys		375,000		329,000
Atmel		1,958,000		1,307,000
Concur Technologies		243,000		196,000
Micros Systems		698,000		633,000
SABA		337,000		25,050
Syntel		97,000		87,000
WMS Industries		167,000		83,500
Industrial Goods & Services
Acorn Energy		600,919		542,836
Ametek		1,264,000		1,082,000
Clean Harbors		50,000		0
GrafTech International		413,634		0
Oshkosh Corporation		146,000		76,000
TrueBlue		240,000		0
Consumer Goods & Services
Deckers Outdoor		73,000		0
Herman Miller		148,000		78,000
lululemon athletica		565,000		522,000
Pool		429,000		393,000
Skullcandy		230,000		213,494
Teavana		120,000		0
Vail Resorts		64,000		32,000
Warnaco Group		222,000		0
Finance
City National		211,000		190,000
Eaton Vance		306,500		203,500
Pacific Continental Bank		217,117		0
Health Care
Alexion Pharmaceuticals		75,000		63,000
Auxilium Pharmaceuticals		421,000		103,527
BioMarin Pharmaceutical		415,000		381,000
Hill-Rom Holdings		268,000		0
Isis Pharmaceuticals		643,000		0
Other Industries
Dupont Fabros Technology		625,000		499,100
Energy & Minerals
Hornbeck Offshore		125,000		0
Rosetta Resources		129,000		93,000
SM Energy		133,000		99,000

See accompanying notes to financial statements.

55

Columbia Acorn USA

Statement of Investments, December 31, 2012

Number of Shares			Value
			Equities: 99.1%
Information 29.2%
		> Business Software 7.6%
	910,000	Informatica (a)	$	27,591,200
		Enterprise Data Integration Software
	633,000	Micros Systems (a)		26,864,520
		Information Systems for Hotels, Restaurants & Retailers
	329,000	Ansys (a)		22,154,860
		Simulation Software for Engineers & Designers
	197,000	NetSuite (a)		13,258,100
		End-to-end IT Systems Solutions Delivered Over the Web
	196,000	Concur Technologies (a)		13,233,920
		Web Enabled Cost & Expense Management Software
	290,000	SPS Commerce (a)		10,808,300
		Supply Chain Management Software Delivered via the Web
	125,442	RealPage (a)(b)		2,705,784
		Software for Managing Rental Properties Delivered Via the Web
	270,337	Exa (a)		2,630,379
		Simulation Software
	400,000	Velti (a)(b)		1,800,000
		Mobile Marketing Software Platform
	25,050	SABA (a)		218,937
		Learning Management Systems
				121,266,000
		> Instrumentation 4.9%
	525,000	IPG Photonics (b)		34,991,250
		Fiber Lasers
	180,000	Mettler-Toledo International (a)		34,794,000
		Laboratory Equipment
	151,000	Trimble Navigation (a)		9,026,780
		GPS-based Instruments
				78,812,030
		> Semiconductors & Related Equipment 3.9%
	690,000	Microsemi (a)		14,517,600
		Analog/Mixed Signal Semiconductors
	262,000	Ultratech (a)		9,772,600
		Semiconductor Equipment
	1,307,000	Atmel (a)		8,560,850
		Microcontrollers, Radio Frequency & Memory Semiconductors
	366,000	Monolithic Power Systems		8,154,480
		High Performance Analog & Mixed Signal Integrated Circuits
	961,000	ON Semiconductor (a)		6,775,050
		Mixed Signal & Power Management Semiconductors
	1,075,000	TriQuint Semiconductor (a)		5,203,000
		Radio Frequency Semiconductors
	130,000	Semtech (a)		3,763,500
		Analog Semiconductors
	390,000	Pericom Semiconductor (a)		3,131,700
		Interface Integrated Circuits & Frequency Control Products

Number of Shares			Value
	50,000	Hittite Microwave (a)	$	3,105,000
		Radio Frequency, Microwave & Millimeterwave Semiconductors
				62,983,780
		> Telephone & Data Services 2.5%
	1,457,000	tw telecom (a)		37,109,790
		Fiber Optic Telephone/Data Services
	400,000	Boingo Wireless (a)(b)		3,020,000
		Wholesale & Retail WiFi Networks
				40,129,790
		> Computer Hardware & Related Equipment 2.1%
	1,317,000	II-VI (a)		24,061,590
		Laser Optics & Specialty Materials
	160,000	Nice Systems - ADR (Israel) (a)		5,356,800
		Audio & Video Recording Solutions
	97,000	Netgear (a)		3,823,740
		Networking Products for Small Business & Home
	4,558	Rogers (a)		226,350
		Printed Circuit Materials & High-performance Foams
				33,468,480
		> Computer Services 2.1%
	556,000	ExlService Holdings (a)		14,734,000
		Business Process Outsourcing
	87,000	Syntel		4,662,330
		Offshore IT Services
	359,000	WNS - ADR (India) (a)		3,740,780
		Offshore BPO (Business Process Outsourcing) Services
	776,766	Hackett Group		3,324,559
		IT Integration & Best Practice Research
	640,000	RCM Technologies (c)		3,232,000
		Technology & Engineering Services
	192,000	Virtusa (a)		3,154,560
		Offshore IT Outsourcing
				32,848,229
		> Gaming Equipment & Services 1.9%
	660,000	Bally Technologies (a)		29,508,600
		Slot Machines & Software
	83,500	WMS Industries (a)		1,461,250
		Slot Machine Provider
				30,969,850
		> Telecommunications Equipment 1.7%
	813,000	Ixia (a)		13,804,740
		Telecom Network Test Equipment
	732,000	Finisar (a)		11,931,600
		Optical Subsystems & Components
	323,278	Infinera (a)(b)		1,878,245
		Optical Networking Equipment
				27,614,585
		> Mobile Communications 1.3%
	300,000	SBA Communications (a)		21,306,000
		Communications Towers
				21,306,000

See accompanying notes to financial statements.

56

Number of Shares			Value
		> Financial Processors 0.7%
	153,000	Global Payments	$	6,930,900
		Credit Card Processor
	81,000	Liquidity Services (a)		3,309,660
		E-Auctions for Surplus & Salvage Goods
				10,240,560
		> Contract Manufacturing 0.4%
	236,000	Plexus (a)		6,088,800
		Electronic Manufacturing Services
				6,088,800
		> TV Broadcasting 0.1%
	875,000	Entravision Communications		1,452,500
		Spanish Language TV & Radio Stations
				1,452,500
Information: Total				467,180,604
Industrial Goods & Services 18.3%
		> Machinery 14.5%
	747,200	Nordson		47,163,264
		Dispensing Systems for Adhesives & Coatings
	1,082,000	Ametek		40,650,740
		Aerospace/Industrial Instruments
	835,000	ESCO Technologies		31,237,350
		Automatic Electric Meter Readers
	890,000	Donaldson		29,227,600
		Industrial Air Filtration
	631,000	HEICO		20,179,380
		FAA Approved Aircraft Replacement Parts
	436,000	Moog (a)		17,889,080
		Motion Control Products for Aerospace, Defense & Industrial Markets
	260,000	Toro		11,174,800
		Turf Maintenance Equipment
	227,000	Polypore International (a)(b)		10,555,500
		Battery Separators & Filtration Media
	204,000	Kennametal		8,160,000
		Consumable Cutting Tools
	183,963	Generac		6,311,771
		Standby Power Generators
	97,000	Dorman Products		3,427,980
		Aftermarket Auto Parts Distributor
	26,000	Middleby (a)		3,333,460
		Manufacturer of Cooking Equipment
	76,000	Oshkosh Corporation (a)		2,253,400
		Specialty Truck Manufacturer
				231,564,325
		> Industrial Materials & Specialty Chemicals 1.3%
	539,000	Drew Industries		17,382,750
		RV & Manufactured Home Components
	180,000	Polyone		3,675,600
		Intermediate Stage Chemicals Producer
				21,058,350

Number of Shares			Value
		> Electrical Components 1.3%
	209,000	Acuity Brands	$	14,155,570
		Commercial Lighting Fixtures
	260,000	Thermon (a)		5,857,800
		Global Engineered Thermal Solutions
				20,013,370
		> Other Industrial Services 0.7%
	207,000	Forward Air		7,247,070
		Freight Transportation Between Airports
	542,836	Acorn Energy (b)		4,239,549
		Frac Well Exploration/Monitoring Device, Sonar Security, Electric Grid Monitoring
				11,486,619
		> Construction 0.3%
	180,000	Fortune Brands Home & Security (a)		5,259,600
		Home Building Supplies & Small Locks
				5,259,600
		> Waste Management 0.2%
	90,000	Waste Connections		3,041,100
		Solid Waste Management
				3,041,100
Industrial Goods & Services: Total				292,423,364
Consumer Goods & Services 17.4%
		> Retail 6.2%
	522,000	lululemon athletica (a)		39,792,060
		Premium Active Apparel Retailer
	468,500	Abercrombie & Fitch		22,473,945
		Teen Apparel Retailer
	805,000	Pier 1 Imports		16,100,000
		Home Furnishing Retailer
	356,000	Shutterfly (a)		10,633,720
		Internet Photo-centric Retailer
	715,000	Saks (a)(b)		7,514,650
		Luxury Department Store Retailer
	63,000	Casey's General Stores		3,345,300
		Owner/Operator of Convenience Stores
				99,859,675
		> Travel 5.4%
	997,722	Ryman Hospitality Properties		38,372,388
		Convention Hotels
	1,300,950	Avis Budget Group (a)		25,784,829
		Second Largest Car Rental Company
	675,000	Hertz (a)		10,982,250
		Largest US Rental Car Operator
	173,000	Choice Hotels		5,816,260
		Franchisor of Budget Hotel Brands
	140,000	HomeAway (a)(b)		3,080,000
		Vacation Rental Online Marketplace
	32,000	Vail Resorts		1,730,880
		Ski Resort Operator & Developer
				85,766,607

See accompanying notes to financial statements.

57

Columbia Acorn USA

Statement of Investments, continued

Number of Shares			Value
		> Furniture & Textiles 1.9%
	880,000	Knoll	$	13,516,800
		Office Furniture
	756,000	Interface		12,156,480
		Modular Carpet
	200,000	Caesarstone (Israel) (a)		3,230,000
		Quartz Countertops
	78,000	Herman Miller		1,670,760
		Office Furniture
				30,574,040
		> Consumer Goods Distribution 1.0%
	393,000	Pool		16,631,760
		Distributor of Swimming Pool Supplies & Equipment
				16,631,760
		> Other Consumer Services 0.7%
	233,000	Lifetime Fitness (a)		11,465,930
		Sport & Fitness Club Operator
				11,465,930
		> Casinos & Gaming 0.7%
	698,000	Pinnacle Entertainment (a)		11,049,340
		Regional Casino Operator
				11,049,340
		> Other Durable Goods 0.7%
	206,000	Cavco Industries (a)		10,295,880
		Manufactured Homes
				10,295,880
		> Nondurables 0.6%
	262,000	Helen of Troy (a)		8,748,180
		Personal Care, Housewares, Healthcare & Home Environment Products
				8,748,180
		> Food & Beverage 0.1%
	149,000	Boulder Brands Inc (a)		1,922,100
		Healthy Food Products
				1,922,100
		> Leisure Products 0.1%
	213,494	Skullcandy (a)(b)		1,663,118
		Lifestyle Branded Headphones
				1,663,118
		> Educational Services —%
	37,350	ITT Educational Services (a)		646,529
		Postsecondary Degree Services
				646,529
Consumer Goods & Services: Total				278,623,159
Finance 13.4%
		> Banks 7.0%
	833,000	MB Financial		16,451,750
		Chicago Bank
	1,053,000	Associated Banc-Corp		13,815,360
		Midwest Bank
	431,597	Lakeland Financial		11,152,466
		Indiana Bank
	170,000	SVB Financial Group (a)		9,514,900
		Bank to Venture Capitalists

Number of Shares			Value
	190,000	City National	$	9,408,800
		Bank & Asset Manager
	251,000	Hancock Holding		7,966,740
		Gulf Coast Bank
	1,478,200	First Busey		6,873,630
		Illinois Bank
	535,000	TCF Financial		6,500,250
		Great Lakes Bank
	641,750	Valley National Bancorp (b)		5,968,275
		New Jersey/New York Bank
	834,000	First Commonwealth		5,687,880
		Western Pennsylvania Bank
	242,000	Eagle Bancorp (a)		4,832,740
		Metro D.C. Bank
	764,000	TrustCo Bank		4,033,920
		New York State Bank
	178,826	Sandy Spring Bancorp		3,472,801
		Baltimore, D.C. Bank
	210,000	CVB Financial		2,184,000
		Inland Empire Business Bank
	851,247	Guaranty Bancorp (a)		1,659,932
		Colorado Bank
	105,700	Hudson Valley		1,645,749
		Metro New York City Bank
	90,000	TriCo Bancshares		1,507,500
		California Central Valley Bank
				112,676,693
		> Finance Companies 4.1%
	315,000	World Acceptance (a)		23,486,400
		Personal Loans
	389,000	Textainer Group Holdings		12,237,940
		Top International Container Leasor
	542,055	CAI International (a)		11,898,107
		International Container Leasing
	346,000	McGrath Rentcorp		10,040,920
		Temporary Space & IT Rentals
	357,861	H & E Equipment Services		5,392,966
		Heavy Equipment Leasing
	100,000	Marlin Business Services		2,006,000
		Small Equipment Leasing
	32,071	Regional Management (a)(b)		530,775
		Consumer Loans
				65,593,108
		> Savings & Loans 1.2%
	602,487	ViewPoint Financial		12,616,078
		Texas Thrift
	144,000	Berkshire Hills Bancorp		3,435,840
		Northeast Thrift
	173,073	Simplicity Bancorp		2,587,441
		Los Angeles Savings & Loan
				18,639,359
		> Brokerage & Money Management 0.6%
	203,500	Eaton Vance		6,481,475
		Specialty Mutual Funds
	139,000	SEI Investments		3,244,260
		Mutual Fund Administration & Investment Management
				9,725,735

See accompanying notes to financial statements.

58

Number of Shares			Value
		> Insurance 0.5%
	39,000	Enstar Group (a)	$	4,367,220
		Insurance/Reinsurance & Related Services
	50,000	Allied World Holdings		3,940,000
		Commerical Lines Insurance/Reinsurance
				8,307,220
Finance: Total				214,942,115
Health Care 9.2%
		> Biotechnology & Drug Delivery 5.6%
	381,000	BioMarin Pharmaceutical (a)		18,764,250
		Biotech Focused on Orphan Diseases
	696,000	Seattle Genetics (a)(b)		16,147,200
		Antibody-based Therapies for Cancer
	1,196,450	NPS Pharmaceuticals (a)		10,887,695
		Orphan Drugs & Healthy Royalties
	197,000	Synageva Biopharma (a)		9,119,130
		Biotech Focused on Orphan Diseases
	466,000	ARIAD Pharmaceuticals (a)		8,937,880
		Biotech Focused on Cancer
	100,000	Onyx Pharmaceuticals (a)		7,553,000
		Commercial-stage Biotech Focused on Cancer
	63,000	Alexion Pharmaceuticals (a)		5,910,030
		Biotech Focused on Orphan Diseases
	179,000	Sarepta Therapeutics (a)(b)		4,618,200
		Biotech Focused On Rare Diseases
	400,000	InterMune (a)(b)		3,876,000
		Drugs for Pulmonary Fibrosis & Hepatitis C
	103,527	Auxilium Pharmaceuticals (a)		1,918,355
		Biotech Focused on Niche Disease Areas
	259,000	Raptor Pharmaceutical (a)(b)		1,515,150
		Orphan Drug Company
	815,900	Chelsea Therapeutics International (a)(b)		620,084
		Biotech Focused on Rare Diseases
	18,181	Metabolex (a)(d)(e)		3,636
		Diabetes Drug Development
				89,870,610
		> Medical Supplies 1.7%
	587,600	Cepheid (a)		19,866,756
		Molecular Diagnostics
	96,000	Techne		6,560,640
		Cytokines, Antibodies & Other Reagents for Life Science
				26,427,396
		> Medical Equipment & Devices 1.0%
	246,012	Sirona Dental Systems (a)		15,857,934
		Manufacturer of Dental Equipment
				15,857,934
		> Pharmaceuticals 0.5%
	642,000	Akorn (a)		8,577,120
		Develops, Manufactures & Sells Specialty Generic Drugs
	133,180	Alimera Sciences (a)		209,093
		Ophthalmology-focused Pharmaceutical Company
				8,786,213

Number of Shares			Value
		> Health Care Services 0.4%
	664,900	Health Management Associates (a)	$	6,196,868
		Non-urban Hospitals
				6,196,868
Health Care: Total				147,139,021
Other Industries 7.4%
		> Real Estate 6.3%
	915,000	Extra Space Storage		33,296,850
		Self Storage Facilities
	499,100	Dupont Fabros Technology		12,058,256
		Technology-focused Office Buildings
	1,084,800	EdR		11,542,272
		Student Housing
	561,200	Biomed Realty Trust		10,847,996
		Life Science-focused Office Buildings
	540,000	Associated Estates Realty		8,704,800
		Multifamily Properties
	1,380,000	Kite Realty Group		7,714,200
		Community Shopping Centers
	958,000	DCT Industrial Trust		6,217,420
		Industrial Properties
	100,000	Post Properties		4,995,000
		Multifamily Properties
	200,000	St. Joe (a)(b)		4,616,000
		Florida Panhandle Landowner
				99,992,794
		> Transportation 1.1%
	515,091	Rush Enterprises, Class A (a)		10,646,931
	115,000	Rush Enterprises, Class B (a)		1,990,650
		Truck Sales & Service
	128,000	World Fuel Services		5,269,760
		Global Fuel Broker
				17,907,341
Other Industries: Total				117,900,135
Energy & Minerals 4.2%
		> Oil Services 2.2%
	725,000	Atwood Oceanics (a)		33,197,750
		Offshore Drilling Contractor
	27,050	Chart Industries (a)		1,803,423
		Manufacturer of Natural Gas Processing/Storage Equipment
				35,001,173
		> Oil & Gas Producers 1.3%
	182,000	PDC Energy (a)		6,044,220
		Oil & Gas Producer in US
	99,000	SM Energy		5,168,790
		Oil & Gas Producer
	174,000	Approach Resources (a)		4,351,740
		Oil & Gas Producer in West Texas Permian
	93,000	Rosetta Resources (a)		4,218,480
		Oil & Gas Producer Exploring in South Texas & Montana

See accompanying notes to financial statements.

59

Columbia Acorn USA

Statement of Investments, continued

Number of Shares			Value
		> Oil & Gas Producers—continued
	510,000	Quicksilver Resources (a)	$	1,458,600
		Natural Gas & Coal Seam Gas Producer
	262,200	Houston American Energy (a)(b)		57,684
		Oil & Gas Exploration/Production in Colombia
				21,299,514
		> Mining 0.7%
	77,000	Core Labs (Netherlands)		8,416,870
		Oil & Gas Reservoir Consulting
	600,000	Alexco Resource (a)		2,142,000
		Mining, Exploration & Environmental Services
	180,000	Augusta Resource (a)(b)		441,000
		US Copper/Molybdenum Mine
				10,999,870
Energy & Minerals: Total				67,300,557
Total Equities: 99.1% (Cost: $1,033,776,261)				1,585,508,955	(f)
Short-Term Investments: 0.6%
	10,223,537	J.P. Morgan U.S. Government Money Market Fund - Agency Shares (7 day yield of 0.01%)		10,223,537
Total Short-Term Investments: 0.6% (Cost: $10,223,537)				10,223,537

Number of Shares			Value
Securities Lending Collateral 3.2%
	51,263,955	Dreyfus Government Cash Management Fund (7 day yield of 0.01%) (g)	$	51,263,955
Total Securities Lending Collateral: (Cost: $51,263,955)				51,263,955
Total Investments: 102.9% (Cost: $1,095,263,753)(h)				1,646,996,447
Obligation to Return Collateral for Securities Loaned: (3.2)%				(51,263,955	)
Cash and Other Assets Less Liabilities: 0.3%				4,362,181
Net Assets: 100.0%			$	1,600,094,673

ADR - American Depositary Receipts

> Notes to Statement of Investments

(a)  Non-income producing security.

(b)  All or a portion of this security was on loan at December 31, 2012. The total market value of securities on loan at December 31, 2012 was $50,627,612.

(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 this affiliated company during the year ended December 31, 2012, are as follows:

Security	Balance of Shares Held 12/31/11		Purchases/ Additions		Sales/ Reductions		Balance of Shares Held 12/31/12		Value		Dividend
RCM Technologies		640,000		-		-		640,000	$	3,232,000	$	640,000
Total of Affiliated Transactions		640,000		-		-		640,000	$	3,232,000	$	640,000

  The aggregate cost and value of these companies at December 31, 2012, were $3,624,095 and $3,232,000, respectively. Investments in affiliated companies represented 0.20% of the Fund's total net assets at December 31, 2012.

(d)  Denotes a restricted security, which is subject to restrictions on resale under federal securities laws. This security is valued at fair value determined in good faith under consistently applied procedures established by the Board of Trustees. At December 31, 2012, the market value of this security amounted to $3,636, which represented less than 0.01% of total net assets.   Additional information on this security is as follows:

Security	Acquisition Dates	Shares		Cost		Value
Metabolex	2/11/00		18,181	$	1,999,910	$	3,636
				$	1,999,910	$	3,636

(e)  Illiquid security.

See accompanying notes to financial statements.

60

> Notes to Statement of Investments

(f)  At December 31, 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
Israel	$	8,586,800		0.54
Netherlands		8,416,870		0.53
India		3,740,780		0.23
Total Foreign Portfolio	$	20,744,450		1.30

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

(h)  At December 31, 2012, for federal income tax purposes, the cost of investments was $1,099,408,351 and net unrealized appreciation was $547,588,096 consisting of gross unrealized appreciation of $626,018,281 and gross unrealized depreciation of $78,430,185.

Fair Value Measurements

  Various inputs are used in determining the value of the Fund's investments, following the input prioritization hierarchy established by accounting principles generally accepted in the United States of America (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, to review the appropriateness of the Trust's Portfolio Pricing Policy and the pricing procedures of the investment manager (the Policies), and to review the continuing appropriateness of the current value of any security subject to 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.

61

Columbia Acorn USA

Statement of Investments, continued

> Notes to Statement of Investments

  The following table summarizes the inputs used, as of December 31, 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	$	467,180,604	$	-	$	-	$	467,180,604
Industrial Goods & Services		292,423,364		-		-		292,423,364
Consumer Goods & Services		278,623,159		-		-		278,623,159
Finance		214,942,115		-		-		214,942,115
Health Care		147,135,385		-		3,636		147,139,021
Other Industries		117,900,135		-		-		117,900,135
Energy & Minerals		67,300,557		-		-		67,300,557
Total Equities		1,585,505,319		-		3,636		1,585,508,955
Total Short-Term Investments		10,223,537		-		-		10,223,537
Total Securities Lending Collateral		51,263,955		-		-		51,263,955
Total Investments	$	1,646,992,811	$	-	$	3,636	$	1,646,996,447

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

  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.

See accompanying notes to financial statements.

62

Columbia Acorn International Select

Major Portfolio Changes in the Fourth Quarter (Unaudited)

	Number of Shares
	9/30/12		12/31/12
Purchases
Asia
> Singapore
Mapletree Logistics Trust		11,142,000		14,162,000
> Taiwan
Taiwan Mobile		3,810,000		4,810,000
> Japan
FP Corporation		0		55,400
Miraca Holdings		0		187,000
Park24		0		110,400
> Korea
Hite Jinro		28,690		156,680
Other Countries
> Australia
Challenger Financial		3,461,296		4,170,000
Commonwealth Property Office Fund		11,089,000		12,057,000
Regis Resources		95,201		562,088
> Canada
Alamos Gold		0		643,000
Central Fund of Canada		213,503		263,000
Goldcorp		464,000		500,000
> United States
Allied Nevada Gold		0		277,000
> New Zealand
Telecom NZ		744,857		1,980,000
Europe
> United Kingdom
JLT Group		296,000		501,000
> Netherlands
Imtech		123,416		184,186
> France
Gemalto		7,031		45,000
Latin America
> Guatemala
Tahoe Resources		401,000		588,000
> Brazil
Beadell Resources		0		2,755,603

	Number of Shares
	9/30/12		12/31/12
Sales
Asia
> Singapore
Mapletree Industrial Trust		20,395,000		16,000,000
> Taiwan
CTCI Corp		3,920,000		3,750,000
> Japan
Jupiter Telecommunications		13,964		0
Seven Bank		5,750,000		5,421,000
> China
Zhaojin Mining Industry		2,839,000		0
Other Countries
> Australia
IAG		1,652,046		1,335,000
UGL		1,058,050		498,000
> Canada
Kirkland Lake Gold		290,000		0
> United States
Atwood Oceanics		94,000		82,000
> South Africa
Adcock Ingram Holdings		1,001,517		0
Rand Merchant Insurance		4,798,015		3,106,606
> Israel
Israel Chemicals		349,000		307,000
Europe
> United Kingdom
Intertek Group		79,000		75,000
> Germany
Wirecard		538,000		355,000
> Iceland
Marel		3,958,835		3,488,000
> Denmark
Novozymes		125,000		0

See accompanying notes to financial statements.

63

Columbia Acorn International Select

Statement of Investments, December 31, 2012

Number of Shares			Value
			Equities: 94.0%
Asia 43.4%
		> Singapore 14.9%
	13,130,000	Ascendas REIT	$	25,694,375
		Industrial Property Landlord
	16,000,000	Mapletree Industrial Trust		17,865,446
		Industrial Property Landlord
	14,162,000	Mapletree Logistics Trust		13,328,453
		Industrial Property Landlord
				56,888,274
		> Taiwan 14.1%
	11,103,000	Far EasTone Telecom		28,350,161
		Taiwan's Third Largest Mobile Operator
	4,810,000	Taiwan Mobile		17,775,618
		Taiwan's Second Largest Mobile Operator
	3,750,000	CTCI Corp		7,450,018
		International Engineering Firm
				53,575,797
		> Japan 9.4%
	5,421,000	Seven Bank		14,299,466
		ATM Processing Services
	869,000	Start Today (a)		8,044,532
		Online Japanese Apparel Retailer
	187,000	Miraca Holdings		7,539,985
		Outsourced Lab Testing, Diagnostic Equipment & Reagents
	55,400	FP Corporation		3,685,528
		Disposable Food Trays & Containers
	110,400	Park24		1,743,540
		Parking Lot Operator
	390	GLP J-REIT (b)		298,009
		Logistics REIT in Japan
				35,611,060
		> Indonesia 2.8%
	11,136,600	Archipelago Resources (a)(b)		10,854,509
		Gold Mining Projects in Indonesia, Vietnam & the Philippines
				10,854,509
		> Korea 1.2%
	156,680	Hite Jinro (b)		4,448,001
		Beer & Spirits Manufacturer
				4,448,001
		> China 1.0%
	2,770,000	Want Want		3,881,894
		Chinese Branded Consumer Food Company
				3,881,894
Asia: Total				165,259,535
Other Countries 29.7%
		> Australia 11.5%
	4,170,000	Challenger Financial		15,537,857
		Largest Annuity Provider

Number of Shares			Value
	12,057,000	Commonwealth Property Office Fund	$	12,844,733
		Australia Prime Office REIT
	1,335,000	IAG		6,575,334
		General Insurance Provider
	498,000	UGL		5,684,875
		Engineering & Facilities Management
	562,088	Regis Resources (b)		3,016,412
		Gold Mining in Australia
				43,659,211
		> Canada 8.8%
	500,000	Goldcorp		18,350,000
		Gold Mining
	643,000	Alamos Gold		11,280,135
		Gold Mining
	91,400	CCL Industries		3,950,222
		Leading Global Label Manufacturer
				33,580,357
		> United States 3.9%
	277,000	Allied Nevada Gold (b)		8,346,010
		Gold & Silver Mining
	82,000	Atwood Oceanics (b)		3,754,780
		Offshore Drilling Contractor
	52,000	SM Energy		2,714,920
		Oil & Gas Producer
				14,815,710
		> South Africa 3.6%
	3,106,606	Rand Merchant Insurance		7,618,174
		Directly Sold Property & Casualty Insurance; Holdings in Other Insurers
	95,700	Naspers		6,181,342
		Media in Africa, China, Russia & Other Emerging Markets
				13,799,516
		> New Zealand 1.0%
	1,980,000	Telecom NZ		3,747,767
		Primary Telecom Operator
				3,747,767
		> Israel 0.9%
	307,000	Israel Chemicals		3,697,245
		Producer of Potash, Phosphates, Bromine & Specialty Chemicals
				3,697,245
Other Countries: Total				113,299,806
Europe 10.7%
		> United Kingdom 2.7%
	501,000	JLT Group		6,488,114
		International Business Insurance Broker
	75,000	Intertek Group		3,809,753
		Testing, Inspection, Certification Services
				10,297,867

See accompanying notes to financial statements.

64

Number of Shares			Value
		> Germany 2.3%
	355,000	Wirecard	$	8,764,044
		Online Payment Processing & Risk Management
				8,764,044
		> Sweden 1.3%
	192,000	Hexagon		4,855,342
		Design, Measurement & Visualization Software & Equipment
				4,855,342
		> Switzerland 1.2%
	19,800	Partners Group		4,577,356
		Private Markets Asset Management
				4,577,356
		> Netherlands 1.1%
	184,186	Imtech		4,278,093
		Technical Installation & Maintenance
				4,278,093
		> France 1.1%
	45,000	Gemalto		4,061,918
		Digital Security Solutions
				4,061,918
		> Iceland 1.0%
	3,488,000	Marel		3,845,556
		Largest Manufacturer of Poultry & Fish Processing Equipment
				3,845,556
Europe: Total				40,680,176
Latin America 10.2%
		> Mexico 6.0%
	745,000	Fresnillo		22,850,303
		Silver & Metal Byproduct Mining in Mexico
				22,850,303
		> Guatemala 2.8%
	588,000	Tahoe Resources (b)		10,758,621
		Silver Project in Guatemala
				10,758,621
		> Brazil 0.8%
	2,755,603	Beadell Resources (b)		2,847,087
		Gold Mining in Brazil
				2,847,087
		> Uruguay 0.5%
	191,666	Union Agriculture Group (b)(c)(d)		1,962,660
		Farmland Operator in Uruguay
				1,962,660

Number of Shares			Value
		> Colombia 0.1%
	1,880,000	Santa Maria Petroleum (b)(d)	$	154,225
		Explores for Oil & Gas in Latin America
				154,225
Latin America: Total				38,572,896
Total Equities: 94.0% (Cost: $298,860,688)				357,812,413	(e)
			Investment Funds 1.4%
Other Countries 1.4%
		> Canada 1.4%
	263,000	Central Fund of Canada		5,530,890
		Allocated Gold & Silver Closed End Fund
Other Countries: Total				5,530,890
Total Investment Funds: 1.4% (Cost: $6,183,324)				5,530,890
Short-Term Investments: 4.3%
	16,208,432	J.P. Morgan U.S. Government Money Market Fund - Agency Shares (7 day yield of 0.01%)		16,208,432
Total Short-Term Investments: 4.3% (Cost: $16,208,432)				16,208,432
Securities Lending Collateral 1.7%
	6,389,590	Dreyfus Government Cash Management Fund (7 day yield of 0.01%) (f)		6,389,590
Total Securities Lending Collateral: (Cost: $6,389,590)				6,389,590
Total Investments: 101.4% (Cost: $327,642,034)(g)				385,941,325
Obligation to Return Collateral for Securities Loaned: (1.7)%				(6,389,590	)
Cash and Other Assets Less Liabilities: 0.3%				902,319
Net Assets: 100.0%			$	380,454,054

REIT - Real Estate Investment Trust

See accompanying notes to financial statements.

65

Columbia Acorn International Select

Statement of Investments, continued

> Notes to Statement of Investments

(a)  All or a portion of this security was on loan at December 31, 2012. The total market value of securities on loan at December 31, 2012 was $6,077,787.

(b)  Non-income producing security.

(c)  Illiquid security.

(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 December 31, 2012, the market value of these securities amounted to $2,116,885, which represented 0.56% 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	$	2,200,000	$	1,962,660
Santa Maria Petroleum	1/14/11		1,880,000		2,375,897		154,225
				$	4,575,897	$	2,116,885

(e)  On December 31, 2012, the Fund's total investments were denominated in currencies as follows:

Currency	Value		Percentage of Net Assets
Singapore Dollar	$	56,888,274		14.9
Taiwan Dollar		53,575,797		14.1
Australian Dollar		46,506,298		12.2
British Pound		44,002,679		11.6
United States Dollar		40,659,260		10.7
Japanese Yen		35,611,060		9.4
Canadian Dollar		20,612,313		5.4
Other currencies less than 5% of total net assets		59,956,732		15.7
Total Equities	$	357,812,413		94.0

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

(g)  At December 31, 2012, for federal income tax purposes, the cost of investments was $347,187,320 and net unrealized appreciation was $38,754,005 consisting of gross unrealized appreciation of $53,206,551 and gross unrealized depreciation of $14,452,546.

  At December 31, 2012, the Fund had entered into the following forward foreign currency exchange contract:

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		173,346,000	$	20,000,000	1/15/13	$	(411,753	)

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 accounting principles generally accepted in the United States of America (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.

See accompanying notes to financial statements.

66

> Notes to Statement of Investments

  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, to review the appropriateness of the Trust's Portfolio Pricing Policy and the pricing procedures of the investment manager (the Policies), and to review the continuing appropriateness of the current value of any security subject to 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 December 31, 2012, in valuing the Fund's assets:

Investment Type	(Level 1)		Other Significant Observable Quoted Prices (Level 2)			Significant Unobservable Inputs (Level 3)		Inputs Total
Equities
Asia	$	-	$	165,259,535		$	-	$	165,259,535
Other Countries		48,396,067		64,903,739			-		113,299,806
Europe		-		40,680,176			-		40,680,176
Latin America		10,758,621		25,851,615			1,962,660		38,572,896
Total Equities		59,154,688		296,695,065			1,962,660		357,812,413
Investment Funds
Other Countries		5,530,890		-			-		5,530,890
Total Short-Term Investments		16,208,432		-			-		16,208,432
Total Securities Lending Collateral		6,389,590		-			-		6,389,590
Total Investments	$	87,283,600	$	296,695,065		$	1,962,660	$	385,941,325
Unrealized Depreciation on Forward Foreign Currency Exchange Contracts		-		(411,753	)		-		(411,753	)
Total Investments	$	87,283,600	$	296,283,312		$	1,962,660	$	385,529,572

  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 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.

See accompanying notes to financial statements.

67

Columbia Acorn International Select

Portfolio Diversification

At December 31, 2012, the Fund's portfolio investments as a percentage of net assets were diversified as follows:

	Value		Percentage of Net Assets
> Energy & Minerals
Mining	$	88,303,077		23.2
Oil Services		3,754,780		1.0
Oil & Gas Producers		2,869,145		0.7
Agricultural Commodities		1,962,660		0.5
		96,889,662		25.4
> Information
Mobile Communications		46,125,779		12.1
Financial Processors		8,764,044		2.3
Internet Related		6,181,342		1.6
Business Software		4,855,342		1.3
Computer Hardware & Related Equipment		4,061,918		1.1
Telephone & Data Services		3,747,767		1.0
		73,736,192		19.4
> Other Industries
Real Estate		70,031,015		18.4
		70,031,015		18.4
> Finance
Insurance		36,219,479		9.5
Banks		14,299,466		3.8
Brokerage & Money Management		4,577,356		1.2
		55,096,301		14.5
> Industrial Goods & Services
Other Industrial Services		15,516,261		4.1
Construction		7,450,018		2.0
Industrial Materials & Specialty Chemicals		7,382,773		1.9
Machinery		3,845,556		1.0
		34,194,608		9.0

	Value			Percentage of Net Assets
> Consumer Goods & Services
Food & Beverage	$	8,329,896			2.2
Retail		8,044,532			2.1
Nondurables		3,950,222			1.0
		20,324,650			5.3
> Health Care
Health Care Services		7,539,985			2.0
		7,539,985			2.0
Total Equities:		357,812,413			94.0
Total Investment Funds:		5,530,890			1.4
Total Short-Term Investments:		16,208,432			4.3
Securities Lending Collateral:		6,389,590			1.7
Total Investments:		385,941,325			101.4
Obligation to Return Collateral for Securities Loaned:		(6,389,590	)		(1.7	)
Cash and Other Assets Less Liabilities:		902,319			0.3
Net Assets:	$	380,454,054			100.0

See accompanying notes to financial statements.

68

Columbia Acorn Select Fund

Major Portfolio Changes in the Fourth Quarter (Unaudited)

	Number of Shares
	9/30/12		12/31/12
Purchases
Information
F5 Networks		80,000		140,000
Industrial Goods & Services
Airgas		0		74,233
Forward Air		0		106,509
Consumer Goods & Services
Choice Hotels		0		87,591
Ryman Hospitality Properties		900,000		1,020,783
Energy & Minerals
Kirkland Lake Gold (Canada)		925,000		1,200,000

	Number of Shares
	9/30/12		12/31/12
Sales
Information
Amphenol		540,000		510,000
Ansys		95,000		74,000
Concur Technologies		167,000		0
Crown Castle International		680,000		566,000
Sanmina-SCI		2,415,000		1,990,000
SBA Communications		455,000		431,000
WNS - ADR (India)		3,300,000		3,034,100
Industrial Goods & Services
Ametek		1,860,000		1,533,000
Donaldson		1,110,000		1,065,000
Expeditors International of Washington		230,000		0
Kennametal		835,000		713,000
Pall		605,000		426,000
Consumer Goods & Services
Abercrombie & Fitch		455,000		445,000
Coach		515,000		285,000
Hertz		4,020,000		2,976,000
lululemon athletica		288,000		209,000
RexLot Holdings (China)		208,000,000		187,475,000
Tiffany & Co.		149,000		0
Vail Resorts		235,000		205,000
Finance
City National		520,000		496,000
CNO Financial Group		6,315,000		5,539,000
Discover Financial Services		1,700,000		1,412,000
Energy & Minerals
Houston American Energy		1,455,000		0
Pacific Rubiales Energy (Colombia)		1,035,000		757,000
Shamaran Petroleum (Iraq)		27,100,000		26,965,500
Health Care
NPS Pharmaceuticals		1,875,000		1,444,255
Other Industries
Biomed Realty Trust		1,375,000		954,000
Wisconsin Energy		316,000		220,000

See accompanying notes to financial statements.

69

Columbia Acorn Select

Statement of Investments, December 31, 2012

Number of Shares			Value
			Equities: 96.4%
Information 21.9%
		> Mobile Communications 8.0%
	566,000	Crown Castle International (a)	$	40,842,560
		Communications Towers
	431,000	SBA Communications (a)		30,609,620
		Communications Towers
	19,000,000	Globalstar (a)(b)(c)		5,795,000
		Satellite Mobile Voice & Data Carrier
				77,247,180
		> Computer Hardware & Related Equipment 3.4%
	510,000	Amphenol		32,997,000
		Electronic Connectors
				32,997,000
		> Computer Services 3.3%
	3,034,100	WNS - ADR (India) (a)(b)		31,615,322
		Offshore BPO (Business Process Outsourcing) Services
				31,615,322
		> Contract Manufacturing 2.3%
	1,990,000	Sanmina-SCI (a)		22,029,300
		Electronic Manufacturing Services
				22,029,300
		> Instrumentation 2.2%
	111,000	Mettler-Toledo International (a)		21,456,300
		Laboratory Equipment
				21,456,300
		> Telecommunications Equipment 1.4%
	140,000	F5 Networks (a)		13,601,000
		Internet Traffic Management Equipment
				13,601,000
		> Semiconductors & Related Equipment 0.8%
	1,140,000	Atmel (a)		7,467,000
		Microcontrollers, Radio Frequency & Memory Semiconductors
				7,467,000
		> Business Software 0.5%
	74,000	Ansys (a)		4,983,160
		Simulation Software for Engineers & Designers
				4,983,160
Information: Total				211,396,262
Industrial Goods & Services 21.8%
		> Machinery 16.6%
	1,533,000	Ametek		57,594,810
		Aerospace/Industrial Instruments
	1,065,000	Donaldson		34,974,600
		Industrial Air Filtration
	713,000	Kennametal		28,520,000
		Consumable Cutting Tools
	426,000	Pall		25,670,760
		Life Science, Water & Industrial Filtration
	214,000	Nordson		13,507,680
		Dispensing Systems for Adhesives & Coatings
				160,267,850

Number of Shares			Value
		> Outsourcing Services 2.4%
	865,000	Quanta Services (a)	$	23,605,850
		Electrical & Telecom Construction Services
				23,605,850
		> Industrial Materials & Specialty Chemicals 1.7%
	273,000	FMC Corporation		15,975,960
		Niche Specialty Chemicals
				15,975,960
		> Industrial Distribution 0.7%
	74,233	Airgas		6,776,731
		Industrial Gas Distributor
				6,776,731
		> Other Industrial Services 0.4%
	106,509	Forward Air		3,728,880
		Freight Transportation Between Airports
				3,728,880
Industrial Goods & Services: Total				210,355,271
Consumer Goods & Services 18.2%
		> Travel 10.5%
	2,976,000	Hertz (a)		48,419,520
		Largest US Rental Car Operator
	1,020,783	Ryman Hospitality Properties		39,259,314
		Convention Hotels
	205,000	Vail Resorts		11,088,450
		Ski Resort Operator & Developer
	87,591	Choice Hotels		2,944,810
		Franchisor of Budget Hotel Brands
				101,712,094
		> Retail 3.9%
	445,000	Abercrombie & Fitch		21,346,650
		Teen Apparel Retailer
	209,000	lululemon athletica (a)		15,932,070
		Premium Active Apparel Retailer
				37,278,720
		> Apparel 1.6%
	285,000	Coach		15,820,350
		Designer & Retailer of Branded Leather Accessories
				15,820,350
		> Casinos & Gaming 1.5%
	187,475,000	RexLot Holdings (China)		14,382,858
		Lottery Equipment Supplier in China
				14,382,858
		> Educational Services 0.4%
	223,000	ITT Educational Services (a)(c)		3,860,130
		Postsecondary Degree Services
				3,860,130
		> Other Consumer Services 0.3%
	1,300,000	IFM Investments (Century 21 China RE) - ADR (China) (a)(b)		2,379,000
		Provide Real Estate Services in China
				2,379,000

See accompanying notes to financial statements.

70

Number of Shares			Value
		> Food & Beverage —%
	1,500,000	GLG Life Tech (Canada) (a)(d)	$	391,500
		Produces an All-natural Sweetener Extracted from the Stevia Plant
				391,500
Consumer Goods & Services: Total				175,824,652
Finance 16.7%
		> Credit Cards 5.6%
	1,412,000	Discover Financial Services		54,432,600
		Credit Card Company
				54,432,600
		> Insurance 5.3%
	5,539,000	CNO Financial Group		51,678,870
		Life, Long-term Care & Medical Supplement Insurance
				51,678,870
		> Banks 4.0%
	496,000	City National		24,561,920
		Bank & Asset Manager
	1,075,000	Associated Banc-Corp		14,104,000
		Midwest Bank
				38,665,920
		> Brokerage & Money Management 1.8%
	731,000	SEI Investments		17,061,540
		Mutual Fund Administration & Investment Management
				17,061,540
Finance: Total				161,838,930
Energy & Minerals 8.8%
		> Oil & Gas Producers 5.1%
	757,000	Pacific Rubiales Energy (Colombia) (c)		17,587,483
		Oil Production & Exploration in Colombia
	26,965,500	Shamaran Petroleum (Iraq) (a)		10,572,580
		Oil Exploration in Kurdistan
	2,918,740	Canacol (Colombia) (a)		9,360,391
		Oil Producer in South America
	24,000,000	Canadian Overseas Petroleum (United Kingdom) (a)(b)(e)		4,169,297
	12,000,000	Canadian Overseas Petroleum - Warrants (United Kingdom) (a)(d)(e)		186,026
		Oil & Gas Exploration/Production in the North Sea
	33,700,000	Petrodorado Energy (Colombia) (a)(b)		4,065,547
		Oil & Gas Exploration & Production in Colombia, Peru & Paraguay
	17,575,000	Petromanas (Canada) (a)		3,092,013
		Exploring for Oil in Albania
				49,033,337
		> Agricultural Commodities 1.8%
	1,742,424	Union Agriculture Group (Uruguay) (a)(d)(e)		17,842,422
		Farmland Operator in Uruguay
				17,842,422

Number of Shares			Value
		> Alternative Energy 0.9%
	1,500,000	Canadian Solar (China) (a)(c)	$	5,100,000
		Solar Cell & Module Manufacturer
	2,200,000	Synthesis Energy Systems (China) (a)		2,354,000
		Owner/Operator of Gasification Plants
	1,165,000	Real Goods Solar (a)		873,750
		Residential Solar Energy Installer
				8,327,750
		> Mining 0.7%
	1,200,000	Kirkland Lake Gold (Canada) (a)(c)		7,057,404
		Gold Mining
				7,057,404
		> Oil Services 0.3%
	10,559,800	Tuscany International Drilling (Colombia) (a)(c)		2,441,695
		South America Based Drilling Rig Contractor
				2,441,695
Energy & Minerals: Total				84,702,608
Health Care 5.1%
		> Medical Supplies 2.6%
	176,000	Henry Schein (a)		14,160,960
		Largest Distributor of Healthcare Products
	320,000	Cepheid (a)		10,819,200
		Molecular Diagnostics
				24,980,160
		> Biotechnology & Drug Delivery 2.5%
	1,444,255	NPS Pharmaceuticals (a)		13,142,720
		Orphan Drugs & Healthy Royalties
	468,000	Seattle Genetics (a)(c)		10,857,600
		Antibody-based Therapies for Cancer
				24,000,320
Health Care: Total				48,980,480
Other Industries 3.9%
		> Real Estate 3.1%
	954,000	Biomed Realty Trust		18,440,820
		Life Science-focused Office Buildings
	466,196	Dupont Fabros Technology		11,263,295
		Technology-focused Office Buildings
				29,704,115
		> Regulated Utilities 0.8%
	220,000	Wisconsin Energy		8,107,000
		Wisconsin Utility
				8,107,000
Other Industries: Total				37,811,115
Total Equities: 96.4% (Cost: $658,483,772)				930,909,318	(f)

See accompanying notes to financial statements.

71

Columbia Acorn Select

Statement of Investments, continued

Number of Shares			Value
Short-Term Investments: 0.3%
	2,654,408	J.P. Morgan U.S. Government Money Market Fund - Capital Shares (7 day yield of 0.01%)	$	2,654,408
Total Short-Term Investments: 0.3% (Cost: $2,654,408)				2,654,408
Securities Lending Collateral 1.2%
	11,106,378	Dreyfus Government Cash Management Fund (7 day yield of 0.01%) (g)		11,106,378
Total Securities Lending Collateral: (Cost: $11,106,378)				11,106,378
Total Investments: 97.9% (Cost: $672,244,558)(h)				944,670,104
Obligation to Return Collateral for Securities Loaned: (1.2)%				(11,106,378	)
Cash and Other Assets Less Liabilities: 3.3%				32,063,188
Net Assets: 100.0%			$	965,626,914

ADR - American Depositary Receipts

> Notes to Statement of Investments

(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 year ended December 31, 2012, are as follows:

Security	Balance of Shares Held 12/31/11		Purchases/ Additions		Sales/ Reductions		Balance of Shares Held 12/31/12		Value		Dividend
Canacol (1)(2)		31,372,300		-		28,453,560		2,918,740	$	9,360,391	$	-
Canadian Overseas Petroleum		24,000,000		-		-		24,000,000		4,169,297		-
Canadian Solar (1)		2,700,000		601,200		1,801,200		1,500,000		5,100,000		-
Eacom Timber (1)		36,000,000		-		36,000,000		-		-		-
GLG Life Tech (1)		1,850,000		-		350,000		1,500,000		391,500		-
Globalstar		13,184,322		10,815,678		5,000,000		19,000,000		5,795,000		-
IFM Investments (Century 21 China RE) - ADR (2)		3,430,000		302,000		2,432,000		1,300,000		2,379,000		-
Petrodorado Energy		34,700,000		-		1,000,000		33,700,000		4,065,547		-
Real Goods Solar (1)		1,500,000		-		335,000		1,165,000		873,750		-
Sanmina-SCI (1)		6,100,000		-		4,110,000		1,990,000		22,029,300		-
Synthesis Energy Systems (1)		2,950,372		-		750,372		2,200,000		2,354,000		-
VisionChina Media - ADR (1)		7,000,000		-		7,000,000		-		-		-
WNS - ADR		4,254,230		-		1,220,130		3,034,100		31,615,322		-
Total of Affiliated Transactions		169,041,224		11,718,878		88,452,262		92,307,840	$	88,133,107	$	-

(1)  At December 31, 2012, the Fund owned less than five percent of the company's outstanding voting shares.

(2)  Includes the effects of a stock split.

  The aggregate cost and value of these companies at December 31, 2012, were $77,398,151 and $48,024,166, respectively. Investments in affiliated companies represented 4.97% of the Fund's total net assets at December 31, 2012.

See accompanying notes to financial statements.

72

> Notes to Statement of Investments

(c)  All or a portion of this security was on loan at December 31, 2012. The total market value of securities on loan at December 31, 2012 was $10,135,994.

(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 December 31, 2012, the market value of these securities amounted to $22,197,745, which represented 2.30% 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		1,742,424	$	20,000,000	$	17,842,422
Canadian Overseas Petroleum	11/24/10		24,000,000		10,260,435		4,169,297
Canadian Overseas Petroleum - Warrants	11/24/10		12,000,000		1,501,964		186,026
				$	31,762,399	$	22,197,745

(f)  On December 31, 2012, the market value of foreign securities represented 13.73% of total net assets. The Fund's foreign portfolio was diversified as follows:

Country	Value		Percentage of Net Assets
Colombia	$	33,455,116		3.47
India		31,615,322		3.27
China		24,215,858		2.51
Uruguay		17,842,422		1.85
Iraq		10,572,580		1.09
Canada		10,540,917		1.09
United Kingdom		4,355,323		0.45
Total Foreign Portfolio	$	132,597,538		13.73

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

(h)  At December 31, 2012, for federal income tax purposes, the cost of investments was $682,147,469 and net unrealized appreciation was $262,522,635 consisting of gross unrealized appreciation of $359,494,803 and gross unrealized depreciation of $96,972,168.

Fair Value Measurements

  Various inputs are used in determining the value of the Fund's investments, following the input prioritization hierarchy established by accounting principles generally accepted in the United States of America (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, to review the appropriateness of the Trust's Portfolio Pricing Policy and the pricing procedures of the investment manager (the Policies), and to review the continuing appropriateness of the current value of any security subject to 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.

73

Columbia Acorn Select

Statement of Investments, continued

> Notes to Statement of Investments

  The following table summarizes the inputs used, as of December 31, 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	$	211,396,262	$	-	$	-	$	211,396,262
Industrial Goods & Services		210,355,271		-		-		210,355,271
Consumer Goods & Services		161,050,294		14,774,358		-		175,824,652
Finance		161,838,930		-		-		161,838,930
Energy & Minerals		62,504,863		4,355,323		17,842,422		84,702,608
Health Care		48,980,480		-		-		48,980,480
Other Industries		37,811,115		-		-		37,811,115
Total Equities		893,937,215		19,129,681		17,842,422		930,909,318
Total Short-Term Investments		2,654,408		-		-		2,654,408
Total Securities Lending Collateral		11,106,378		-		-		11,106,378
Total Investments	$	907,698,001	$	19,129,681	$	17,842,422	$	944,670,104

  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
$	-	$	1,665,000	$	1,665,000	$	-

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

	Fair Value at 12/31/12		Valuation Technique(s)	Unobservable Input(s)	Range (Weighted Average)
Equities	$	17,842,422	Market comparable companies	Discount for lack of marketability		-2	% to 3% (-8%)

  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.

See accompanying notes to financial statements.

74

Columbia Thermostat Fund

Statement of Investments, December 31, 2012

Number of Shares			Value
		> Affiliated Bond Funds: 54.0%
	18,877,615	Columbia Short Term Bond Fund, Class I	$	188,776,150
	14,098,807	Columbia Income Opportunities Fund, Class I		141,974,994
	14,950,850	Columbia Intermediate Bond Fund, Class I		141,734,058
Total Bond Funds: (Cost: $464,614,483)				472,485,202
		> Affiliated Stock Funds: 44.6%
	5,273,173	Columbia Dividend Income Fund, Class I		77,832,029
	1,899,103	Columbia Acorn International, Class I		77,597,366
	1,924,624	Columbia Acorn Fund, Class I		58,643,291
	3,628,435	Columbia Contrarian Core Fund, Class I		58,599,226
	2,813,972	Columbia Select Large Cap Growth Fund, Class I (a)		39,198,626
	2,773,358	Columbia Large Cap Enhanced Core Fund, Class I		39,076,617
	1,523,738	Columbia Acorn Select, Class I (a)		39,053,399
Total Stock Funds: (Cost: $353,815,430)				390,000,554

Number of Shares			Value
		> Short-Term Investments 0.7%
	5,795,466	J.P. Morgan U.S. Government Money Market Fund - Agency Shares (7 day yield of 0.01%)	$	5,795,466
Total Short-Term Investments: (Cost: $5,795,466)				5,795,466
Total Investments: 99.3% (Cost: $824,225,379)(b)				868,281,222
Cash and Other Assets Less Liabilities: 0.7%				6,341,475
Net Assets: 100.0%			$	874,622,697

> Notes to Statement of Investments

(a)  Non-income producing security.

(b)  At December 31, 2012, for federal income tax purposes, the cost of investments was $829,003,500 and net unrealized appreciation was $39,277,722 consisting of gross unrealized appreciation of $40,011,973 and gross unrealized depreciation of $734,251.

Fair Value Measurements

  Various inputs are used in determining the value of the Fund's investments, following the input prioritization hierarchy established by accounting principles generally accepted in the United States of America (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, 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, to review the appropriateness of the Trust's Portfolio Pricing Policy and the pricing procedures of the investment manager (the Policies), and to review the continuing appropriateness of the current value of any security subject to 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.

75

Columbia Thermostat Fund

Statement of Investments, continued

> Notes to Statement of Investments

The following table summarizes the inputs used, as of December 31, 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 Bond Funds	$	472,485,202	$	-	$	-	$	472,485,202
Total Stock Funds		390,000,554		-		-		390,000,554
Total Short-Term Investments		5,795,466		-		-		5,795,466
Total Investments	$	868,281,222	$	-	$	-	$	868,281,222

  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 Fourth Quarter (Unaudited)

	Number of Shares
	9/30/12		12/31/12
Purchases
Asia
> Taiwan
Advantech		22,169		32,169
CTCI Corp		81,762		99,762
Far Eastone Telecom		74,126		137,000
Flexium Interconnect		0		38,000
Lung Yen		20,500		30,500
PC Home		19,307		46,000
St. Shine Optical		8,000		11,000
Taiwan Hon Chuan		29,689		68,000
> Indonesia
Ace Indonesia		2,790,190		3,078,690
Archipelago Resources		191,539		255,898
Mayora Indah		28,000		48,500
MNC Skyvision		364,000		389,500
Surya Citra Media		373,516		428,440
> India
Adani Ports & Special Economic Zone		46,045		59,839
Bosch		0		597
Colgate Palmolive (India)		0		3,580
Redington India		61,400		74,582
Titan Industries		16,080		19,309
TTK Prestige		1,005		1,627
United Breweries		12,216		12,844
Yes Bank		0		11,731
> Hong Kong
AAC Technologies		31,027		46,027
Lifestyle International		56,589		71,589
Melco Crown Entertainment - ADR		8,650		9,081
Melco International		128,862		200,000
Sa Sa International		99,799		121,799
> Thailand
Home Product Center		372,000		472,000
Samui Airport Property Fund		7,700		180,800
Siam Makro		0		6,400
> China
AMVIG Holdings		212,000		312,000
Digital China		61,151		115,151
> Cambodia
Nagacorp		420,000		482,000
> Philippines
Manila Water Company		109,465		127,365
SM Prime Holdings		195,818		242,518
> Mongolia
Mongolian Mining		255,100		345,100
> Japan
Kansai Paint		5,760		13,760

	Number of Shares
	9/30/12		12/31/12
> Singapore
Petra Foods		32,000		40,000
> Korea
Paradise Co		0		6,500
Europe
> Kazakhstan
Halyk Savings Bank of Kazakhstan - GDR		23,202		35,257
> Sweden
Hexagon		8,731		10,359
> Switzerland
Dufry Group		1,320		1,866
> Italy
Pirelli		7,631		13,812
> Finland
Vacon		0		2,220
> Germany
Dürr		962		1,119
> Turkey
Bizim Toptan		0		2,496
Other Countries
> South Africa
Coronation Fund Managers		47,172		55,348
Massmart Holdings		5,847		8,306
Mr. Price		5,897		6,722
> United States
Atwood Oceanics		952		3,076
Textainer Group Holdings		4,404		5,419
> Canada
Alliance Grain Traders		7,801		9,973
Latin America
> Brazil
Arcos Dorados		4,622		9,977
Beadell Resources		0		101,706
Localiza Rent A Car		8,000		10,700
Multiplus		4,200		6,300
Odontoprev		0		18,500
> Mexico
Genomma Lab International		38,000		48,300
> Chile
Viña Concha y Toro		34,333		44,806
> Argentina
Madalena Ventures		81,500		106,000

See accompanying notes to financial statements.

77

Columbia Acorn Emerging Markets Fund

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

	Number of Shares
	9/30/12		12/31/12
Sales
Asia
> Taiwan
Radiant Opto-Electronics		15,735		10,735
Tripod Technologies		28,300		20,248
> China
NetEase.com - ADR		1,549		0
RexLot Holdings		1,575,000		0
Europe
> France
Compagnie Française de l'Afrique Occidentale		1,333		0
Other Countries
> South Africa
Adcock Ingram Holdings		10,076		0
Northam Platinum		10,854		0
Latin America
> Brazil
MRV Engenharia		12,425		0

See accompanying notes to financial statements.

78

Columbia Acorn Emerging Markets Fund

Statement of Investments, December 31, 2012

Number of Shares			Value
			Equities: 97.3%
Asia 61.8%
		> Taiwan 16.3%
	137,000	Far EasTone Telecom	$	349,813
		Taiwan's Third Largest Mobile Operator
	46,000	PC Home		214,704
		Taiwanese Internet Retail Company
	99,762	CTCI Corp		198,194
		International Engineering Firm
	11,000	St. Shine Optical		168,241
		World's Leading Disposable Contact Lens Original Equipment Manufacturer
	68,000	Taiwan Hon Chuan		149,626
		Beverage Packaging (Bottles, Caps, Labels) Manufacturer
	32,169	Advantech		136,319
		Industrial PC & Components
	38,000	Flexium Interconnect		134,667
		Flexible Printed Circuit for Mobile Electronics
	30,500	Lung Yen		98,662
		Funeral Services & Columbaria
	42,990	Chroma Ate		96,222
		Automatic Test Systems, Testing & Measurement Instruments
	17,576	Simplo Technology		89,337
		Battery Packs for Notebook & Tablet PCs
	10,735	Radiant Opto-Electronics		44,577
		LCD Back Light Units & Modules
	20,248	Tripod Technologies		43,775
		Printed Circuit Boards (PCB)
				1,724,137
		> Indonesia 10.7%
	537,609	Tower Bersama Infrastructure (a)		318,233
		Communications Towers
	3,078,691	Ace Indonesia		263,334
		Home Improvement Retailer
	255,898	Archipelago Resources (a)		249,416
		Gold Mining Projects in Indonesia, Vietnam & the Philippines
	48,500	Mayora Indah		101,017
		Consumer Branded Food Manufacturer
	428,440	Surya Citra Media		100,025
		Free to Air TV in Indonesia
	389,500	MNC Skyvision (a)		96,996
		Largest Satellite Pay TV Operator in Indonesia
				1,129,021
		> India 9.4%
	12,844	United Breweries		220,201
		India's Largest Brewer
	59,839	Adani Ports & Special Economic Zone		148,704
		Indian West Coast Shipping Port
	74,582	Redington India		118,689
		Supply Chain Solutions for IT & Mobile Handsets in Emerging Markets
	597	Bosch		104,506
		Automotive Parts
	3,580	Colgate Palmolive India		103,334
		Consumer Products in Oral Care

Number of Shares					Value
	19,309	Titan Industries			$	101,209
		Jewlery, Watches, Eyeglasses
	1,627	TTK Prestige				101,093
		Branded Cooking Equipment
	11,731	Yes Bank				99,913
		Commercial Banking in India
						997,649
		> Hong Kong 7.8%
	200,000	Melco International				237,449
		Macau Casino Operator
	71,589	Lifestyle International				177,088
		Mid- to High-end Department Store Operator in Hong Kong & China
	46,027	AAC Technologies				163,203
		Miniature Acoustic Components
	9,081	Melco Crown Entertainment - ADR (a)				152,924
		Macau Casino Operator
	121,799	Sa Sa International				101,139
		Cosmetics Retailer
						831,803
		> Thailand 3.7%
	472,000	Home Product Center				196,251
		Home Improvement Retailer
	180,800	Samui Airport Property Fund				99,295
		Thai Airport Operator
	6,400	Siam Makro				93,604
		General Merchadise Wholesaler in Thailand
						389,150
		> China 3.4%
	115,151	Digital China				199,128
		IT Distribution & Systems Integration Services
	312,000	AMVIG Holdings				113,918
		Chinese Tobacco Packaging Material Supplier
	1,057		51	job - ADR (a)		49,415
		Integrated Human Resource Services
						362,461
		> Cambodia 2.8%
	482,000	Nagacorp				294,476
		Casino/Entertainment Complex in Cambodia
						294,476
		> Philippines 2.6%
	127,365	Manila Water Company				99,476
		Water Utility Company in Philippines
	242,518	SM Prime Holdings				97,757
		Shopping Mall Operator
	44,487	Int'l Container Terminal				80,370
		Container Handling Terminals & Port Management
						277,603
		> Mongolia 1.6%
	345,100	Mongolian Mining (a)				171,026
		Coking Coal Mining in Mongolia
						171,026

See accompanying notes to financial statements.

79

Columbia Acorn Emerging Markets Fund

Statement of Investments, continued

Number of Shares			Value
		> Japan 1.4%
	13,760	Kansai Paint	$	148,290
		Paint Producer in Japan, India, China & Southeast Asia
				148,290
		> Singapore 1.1%
	40,000	Petra Foods		112,841
		Cocoa Processor & Chocolate Manufacturer
				112,841
		> Korea 1.0%
	6,500	Paradise Co		105,160
		Korean 'Foreigner Only' Casino Operator
				105,160
Asia: Total				6,543,617
Europe 12.8%
		> Kazakhstan 2.7%
	35,257	Halyk Savings Bank of Kazakhstan - GDR (a)		289,107
		Largest Retail Bank & Insurer in Kazakhstan
				289,107
		> Sweden 2.5%
	10,359	Hexagon		261,961
		Design, Measurement & Visualization Software & Equipment
				261,961
		> Switzerland 2.3%
	1,866	Dufry Group (a)		246,745
		Operates Airport Duty Free & Duty Paid Shops
				246,745
		> Italy 1.5%
	13,812	Pirelli		159,138
		Global Tire Supplier
				159,138
		> Czech Republic 1.3%
	665	Komercni Banka		140,579
		Leading Czech Universal Bank
				140,579
		> Finland 1.1%
	2,220	Vacon		117,798
		Leading Independent Manufacturer of Variable Speed Alternating Current Drives
				117,798
		> Germany 1.0%
	1,119	Dürr		100,271
		Automotive Plant Engineering & Associated Capital Equipment
				100,271
		> Turkey 0.4%
	2,496	Bizim Toptan		39,004
		Cash & Carry Stores in Turkey
				39,004
Europe: Total				1,354,603

Number of Shares			Value
Other Countries 12.4%
		> South Africa 7.2%
	55,348	Coronation Fund Managers	$	259,133
		South African Fund Manager
	81,332	Rand Merchant Insurance		199,446
		Directly Sold Property & Casualty Insurance; Holdings in Other Insurers
	8,306	Massmart Holdings		188,319
		General Merchandise, Food & Home Improvement Stores; Wal-Mart Subsidiary
	6,722	Mr. Price		111,405
		South African Retailer of Apparel, Household & Sporting Goods
				758,303
		> United States 2.9%
	5,419	Textainer Group Holdings (b)		170,482
		Top International Container Leasor
	3,076	Atwood Oceanics (a)		140,850
		Offshore Drilling Contractor
				311,332
		> Canada 2.3%
	9,973	Alliance Grain Traders		130,941
		Global Leader in Pulse Processing & Distribution
	36,607	Americas Petrogas (a)		110,406
		Oil & Gas Exploration in Argentina, Potash in Peru
				241,347
Other Countries: Total				1,310,982
Latin America 10.3%
		> Brazil 6.2%
	10,700	Localiza Rent A Car		195,971
		Car Rental
	6,300	Multiplus		146,831
		Loyalty Program Operator in Brazil
	9,977	Arcos Dorados (b)		119,325
		McDonald's Master Franchise for Latin America
	101,706	Beadell Resources (a)		105,082
		Gold Mining in Brazil
	18,500	Odontoprev		96,950
		Dental Insurance
				664,159
		> Mexico 2.9%
	1,808	Grupo Aeroportuario del Sureste - ADR		206,112
		Mexican Airport Operator
	48,300	Genomma Lab International (a)		99,243
		Develops, Markets & Distributes Consumer Products
				305,355
		> Chile 0.8%
	44,806	Viña Concha y Toro		87,281
		Global Branded Wine Manufacturer
				87,281

See accompanying notes to financial statements.

80

Number of Shares			Value
		> Argentina 0.4%
	106,000	Madalena Ventures (a)	$	41,027
		Oil & Gas Exploration in Argentina
				41,027
Latin America: Total				1,097,822
Total Equities: 97.3% (Cost: $8,851,918)				10,307,024	(c)
Short-Term Investments: 9.0%
	952,603	J.P. Morgan U.S. Government Money Market Fund - Capital Shares (7 day yield of 0.01%)		952,603
Total Short-Term Investments: 9.0% (Cost: $952,603)				952,603

Number of Shares			Value
Securities Lending Collateral 0.8%
	86,100	Dreyfus Government Cash Management Fund (7 day yield of 0.01%) (d)	$	86,100
Total Securities Lending Collateral: (Cost: $86,100)				86,100
Total Investments: 107.1% (Cost: $9,890,621)(e)				11,345,727
Obligation to Return Collateral for Securities Loaned: (0.8)%				(86,100	)
Cash and Other Assets Less Liabilities: (6.3)%				(669,816	)
Net Assets: 100.0%			$	10,589,811

ADR - American Depositary Receipts

GDR - Global Depositary Receipts

See accompanying notes to financial statements.

> Notes to Statement of Investments

(a)  Non-income producing security.

(b)  All or a portion of this security was on loan at December 31, 2012. The total market value of securities on loan at December 31, 2012 was $84,708.

(c)  On December 31, 2012, the Fund's total investments were denominated in currencies as follows:

Currency	Value		Percentage of Net Assets
Taiwan Dollar	$	1,724,137		16.3
Hong Kong Dollar		1,457,427		13.8
United States Dollar		1,128,215		10.7
Indian Rupee		997,649		9.4
Indonesian Rupiah		879,604		8.3
South African Rand		758,303		7.2
Other currencies less than 5% of total net assets		3,361,689		31.6
Total Equities	$	10,307,024		97.3

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

(e)  At December 31, 2012, for federal income tax purposes, the cost of investments was $9,916,215 and net unrealized appreciation was $1,429,512 consisting of gross unrealized appreciation of $1,673,371 and gross unrealized depreciation of $243,859.

Fair Value Measurements

  Various inputs are used in determining the value of the Fund's investments, following the input prioritization hierarchy established by accounting principles generally accepted in the United States of America (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.

81

Columbia Acorn Emerging Markets Fund

Statement of Investments, continued

> Notes to Statement of Investments

  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, to review the appropriateness of the Trust's Portfolio Pricing Policy and the pricing procedures of the investment manager (the Policies), and to review the continuing appropriateness of the current value of any security subject to 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 December 31, 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	$	202,339	$	6,341,278	$	-	$	6,543,617
Europe		-		1,354,603		-		1,354,603
Other Countries		552,679		758,303		-		1,310,982
Latin America		992,740		105,082		-		1,097,822
Total Equities		1,747,758		8,559,266		-		10,307,024
Total Short-Term Investments		952,603		-		-		952,603
Total Securities Lending Collateral		86,100		-		-		86,100
Total Investments	$	2,786,461	$	8,559,266	$	-	$	11,345,727

  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

At December 31, 2012, the Fund's portfolio investments as a percentage of net assets were diversified as follows:

	Value		Percentage of Net Assets
> Consumer Goods & Services
Retail	$	1,555,713		14.7
Casinos & Gaming		790,008		7.5
Food & Beverage		787,495		7.4
Other Consumer Services		325,165		3.1
Other Durable Goods		260,231		2.5
Consumer Goods Distribution		222,023		2.1
Travel		195,971		1.8
Nondurables		99,243		0.9
		4,235,849		40.0
> Information
Mobile Communications		668,046		6.3
Computer Hardware & Related Equipment		477,211		4.5
Business Software		261,961		2.5
Electronics Distribution		199,129		1.9
Semiconductors & Related Equipment		134,667		1.3
TV Broadcasting		100,025		0.9
Satellite Broadcasting & Services		96,996		0.9
Instrumentation		96,223		0.9
		2,034,258		19.2
> Finance
Banks		529,599		5.0
Insurance		296,396		2.8
Brokerage & Money Management		259,133		2.5
Finance Companies		170,482		1.6
		1,255,610		11.9
> Industrial Goods & Services
Industrial Materials & Specialty Chemicals		411,834		3.9
Other Industrial Services		229,074		2.2
Machinery		204,777		1.9
Construction		198,194		1.9
Electrical Components		117,797		1.1
		1,161,676		11.0
> Energy & Minerals
Mining		525,524		5.0
Oil & Gas Producers		151,434		1.4
Oil Services		140,850		1.3
Agricultural Commodities		130,941		1.3
		948,749		9.0
> Other Industries
Transportation		305,407		2.9
Regulated Utilities		99,476		0.9
Real Estate		97,758		0.9
		502,641		4.7

	Value			Percentage of Net Assets
> Health Care
Medical Supplies	$	168,241			1.5
		168,241			1.5
Total Equities:		10,307,024			97.3
Short-Term Investments:		952,603			9.0
Securities Lending Collateral:		86,100			0.8
Total Investments:		11,345,727			107.1
Obligation to Return Collateral for Securities Loaned:		(86,100	)		(0.8	)
Cash and Other Assets Less Liabilities:		(669,816	)		(6.3	)
Net Assets:	$	10,589,811			100.0

See accompanying notes to financial statements.

83

Columbia Acorn European Fund

Major Portfolio Changes in the Fourth Quarter (Unaudited)

	Number of Shares
	9/30/12		12/31/12
Purchases
Europe
> United Kingdom
Abcam		3,190		5,300
BBA Aviation		7,480		9,339
Charles Taylor		22,220		28,000
Elementis		5,768		8,300
Greggs		3,200		5,000
IG Group		0		4,000
Intertek Group		500		660
JLT Group		1,827		5,500
Ocado		25,000		31,000
WH Smith		3,500		4,300
> France
Neopost		600		900
Saft		1,300		1,829
> Germany
CTS Eventim		590		882
Stratec Biomedical Systems		500		965
TAG Immobilien		0		2,500
> Switzerland
Dufry Group		480		638
> Netherlands
Aalberts Industries		3,400		3,573
Imtech		1,499		2,575
> Sweden
Sweco		4,570		5,745
> Italy
Geox		13,500		17,223
> Finland
Vacon		0		1,000
> Norway
Atea		5,310		6,044
>Belgium
EVS Broadcast Equipment		630		830
> Turkey
Bizim Toptan		0		761
Asia
> Indonesia
Archipelago Resources		0		83,300
> Hong Kong
L'Occitane International		13,000		18,000

	Number of Shares
	9/30/12		12/31/12
Sales
Europe
> United Kingdom
Premier Oil		2,315		0
Rotork		660		95
> Netherlands
Koninklijke TenCate		975		0
> Italy
Fiat		4,400		0
Other Countries
> United States
Velti		2,550		0

See accompanying notes to financial statements.

84

Columbia Acorn European Fund

Statement of Investments, December 31, 2012

Number of Shares					Value
					Equities: 93.7%
Europe 88.2%
		> United Kingdom 21.5%
	28,000	Charles Taylor			$	76,642
		Insurance Services
	5,500	JLT Group				71,227
		International Business Insurance Broker
	8,500	Domino's Pizza UK & Ireland				69,388
		Pizza Delivery in UK, Ireland & Germany
	2,470	Rightmove				58,069
		Internet Real Estate Listings
	4,300	WH Smith				47,061
		Newsprint, Books & General Stationery Retailer
	31,000	Ocado (a)				44,285
		Leading Online Grocery Retailer
	1,000	Asos (a)				44,108
		Internet-based Retailer to Hipsters Up to Age 35
	5,000	Greggs				37,299
		Bakery
	9,339	BBA Aviation				34,080
		Aviation Support Services
	660	Intertek Group				33,526
		Testing, Inspection, Certification Services
	886	Spirax Sarco				33,175
		Steam Systems for Manufacturing & Process Industries
	5,300	Abcam				33,168
		Online Sales of Antibodies
	8,300	Elementis				31,691
		Clay-based Additives
	3,408	Shaftesbury				31,351
		London Prime Retail REIT
	4,000	IG Group				29,439
		On-line Retail Spread Betting Platform
	877	Aggreko				25,028
		Temporary Power & Temperature Control Services
	95	Rotork				3,966
		Valve Actuators for Oil & Water Pipelines
						703,503
		> France 13.1%
	570	Eurofins Scientific				92,720
		Food, Pharmaceuticals & Materials Screening & Testing
	1,650		1000	mercis		89,077
		Interactive Advertising & Marketing
	900	Gemalto				81,238
		Digital Security Solutions
	900	Neopost				47,729
		Postage Meter Machines
	1,829	Saft				43,043
		Niche Battery Manufacturer
	556	Norbert Dentressangle				42,896
		Leading European Logistics & Transport Group
	12,000	Hi-Media (a)				33,045
		Online Advertiser in Europe
						429,748

Number of Shares			Value
		> Germany 11.7%
	2,906	Wirecard	$	71,742
		Online Payment Processing & Risk Management
	233	Rational		67,306
		Commercial Ovens
	965	Stratec Biomedical Systems		48,141
		Diagnostic Instrumentation
	420	Bertrandt		42,168
		Outsourced Engineering
	1,166	NORMA Group		32,320
		Clamps for Automotive & Industrial Applications
	360	Dürr		32,259
		Automotive Plant Engineering & Associated Capital Equipment
	2,500	TAG Immobilien		31,332
		Owner of Residential Properties in Germany
	882	CTS Eventim		31,079
		Event Ticket Sales
	230	Pfeiffer Vacuum		28,028
		Vacuum Pumps
				384,375
		> Switzerland 10.4%
	414	Geberit (a)		91,773
		Plumbing Supplies
	384	Partners Group		88,773
		Private Markets Asset Management
	638	Dufry Group (a)		84,364
		Operates Airport Duty Free & Duty Paid Shops
	20	Sika		46,259
		Chemicals for Construction & Industrial Applications
	643	Zehnder		31,093
		Radiators & Heat Recovery Ventilation Systems
				342,262
		> Netherlands 10.2%
	3,573	Aalberts Industries		74,805
		Flow Control & Heat Treatment
	2,011	UNIT4		60,705
		Business Software Development
	2,575	Imtech		59,810
		Technical Installation & Maintenance
	1,577	TKH Group		40,819
		Dutch Industrial Conglomerate
	1,680	Arcadis		39,889
		Engineering Consultants
	263	Core Labs		28,748
		Oil & Gas Reservoir Consulting
	402	Vopak		28,416
		World's Largest Operator of Petroleum & Chemical Storage Terminals
				333,192
		> Sweden 5.7%
	3,370	Hexagon		85,221
		Design, Measurement & Visualization Software & Equipment
	5,745	Sweco		64,490
		Engineering Consultants

See accompanying notes to financial statements.

85

Columbia Acorn European Fund

Statement of Investments, continued

Number of Shares			Value
		> Sweden—continued
	1,211	Unibet	$	38,770
		European Online Gaming Operator
				188,481
		> Italy 3.8%
	17,223	Geox		49,987
		Apparel & Shoe Maker
	300	Tod's		38,091
		Leather Shoes & Bags
	2,800	Pirelli		32,261
		Global Tire Supplier
	5,391	CIR		5,683
		Italian Holding Company
				126,022
		> Finland 2.2%
	1,000	Vacon		53,062
		Leading Independent Manufacturer of Variable Speed Alternating Current Drives
	1,063	Stockmann		19,093
		Department Store & Fashion Retailer in Scandinavia & Russia
				72,155
		> Norway 2.0%
	6,044	Atea		64,664
		Leading Nordic IT Hardware/Software Reseller & Installation Company
				64,664
		> Belgium 1.5%
	830	EVS Broadcast Equipment		48,802
		Digital Live Mobile Production Software & Systems
				48,802
		> Iceland 1.5%
	43,750	Marel		48,235
		Largest Manufacturer of Poultry & Fish Processing Equipment
				48,235
		> Portugal 1.1%
	13,480	Redes Energéticas Nacionais		36,565
		Portuguese Power Transmission & Gas Transportation
				36,565
		> Denmark 1.0%
	700	Solar		32,055
		Technical Wholesaler of Electrical, Plumbing & HVAC Equipment
				32,055
		> Czech Republic 0.9%
	140	Komercni Banka		29,596
		Leading Czech Universal Bank
				29,596
		> Russia 0.7%
	1,049	Yandex (a)		22,627
		Search Engine for Russian & Turkish Languages
				22,627

Number of Shares			Value
		> Poland 0.5%
	4,000	FX Energy (a)	$	16,440
		Oil & Gas Producer in Poland
				16,440
		> Turkey 0.4%
	761	Bizim Toptan (a)		11,892
		Cash & Carry Stores in Turkey
				11,892
Europe: Total				2,890,614
Asia 4.2%
		> Indonesia 2.5%
	83,300	Archipelago Resources (a)		81,190
		Gold Mining Projects in Indonesia, Vietnam & the Philippines
				81,190
		> Hong Kong 1.7%
	18,000	L'Occitane International		57,597
		Skin Care & Cosmetics Producer
				57,597
Asia: Total				138,787
Other Countries 1.3%
		> Canada 1.3%
	3,270	Alliance Grain Traders		42,934
		Global Leader in Pulse Processing & Distribution
				42,934
Other Countries: Total				42,934
Total Equities: 93.7% (Cost: $2,679,610)				3,072,335	(b)
Short-Term Investments: 8.2%
	269,451	J.P. Morgan U.S. Government Money Market Fund - Agency Shares (7 day yield of 0.01%)		269,451
Total Short-Term Investments: 8.2% (Cost: $269,451)				269,451
Total Investments: 101.9% (Cost: $2,949,061)(c)				3,341,786
Cash and Other Assets Less Liabilities: (1.9)%				(63,751	)
Net Assets: 100.0%			$	3,278,035

REIT - Real Estate Investment Trust

See accompanying notes to financial statements.

86

> Notes to Statement of Investments

(a)  Non-income producing security.

(b)  On December 31, 2012, the Fund's total investments were denominated in currencies as follows:

Currency	Value		Percentage of Net Assets
Euro	$	1,402,111		42.8
British Pound		784,693		23.9
Swiss Franc		342,262		10.4
Swedish Krona		188,481		5.8
Other currencies less than 5% of total net assets		354,788		10.8
Total Equities	$	3,072,335		93.7

(c)  At December 31, 2012, for federal income tax purposes, the cost of investments was $2,957,119 and net unrealized appreciation was $384,667 consisting of gross unrealized appreciation of $452,659 and gross unrealized depreciation of $67,992.

Fair Value Measurements

  Various inputs are used in determining the value of the Fund's investments, following the input prioritization hierarchy established by accounting principles generally accepted in the United States of America (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, to review the appropriateness of the Trust's Portfolio Pricing Policy and the pricing procedures of the investment manager (the Policies), and to review the continuing appropriateness of the current value of any security subject to 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 December 31, 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	$	67,815	$	2,822,799	$	-	$	2,890,614
Asia		-		138,787		-		138,787
Other Countries		42,934		-		-		42,934
Total Equities		110,749		2,961,586		-		3,072,335
Total Short-Term Investments		269,451		-		-		269,451
Total Investments	$	380,200	$	2,961,586	$	-	$	3,341,786

See accompanying notes to financial statements.

87

Columbia Acorn European Fund

Statement of Investments, continued

> Notes to Statement of Investments

  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

At December 31, 2012, the Fund's portfolio investments as a percentage of net assets were diversified as follows:

	Value		Percentage of Net Assets
> Industrial Goods & Services
Other Industrial Services	$	349,542		10.7
Machinery		293,017		8.9
Conglomerates		121,307		3.7
Electrical Components		96,106		2.9
Construction		91,774		2.8
Industrial Materials & Specialty Chemicals		77,950		2.4
Outsourcing Services		42,168		1.3
Industrial Distribution		32,055		1.0
		1,103,919		33.7
> Consumer Goods & Services
Retail		187,602		5.7
Nondurables		95,688		2.9
Restaurants		69,388		2.1
Apparel		69,080		2.1
Other Durable Goods		63,353		1.9
Consumer Goods Distribution		44,108		1.4
Casinos & Gaming		38,770		1.2
Food & Beverage		37,299		1.1
Other Entertainment		31,079		1.0
		636,367		19.4
> Information
Business Software		145,926		4.4
Computer Hardware & Related Equipment		130,041		4.0
Business Information & Marketing Services		89,077		2.7
Internet Related		80,696		2.5
Financial Processors		71,742		2.2
Computer Services		64,664		2.0
Advertising		33,045		1.0
		615,191		18.8
> Finance
Insurance		147,868		4.5
Brokerage & Money Management		118,212		3.6
Banks		29,596		0.9
		295,676		9.0
> Energy & Minerals
Mining		109,939		3.3
Agricultural Commodities		42,934		1.3
Oil Refining, Marketing & Distribution		28,416		0.9
Oil & Gas Producers		16,440		0.5
		197,729		6.0

	Value			Percentage of Net Assets
> Other Industries
Real Estate	$	62,683			1.9
Transportation		42,896			1.3
Regulated Utilities		36,564			1.1
		142,143			4.3
> Health Care
Medical Equipment & Devices		48,141			1.5
Medical Supplies		33,169			1.0
		81,310			2.5
Total Equities:		3,072,335			93.7
Short-Term Investments:		269,451			8.2
Total Investments:		3,341,786			101.9
Cash and Other Assets Less Liabilities:		(63,751	)		(1.9	)
Net Assets:	$	3,278,035			100.0

See accompanying notes to financial statements.

89

Columbia Acorn Family of Funds

Statements of Assets and Liabilities

December 31, 2012	Columbia Acorn Fund			Columbia Acorn International			Columbia Acorn USA			Columbia Acorn International Select
Assets:
Unaffiliated investments, at cost	$	8,791,073,761		$	5,151,321,929		$	1,091,639,658		$	327,642,034
Affiliated investments, at cost (See Note 4)		2,466,414,630			112,040,756			3,624,095			—
Unaffiliated investments, at value (including securities on loan: Columbia Acorn Fund $368,048,192; Columbia Acorn International $125,494,564; Columbia Acorn USA $50,627,612; Columbia Acorn International Select $6,077,787; Columbia Acorn Select $10,135,994; Columbia Thermostat Fund $—; Columbia Acorn Emerging Markets Fund $84,708; Columbia Acorn European Fund $—)	$	13,932,301,078		$	6,677,312,055		$	1,643,764,447		$	385,941,325
Affiliated investments, at value (See Note 4)		3,952,846,905			183,261,261			3,232,000			—
Cash		—			—			—			—
Foreign currency (cost: Columbia Acorn Fund $—; Columbia Acorn International $6,525,747; Columbia Acorn USA $—; Columbia Acorn International Select $61; Columbia Acorn Select $—; Columbia Thermostat Fund $—; Columbia Acorn Emerging Markets Fund $1,168; Columbia Acorn European Fund $—)		—			6,750,603			—			62
Receivable for:
Investments sold		16,286,994			7,267,659			3,338,740			—
Fund shares sold		68,211,999			13,794,588			6,833,315			2,634,979
Dividends and interest		7,537,489			5,054,931			613,603			280,461
Securities lending income		1,529,160			215,947			169,559			7,005
Foreign tax reclaims		234,119			4,031,568			—			214,919
Expense reimbursement due from Adviser		—			3,472			—			—
Trustees' deferred compensation investments		2,668,496			774,532			228,226			—
Other assets		279,704			70,654			18,384			3,883
Total Assets		17,981,895,944			6,898,537,270			1,658,198,274			389,082,634
Liabilities:
Payable to custodian bank		218,390			—			11,582			—
Collateral on securities loaned		371,676,935			131,072,367			51,263,955			6,389,590
Unrealized depreciation on forward foreign currency exchange contracts		—			—			—			411,753
Payable for:
Investments purchased		20,285,925			10,036,277			4,251,671			588,894
Fund shares redeemed		58,768,193			10,080,883			1,713,554			1,036,400
Management fee		907,328			415,756			110,751			28,942
Administration fee		54,690			21,182			4,964			1,190
12b-1 Service and Distribution fees		128,684			29,239			5,657			2,376
Reports to shareholders		898,725			444,010			161,450			37,735
Deferred Trustees' fees		2,668,496			774,532			228,226			—
Transfer agent fees		1,996,074			506,158			255,326			28,746
Trustees' fees		16,852			19,641			1,579			35,622
Custody fees		930			279,308			2,155			16,290
Professional fee		292,774			128,924			50,264			32,041
Chief compliance officer expenses		19,744			5,464			1,980			253
Deferred foreign capital gains tax payable		—			779,466			—			—
Other liabilities		96,293			146,457			40,487			18,748
Total Liabilities		458,030,033			154,739,664			58,103,601			8,628,580
Net Assets	$	17,523,865,911		$	6,743,797,606		$	1,600,094,673		$	380,454,054
Composition of Net Assets:
Paid-in capital	$	10,730,224,359		$	5,408,888,462		$	1,050,613,572		$	338,142,976
Undistributed (Overdistributed) net investment income		(27,792,423	)		(74,303,358	)		(4,074,947	)		(22,556,622	)
Accumulated net realized gain (loss)		193,768,390			(187,066,939	)		1,823,354			6,989,036
Net unrealized appreciation (depreciation) on:
Unaffiliated investments		5,141,227,317			1,525,990,126			552,124,789			58,299,291
Affiliated investments (See Note 4)		1,486,432,275			71,220,505			(392,095	)		—
Foreign currency translations		5,993			(151,724	)		—			(8,874	)
Forward foreign currency exchange contracts		—			—			—			(411,753	)
Foreign capital gains tax		—			(779,466	)		—			—
Net Assets	$	17,523,865,911		$	6,743,797,606		$	1,600,094,673		$	380,454,054
Net asset value per share – Class A (a)	$	29.36		$	40.79		$	28.21		$	25.61
(Net assets/shares)	($	3,233,494,173/ 110,115,360)		($	1,007,236,229/ 24,691,595)		($	152,163,790/ 5,394,458)		($	74,166,705/ 2,895,670)
Maximum offering price per share – Class A (b)	$	31.15		$	43.28		$	29.93		$	27.17
(Net asset value per share/front-end sales charge)	($29.36/0.9425)			($40.79/0.9425)			($28.21/0.9425)			($25.61/0.9425)
Net asset value and offering price per share – Class B (a)	$	26.80		$	39.67		$	25.81		$	24.40
(Net assets/shares)	($	33,623,177/ 1,254,671)		($	17,909,992/ 451,423)		($	1,055,794/ 40,908)		($	1,250,387/ 51,243)
Net asset value and offering price per share – Class C (a)	$	26.34		$	39.50		$	25.49		$	24.28
(Net assets/shares)	($	756,709,209/ 28,728,670)		($	92,747,897/ 2,347,814)		($	31,410,280/ 1,232,210)		($	9,785,692/ 403,025)
Net asset value and offering price per share – Class I (c)	$	30.47		$	40.86		$	29.47	(d)	$	25.85	(d)
(Net assets/shares)	($	58,652,328/ 1,924,717)		($	97,483,849/ 2,385,999)		($3,039/103)			($2,475/96)
Net asset value and offering price per share – Class R (c)	$	—		$	40.79		$	—		$	—
(Net assets/shares)	($	—/—	)	($2,799,425/68,635)			($	—/—	)	($	—/—	)
Net asset value and offering price per share – Class R4 (c)	$	30.90	(e)	$	41.08	(d)(e)	$	29.92	(e)	$	25.99	(d)(e)
(Net assets/shares)	($17,087/553)			($15,459/376)			($14,930/499)			($13,006/500)
Net asset value and offering price per share – Class R5 (c)	$	30.88	(d)(e)	$	40.81		$	29.90	(d)(e)	$	25.98	(d)(e)
(Net assets/shares)	($2,524/82)			($242,486/5,942)			($2,487/83)			($2,167/83)
Net asset value and offering price per share – Class Y (c)	$	30.90	(e)	$	41.08	(e)	$	29.93	(d)(e)	$	25.98	(d)(e)
(Net assets/shares)	($	67,012,003/ 2,168,603)		($	30,856,334/ 751,123)		($2,486/83)			($2,166/83)
Net asset value and offering price per share – Class Z (c)	$	30.45		$	40.84		$	29.45		$	25.86
(Net assets/shares)	($	13,374,355,410/ 439,157,444)		($	5,494,505,935/ 134,552,036)		($	1,415,441,867/ 48,061,766)		($	295,231,456/ 11,417,033)

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

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

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

(d)  Net asset value per share rounds to this amount due to fractional shares outstanding.

(e)  Shares commenced operations on November 8, 2012.

See accompanying notes to financial statements.

90

December 31, 2012	Columbia Acorn Select			Columbia Thermostat Fund			Columbia Acorn Emerging Markets Fund			Columbia Acorn European Fund
Assets:
Unaffiliated investments, at cost	$	594,846,407		$	—		$	9,890,621		$	2,949,061
Affiliated investments, at cost (See Note 4)		77,398,151			824,225,379			—			—
Unaffiliated investments, at value (including securities on loan: Columbia Acorn Fund $368,048,192; Columbia Acorn International $125,494,564; Columbia Acorn USA $50,627,612; Columbia Acorn International Select $6,077,787; Columbia Acorn Select $10,135,994; Columbia Thermostat Fund $—; Columbia Acorn Emerging Markets Fund $84,708; Columbia Acorn European Fund $—)	$	896,645,938		$	—		$	11,345,727		$	3,341,786
Affiliated investments, at value (See Note 4)		48,024,166			868,281,222			—			—
Cash		68,495			—			—			—
Foreign currency (cost: Columbia Acorn Fund $—; Columbia Acorn International $6,525,747; Columbia Acorn USA $—; Columbia Acorn International Select $61; Columbia Acorn Select $—; Columbia Thermostat Fund $—; Columbia Acorn Emerging Markets Fund $1,168; Columbia Acorn European Fund $—)		—			—			1,168			—
Receivable for:
Investments sold		46,942,769			—			—			1,690
Fund shares sold		1,001,128			8,844,857			113,273			10,066
Dividends and interest		687,570			1,134,771			1,128			370
Securities lending income		35,665			—			49			1
Foreign tax reclaims		10,340			—			1,842			2,410
Expense reimbursement due from Adviser		—			7,003			3,306			2,953
Trustees' deferred compensation investments		270,217			—			—			—
Other assets		12,031			5,478			70			26
Total Assets		993,698,319			878,273,331			11,466,563			3,359,302
Liabilities:
Payable to custodian bank		—			—			—			—
Collateral on securities loaned		11,106,378			—			86,100			—
Unrealized depreciation on forward foreign currency exchange contracts		—			—			—			—
Payable for:
Investments purchased		1,776,748			2,587,560			703,201			790
Fund shares redeemed		14,494,223			862,727			14,518			23,910
Management fee		66,113			7,087			1,058			318
Administration fee		3,056			2,740			33			10
12b-1 Service and Distribution fees		10,743			27,362			107			18
Reports to shareholders		146,424			34,613			10,890			10,900
Deferred Trustees' fees		270,217			—			—			—
Transfer agent fees		121,709			48,342			459			66
Trustees' fees		1,078			20,647			468			334
Custody fees		1,813			834			7,253			5,090
Professional fee		42,013			20,398			25,195			25,137
Chief compliance officer expenses		1,432			1,233			3			1
Deferred foreign capital gains tax payable		—			—			12,859			—
Other liabilities		29,458			37,091			14,608			14,693
Total Liabilities		28,071,405			3,650,634			876,752			81,267
Net Assets	$	965,626,914		$	874,622,697		$	10,589,811		$	3,278,035
Composition of Net Assets:
Paid-in capital	$	658,289,312		$	843,632,414		$	9,279,708		$	2,895,563
Undistributed (Overdistributed) net investment income		2,866,367			650,727			(17,167	)		(8,259	)
Accumulated net realized gain (loss)		32,045,843			(13,716,287	)		(114,816	)		(2,063	)
Net unrealized appreciation (depreciation) on:
Unaffiliated investments		301,799,531			—			1,455,106			392,725
Affiliated investments (See Note 4)		(29,373,985	)		44,055,843			—			—
Foreign currency translations		(154	)		—			(161	)		69
Forward foreign currency exchange contracts		—			—			—			—
Foreign capital gains tax		—			—			(12,859	)		—
Net Assets	$	965,626,914		$	874,622,697		$	10,589,811		$	3,278,035
Net asset value per share – Class A (a)	$	24.72		$	14.29		$	12.04		$	11.76
(Net assets/shares)	($	271,628,345/ 10,989,670)		($	323,749,858/ 22,652,039)		($	3,103,467/ 257,660)		($	453,307/ 38,560)
Maximum offering price per share – Class A (b)	$	26.23		$	15.16		$	12.77		$	12.48
(Net asset value per share/front-end sales charge)	($24.72/0.9425)			($14.29/0.9425)			($12.04/0.9425)			($11.76/0.9425)
Net asset value and offering price per share – Class B (a)	$	22.75		$	14.39		$	—		$	—
(Net assets/shares)	($	9,937,628/ 436,746)		($	4,479,695/ 311,294)		($	—/—	)	($	—/—	)
Net asset value and offering price per share – Class C (a)	$	22.48		$	14.39		$	12.01		$	11.73
(Net assets/shares)	($	57,308,635/ 2,548,954)		($	253,640,911/ 17,628,876)		($	615,451/ 51,234)		($	88,963/ 7,582)
Net asset value and offering price per share – Class I (c)	$	25.63		$	—		$	12.08		$	11.75	(d)
(Net assets/shares)	($	39,053,882/ 1,523,839)		($	—/—	)	($6,101/505)			($5,985/509)
Net asset value and offering price per share – Class R (c)	$	—		$	—		$	—		$	—
(Net assets/shares)	($	—/—	)	($	—/—	)	($	—/—	)	($	—/—	)
Net asset value and offering price per share – Class R4 (c)	$	25.92	(e)	$	14.19	(e)	$	12.14	(d)(e)	$	—
(Net assets/shares)	($15,008/579)			($15,114/1,065)			($15,924/1,311)			($	—/—	)
Net asset value and offering price per share – Class R5 (c)	$	25.93	(d)(e)	$	14.19	(d)(e)	$	12.14	(d)(e)	$	11.86	(d)(e)
(Net assets/shares)	($2,501/96)			($2,520/178)			($2,653/219)			($2,650/223)
Net asset value and offering price per share – Class Y (c)	$	25.98	(d)(e)	$	14.18	(d)(e)	$	—		$	—
(Net assets/shares)	($2,502/96)			($2,518/178)			($	—/—	)	($	—/—	)
Net asset value and offering price per share – Class Z (c)	$	25.57		$	14.13		$	12.07		$	11.76
(Net assets/shares)	($	587,678,413/ 22,983,300)		($	292,732,081/ 20,721,743)		($	6,846,215/ 567,354)		($	2,727,130/ 231,922)

See accompanying notes to financial statements.

91

Columbia Acorn Family of Funds

Statements of Operations For the Year Ended December 31, 2012

	Columbia Acorn Fund			Columbia Acorn International			Columbia Acorn USA			Columbia Acorn International Select
Investment Income:
Dividend income	$	159,371,982		$	163,085,641		$	20,822,554		$	11,895,529
Dividend income from affiliates (See Note 4)		64,771,821			3,449,258			640,000			—
Dividends from affiliated investment company shares (See Note 4)		—			—			—			—
Interest income		80			39,718			—			3,706
Securities lending income, net		13,829,543			1,953,896			1,754,009			38,971
		237,973,426			168,528,513			23,216,563			11,938,206
Foreign taxes withheld		(2,724,315	)		(15,916,807	)		(13,608	)		(1,238,581	)
Total Investment Income		235,249,111			152,611,706			23,202,955			10,699,625
Expenses:
Management fee		112,165,480			47,191,198			14,027,089			3,407,749
Administration fee		6,786,725			2,408,151			631,621			140,638
12b-1 Service and Distribution fees:
Class A		8,411,136			2,428,249			404,377			156,318
Class B		369,947			159,618			12,846			11,380
Class C		7,641,208			964,952			320,406			91,391
Class R		—			6,596			—			—
Transfer agent fees:
Class A		3,092,580			1,518,464			161,367			72,453
Class B		86,533			80,272			4,728			3,578
Class C		628,306			138,828			25,903			13,840
Class R		—			1,940			—			—
Class R4		3			3			3			3
Class R5		—			353			—			—
Class Z		7,557,416			2,732,248			1,510,571			199,463
Trustees' fees		970,891			336,803			92,597			27,839
Custody fees		762,741			1,675,551			20,961			115,015
Registration and blue sky fees		252,212			214,331			150,912			146,958
Reports to shareholders		2,480,740			1,393,048			522,940			142,414
Audit fees		98,941			154,323			45,526			46,202
Legal fees		1,636,932			576,736			155,016			33,150
Interest expense (See Note 5)		—			—			742			247
Chief compliance officer expenses (See Note 4)		479,405			168,581			44,835			8,809
Organizational expenses (See Note 4)		—			—			—			—
Other expenses		779,409			448,035			80,017			20,227
Total Expenses		154,200,605			62,598,280			18,212,457			4,637,674
Less custody earnings credit		(762,741	)		(323,112	)		(10,325	)		(27,768	)
Less reimbursement of expenses by Investment Manager (See Note 4)		—			(414,204	)		—			—
Net Expenses		153,437,864			61,860,964			18,202,132			4,609,906
Net Investment Income		81,811,247			90,750,742			5,000,823			6,089,719
Net Realized and Unrealized Gain (Loss) on Portfolio Positions:
Net realized gain (loss) on:
Unaffiliated investments		1,113,526,734			141,080,163			120,638,007			37,862,228
Affiliated investments (See Note 4)		4,469,667			(103,501	)		—			—
Foreign currency transactions		(251,943	)		(2,522,072	)		—			(133,506	)
Forward foreign currency exchange contracts		—			5,422,582			—			(324,460	)
Distributions from affiliated investment company shares		—			—			—			—
Net realized gain (loss)		1,117,744,458			143,877,172			120,638,007			37,404,262
Net change in net unrealized appreciation (depreciation) on:
Unaffiliated investments		1,224,609,167			923,634,193			149,564,276			26,469,865
Affiliated investments (See Note 4)		408,220,687			31,907,664			(83,200	)		—
Foreign currency translations		18,321			(71,882	)		—			3,771
Forward foreign currency exchange contracts		—			(4,539,004	)		—			536,271
Foreign capital gains tax		—			1,541,277			—			—
Net change in unrealized appreciation (depreciation)		1,632,848,175			952,472,248			149,481,076			27,009,907
Net realized and unrealized gain		2,750,592,633			1,096,349,420			270,119,083			64,414,169
Net Increase in Net Assets from Operations	$	2,832,403,880		$	1,187,100,162		$	275,119,906		$	70,503,888

See accompanying notes to financial statements.

92

	Columbia Acorn Select			Columbia Thermostat Fund			Columbia Acorn Emerging Markets Fund			Columbia Acorn European Fund
Investment Income:
Dividend income	$	15,090,039		$	—		$	172,638		$	52,254
Dividend income from affiliates (See Note 4)		—			—			—			—
Dividends from affiliated investment company shares (See Note 4)		—			13,324,451			—			—
Interest income		—			—			3			11
Securities lending income, net		2,022,571			—			340			167
		17,112,610			13,324,451			172,981			52,432
Foreign taxes withheld		(80,355	)		—			(15,229	)		(6,061	)
Total Investment Income		17,032,255			13,324,451			157,752			46,371
Expenses:
Management fee		9,810,516			482,102			78,222			26,888
Administration fee		458,713			186,962			2,427			876
12b-1 Service and Distribution fees:
Class A		796,812			455,829			3,350			572
Class B		130,133			50,533			—			—
Class C		630,190			1,232,329			2,606			369
Class R		—			—			—			—
Transfer agent fees:
Class A		342,668			154,868			1,534			124
Class B		35,367			11,640			—			—
Class C		69,251			101,936			381			2
Class R		—			—			—			—
Class R4		3			3			3			—
Class R5		—			—			—			—
Class Z		573,742			104,168			2,190			446
Trustees' fees		71,690			23,389			558			331
Custody fees		36,722			9,384			46,534			17,572
Registration and blue sky fees		139,093			195,995			119,534			106,557
Reports to shareholders		390,663			170,911			38,338			37,432
Audit fees		45,366			24,255			62,868			53,960
Legal fees		109,566			37,009			489			164
Interest expense (See Note 5)		1,408			—			—			—
Chief compliance officer expenses (See Note 4)		29,484			13,837			159			41
Organizational expenses (See Note 4)		—			—			26,291			24,026
Other expenses		194,700			15,093			5,461			4,284
Total Expenses		13,866,087			3,270,243			390,945			273,644
Less custody earnings credit		(33,584	)		(4,387	)		(398	)		(207	)
Less reimbursement of expenses by Investment Manager (See Note 4)		—			(321,910	)		(292,249	)		(242,324	)
Net Expenses		13,832,503			2,943,946			98,298			31,113
Net Investment Income		3,199,752			10,380,505			59,454			15,258
Net Realized and Unrealized Gain (Loss) on Portfolio Positions:
Net realized gain (loss) on:
Unaffiliated investments		146,050,604			—			(60,595	)		9,793
Affiliated investments (See Note 4)		(32,861,769	)		(680,088	)		—			—
Foreign currency transactions		(9,264	)		—			(678	)		(1,082	)
Forward foreign currency exchange contracts		—			—			—			—
Distributions from affiliated investment company shares		—			10,645,025			—			—
Net realized gain (loss)		113,179,571			9,964,937			(61,273	)		8,711
Net change in net unrealized appreciation (depreciation) on:
Unaffiliated investments		9,007,034			—			1,589,015			478,541
Affiliated investments (See Note 4)		76,071,172			30,128,824			—			—
Foreign currency translations		(154	)		—			(160	)		107
Forward foreign currency exchange contracts		—			—			—			—
Foreign capital gains tax		—			—			(11,580	)		—
Net change in unrealized appreciation (depreciation)		85,078,052			30,128,824			1,577,275			478,648
Net realized and unrealized gain		198,257,623			40,093,761			1,516,002			487,359
Net Increase in Net Assets from Operations	$	201,457,375		$	50,474,266		$	1,575,456		$	502,617

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	Year ended December 31,						Year ended December 31,						Year ended December 31,						Year ended December 31,
	2012 (a)(b)(c)			2011			2012 (a)(c)			2011 (d)			2012 (a)(b)(c)			2011			2012 (a)(b)(c)			2011
Operations:
Net investment income (loss)	$	81,811,247		$	(26,857,762	)	$	90,750,742		$	70,395,348		$	5,000,823		$	(9,383,201	)	$	6,089,719		$	3,857,076
Net realized gain (loss) on investments, foreign currency transactions, forward foreign currency exchange contracts and foreign capital gains tax		1,113,274,791			756,713,680			143,980,673			226,123,538			120,638,007			41,208,252			37,404,262			45,952,002
Net realized gain (loss) on affiliated investments and distributions from affiliated investment companies and affiliated investment company shares		4,469,667			(10,816,845	)		(103,501	)		(3,603,000	)		—			(511,503	)		—			—
Reimbursement from affiliate (See Note 4)		—			—			—			174,055			—			—			—			—
Net change in net unrealized appreciation (depreciation) on investments, foreign currency translations, forward foreign currency exchange contracts and foreign capital gains tax		1,224,627,488			(1,530,795,009	)		920,564,584			(1,230,964,786	)		149,564,276			(112,789,973	)		27,009,907			(89,001,498	)
Net change in net unrealized appreciation (depreciation) on affiliated investment companies and affiliated investment company shares		408,220,687			(43,543,412	)		31,907,664			22,439,508			(83,200	)		875,717			—			—
Net Increase (Decrease) in Net Assets from Operations		2,832,403,880			(855,299,348	)		1,187,100,162			(915,435,337	)		275,119,906			(80,600,708	)		70,503,888			(39,192,420	)
Distributions to Shareholders From:
Net investment income – Class A		(6,663,987	)		(2,049,259	)		(14,411,473	)		(21,972,254	)		(599,485	)		—			(4,362,966	)		(1,392,316	)
Net realized gain – Class A		(197,512,972	)		(144,445,416	)		—			—			(11,879,641	)		(1,096,345	)		(5,497,945	)		(901,438	)
Net investment income – Class B		—			—			(110,407	)		(600,382	)		—			—			(72,287	)		(22,776	)
Net realized gain – Class B		(2,528,156	)		(4,964,015	)		—			—			(115,000	)		(20,402	)		(103,484	)		(30,723	)
Net investment income – Class C		—			—			(564,735	)		(2,368,917	)		—			—			(545,569	)		(70,087	)
Net realized gain – Class C		(50,561,092	)		(35,290,933	)		—			—			(2,747,308	)		(216,751	)		(788,458	)		(150,074	)
Net investment income – Class I		(314,994	)		(33,681	)		(2,000,370	)		(675,509	)		(23	)		—			(176	)		(79	)
Net realized gain – Class I		(3,228,769	)		(670,263	)		—			—			(1,468	)		(16,297	)		(212	)		(38	)
Net investment income – Class R		—			—			(25,256	)		—			—			—			—			—
Net investment income – Class R4		(56	)		—			(223	)		—			(79	)		—			(894	)		—
Net realized gain – Class R4		(717	)		—			—			—			(1,157	)		—			(1,048	)		—
Net investment income – Class R5		(11	)		—			(16,524	)		—			(15	)		—			(150	)		—
Net realized gain – Class R5		(119	)		—			—			—			(193	)		—			(175	)		—
Net investment income – Class Y		(88,761	)		—			(19,488	)		—			(16	)		—			(151	)		—
Net realized gain – Class Y		(850,641	)		—			—			—			(193	)		—			(174	)		—
Net investment income – Class Z		(63,442,374	)		(36,822,645	)		(111,633,313	)		(131,454,754	)		(8,664,877	)		—			(19,872,784	)		(9,039,073	)
Net realized gain – Class Z		(774,147,758	)		(521,914,461	)		—			—			(105,839,468	)		(8,480,983	)		(23,989,252	)		(4,185,448	)
Total Distributions to Shareholders		(1,099,340,407	)		(746,190,673	)		(128,781,789	)		(157,071,816	)		(129,848,923	)		(9,830,778	)		(55,235,725	)		(15,792,052	)
Share Transactions:
Subscriptions – Class A		504,132,337			881,347,513			192,174,434			302,658,475			23,184,962			41,839,313			28,487,144			18,154,050
Distributions reinvested – Class A		192,504,936			134,124,557			13,849,288			18,983,083			11,472,496			993,440			9,540,300			2,039,159
Net assets of shares issued in connection with Merger – Class A		—			—			—			204,929,893			—			—			—			—
Redemptions – Class A		(1,043,161,042	)		(1,072,697,473	)		(288,655,100	)		(251,676,760	)		(65,386,017	)		(80,479,403	)		(22,115,770	)		(26,421,899	)
Net Increase (Decrease) – Class A		(346,523,769	)		(57,225,403	)		(82,631,378	)		274,894,691			(30,728,559	)		(37,646,650	)		15,911,674			(6,228,690	)
Distributions reinvested – Class B (f)		2,488,680			4,776,785			109,244			558,478			112,821			26,565			171,043			51,060
Net assets of shares issued in connection with Merger – Class B		—			—			—			12,516,646			—			—			—			—
Redemptions – Class B		(42,408,789	)		(215,635,845	)		(10,614,723	)		(13,183,025	)		(1,506,892	)		(6,779,156	)		(821,529	)		(1,017,074	)
Net Increase (Decrease) – Class B		(39,920,109	)		(210,859,060	)		(10,505,479	)		(107,901	)		(1,394,071	)		(6,752,591	)		(650,486	)		(966,014	)
Subscriptions – Class C		75,456,034			101,180,823			9,589,255			19,818,591			1,894,599			2,254,840			1,909,549			966,467
Distributions reinvested – Class C		41,007,235			27,312,778			462,763			1,844,621			2,504,682			193,429			1,184,774			188,226
Net assets of shares issued in connection with Merger – Class C		—			—			—			25,563,134			—			—			—			—
Redemptions – Class C		(147,063,884	)		(154,449,467	)		(31,713,431	)		(42,186,965	)		(6,051,022	)		(5,936,913	)		(2,386,931	)		(2,975,326	)
Net Increase (Decrease) – Class C		(30,600,615	)		(25,955,866	)		(21,661,413	)		5,039,381			(1,651,741	)		(3,488,644	)		707,392			(1,820,633	)

(a)  Class R4 shares reflect activity for the period from November 8, 2012 (commencement of operations) through December 31, 2012.

(b)  Class R5 shares reflect activity for the period from November 8, 2012 (commencement of operations) through December 31, 2012.

(c)  Class Y shares reflect activity for the period from November 8, 2012 (commencement of operations) through December 31, 2012.

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

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

(f)  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	Year ended December 31,						Year ended December 31,						Year ended December 31,						Year ended December 31,
	2012 (a)(b)(c)			2011			2012 (a)(b)(c)			2011			2012 (a)(b)			2011 (e)			2012 (b)			2011 (e)
Operations:
Net investment income (loss)	$	3,199,752		$	(7,973,307	)	$	10,380,505		$	2,784,210		$	59,454		$	1,307		$	15,258		$	(3,253	)
Net realized gain (loss) on investments, foreign currency transactions, forward foreign currency exchange contracts and foreign capital gains tax		146,041,340			209,797,019			—			—			(61,273	)		(57,599	)		8,711			5,764
Net realized gain (loss) on affiliated investments and distributions from affiliated investment companies and affiliated investment company shares		(32,861,769	)		(66,391,196	)		9,964,937			8,878,053			—			—			—			—
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		9,006,880			(347,747,328	)		—			—			1,577,275			(135,189	)		478,648			(85,854	)
Net change in net unrealized appreciation (depreciation) on affiliated investment companies and affiliated investment company shares		76,071,172			(112,603,396	)		30,128,824			(4,865,908	)		—			—			—			—
Net Increase (Decrease) in Net Assets from Operations		201,457,375			(324,918,208	)		50,474,266			6,796,355			1,575,456			(191,481	)		502,617			(83,343	)
Distributions to Shareholders From:
Net investment income – Class A		—			(7,161,966	)		(5,054,209	)		(1,706,583	)		(15,490	)		—			(1,646	)		(796	)
Net realized gain – Class A		(22,932,516	)		—			—			—			—			—			(87	)		(207	)
Net investment income – Class B		—			(499,744	)		(54,808	)		(351,024	)		—			—			—			—
Net realized gain – Class B		(1,087,328	)		—			—			—			—			—			—			—
Net investment income – Class C		—			(672,184	)		(2,121,887	)		(405,817	)		—			—			(20	)		(16	)
Net realized gain – Class C		(5,136,384	)		—			—			—			—			—			(8	)		(8	)
Net investment income – Class I		—			(140,882	)		—			—			(61	)		—			(48	)		(38	)
Net realized gain – Class I		(2,740,487	)		—			—			—			—			—			(2	)		(8	)
Net investment income – Class R		—			—			—			—			—			—			—			—
Net investment income – Class R4		—			—			(272	)		—			(135	)		—			—			—
Net realized gain – Class R4		(872	)		—			—			—			—			—			—			—
Net investment income – Class R5		—			—			(45	)		—			(24	)		—			(17	)		—
Net realized gain – Class R5		(145	)		—			—			—			—			—			—			—
Net investment income – Class Y		—			—			(46	)		—			—			—			—			—
Net realized gain – Class Y		(145	)		—			—			—			—			—			—			—
Net investment income – Class Z		—			(22,715,133	)		(5,300,668	)		(1,460,001	)		(60,520	)		—			(20,402	)		(10,925	)
Net realized gain – Class Z		(51,934,084	)		—			—			—			—			—			(815	)		(2,458	)
Total Distributions to Shareholders		(83,831,961	)		(31,189,909	)		(12,531,935	)		(3,923,425	)		(76,230	)		—			(23,045	)		(14,456	)
Share Transactions:
Subscriptions – Class A		40,027,597			72,440,740			273,105,947			44,384,781			2,701,324			351,565			295,687			163,602
Distributions reinvested – Class A		21,373,765			6,306,938			4,549,410			1,390,763			15,419			—			1,697			1,003
Net assets of shares issued in connection with Merger – Class A		—			—			—			—			—			—			—			—
Redemptions – Class A		(159,108,074	)		(203,498,579	)		(48,212,223	)		(11,538,308	)		(234,401	)		(12,847	)		(46,529	)		—
Net Increase (Decrease) – Class A		(97,706,712	)		(124,750,901	)		229,443,134			34,237,236			2,482,342			338,718			250,855			164,605
Distributions reinvested – Class B (f)		1,050,259			464,296			52,935			381,262			—			—			—			—
Net assets of shares issued in connection with Merger – Class B		—			—			—			—			—			—			—			—
Redemptions – Class B		(19,619,654	)		(37,412,784	)		(7,803,976	)		(18,369,136	)		—			—			—			—
Net Increase (Decrease) – Class B		(18,569,395	)		(36,948,488	)		(7,751,041	)		(17,987,874	)		—			—			—			—
Subscriptions – Class C		3,033,655			3,602,724			220,660,384			15,268,427			479,073			137,805			102,697			5,000
Distributions reinvested – Class C		4,111,417			494,683			1,498,365			312,780			—			—			28			23
Net assets of shares issued in connection with Merger – Class C		—			—			—			—			—			—			—			—
Redemptions – Class C		(17,080,513	)		(23,948,063	)		(11,490,278	)		(4,725,014	)		(62,650	)		(10,000	)		(23,910	)		—
Net Increase (Decrease) – Class C		(9,935,441	)		(19,850,656	)		210,668,471			10,856,193			416,423			127,805			78,815			5,023

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	Year ended December 31,						Year ended December 31,						Year ended December 31,						Year ended December 31,
	2012 (a)(b)(c)			2011			2012 (a)(c)			2011 (d)			2012 (a)(b)(c)			2011			2012 (a)(b)(c)			2011
Subscriptions – Class I		67,198,938			17,610,293			89,544,891			27,930,224			2,149,882			11,069,761			—			—
Distributions reinvested – Class I		3,543,577			703,825			1,999,919			675,441			1,223			16,280			—			—
Net assets of shares issued in connection with Merger – Class I		—			—			—			152,987,093			—			—			—			—
Redemptions – Class I		(30,814,450	)		(13,595,009	)		(56,555,211	)		(184,759,915	)		(4,920,409	)		(38,709,258	)		—			—
Net Increase (Decrease) – Class I		39,928,065			4,719,109			34,989,599			(3,167,157	)		(2,769,304	)		(27,623,217	)		—			—
Subscriptions – Class R		—			—			4,849,766			369,489			—			—			—			—
Distributions reinvested – Class R		—			—			20,880			—			—			—			—			—
Net assets of shares issued in connection with Merger – Class R		—			—			—			2,027,456			—			—			—			—
Redemptions – Class R		—			—			(4,484,989	)		(76,789	)		—			—			—			—
Net Increase – Class R		—			—			385,657			2,320,156			—			—			—			—
Subscriptions – Class R4		16,900			—			15,000			—			15,000			—			15,000			—
Net Increase – Class R4		16,900			—			15,000			—			15,000			—			15,000			—
Subscriptions – Class R5		2,500			—			445			2,624			2,500			—			2,500			—
Distributions reinvested – Class R5		—			—			5,613			—			—			—			—			—
Net assets of shares issued in connection with Merger – Class R5		—			—			—			2,232,537			—			—			—			—
Redemptions – Class R5		—			—			(2,089,711	)		(7	)		—			—			—			—
Net Increase (Decrease) – Class R5		2,500			—			(2,083,653	)		2,235,154			2,500			—			2,500			—
Subscriptions – Class Y		66,583,143			—			30,626,355			—			2,500			—			2,500			—
Distributions reinvested – Class Y		939,270			—			19,448			—			—			—			—			—
Redemptions – Class Y		(326,942	)		—			—			—			—			—			—			—
Net Increase – Class Y		67,195,471			—			30,645,803			—			2,500			—			2,500			—
Subscriptions – Class Z		1,687,350,294			2,172,346,851			1,168,999,243			965,616,527			222,245,731			349,840,792			86,732,266			45,935,610
Distributions reinvested – Class Z		734,024,683			471,639,563			86,747,474			91,323,594			102,214,147			7,533,719			21,542,287			5,069,068
Redemptions – Class Z		(2,657,246,336	)		(2,515,311,322	)		(936,482,410	)		(973,864,897	)		(391,557,641	)		(331,532,754	)		(85,460,095	)		(113,289,031	)
Net Increase (Decrease) – Class Z		(235,871,359	)		128,675,092			319,264,307			83,075,224			(67,097,763	)		25,841,757			22,814,458			(62,284,353	)
Net Increase (Decrease) from Share Transactions		(545,772,916	)		(160,646,128	)		268,418,443			364,289,548			(103,621,438	)		(49,669,345	)		38,803,038			(71,299,690	)
Increase from regulatory settlements (See Note 7)		—			—			107,802			107,617			—			—			—			—
Increase from contribution from affiliate (See Note 4)		—			—			—			—			—			—			—			—
Total Increase (Decrease) in Net Assets		1,187,290,557			(1,762,136,149	)		1,326,844,618			(708,109,988	)		41,649,545			(140,100,831	)		54,071,201			(126,284,162	)
Net Assets:
Beginning of period		16,336,575,354			18,098,711,503			5,416,952,988			6,125,062,976			1,558,445,128			1,698,545,959			326,382,853			452,667,015
End of period	$	17,523,865,911		$	16,336,575,354		$	6,743,797,606		$	5,416,952,988		$	1,600,094,673		$	1,558,445,128		$	380,454,054		$	326,382,853
Undistributed (Overdistributed) net investment income	$	(27,792,423	)	$	(32,073,997	)	$	(74,303,358	)	$	(60,514,153	)	$	(4,074,947	)	$	(167,486	)	$	(22,556,622	)	$	(5,294,000	)

(a)  Class R4 shares reflect activity for the period from November 8, 2012 (commencement of operations) through December 31, 2012.

(b)  Class R5 shares reflect activity for the period from November 8, 2012 (commencement of operations) through December 31, 2012.

(c)  Class Y shares reflect activity for the period from November 8, 2012 (commencement of operations) through December 31, 2012.

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

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

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

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	Year ended December 31,						Year ended December 31,						Year ended December 31,						Year ended December 31,
	2012 (a)(b)(c)			2011			2012 (a)(b)(c)			2011			2012 (a)(b)			2011 (e)			2012 (b)			2011 (e)
Subscriptions – Class I		45,199,109			12,447,313			—			—			—			5,000			—			5,000
Distributions reinvested – Class I		2,740,281			140,834			—			—			61			—			50			46
Net assets of shares issued in connection with Merger – Class I		—			—			—			—			—			—			—			—
Redemptions – Class I		(20,749,765	)		(8,781,953	)		—			—			—			—			—			—
Net Increase (Decrease) – Class I		27,189,625			3,806,194			—			—			61			5,000			50			5,046
Subscriptions – Class R		—			—			—			—			—			—			—			—
Distributions reinvested – Class R		—			—			—			—			—			—			—			—
Net assets of shares issued in connection with Merger – Class R		—			—			—			—			—			—			—			—
Redemptions – Class R		—			—			—			—			—			—			—			—
Net Increase – Class R		—			—			—			—			—			—			—			—
Subscriptions – Class R4		15,000			—			15,000			—			15,000			—			—			—
Net Increase – Class R4		15,000			—			15,000			—			15,000			—			—			—
Subscriptions – Class R5		2,500			—			2,500			—			2,500			—			2,500			—
Distributions reinvested – Class R5		—			—			—			—			—			—			—			—
Net assets of shares issued in connection with Merger – Class R5		—			—			—			—			—			—			—			—
Redemptions – Class R5		—			—			—			—			—			—			—			—
Net Increase (Decrease) – Class R5		2,500			—			2,500			—			2,500			—			2,500			—
Subscriptions – Class Y		2,500			—			2,500			—			—			—			—			—
Distributions reinvested – Class Y		—			—			—			—			—			—			—			—
Redemptions – Class Y		—			—			—			—			—			—			—			—
Net Increase – Class Y		2,500			—			2,500			—			—			—			—			—
Subscriptions – Class Z		92,416,113			177,361,634			280,471,623			42,101,307			3,279,578			2,948,759			774,240			1,588,892
Distributions reinvested – Class Z		40,196,957			17,487,932			3,443,888			1,165,088			58,786			—			20,822			13,383
Redemptions – Class Z		(476,230,534	)		(653,288,529	)		(69,222,297	)		(14,913,772	)		(392,871	)		(35	)		(7,954	)		(15	)
Net Increase (Decrease) – Class Z		(343,617,464	)		(458,438,963	)		214,693,214			28,352,623			2,945,493			2,948,724			787,108			1,602,260
Net Increase (Decrease) from Share Transactions		(442,619,387	)		(636,182,814	)		647,073,778			55,458,178			5,861,819			3,420,247			1,119,328			1,776,934
Increase from regulatory settlements (See Note 7)		—			—			—			—			—			—			—			—
Increase from contribution from affiliate (See Note 4)		—			56,666			—			—			—			—			—			—
Total Increase (Decrease) in Net Assets		(324,993,973	)		(992,234,265	)		685,016,109			58,331,108			7,361,045			3,228,766			1,598,900			1,679,135
Net Assets:
Beginning of period		1,290,620,887			2,282,855,152			189,606,588			131,275,480			3,228,766			—			1,679,135			—
End of period	$	965,626,914		$	1,290,620,887		$	874,622,697		$	189,606,588		$	10,589,811		$	3,228,766		$	3,278,035		$	1,679,135
Undistributed (Overdistributed) net investment income	$	2,866,367		$	(324,122	)	$	650,727		$	470,857		$	(17,167	)	$	(922	)	$	(8,259	)	$	(340	)

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:	Year ended December 31,						Year ended December 31,						Year ended December 31,						Year ended December 31,
	2012 (a)(b)(c)			2011			2012 (a)(c)			2011 (d)			2012 (a)(b)(c)			2011			2012 (a)(b)(c)			2011
Subscriptions – Class A		17,231,624			30,308,575			5,036,565			7,713,244			809,060			1,506,914			1,023,664			665,384
Shares issued in reinvestment and capital gains – Class A		6,767,946			4,849,511			349,670			463,002			419,501			37,645			374,787			78,166
Shares issued in connection with merger – Class A		—			—			—			5,466,934			—			—			—			—
Less shares redeemed – Class A		(35,802,801	)		(37,724,697	)		(7,580,692	)		(6,592,650	)		(2,274,459	)		(2,878,665	)		(825,702	)		(979,677	)
Net Increase (Decrease) – Class A		(11,803,231	)		(2,566,611	)		(2,194,457	)		7,050,530			(1,045,898	)		(1,334,106	)		572,749			(236,127	)
Shares issued in reinvestment and capital gains – Class B (f)		95,443			184,819			2,774			13,998			4,518			1,075			7,046			2,043
Shares issued in connection with merger – Class B		—			—			—			342,758			—			—			—			—
Less shares redeemed – Class B		(1,578,470	)		(8,045,886	)		(290,213	)		(352,784	)		(57,586	)		(267,391	)		(32,062	)		(39,168	)
Net Increase (Decrease) – Class B		(1,483,027	)		(7,861,067	)		(287,439	)		3,972			(53,068	)		(266,316	)		(25,016	)		(37,125	)
Subscriptions – Class C		2,852,549			3,778,865			259,798			519,373			72,817			90,021			71,372			36,299
Shares issued in reinvestment and capital gains – Class C		1,604,270			1,085,991			11,902			46,324			101,628			8,013			49,061			7,679
Shares issued in connection with merger – Class C		—			—			—			702,540			—			—			—			—
Less shares redeemed – Class C		(5,562,067	)		(5,913,273	)		(870,089	)		(1,110,263	)		(231,588	)		(230,475	)		(93,117	)		(115,449	)
Net Increase (Decrease) – Class C		(1,105,248	)		(1,048,417	)		(598,389	)		157,974			(57,143	)		(132,441	)		27,316			(71,471	)
Subscriptions – Class I		2,226,501			639,251			2,338,136			764,242			69,785			370,935			—			—
Shares issued in reinvestment and capital gains – Class I		119,925			24,710			50,947			16,426			42			593			—			—
Shares issued in connection with merger – Class I		—			—			—			4,062,014			—			—			—			—
Less shares redeemed – Class I		(1,016,424	)		(454,350	)		(1,469,126	)		(5,003,583	)		(167,312	)		(1,288,985	)		—			—
Net Increase (Decrease) – Class I		1,330,002			209,611			919,957			(160,901	)		(97,485	)		(917,457	)		—			—
Subscriptions – Class R		—			—			123,992			10,551			—			—			—			—
Shares issued in reinvestment and capital gains – Class R		—			—			521			—			—			—			—			—
Shares issued in connection with merger – Class R		—			—			—			54,059			—			—			—			—
Less shares redeemed – Class R		—			—			(118,346	)		(2,142	)		—			—			—			—
Net Increase – Class R		—			—			6,167			62,468			—			—			—			—
Subscriptions – Class R4		553			—			376			—			499			—			500			—
Net Increase – Class R4		553			—			376			—			499			—			500			—
Subscriptions – Class R5		82			—			8			66			83			—			83			—
Shares issued in reinvestment and capital gains – Class R5		—			—			145			—			—			—			—			—
Shares issued in connection with merger – Class R5		—			—			—			59,324			—			—			—			—
Less shares redeemed – Class R5		—			—			(53,601	)		—			—			—			—			—
Net Increase (Decrease) – Class R5		82			—			(53,448	)		59,390			83			—			83			—
Subscriptions – Class Y		2,148,017			—			750,647			—			83			—			83			—
Shares issued in reinvestment and capital gains – Class Y		31,278			—			476			—			—			—			—			—
Less shares redeemed – Class Y		(10,692	)		—			—			—			—			—			—			—
Net Increase – Class Y		2,168,603			—			751,123			—			83			—			83			—
Subscriptions – Class Z		55,847,077			72,817,179			30,630,548			24,482,095			7,413,473			12,164,332			3,087,336			1,655,528
Shares issued in reinvestment and capital gains – Class Z		24,884,327			16,442,041			2,218,261			2,221,985			3,580,586			274,452			838,401			192,067
Less shares redeemed – Class Z		(87,379,864	)		(85,040,148	)		(24,297,024	)		(25,537,246	)		(13,185,688	)		(11,564,391	)		(3,121,838	)		(4,157,219	)
Net Increase (Decrease) – Class Z		(6,648,460	)		4,219,072			8,551,785			1,166,834			(2,191,629	)		874,393			803,899			(2,309,624	)
Net Increase (Decrease) in Shares of Beneficial Interest		(17,540,726	)		(7,047,412	)		7,095,675			8,340,267			(3,444,558	)		(1,775,927	)		1,379,614			(2,654,347	)

(a)  Class R4 shares reflect activity for the period from November 8, 2012 (commencement of operations) through December 31, 2012.

(b)  Class R5 shares reflect activity for the period from November 8, 2012 (commencement of operations) through December 31, 2012.

(c)  Class Y shares reflect activity for the period from November 8, 2012 (commencement of operations) through December 31, 2012.

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

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

(f)  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:	Year ended December 31,						Year ended December 31,						Year ended December 31,						Year ended December 31,
	2012 (a)(b)(c)			2011			2012 (a)(b)(c)			2011			2012 (a)(b)			2011 (e)			2012 (b)			2011 (e)
Subscriptions – Class A		1,572,755			2,804,118			19,574,784			3,467,554			242,160			37,163			26,410			16,225
Shares issued in reinvestment and capital gains – Class A		878,414			242,109			319,205			109,048			1,308			—			152			104
Shares issued in connection with merger – Class A		—			—			—			—			—			—			—			—
Less shares redeemed – Class A		(6,287,849	)		(8,092,457	)		(3,461,158	)		(898,243	)		(21,619	)		(1,352	)		(4,331	)		—
Net Increase (Decrease) – Class A		(3,836,680	)		(5,046,230	)		16,432,831			2,678,359			221,849			35,811			22,231			16,329
Shares issued in reinvestment and capital gains – Class B (f)		46,775			19,069			3,716			29,853			—			—			—			—
Shares issued in connection with merger – Class B		—			—			—			—			—			—			—			—
Less shares redeemed – Class B		(830,866	)		(1,568,983	)		(568,981	)		(1,427,236	)		—			—			—			—
Net Increase (Decrease) – Class B		(784,091	)		(1,549,914	)		(565,265	)		(1,397,383	)		—			—			—			—
Subscriptions – Class C		130,998			145,444			15,757,125			1,195,517			43,007			14,831			9,113			500
Shares issued in reinvestment and capital gains – Class C		185,145			20,476			104,556			24,387			—			—			3			2
Shares issued in connection with merger – Class C		—			—			—			—			—			—			—			—
Less shares redeemed – Class C		(733,680	)		(1,010,864	)		(818,151	)		(367,683	)		(5,549	)		(1,055	)		(2,036	)		—
Net Increase (Decrease) – Class C		(417,537	)		(844,944	)		15,043,530			852,221			37,458			13,776			7,080			502
Subscriptions – Class I		1,751,104			519,581			—			—			—			500			—			500
Shares issued in reinvestment and capital gains – Class I		108,517			5,262			—			—			5			—			4			5
Shares issued in connection with merger – Class I		—			—			—			—			—			—			—			—
Less shares redeemed – Class I		(798,545	)		(334,605	)		—			—			—			—			—			—
Net Increase (Decrease) – Class I		1,061,076			190,238			—			—			5			500			4			505
Subscriptions – Class R		—			—			—			—			—			—			—			—
Shares issued in reinvestment and capital gains – Class R		—			—			—			—			—			—			—			—
Shares issued in connection with merger – Class R		—			—			—			—			—			—			—			—
Less shares redeemed – Class R		—			—			—			—			—			—			—			—
Net Increase – Class R		—			—			—			—			—			—			—			—
Subscriptions – Class R4		579			—			1,065			—			1,311			—			—			—
Net Increase – Class R4		579			—			1,065			—			1,311			—			—			—
Subscriptions – Class R5		96			—			178			—			219			—			223			—
Shares issued in reinvestment and capital gains – Class R5		—			—			—			—			—			—			—			—
Shares issued in connection with merger – Class R5		—			—			—			—			—			—			—			—
Less shares redeemed – Class R5		—			—			—			—			—			—			—			—
Net Increase (Decrease) – Class R5		96			—			178			—			219			—			223			—
Subscriptions – Class Y		96			—			178			—			—			—			—			—
Shares issued in reinvestment and capital gains – Class Y		—			—			—			—			—			—			—			—
Less shares redeemed – Class Y		—			—			—			—			—			—			—			—
Net Increase – Class Y		96			—			178			—			—			—			—			—
Subscriptions – Class Z		3,534,761			6,576,496			20,385,294			3,337,874			299,290			298,053			70,205			159,229
Shares issued in reinvestment and capital gains – Class Z		1,598,571			653,510			244,437			92,364			5,008			—			1,859			1,384
Less shares redeemed – Class Z		(18,152,892	)		(25,141,231	)		(5,049,709	)		(1,192,353	)		(34,993	)		(4	)		(754	)		(1	)
Net Increase (Decrease) – Class Z		(13,019,560	)		(17,911,225	)		15,580,022			2,237,885			269,305			298,049			71,310			160,612
Net Increase (Decrease) in Shares of Beneficial Interest		(16,996,021	)		(25,162,075	)		46,492,539			4,371,082			530,147			348,136			100,848			177,948

See accompanying notes to financial statements.

99

Columbia Acorn Family of Funds

Financial Highlights

The following tables are intended to help you understand the Fund's financial performance. Certain information reflects financial results for a single share of a class held for the periods shown. Per share net investment income (loss) amounts are calculated based on average shares outstanding during the period. Total return assumes reinvestment of all dividends and distributions. Total return does not reflect payment of sales charges, if any, and is not annualized for periods of less than one year.

Columbia Acorn Fund

			Income from Investment Operations									Less Distributions to Shareholders
	Net Asset Value, Beginning of Period		Net investment income (loss)			Net realized and unrealized gain (loss)			Total from investment operations			From net investment income			From net realized gains			Total Distributions to Shareholders			Increase from regulatory settlements
Class A
Year Ended December 31, 2012	$	26.63		0.08			4.53			4.61			(0.06	)		(1.82	)		(1.88	)		—
Year Ended December 31, 2011	$	29.24		(0.10	)		(1.30	)		(1.40	)		(0.02	)		(1.19	)		(1.21	)		—
Year Ended December 31, 2010	$	23.98		(0.06	)		6.18			6.12			(0.02	)		(0.84	)		(0.86	)		0.00	(d)
Year Ended December 31, 2009	$	17.22		(0.02	)		6.78			6.76			—			—			—			0.00	(d)
Year Ended December 31, 2008	$	28.87		(0.01	)		(10.98	)		(10.99	)		—			(0.66	)		(0.66	)		—
Class B
Year Ended December 31, 2012	$	24.53		(0.11	)		4.20			4.09			—			(1.82	)		(1.82	)		—
Year Ended December 31, 2011	$	27.14		(0.27	)		(1.15	)		(1.42	)		—			(1.19	)		(1.19	)		—
Year Ended December 31, 2010	$	22.43		(0.21	)		5.76			5.55			—			(0.84	)		(0.84	)		0.00	(d)
Year Ended December 31, 2009	$	16.21		(0.14	)		6.36			6.22			—			—			—			0.00	(d)
Year Ended December 31, 2008	$	27.39		(0.15	)		(10.37	)		(10.52	)		—			(0.66	)		(0.66	)		—
Class C
Year Ended December 31, 2012	$	24.18		(0.12	)		4.10			3.98			—			(1.82	)		(1.82	)		—
Year Ended December 31, 2011	$	26.85		(0.29	)		(1.19	)		(1.48	)		—			(1.19	)		(1.19	)		—
Year Ended December 31, 2010	$	22.23		(0.24	)		5.70			5.46			—			(0.84	)		(0.84	)		0.00	(d)
Year Ended December 31, 2009	$	16.09		(0.17	)		6.31			6.14			—			—			—			0.00	(d)
Year Ended December 31, 2008	$	27.25		(0.19	)		(10.31	)		(10.50	)		—			(0.66	)		(0.66	)		—
Class I
Year Ended December 31, 2012	$	27.57		0.26			4.62			4.88			(0.16	)		(1.82	)		(1.98	)		—
Year Ended December 31, 2011	$	30.19		0.01			(1.35	)		(1.34	)		(0.09	)		(1.19	)		(1.28	)		—
Year Ended December 31, 2010 (e)	$	26.80		(0.01	)		4.26			4.25			(0.02	)		(0.84	)		(0.86	)		—
Class R4
Year Ended December 31, 2012 (g)	$	30.59		0.05			1.84			1.89			(0.12	)		(1.46	)		(1.58	)		—
Class R5
Year Ended December 31, 2012 (h)	$	30.59		0.06			1.83			1.89			(0.14	)		(1.46	)		(1.60	)		—
Class Y
Year Ended December 31, 2012 (i)	$	30.62		0.09			1.80			1.89			(0.15	)		(1.46	)		(1.61	)		—
Class Z
Year Ended December 31, 2012	$	27.56		0.17			4.69			4.86			(0.15	)		(1.82	)		(1.97	)		—
Year Ended December 31, 2011	$	30.19		(0.01	)		(1.34	)		(1.35	)		(0.09	)		(1.19	)		(1.28	)		—
Year Ended December 31, 2010	$	24.68		0.02			6.37			6.39			(0.04	)		(0.84	)		(0.88	)		0.00	(d)
Year Ended December 31, 2009	$	17.71		0.04			6.98			7.02			(0.05	)		—			(0.05	)		0.00	(d)
Year Ended December 31, 2008	$	29.61		0.06			(11.29	)		(11.23	)		(0.01	)		(0.66	)		(0.67	)		—

(a)  Certain line items from prior years have been reclassified to conform to the current presentation.

(b)  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 underlying funds in which it invests. Such indirect expenses are not included in the reported expense ratios.

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

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

(e)  Class I shares commenced operations on September 27, 2010. Per share data and total return reflect activity from that date.

(f)  Annualized.

(g)  Class R4 shares commenced operations on November 8, 2012. Per share data and total return reflect activity from that date.

(h)  Class R5 shares commenced operations on November 8, 2012. Per share data and total return reflect activity from that date.

(i)  Class Y shares commenced operations on November 8, 2012. Per share data and total return reflect activity from that date.

See accompanying notes to financial statements.

100

						Ratio to Average Net Assets									Supplemental Data
	Net Asset Value, End of Period		Total Return			Total gross expenses (a)			Total net expenses (b)(c)			Net investment income (loss)			Portfolio turnover rate			Net assets, end of period (000s)
Class A
Year Ended December 31, 2012	$	29.36		17.62	%		1.06	%		1.06	%		0.27	%		16	%	$	3,233,494
Year Ended December 31, 2011	$	26.63		(4.91	)%		1.06	%		1.06	%		(0.33	)%		18	%	$	3,246,833
Year Ended December 31, 2010	$	29.24		25.61	%		1.07	%		1.07	%		(0.22	)%		28	%	$	3,639,788
Year Ended December 31, 2009	$	23.98		39.26	%		1.07	%		1.07	%		(0.12	)%		27	%	$	2,937,761
Year Ended December 31, 2008	$	17.22		(38.72	)%		1.05	%		1.05	%		(0.04	)%		21	%	$	2,221,100
Class B
Year Ended December 31, 2012	$	26.80		16.98	%		1.65	%		1.64	%		(0.42	)%		16	%	$	33,623
Year Ended December 31, 2011	$	24.53		(5.34	)%		1.67	%		1.67	%		(0.98	)%		18	%	$	67,153
Year Ended December 31, 2010	$	27.14		24.81	%		1.69	%		1.69	%		(0.88	)%		28	%	$	287,650
Year Ended December 31, 2009	$	22.43		38.37	%		1.74	%		1.74	%		(0.77	)%		27	%	$	525,072
Year Ended December 31, 2008	$	16.21		(39.11	)%		1.65	%		1.65	%		(0.64	)%		21	%	$	581,587
Class C
Year Ended December 31, 2012	$	26.34		16.77	%		1.80	%		1.80	%		(0.46	)%		16	%	$	756,709
Year Ended December 31, 2011	$	24.18		(5.63	)%		1.82	%		1.82	%		(1.10	)%		18	%	$	721,446
Year Ended December 31, 2010	$	26.85		24.63	%		1.85	%		1.85	%		(1.00	)%		28	%	$	829,181
Year Ended December 31, 2009	$	22.23		38.16	%		1.89	%		1.89	%		(0.93	)%		27	%	$	736,818
Year Ended December 31, 2008	$	16.09		(39.23	)%		1.83	%		1.83	%		(0.82	)%		21	%	$	622,665
Class I
Year Ended December 31, 2012	$	30.47		18.02	%		0.72	%		0.72	%		0.86	%		16	%	$	58,652
Year Ended December 31, 2011	$	27.57		(4.57	)%		0.72	%		0.72	%		0.02	%		18	%	$	16,397
Year Ended December 31, 2010 (e)	$	30.19		15.94	%		0.71	%(f)		0.71	%(f)		(0.13	)%(f)		28	%	$	11,627
Class R4
Year Ended December 31, 2012 (g)	$	30.90		6.31	%		0.87	%(f)		0.86	%(f)		1.24	%(f)		16	%	$	17
Class R5
Year Ended December 31, 2012 (h)	$	30.88		6.33	%		0.82	%(f)		0.81	%(f)		1.29	%(f)		16	%	$	3
Class Y
Year Ended December 31, 2012 (i)	$	30.90		6.34	%		0.75	%(f)		0.75	%(f)		2.21	%(f)		16	%	$	67,012
Class Z
Year Ended December 31, 2012	$	30.45		17.93	%		0.78	%		0.78	%		0.57	%		16	%	$	13,374,355
Year Ended December 31, 2011	$	27.56		(4.61	)%		0.76	%		0.76	%		(0.03	)%		18	%	$	12,284,748
Year Ended December 31, 2010	$	30.19		26.00	%		0.76	%		0.76	%		0.09	%		28	%	$	13,330,466
Year Ended December 31, 2009	$	24.68		39.65	%		0.77	%		0.77	%		0.18	%		27	%	$	10,527,500
Year Ended December 31, 2008	$	17.71		(38.55	)%		0.76	%		0.76	%		0.26	%		21	%	$	7,445,862

See accompanying notes to financial statements.

101

Columbia Acorn Family of Funds

Financial Highlights, continued

Columbia Acorn International

			Income from Investment Operations												Less Distributions to Shareholders
	Net Asset Value, Beginning of Period		Net investment income (loss)			Net realized and unrealized gain (loss)			Reimbursement from affiliate			Total from investment operations			From net investment income			From net realized gains			Total Distributions to Shareholders			Redemption fees added to paid in capital
Class A
Year Ended December 31, 2012	$	34.15		0.47			6.75			—			7.22			(0.58	)		—			(0.58	)		—
Year Ended December 31, 2011	$	40.87		0.32			(6.02	)		0.00	(c)		(5.70	)		(1.02	)		—			(1.02	)		—
Year Ended December 31, 2010	$	34.13		0.22			7.21			—			7.43			(0.69	)		—			(0.69	)		0.00	(c)
Year Ended December 31, 2009	$	23.03		0.23			11.27			—			11.50			(0.41	)		—			(0.41	)		0.00	(c)
Year Ended December 31, 2008	$	43.42		0.47			(20.20	)		—			(19.73	)		(0.06	)		(0.60	)		(0.66	)		0.00	(c)
Class B
Year Ended December 31, 2012	$	33.17		0.19			6.55			—			6.74			(0.24	)		—			(0.24	)		—
Year Ended December 31, 2011	$	39.96		0.06			(5.85	)		0.00	(c)		(5.79	)		(1.00	)		—			(1.00	)		—
Year Ended December 31, 2010	$	33.22		0.03			7.02			—			7.05			(0.31	)		—			(0.31	)		0.00	(c)
Year Ended December 31, 2009	$	22.41		0.08			10.92			—			11.00			(0.20	)		—			(0.20	)		0.00	(c)
Year Ended December 31, 2008	$	42.46		0.27			(19.72	)		—			(19.45	)		—			(0.60	)		(0.60	)		0.00	(c)
Class C
Year Ended December 31, 2012	$	33.03		0.18			6.52			—			6.70			(0.23	)		—			(0.23	)		—
Year Ended December 31, 2011	$	39.79		0.04			(5.86	)		0.00	(c)		(5.82	)		(0.94	)		—			(0.94	)		—
Year Ended December 31, 2010	$	33.08		(0.05	)		7.03			—			6.98			(0.27	)		—			(0.27	)		0.00	(c)
Year Ended December 31, 2009	$	22.30		0.02			10.89			—			10.91			(0.14	)		—			(0.14	)		0.00	(c)
Year Ended December 31, 2008	$	42.32		0.21			(19.63	)		—			(19.42	)		—			(0.60	)		(0.60	)		0.00	(c)
Class I
Year Ended December 31, 2012	$	34.33		0.57			6.83			—			7.40			(0.87	)		—			(0.87	)		—
Year Ended December 31, 2011	$	40.92		0.37			(5.94	)		0.00	(c)		(5.57	)		(1.02	)		—			(1.02	)		—
Year Ended December 31, 2010 (g)	$	37.69		0.08			3.49			—			3.57			(0.34	)		—			(0.34	)		0.00	(c)
Class R
Year Ended December 31, 2012	$	34.11		0.21			6.89			—			7.10			(0.42	)		—			(0.42	)		—
Year Ended December 31, 2011 (i)	$	40.11		(0.00	)(c)		(6.00	)		0.00	(c)		(6.00	)		—			—			—			—
Class R4
Year Ended December 31, 2012 (j)	$	39.86		(0.00	)(c)		1.81			—			1.81			(0.59	)		—			(0.59	)		—
Class R5
Year Ended December 31, 2012	$	34.31		0.75			6.62			—			7.37			(0.87	)		—			(0.87	)		—
Year Ended December 31, 2011 (k)	$	40.24		0.09			(6.02	)		0.00	(c)		(5.93	)		—			—			—			—
Class Y
Year Ended December 31, 2012 (l)	$	39.90		0.04			1.78			—			1.82			(0.64	)		—			(0.64	)		—
Class Z
Year Ended December 31, 2012	$	34.31		0.59			6.78			—			7.37			(0.84	)		—			(0.84	)		—
Year Ended December 31, 2011	$	40.92		0.48			(6.07	)		0.00	(c)		(5.59	)		(1.02	)		—			(1.02	)		—
Year Ended December 31, 2010	$	34.26		0.35			7.23			—			7.58			(0.92	)		—			(0.92	)		0.00	(c)
Year Ended December 31, 2009	$	23.13		0.34			11.31			—			11.65			(0.53	)		—			(0.53	)		0.00	(c)
Year Ended December 31, 2008	$	43.60		0.60			(20.26	)		—			(19.66	)		(0.21	)		(0.60	)		(0.81	)		0.00	(c)

(a)  Certain line items from prior years have been reclassified to conform to the current presentation.

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

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

(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)  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 underlying funds in which it invests. Such indirect expenses are not included in the reported expense ratios.

(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)  Class I shares commenced operations on September 27, 2010. Per share data and total return reflect activity from that date.

(h)  Annualized.

(i)  Class R shares commenced operations on August 15, 2011. Per share data and total return reflect activity from that date.

(j)  Class R4 shares commenced operations on November 8, 2012. Per share data and total return reflect activity from that date.

(k)  Class R5 shares commenced operations on August 15, 2011. Per share data and total return reflect activity from that date.

(l)  Class Y shares commenced operations on November 8, 2012. Per share data and total return reflect activity from that date.

See accompanying notes to financial statements.

102

									Ratio to Average Net Assets									Supplemental Data
	Increase from regulatory settlements			Net Asset Value, End of Period		Total Return			Total gross expenses (a)			Total net expenses (b)			Net investment income (loss)			Portfolio turnover rate			Net assets, end of period (000s)
Class A
Year Ended December 31, 2012		0.00	(c)	$	40.79		21.21	%(d)		1.28	%		1.24	%(e)		1.22	%		33	%	$	1,007,236
Year Ended December 31, 2011		0.00	(c)	$	34.15		(14.37	%)(d)(f)		1.32	%		1.30	%(e)		0.84	%		32	%	$	918,112
Year Ended December 31, 2010		0.00	(c)	$	40.87		22.23	%		1.35	%		1.35	%(e)		0.62	%		25	%	$	810,603
Year Ended December 31, 2009		0.01		$	34.13		50.40	%		1.36	%		1.36	%(e)		0.85	%		31	%	$	578,599
Year Ended December 31, 2008		—		$	23.03		(46.09	%)		1.31	%		1.31	%		1.36	%		38	%	$	366,820
Class B
Year Ended December 31, 2012		0.00	(c)	$	39.67		20.33	%(d)		2.00	%		1.97	%(e)		0.51	%		33	%	$	17,910
Year Ended December 31, 2011		0.00	(c)	$	33.17		(14.92	%)(d)(f)		1.98	%		1.96	%(e)		0.15	%		32	%	$	24,510
Year Ended December 31, 2010		0.00	(c)	$	39.96		21.49	%		1.96	%		1.96	%(e)		0.08	%		25	%	$	29,368
Year Ended December 31, 2009		0.01		$	33.22		49.36	%		2.03	%		2.03	%(e)		0.29	%		31	%	$	38,835
Year Ended December 31, 2008		—		$	22.41		(46.41	%)		1.90	%		1.90	%		0.77	%		38	%	$	39,153
Class C
Year Ended December 31, 2012		0.00	(c)	$	39.50		20.31	%(d)		2.02	%		2.00	%(e)		0.48	%		33	%	$	92,748
Year Ended December 31, 2011		0.00	(c)	$	33.03		(15.02	%)(d)(f)		2.07	%		2.06	%(e)		0.10	%		32	%	$	97,328
Year Ended December 31, 2010		0.00	(c)	$	39.79		21.34	%		2.11	%		2.11	%(e)		(0.13	%)		25	%	$	110,931
Year Ended December 31, 2009		0.01		$	33.08		49.12	%		2.17	%		2.17	%(e)		0.07	%		31	%	$	85,625
Year Ended December 31, 2008		—		$	22.30		(46.50	%)		2.08	%		2.08	%		0.60	%		38	%	$	62,906
Class I
Year Ended December 31, 2012		0.00	(c)	$	40.86		21.69	%		0.88	%		0.88	%(e)		1.48	%		33	%	$	97,484
Year Ended December 31, 2011		0.00	(c)	$	34.33		(14.02	%)(f)		0.91	%		0.91	%(e)		0.99	%		32	%	$	50,335
Year Ended December 31, 2010 (g)		—		$	40.92		9.50	%		0.94	%(h)		0.94	%(e)(h)		0.77	%(h)		25	%	$	66,581
Class R
Year Ended December 31, 2012		0.00	(c)	$	40.79		20.83	%		1.52	%		1.51	%(e)		0.54	%		33	%	$	2,799
Year Ended December 31, 2011 (i)		0.00	(c)	$	34.11		(14.96	%)		1.59	%(h)		1.59	%(e)(h)		(0.02	%)(h)		32	%	$	2,130
Class R4
Year Ended December 31, 2012 (j)		—		$	41.08		4.57			1.03	%(h)		1.02	%(e)(h)		(0.02	%)(h)		33	%	$	15
Class R5
Year Ended December 31, 2012		0.00	(c)	$	40.81		21.61	%		0.89	%		0.89	%(e)		1.99	%		33	%	$	242
Year Ended December 31, 2011 (k)		0.00	(c)	$	34.31		(14.74	%)		0.91	%(h)		0.91	%(e)(h)		0.65	%(h)		32	%	$	2,038
Class Y
Year Ended December 31, 2012 (l)		—		$	41.08		4.59	%		0.91	%(h)		0.90	%(e)(h)		0.75	%(h)		33	%	$	30,856
Class Z
Year Ended December 31, 2012		0.00	(c)	$	40.84		21.60	%		0.93	%		0.93	%(e)		1.53	%		33	%	$	5,494,506
Year Ended December 31, 2011		0.00	(c)	$	34.31		(14.06	%)(f)		0.95	%		0.95	%(e)		1.24	%		32	%	$	4,322,500
Year Ended December 31, 2010		0.00	(c)	$	40.92		22.70	%		0.97	%		0.97	%(e)		0.99	%		25	%	$	5,107,580
Year Ended December 31, 2009		0.01		$	34.26		50.97	%		0.99	%		0.99	%(e)		1.23	%		31	%	$	3,727,679
Year Ended December 31, 2008		—		$	23.13		(45.89	%)		0.96	%		0.96	%		1.72	%		38	%	$	2,371,688

See accompanying notes to financial statements.

103

Columbia Acorn Family of Funds

Financial Highlights, continued

Columbia Acorn USA

			Income from Investment Operations									Less Distributions to Shareholders
	Net Asset Value, Beginning of Period		Net investment income (loss)			Net realized and unrealized gain (loss)			Total from investment operations			From net investment income			From net realized gains			Total Distributions to Shareholders			Increase from regulatory settlements
Class A
Year Ended December 31, 2012	$	25.94		0.02			4.73			4.75			(0.11	)		(2.37	)		(2.48	)		—
Year Ended December 31, 2011	$	27.54		(0.22	)		(1.21	)		(1.43	)		—			(0.17	)		(0.17	)		—
Year Ended December 31, 2010	$	22.43		(0.15	)		5.26			5.11			—			—			—			—
Year Ended December 31, 2009	$	15.90		(0.11	)		6.64			6.53			—			—			—			0.00	(e)
Year Ended December 31, 2008	$	27.23		(0.14	)		(10.23	)		(10.37	)		—			(0.96	)		(0.96	)		—
Class B
Year Ended December 31, 2012	$	23.98		(0.19	)		4.39			4.20			—			(2.37	)		(2.37	)		—
Year Ended December 31, 2011	$	25.60		(0.37	)		(1.08	)		(1.45	)		—			(0.17	)		(0.17	)		—
Year Ended December 31, 2010	$	20.99		(0.30	)		4.91			4.61			—			—			—			—
Year Ended December 31, 2009	$	14.98		(0.22	)		6.23			6.01			—			—			—			0.00	(e)
Year Ended December 31, 2008	$	25.87		(0.27	)		(9.66	)		(9.93	)		—			(0.96	)		(0.96	)		—
Class C
Year Ended December 31, 2012	$	23.72		(0.16	)		4.30			4.14			—			(2.37	)		(2.37	)		—
Year Ended December 31, 2011	$	25.39		(0.39	)		(1.11	)		(1.50	)		—			(0.17	)		(0.17	)		—
Year Ended December 31, 2010	$	20.84		(0.31	)		4.86			4.55			—			—			—			—
Year Ended December 31, 2009	$	14.89		(0.24	)		6.19			5.95			—			—			—			0.00	(e)
Year Ended December 31, 2008	$	25.77		(0.30	)		(9.62	)		(9.92	)		—			(0.96	)		(0.96	)		—
Class I
Year Ended December 31, 2012	$	27.00		(0.10	)		5.16			5.06			(0.22	)		(2.37	)		(2.59	)		—
Year Ended December 31, 2011	$	28.56		(0.14	)		(1.25	)		(1.39	)		—			(0.17	)		(0.17	)		—
Year Ended December 31, 2010 (f)	$	24.24		(0.03	)		4.35			4.32			—			—			—			—
Class R4
Year Ended December 31, 2012 (h)	$	30.06		0.06			2.28			2.34			(0.16	)		(2.32	)		(2.48	)		—
Class R5
Year Ended December 31, 2012 (i)	$	30.06		0.07			2.27			2.34			(0.18	)		(2.32	)		(2.50	)		—
Class Y
Year Ended December 31, 2012 (j)	$	30.10		0.07			2.27			2.34			(0.19	)		(2.32	)		(2.51	)		—
Class Z
Year Ended December 31, 2012	$	26.98		0.11			4.92			5.03			(0.19	)		(2.37	)		(2.56	)		—
Year Ended December 31, 2011	$	28.56		(0.14	)		(1.27	)		(1.41	)		—			(0.17	)		(0.17	)		—
Year Ended December 31, 2010	$	23.19		(0.08	)		5.45			5.37			—			—			—			—
Year Ended December 31, 2009	$	16.39		(0.07	)		6.87			6.80			—			—			—			0.00	(e)
Year Ended December 31, 2008	$	27.97		(0.07	)		(10.55	)		(10.62	)		—			(0.96	)		(0.96	)		—

(a)  Certain line items from prior years have been reclassified to conform to the current presentation.

(b)  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 underlying funds in which it invests. Such indirect expenses are not included in the reported expense ratios.

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

(d)  Includes interest expense which rounds to less than 0.01%.

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

(f)  Class I shares commenced operations on September 27, 2010. Per share data and total return reflect activity from that date.

(g)  Annualized.

(h)  Class R4 shares commenced operations on November 8, 2012. Per share data and total return reflect activity from that date.

(i)  Class R5 shares commenced operations on November 8, 2012. Per share data and total return reflect activity from that date.

(j)  Class Y shares commenced operations on November 8, 2012. Per share data and total return reflect activity from that date.

See accompanying notes to financial statements.

104

						Ratio to Average Net Assets									Supplemental Data
	Net Asset Value, End of Period		Total Return			Total gross expenses (a)			Total net expenses (b)(c)			Net investment income (loss)			Portfolio turnover rate			Net assets, end of period (000s)
Class A
Year Ended December 31, 2012	$	28.21		18.67	%		1.32	%(d)		1.32	%(d)		0.08	%		14	%	$	152,164
Year Ended December 31, 2011	$	25.94		(5.21	)%		1.30	%		1.30	%		(0.78	)%		20	%	$	167,038
Year Ended December 31, 2010	$	27.54		22.78	%		1.30	%		1.30	%		(0.64	)%		32	%	$	214,097
Year Ended December 31, 2009	$	22.43		41.07	%		1.32	%		1.32	%		(0.64	)%		28	%	$	178,605
Year Ended December 31, 2008	$	15.90		(39.38	)%		1.29	%		1.29	%		(0.60	)%		23	%	$	136,597
Class B
Year Ended December 31, 2012	$	25.81		17.87	%		1.99	%(d)		1.99	%(d)		(0.71	)%		14	%	$	1,056
Year Ended December 31, 2011	$	23.98		(5.68	)%		1.92	%		1.92	%		(1.42	)%		20	%	$	2,253
Year Ended December 31, 2010	$	25.60		21.96	%		1.98	%		1.98	%		(1.37	)%		32	%	$	9,222
Year Ended December 31, 2009	$	20.99		40.12	%		2.02	%		2.02	%		(1.33	)%		28	%	$	20,903
Year Ended December 31, 2008	$	14.98		(39.75	)%		1.92	%		1.92	%		(1.24	)%		23	%	$	23,633
Class C
Year Ended December 31, 2012	$	25.49		17.82	%		2.05	%(d)		2.05	%(d)		(0.61	)%		14	%	$	31,410
Year Ended December 31, 2011	$	23.72		(5.92	)%		2.05	%		2.05	%		(1.53	)%		20	%	$	30,584
Year Ended December 31, 2010	$	25.39		21.83	%		2.08	%		2.08	%		(1.41	)%		32	%	$	36,101
Year Ended December 31, 2009	$	20.84		39.96	%		2.13	%		2.13	%		(1.45	)%		28	%	$	32,508
Year Ended December 31, 2008	$	14.89		(39.87	)%		2.08	%		2.08	%		(1.39	)%		23	%	$	25,899
Class I
Year Ended December 31, 2012	$	29.47		19.10	%		0.96	%		0.96	%		(0.33	)%		14	%	$	3
Year Ended December 31, 2011	$	27.00		(4.88	)%		0.94	%		0.94	%		(0.47	)%		20	%	$	2,635
Year Ended December 31, 2010 (f)	$	28.56		17.82	%		0.94	%(g)		0.94	%(g)		(0.35	)%(g)		32	%	$	28,993
Class R4
Year Ended December 31, 2012 (h)	$	29.92		8.06	%		1.14	%(d)(g)		1.14	%(d)(g)		1.51	%(g)		14	%	$	15
Class R5
Year Ended December 31, 2012 (i)	$	29.90		8.06	%		1.12	%(g)		1.12	%(g)		1.53	%(g)		14	%	$	2
Class Y
Year Ended December 31, 2012 (j)	$	29.93		8.07	%		1.04	%(g)		1.04	%(g)		1.62	%(g)		14	%	$	2
Class Z
Year Ended December 31, 2012	$	29.45		18.98	%		1.07	%(d)		1.07	%(d)		0.36	%		14	%	$	1,415,442
Year Ended December 31, 2011	$	26.98		(4.95	)%		1.00	%		1.00	%		(0.48	)%		20	%	$	1,355,934
Year Ended December 31, 2010	$	28.56		23.16	%		1.01	%		1.01	%		(0.34	)%		32	%	$	1,410,133
Year Ended December 31, 2009	$	23.19		41.49	%		1.03	%		1.03	%		(0.36	)%		28	%	$	1,157,593
Year Ended December 31, 2008	$	16.39		(39.22	)%		1.01	%		1.01	%		(0.32	)%		23	%	$	758,267

See accompanying notes to financial statements.

105

Columbia Acorn Family of Funds

Financial Highlights, continued

Columbia Acorn International Select

			Income from Investment Operations									Less Distributions to Shareholders
	Net Asset Value, Beginning of Period		Net investment income (loss)			Net realized and unrealized gain (loss)			Total from investment operations			From net investment income			From net realized gains			Total Distributions to Shareholders			Redemption fees added to paid in capital
Class A
Year Ended December 31, 2012	$	24.26		0.39			4.92			5.31			(1.75	)		(2.21	)		(3.96	)		—
Year Ended December 31, 2011	$	28.01		0.18			(2.95	)		(2.77	)		(0.59	)		(0.39	)		(0.98	)		—
Year Ended December 31, 2010	$	23.39		0.08			4.84			4.92			(0.30	)		—			(0.30	)		0.00	(f)
Year Ended December 31, 2009	$	17.99		0.10			5.43			5.53			(0.15	)		—			(0.15	)		0.00	(f)
Year Ended December 31, 2008	$	31.74		0.20			(13.41	)		(13.21	)		—			(0.54	)		(0.54	)		0.00	(f)
Class B
Year Ended December 31, 2012	$	23.27		0.23			4.69			4.92			(1.58	)		(2.21	)		(3.79	)		—
Year Ended December 31, 2011	$	26.72		0.01			(2.82	)		(2.81	)		(0.25	)		(0.39	)		(0.64	)		—
Year Ended December 31, 2010	$	22.34		(0.06	)		4.62			4.56			(0.18	)		—			(0.18	)		0.00	(f)
Year Ended December 31, 2009	$	17.16		(0.01	)		5.17			5.16			—			—			—			0.00	(f)
Year Ended December 31, 2008	$	30.50		0.04			(12.84	)		(12.80	)		—			(0.54	)		(0.54	)		0.00	(f)
Class C
Year Ended December 31, 2012	$	23.17		0.18			4.67			4.85			(1.53	)		(2.21	)		(3.74	)		—
Year Ended December 31, 2011	$	26.58		(0.04	)		(2.81	)		(2.85	)		(0.17	)		(0.39	)		(0.56	)		—
Year Ended December 31, 2010	$	22.21		(0.10	)		4.60			4.50			(0.13	)		—			(0.13	)		0.00	(f)
Year Ended December 31, 2009	$	17.08		(0.06	)		5.17			5.11			—			—			—			0.00	(f)
Year Ended December 31, 2008	$	30.42		0.00	(f)		(12.80	)		(12.80	)		—			(0.54	)		(0.54	)		0.00	(f)
Class I
Year Ended December 31, 2012	$	24.45		0.51			4.94			5.45			(1.84	)		(2.21	)		(4.05	)		—
Year Ended December 31, 2011	$	28.33		0.31			(2.97	)		(2.66	)		(0.83	)		(0.39	)		(1.22	)		—
Year Ended December 31, 2010 (h)	$	26.11		0.03			2.19			2.22			—			—			—			—
Class R4
Year Ended December 31, 2012 (j)	$	29.98		(0.02	)		(0.09	)(k)		(0.11	)		(1.79	)		(2.09	)		(3.88	)		—
Class R5
Year Ended December 31, 2012 (l)	$	29.98		(0.02	)		(0.09	)(k)		(0.11	)		(1.80	)		(2.09	)		(3.89	)		—
Class Y
Year Ended December 31, 2012 (m)	$	29.99		(0.02	)		(0.09	)(k)		(0.11	)		(1.81	)		(2.09	)		(3.90	)		—
Class Z
Year Ended December 31, 2012	$	24.46		0.49			4.95			5.44			(1.83	)		(2.21	)		(4.04	)		—
Year Ended December 31, 2011	$	28.33		0.29			(2.98	)		(2.69	)		(0.79	)		(0.39	)		(1.18	)		—
Year Ended December 31, 2010	$	23.64		0.18			4.89			5.07			(0.38	)		—			(0.38	)		0.00	(f)
Year Ended December 31, 2009	$	18.19		0.17			5.50			5.67			(0.24	)		—			(0.24	)		0.00	(f)
Year Ended December 31, 2008	$	32.02		0.28			(13.53	)		(13.25	)		(0.04	)		(0.54	)		(0.58	)		0.00	(f)

(a)  Certain line items from prior years have been reclassified to conform to the current presentation.

(b)  Includes interest expense which rounds to less than 0.01%.

(c)  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 underlying funds in which it invests. Such indirect expenses are not included in the reported expense ratios.

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

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

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

(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)  Class I shares commenced operations on September 27, 2010. Per share data and total return reflect activity from that date.

(i)  Annualized.

(j)  Class R4 shares commenced operations on November 8, 2012. Per share data and total return reflect activity from that date.

(k)  Calculation of the net gain (loss) per share (both realized and unrealized) does not correlate to the aggregate realized and unrealized gain (loss) presented in the Statements of Operations due to the timing of sales and repurchases of Fund shares in relation to fluctuations in the market value of the portfolio.

(l)  Class R5 shares commenced operations on November 8, 2012. Per share data and total return reflect activity from that date.

(m)  Class Y shares commenced operations on November 8, 2012. Per share data and total return reflect activity from that date.

See accompanying notes to financial statements.

106

									Ratio to Average Net Assets									Supplemental Data
	Increase from regulatory settlements			Net Asset Value, End of Period		Total Return			Total gross expenses (a)			Total net expenses			Net investment income (loss)			Portfolio turnover rate			Net assets, end of period (000s)
Class A
Year Ended December 31, 2012		—		$	25.61		22.05	%		1.49	%(b)		1.49	%(b)(c)(d)		1.43	%		63	%	$	74,167
Year Ended December 31, 2011		—		$	24.26		(10.11	)%		1.51	%		1.51	%(c)(e)		0.66	%		44	%	$	56,350
Year Ended December 31, 2010		0.00	(f)	$	28.01		21.41	%		1.56	%		1.56	%(c)(e)		0.33	%		42	%	$	71,668
Year Ended December 31, 2009		0.02		$	23.39		31.01	%		1.56	%		1.56	%(e)		0.53	%		56	%	$	64,664
Year Ended December 31, 2008		—		$	17.99		(42.30	)%		1.54	%		1.54	%(e)		0.78	%		68	%	$	46,522
Class B
Year Ended December 31, 2012		—		$	24.40		21.29	%		2.11	%(b)		2.10	%(b)(c)(d)		0.87	%		63	%	$	1,250
Year Ended December 31, 2011		—		$	23.27		(10.64	)%		2.14	%		2.14	%(c)(e)		0.04	%		44	%	$	1,774
Year Ended December 31, 2010		0.00	(f)	$	26.72		20.63	%(g)		2.24	%		2.20	%(c)(e)		(0.27	)%		42	%	$	3,030
Year Ended December 31, 2009		0.02		$	22.34		30.19	%(g)		2.32	%		2.20	%(e)		(0.05	)%		56	%	$	3,887
Year Ended December 31, 2008		—		$	17.16		(42.68	)%		2.17	%		2.17	%(e)		0.16	%		68	%	$	4,444
Class C
Year Ended December 31, 2012		—		$	24.28		21.10	%		2.28	%(b)		2.27	%(b)(c)(d)		0.67	%		63	%	$	9,786
Year Ended December 31, 2011		—		$	23.17		(10.81	)%		2.31	%		2.31	%(c)(e)		(0.14	)%		44	%	$	8,704
Year Ended December 31, 2010		0.00	(f)	$	26.58		20.45	%		2.36	%		2.36	%(c)(e)		(0.45	)%		42	%	$	11,885
Year Ended December 31, 2009		0.02		$	22.21		30.04	%		2.42	%		2.42	%(e)		(0.30	)%		56	%	$	11,096
Year Ended December 31, 2008		—		$	17.08		(42.79	)%		2.34	%		2.34	%(e)		0.01	%		68	%	$	9,747
Class I
Year Ended December 31, 2012		—		$	25.85		22.48	%		1.15	%		1.14	%(c)(d)		1.84	%		63	%	$	2
Year Ended December 31, 2011		—		$	24.45		(9.68	)%		1.04	%		1.04	%(c)(e)		1.12	%		44	%	$	2
Year Ended December 31, 2010 (h)		—		$	28.33		8.50	%		1.14	%(i)		1.14	%(c)(e)(i)		0.44	%(i)		42	%	$	3
Class R4
Year Ended December 31, 2012 (j)		—		$	25.99		(0.27	)%		1.30	%(b)(i)		1.30	%(b)(c)(d)(i)		(0.55	)%(i)		63	%	$	13
Class R5
Year Ended December 31, 2012 (l)		—		$	25.98		(0.27	)%		1.29	%(i)		1.28	%(c)(d)(i)		(0.55	)%(i)		63	%	$	2
Class Y
Year Ended December 31, 2012 (m)		—		$	25.98		(0.25	)%		1.21	%(i)		1.20	%(c)(d)(i)		(0.48	)%(i)		63	%	$	2
Class Z
Year Ended December 31, 2012		—		$	25.86		22.42	%		1.20	%(b)		1.19	%(b)(c)(d)		1.77	%		63	%	$	295,231
Year Ended December 31, 2011		—		$	24.46		(9.76	)%		1.14	%		1.14	%(c)(e)		1.03	%		44	%	$	259,553
Year Ended December 31, 2010		0.00	(f)	$	28.33		21.89	%		1.16	%		1.16	%(c)(e)		0.75	%		42	%	$	366,081
Year Ended December 31, 2009		0.02		$	23.64		31.52	%		1.20	%		1.20	%(e)		0.84	%		56	%	$	331,027
Year Ended December 31, 2008		—		$	18.19		(42.10	)%		1.21	%		1.21	%(e)		1.09	%		68	%	$	186,194

See accompanying notes to financial statements.

107

Columbia Acorn Family of Funds

Financial Highlights, continued

Columbia Acorn Select

			Income from Investment Operations												Less Distributions to Shareholders
	Net Asset Value, Beginning of Period		Net investment income (loss)			Net realized and unrealized gain (loss)			Reimbursement from affiliate			Total from investment operations			From net investment income			From net realized gains			Total Distributions to Shareholders
Class A
Year Ended December 31, 2012	$	22.95		0.03			3.78			—			3.81			—			(2.04	)		(2.04	)
Year Ended December 31, 2011	$	27.94		(0.15	)		(4.46	)		—			(4.61	)		(0.38	)		—			(0.38	)
Year Ended December 31, 2010	$	22.81		(0.18	)		5.31			—			5.13			—			—			—
Year Ended December 31, 2009	$	13.77		(0.14	)		9.18			—			9.04			—			—			—
Year Ended December 31, 2008	$	27.89		(0.18	)		(13.25	)		—			(13.43	)		—			(0.69	)		(0.69	)
Class B
Year Ended December 31, 2012	$	21.40		(0.15	)		3.54			—			3.39			—			(2.04	)		(2.04	)
Year Ended December 31, 2011	$	26.06		(0.30	)		(4.13	)		—			(4.43	)		(0.23	)		—			(0.23	)
Year Ended December 31, 2010	$	21.41		(0.31	)		4.96			—			4.65			—			—			—
Year Ended December 31, 2009	$	13.02		(0.24	)		8.63			—			8.39			—			—			—
Year Ended December 31, 2008	$	26.57		(0.31	)		(12.55	)		—			(12.86	)		—			(0.69	)		(0.69	)
Class C
Year Ended December 31, 2012	$	21.20		(0.14	)		3.46			—			3.32			—			(2.04	)		(2.04	)
Year Ended December 31, 2011	$	25.83		(0.32	)		(4.12	)		—			(4.44	)		(0.19	)		—			(0.19	)
Year Ended December 31, 2010	$	21.25		(0.34	)		4.92			—			4.58			—			—			—
Year Ended December 31, 2009	$	12.94		(0.26	)		8.57			—			8.31			—			—			—
Year Ended December 31, 2008	$	26.46		(0.34	)		(12.49	)		—			(12.83	)		—			(0.69	)		(0.69	)
Class I
Year Ended December 31, 2012	$	23.65		0.23			3.79			—			4.02			—			(2.04	)		(2.04	)
Year Ended December 31, 2011	$	28.74		(0.03	)		(4.59	)		—			(4.62	)		(0.47	)		—			(0.47	)
Year Ended December 31, 2010 (f)	$	24.74		0.01			3.99			—			4.00			—			—			—
Class R4
Year Ended December 31, 2012 (h)	$	25.91		0.00	(i)		1.52			—			1.52			—			(1.51	)		(1.51	)
Class R5
Year Ended December 31, 2012 (j)	$	25.91		0.00	(i)		1.53			—			1.53			—			(1.51	)		(1.51	)
Class Y
Year Ended December 31, 2012 (k)	$	25.96		0.01			1.52			—			1.53			—			(1.51	)		(1.51	)
Class Z
Year Ended December 31, 2012	$	23.62		0.11			3.88			—			3.99			—			(2.04	)		(2.04	)
Year Ended December 31, 2011	$	28.73		(0.07	)		(4.58	)		0.00	(i)		(4.65	)		(0.46	)		—			(0.46	)
Year Ended December 31, 2010	$	23.38		(0.10	)		5.45			—			5.35			—			—			—
Year Ended December 31, 2009	$	14.07		(0.08	)		9.39			—			9.31			—			—			—
Year Ended December 31, 2008	$	28.41		(0.12	)		(13.53	)		—			(13.65	)		—			(0.69	)		(0.69	)

(a)  Certain line items from prior years have been reclassified to conform to the current presentation.

(b)  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 underlying funds in which it invests. Such indirect expenses are not included in the reported expense ratios.

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

(d)  Includes interest expense which rounds to less than 0.01%.

(e)  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 0.01% and $0.01, respectively.

(f)  Class I shares commenced operations on September 27, 2010. Per share data and total return reflect activity from that date.

(g)  Annualized.

(h)  Class R4 shares commenced operations on November 8, 2012. Per share data and total return reflect activity from that date.

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

(j)  Class R5 shares commenced operations on November 8, 2012. Per share data and total return reflect activity from that date.

(k)  Class Y shares commenced operations on November 8, 2012. Per share data and total return reflect activity from that date.

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

See accompanying notes to financial statements.

108

						Ratio to Average Net Assets									Supplemental Data
	Net Asset Value, End of Period		Total Return			Total gross expenses (a)			Total net expenses (b)(c)			Net investment income (loss)			Portfolio turnover rate			Net assets, end of period (000s)
Class A
Year Ended December 31, 2012	$	24.72		16.87	%		1.31	%(d)		1.31	%(d)		0.13	%		15	%	$	271,628
Year Ended December 31, 2011	$	22.95		(16.65	)%		1.28	%		1.28	%		(0.57	)%		21	%	$	340,325
Year Ended December 31, 2010	$	27.94		22.49	%		1.28	%		1.28	%		(0.73	)%		28	%	$	555,263
Year Ended December 31, 2009	$	22.81		65.65	%		1.30	%		1.30	%		(0.78	)%		19	%	$	522,443
Year Ended December 31, 2008	$	13.77		(49.31	)%(e)		1.24	%		1.24	%		(0.80	)%		28	%	$	395,794
Class B
Year Ended December 31, 2012	$	22.75		16.11	%		1.91	%(d)		1.90	%(d)		(0.62	)%		15	%	$	9,938
Year Ended December 31, 2011	$	21.40		(17.11	)%		1.88	%		1.88	%		(1.21	)%		21	%	$	26,126
Year Ended December 31, 2010	$	26.06		21.72	%		1.92	%		1.92	%		(1.39	)%		28	%	$	72,203
Year Ended December 31, 2009	$	21.41		64.44	%		2.01	%		2.01	%		(1.49	)%		19	%	$	88,004
Year Ended December 31, 2008	$	13.02		(49.62	)%(e)		1.87	%		1.87	%		(1.43	)%		28	%	$	73,152
Class C
Year Ended December 31, 2012	$	22.48		15.93	%		2.07	%(d)		2.06	%(d)		(0.59	)%		15	%	$	57,309
Year Ended December 31, 2011	$	21.20		(17.27	)%		2.05	%		2.05	%		(1.34	)%		21	%	$	62,887
Year Ended December 31, 2010	$	25.83		21.55	%		2.07	%		2.07	%		(1.52	)%		28	%	$	98,445
Year Ended December 31, 2009	$	21.25		64.22	%		2.14	%		2.14	%		(1.62	)%		19	%	$	93,121
Year Ended December 31, 2008	$	12.94		(49.71	)%(e)		2.04	%		2.04	%		(1.60	)%		28	%	$	70,962
Class I
Year Ended December 31, 2012	$	25.63		17.26	%		0.96	%(d)		0.95	%(d)		0.89	%		15	%	$	39,054
Year Ended December 31, 2011	$	23.65		(16.25	)%		0.92	%		0.92	%		(0.12	)%		21	%	$	10,944
Year Ended December 31, 2010 (f)	$	28.74		16.17	%		0.91	%(g)		0.91	%(g)		0.18	%(g)		28	%	$	7,832
Class R4
Year Ended December 31, 2012 (h)	$	25.92		5.92	%		1.07	%(g)		1.06	%(g)		0.02	%(g)		15	%	$	15
Class R5
Year Ended December 31, 2012 (j)	$	25.93		5.96	%		0.99	%(g)		0.99	%(g)		0.08	%(g)		15	%	$	3
Class Y
Year Ended December 31, 2012 (k)	$	25.98		5.94	%		0.92	%(g)		0.92	%(g)		0.15	%(g)		15	%	$	3
Class Z
Year Ended December 31, 2012	$	25.57		17.15	%		1.03	%(d)		1.03	%(d)		0.40	%		15	%	$	587,678
Year Ended December 31, 2011	$	23.62		(16.37	)%(l)		0.97	%		0.97	%		(0.28	)%		21	%	$	850,338
Year Ended December 31, 2010	$	28.73		22.88	%		0.97	%		0.97	%		(0.41	)%		28	%	$	1,549,112
Year Ended December 31, 2009	$	23.38		66.17	%		0.99	%		0.99	%		(0.47	)%		19	%	$	1,241,277
Year Ended December 31, 2008	$	14.07		(49.18	)%(e)		0.95	%		0.95	%		(0.51	)%		28	%	$	779,892

See accompanying notes to financial statements.

109

Columbia Acorn Family of Funds

Financial Highlights, continued

Columbia Thermostat Fund

			Income from Investment Operations								Less Distributions to Shareholders
	Net Asset Value, Beginning of Period		Net investment income		Net realized and unrealized gain (loss)			Total from investment operations			From net investment income			From net realized gains			Total Distributions to Shareholders
Class A
Year Ended December 31, 2012	$	12.82		0.32		1.39			1.71			(0.24	)		—			(0.24	)
Year Ended December 31, 2011	$	12.58		0.28		0.30			0.58			(0.34	)		—			(0.34	)
Year Ended December 31, 2010	$	10.90		0.19		1.67			1.86			(0.18	)		—			(0.18	)
Year Ended December 31, 2009	$	8.26		0.11		2.53			2.64			(0.00	)(e)		—			(0.00	)(e)
Year Ended December 31, 2008	$	12.31		0.22		(3.98	)		(3.76	)		(0.22	)		(0.07	)		(0.29	)
Class B
Year Ended December 31, 2012	$	12.91		0.20		1.45			1.65			(0.17	)		—			(0.17	)
Year Ended December 31, 2011	$	12.64		0.15		0.38			0.53			(0.26	)		—			(0.26	)
Year Ended December 31, 2010	$	10.93		0.13		1.67			1.80			(0.09	)		—			(0.09	)
Year Ended December 31, 2009	$	8.32		0.06		2.55			2.61			—			—			—
Year Ended December 31, 2008	$	12.38		0.16		(4.00	)		(3.84	)		(0.15	)		(0.07	)		(0.22	)
Class C
Year Ended December 31, 2012	$	12.91		0.22		1.39			1.61			(0.13	)		—			(0.13	)
Year Ended December 31, 2011	$	12.62		0.18		0.31			0.49			(0.20	)		—			(0.20	)
Year Ended December 31, 2010	$	10.91		0.10		1.68			1.78			(0.07	)		—			(0.07	)
Year Ended December 31, 2009	$	8.33		0.03		2.55			2.58			—			—			—
Year Ended December 31, 2008	$	12.37		0.13		(3.97	)		(3.84	)		(0.13	)		(0.07	)		(0.20	)
Class R4
Year Ended December 31, 2012 (f)	$	14.08		0.09		0.28			0.37			(0.26	)		—			(0.26	)
Class R5
Year Ended December 31, 2012 (h)	$	14.08		0.09		0.27			0.36			(0.25	)		—			(0.25	)
Class Y
Year Ended December 31, 2012 (i)	$	14.08		0.09		0.27			0.36			(0.26	)		—			(0.26	)
Class Z
Year Ended December 31, 2012	$	12.67		0.34		1.39			1.73			(0.27	)		—			(0.27	)
Year Ended December 31, 2011	$	12.44		0.31		0.29			0.60			(0.37	)		—			(0.37	)
Year Ended December 31, 2010	$	10.80		0.21		1.66			1.87			(0.23	)		—			(0.23	)
Year Ended December 31, 2009	$	8.19		0.13		2.51			2.64			(0.03	)		—			(0.03	)
Year Ended December 31, 2008	$	12.26		0.24		(3.96	)		(3.72	)		(0.28	)		(0.07	)		(0.35	)

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

(b)  Certain line items from prior years have been reclassified to conform to the current presentation.

(c)  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 underlying funds in which it invests. Such indirect expenses are not included in the reported expense ratios.

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

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

(f)  Class R4 shares commenced operations on November 8, 2012. Per share data and total return reflect activity from that date.

(g)  Annualized.

(h)  Class R5 shares commenced operations on November 8, 2012. Per share data and total return reflect activity from that date.

(i)  Class Y shares commenced operations on November 8, 2012. Per share data and total return reflect activity from that date.

See accompanying notes to financial statements.

110

						Ratio to Average Net Assets									Supplemental Data
	Net Asset Value, End of Period		Total Return (a)			Total gross expenses (b)			Total net expenses (c)(d)			Net investment income			Portfolio turnover rate			Net assets, end of period (000s)
Class A
Year Ended December 31, 2012	$	14.29		13.34	%		0.58	%		0.50	%		2.28	%		109	%	$	323,750
Year Ended December 31, 2011	$	12.82		4.62	%		0.67	%		0.50	%		2.17	%		130	%	$	79,744
Year Ended December 31, 2010	$	12.58		17.28	%		0.72	%		0.50	%		1.64	%		118	%	$	44,527
Year Ended December 31, 2009	$	10.90		31.98	%		0.78	%		0.50	%		1.17	%		17	%	$	42,976
Year Ended December 31, 2008	$	8.26		(30.67	)%		0.68	%		0.50	%		1.99	%		130	%	$	41,032
Class B
Year Ended December 31, 2012	$	14.39		12.78	%		1.16	%		1.00	%		1.47	%		109	%	$	4,480
Year Ended December 31, 2011	$	12.91		4.19	%		1.23	%		1.00	%		1.18	%		130	%	$	11,318
Year Ended December 31, 2010	$	12.64		16.64	%		1.28	%		1.00	%		1.10	%		118	%	$	28,752
Year Ended December 31, 2009	$	10.93		31.37	%		1.32	%		1.00	%		0.64	%		17	%	$	32,758
Year Ended December 31, 2008	$	8.32		(31.10	)%		1.20	%		1.00	%		1.45	%		130	%	$	36,673
Class C
Year Ended December 31, 2012	$	14.39		12.52	%		1.32	%		1.25	%		1.56	%		109	%	$	253,641
Year Ended December 31, 2011	$	12.91		3.87	%		1.43	%		1.25	%		1.40	%		130	%	$	33,378
Year Ended December 31, 2010	$	12.62		16.43	%		1.49	%		1.25	%		0.88	%		118	%	$	21,866
Year Ended December 31, 2009	$	10.91		30.97	%		1.55	%		1.25	%		0.39	%		17	%	$	21,090
Year Ended December 31, 2008	$	8.33		(31.20	)%		1.45	%		1.25	%		1.23	%		130	%	$	24,383
Class R4
Year Ended December 31, 2012 (f)	$	14.19		2.60	%		0.42	%(g)		0.25	%(g)		4.59	%(g)		109	%	$	15
Class R5
Year Ended December 31, 2012 (h)	$	14.19		2.58	%		0.35	%(g)		0.27	%(g)		4.60	%(g)		109	%	$	3
Class Y
Year Ended December 31, 2012 (i)	$	14.18		2.55	%		0.30	%(g)		0.22	%(g)		4.63	%(g)		109	%	$	3
Class Z
Year Ended December 31, 2012	$	14.13		13.69	%		0.30	%		0.25	%		2.48	%		109	%	$	292,732
Year Ended December 31, 2011	$	12.67		4.85	%		0.34	%		0.25	%		2.43	%		130	%	$	65,167
Year Ended December 31, 2010	$	12.44		17.58	%		0.37	%		0.25	%		1.87	%		118	%	$	36,130
Year Ended December 31, 2009	$	10.80		32.29	%		0.39	%		0.25	%		1.48	%		17	%	$	41,765
Year Ended December 31, 2008	$	8.19		(30.53	)%		0.33	%		0.25	%		2.23	%		130	%	$	34,985

See accompanying notes to financial statements.

111

Columbia Acorn Family of Funds

Financial Highlights, continued

Columbia Acorn Emerging Markets Fund

			Income from Investment Operations									Less Distributions to Shareholders
	Net Asset Value, Beginning of Period		Net investment income (loss)			Net realized and unrealized gain (loss)			Total from investment operations			From net investment income			From net realized gains		Total Distributions to Shareholders
Class A
Year Ended December 31, 2012	$	9.26		0.08			2.78			2.86			(0.08	)		—		(0.08	)
Year Ended December 31, 2011 (e)	$	10.00		(0.00	)(f)		(0.74	)		(0.74	)		—			—		—
Class C
Year Ended December 31, 2012	$	9.24		(0.02	)		2.79			2.77			—			—		—
Year Ended December 31, 2011 (i)	$	10.00		(0.02	)		(0.74	)		(0.76	)		—			—		—
Class I
Year Ended December 31, 2012	$	9.29		0.11			2.80			2.91			(0.12	)		—		(0.12	)
Year Ended December 31, 2011 (j)	$	10.00		0.01			(0.72	)		(0.71	)		—			—		—
Class R4
Year Ended December 31, 2012 (k)	$	11.44		(0.01	)		0.81			0.80			(0.10	)		—		(0.10	)
Class R5
Year Ended December 31, 2012 (l)	$	11.44		(0.00	)(f)		0.81			0.81			(0.11	)		—		(0.11	)
Class Z
Year Ended December 31, 2012	$	9.28		0.12			2.79			2.91			(0.12	)		—		(0.12	)
Year Ended December 31, 2011 (m)	$	10.00		0.01			(0.73	)		(0.72	)		—			—		—

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

(b)  Certain line items from prior years have been reclassified to conform to the current presentation.

(c)  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 underlying funds in which it invests. Such indirect expenses are not included in the reported expense ratios.

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

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

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

(g)  Annualized.

(h)  The benefits derived from custody fees paid indirectly had an impact of 0.02%.

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

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

(k)  Class R4 shares commenced operations on November 8, 2012. Per share data and total return reflect activity from that date.

(l)  Class R5 shares commenced operations on November 8, 2012. Per share data and total return reflect activity from that date.

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

Columbia Acorn European Fund

			Income from Investment Operations									Less Distributions to Shareholders
	Net Asset Value, Beginning of Period		Net investment income (loss)			Net realized and unrealized gain (loss)			Total from investment operations			From net investment income			From net realized gains			Total Distributions to Shareholders
Class A
Year Ended December 31, 2012	$	9.43		0.03			2.37			2.40			(0.07	)		(0.00	)(c)		(0.07	)
Year Ended December 31, 2011 (f)	$	10.00		(0.03	)		(0.46	)		(0.49	)		(0.06	)		(0.02	)		(0.08	)
Class C
Year Ended December 31, 2012	$	9.44		(0.15	)		2.46			2.31			(0.02	)		(0.00	)(c)		(0.02	)
Year Ended December 31, 2011 (i)	$	10.00		(0.06	)		(0.45	)		(0.51	)		(0.03	)		(0.02	)		(0.05	)
Class I
Year Ended December 31, 2012	$	9.43		0.10			2.32			2.42			(0.10	)		(0.00	)(c)		(0.10	)
Year Ended December 31, 2011 (j)	$	10.00		(0.02	)		(0.46	)		(0.48	)		(0.07	)		(0.02	)		(0.09	)
Class R5
Year Ended December 31, 2012 (k)	$	11.19		(0.02	)		0.77			0.75			(0.08	)		—			(0.08	)
Class Z
Year Ended December 31, 2012	$	9.44		0.08			2.34			2.42			(0.10	)		(0.00	)(c)		(0.10	)
Year Ended December 31, 2011 (l)	$	10.00		(0.02	)		(0.46	)		(0.48	)		(0.06	)		(0.02	)		(0.08	)

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

(b)  Certain line items from prior years have been reclassified to conform to the current presentation.

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

(d)  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 underlying funds in which it invests. Such indirect expenses are not included in the reported expense ratios.

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

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

(g)  Annualized.

(h)  The benefits derived from custody fees paid indirectly had an impact of 0.02%.

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

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

(k)  Class R5 shares commenced operations on November 8, 2012. Per share data and total return reflect activity from that date.

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

See accompanying notes to financial statements.

112

						Ratio to Average Net Assets									Supplemental Data
	Net Asset Value, End of Period		Total Return(a)			Total gross expenses (b)			Total net expenses			Net investment income (loss)			Portfolio turnover rate			Net assets, end of period (000s)
Class A
Year Ended December 31, 2012	$	12.04		30.86	%		6.42	%		1.77	%(c)(d)		0.77	%		30	%	$	3,103
Year Ended December 31, 2011 (e)	$	9.26		(7.40	)%		20.13	%(g)		1.85	%(g)(h)		(0.01	)%(g)		9	%	$	332
Class C
Year Ended December 31, 2012	$	12.01		29.98	%		7.18	%		2.56	%(c)(d)		(0.15	)%		30	%	$	615
Year Ended December 31, 2011 (i)	$	9.24		(7.60	)%		25.06	%(g)		2.60	%(g)(h)		(0.68	)%(g)		9	%	$	127
Class I
Year Ended December 31, 2012	$	12.08		31.39	%		6.18	%		1.41	%(c)(d)		1.05	%		30	%	$	6
Year Ended December 31, 2011 (j)	$	9.29		(7.10	)%		19.31	%(g)		1.41	%(g)(h)		0.17	%(g)		9	%	$	5
Class R4
Year Ended December 31, 2012 (k)	$	12.14		7.04			5.86	%(g)		1.54	%(c)(d)(g)		(0.31	)%(g)		30	%	$	16
Class R5
Year Ended December 31, 2012 (l)	$	12.14		7.11	%		5.81	%(g)		1.46	%(c)(d)(g)		(0.22	)%(g)		30	%	$	3
Class Z
Year Ended December 31, 2012	$	12.07		31.35	%		6.15	%		1.46	%(c)(d)		1.07	%		30	%	$	6,846
Year Ended December 31, 2011 (m)	$	9.28		(7.20	)%		19.52	%(g)		1.46	%(g)(h)		0.15	%(g)		9	%	$	2,765

						Ratio to Average Net Assets									Supplemental Data
	Net Asset Value, End of Period		Total Return(a)			Total gross expenses (b)			Total net expenses			Net investment income (loss)			Portfolio turnover rate			Net assets, end of period (000s)
Class A
Year Ended December 31, 2012	$	11.76		25.46	%		12.35	%		1.61	%(d)(e)		0.23	%		37	%	$	453
Year Ended December 31, 2011 (f)	$	9.43		(4.97	)%		33.59	%(g)		1.75	%(g)(h)		(0.84	)%(g)		17	%	$	154
Class C
Year Ended December 31, 2012	$	11.73		24.46	%		12.83	%		2.32	%(d)(e)		(1.33	)%		37	%	$	89
Year Ended December 31, 2011 (i)	$	9.44		(5.14	)%		35.79	%(g)		2.50	%(g)(h)		(1.66	)%(g)		17	%	$	5
Class I
Year Ended December 31, 2012	$	11.75		25.71	%		12.05	%		1.31	%(d)(e)		0.94	%		37	%	$	6
Year Ended December 31, 2011 (j)	$	9.43		(4.81	)%		30.00	%(g)		1.31	%(g)(h)		(0.47	)%(g)		17	%	$	5
Class R5
Year Ended December 31, 2012 (k)	$	11.86		6.70	%		14.07	%(g)		1.36	%(d)(e)(g)		(1.07	)%(g)		37	%	$	3
Class Z
Year Ended December 31, 2012	$	11.76		25.66	%		12.07	%		1.33	%(d)(e)		0.76	%		37	%	$	2,727
Year Ended December 31, 2011 (l)	$	9.44		(4.78	)%		30.26	%(g)		1.37	%(g)(h)		(0.52	)%(g)		17	%	$	1,516

See accompanying notes to financial statements.

113

Columbia Acorn Family of Funds

Notes to Financial Statements

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 offer Class A, Class B, Class C, Class I, Class R4, Class R5, Class Y and Class Z shares. Columbia Acorn International currently offers Class A, Class B, Class C, Class I, Class R, Class R4, Class R5, Class Y and Class Z shares. Columbia Thermostat Fund currently offers Class A, Class B, Class C, Class R4, Class R5, Class Y and Class Z shares. Columbia Acorn Emerging Markets Fund currently offers Class A, Class C, Class I, Class R4, Class R5 and Class Z shares. Columbia Acorn European Fund currently offers Class A, Class C, Class I, Class R5 and Class Z shares. Effective February 29, 2008, the Funds generally no longer accept investments by new or existing investors in the Funds' 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, Class R4, Class R5 and Class Y shares are offered at net asset value. There are certain restrictions on who may purchase these share classes. Class R4 and Class Y shares commenced operations on November 8, 2012. Class R5 shares commenced operations on November 8, 2012 for all Funds with the exception of Columbia Acorn International.

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 Investment Distributors, Inc. (CMID) at no additional charge.

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 (the Board). 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

114

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

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. 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.

>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.

>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. 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 Funds' securities.

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 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

115

Columbia Acorn Family of Funds

Notes to Financial Statements, continued

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.

The effect of derivative instruments in Columbia Acorn International's Statements of Operations for the year ended December 31, 2012:

Amount of Realized Gain (Loss) on
Derivatives Recognized in Income

Risk Exposure Category	Forward Foreign Currency Exchange Contracts
Foreign currency exchange rate	$	5,422,582

Change in Unrealized Appreciation (Depreciation)
on Derivatives Recognized in Income

Risk Exposure Category	Forward Foreign Currency Exchange Contracts
Foreign currency exchange rate	$	(4,539,004	)

The following table is a summary of the volume of Columbia Acorn International's derivative instruments for the year ended December 31, 2012:

Derivative Instrument	Contracts Opened
Forward foreign currency exchange contracts		3

The following table is a summary of the fair value of Columbia Acorn International Select's derivative instruments at December 31, 2012:

	Liability Derivatives
Risk Exposure Category	Statements of Assets and Liabilities Location	Fair Value
Foreign currency exchange rate	Unrealized depreciation on forward foreign currency exchange contracts	$	(411,753	)

The effect of derivative instruments in Columbia Acorn International Select's Statements of Operations for the year ended December 31, 2012:

Amount of Realized Gain (Loss)
on Derivatives Recognized in Income

Risk Exposure Category	Forward Foreign Currency Exchange Contracts
Foreign currency exchange rate	$	(324,460	)

Change in Unrealized Appreciation (Depreciation)
on Derivatives Recognized in Income

Risk Exposure Category	Forward Foreign Currency Exchange Contracts
Foreign currency exchange rate	$	536,271

The following table is a summary of the volume of Columbia Acorn International Select's derivative instruments for the year ended December 31, 2012:

Derivative Instrument	Contracts Opened
Forward foreign currency exchange contracts		24

>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.

116

>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 December 31, 2012 by each Fund is included in the Statements of Operations.

>Custody fees/credits

Custody fees are reduced based on each Fund's cash balances maintained with the custodian. The amount is disclosed as a reduction of total expenses 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 Accounting Standards Update (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.

117

Columbia Acorn Family of Funds

Notes to Financial Statements, continued

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.

For the year ended December 31, 2012, permanent book and tax basis differences resulting primarily from capital loss carryforwards, distribution reclassifications, foreign capital gains tax, foreign currency transactions, non-deductible expenses, passive foreign investment company (PFIC) holdings, re-characterization of distributions from investments and earnings and profits distributed to shareholders on the redemption

of shares were identified and reclassified among the components of each Fund's net assets as follows:

	Undistributed/ (Overdistributed) Net Investment Income (Loss)			Accumulated Net Realized Gain (Loss)			Paid-In Capital
Columbia Acorn Fund	$	(7,019,490	)	$	(70,954,396	)	$	77,973,886
Columbia Acorn International		24,241,842			(25,220,387	)		978,545
Columbia Acorn USA		356,211			(356,209	)		(2	)
Columbia Acorn International Select		1,502,636			(1,502,641	)		5
Columbia Acorn Select		(9,263	)		9,263			—
Columbia Thermostat Fund		2,331,300			(2,331,298	)		(2	)
Columbia Acorn Emerging Markets Fund		531			620			(1,151	)
Columbia Acorn European Fund		(1,044	)		1,112			(68	)

Net investment income and net realized gains (losses), as disclosed on the Statements of Operations, and net assets were not affected by these reclassifications.

The tax character of distributions paid during the years ended December 31, 2012 and 2011 were as follows:

	December 31, 2012				December 31, 2011
Fund	Ordinary Income*		Long-Term Capital Gains		Ordinary Income*		Long-Term Capital Gains
Columbia Acorn Fund	$	70,510,183	$	1,028,830,224	$	38,838,016	$	707,352,658
Columbia Acorn International		128,781,789		—		157,071,816		—
Columbia Acorn USA		8,908,286		120,940,637		—		9,830,778
Columbia Acorn International Select		24,643,601		30,592,124		10,288,242		5,503,810
Columbia Acorn Select		—		83,831,961		31,147,585		42,324
Columbia Thermostat Fund		12,531,935		—		3,923,425		—
Columbia Acorn Emerging Markets Fund		76,230		—		—		—
Columbia Acorn European Fund		22,685		360		14,455		—

* For tax purposes short-term capital gain distributions, if any, are considered ordinary income distributions.

As of December 31, 2012, the components of distributable earnings on a tax basis were as follows:

Fund	Undistributed Ordinary Income		Undistributed Accumulated Long-Term Capital Gains		Accumulated Realized Loss			Unrealized Appreciation (Depreciation)
Columbia Acorn Fund	$	21,250,410	$	224,200,890	$	(8,243,176	)	$	6,559,008,085
Columbia Acorn International		80,046,295		—		(177,969,429	)		1,434,490,688
Columbia Acorn USA		—		2,115,795		—			547,588,096
Columbia Acorn International Select		—		7,048,066		—			38,754,005
Columbia Acorn Select		3,241,093		41,833,911		—			262,522,635
Columbia Thermostat Fund		670,600		—		(8,938,163	)		39,277,722
Columbia Acorn Emerging Markets Fund		—		—		(106,036	)		1,429,512
Columbia Acorn European Fund		—		—		(1,940	)		384,667

* The differences between book-basis and tax-basis net unrealized appreciation (depreciation) are primarily due to deferral of losses from wash sales, PFIC adjustments and non-taxable distributions.

The following capital loss carryforward, determined as of December 31, 2012, 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
	2015		2016		2017		2018		Unlimited Short-Term		Total
Columbia Acorn International	$	11,884,052	$	62,714,662	$	102,948,489	$	—	$	—	$	177,547,203
Columbia Thermostat Fund		—		—		5,983,674		2,954,489		—		8,938,163
Columbia Acorn Emerging Markets Fund		—		—		—		—		86,920		86,920

118

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.

The value of capital loss carryforwards that were utilized and expired for the Funds during the year ended December 31, 2012, were as follows:

	Utilized		Expired
Columbia Acorn International	$	110,637,154	$	—
Columbia Thermostat Fund		11,749,824		—

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. As of December 31, 2012, the Funds will elect to treat the following late-year ordinary losses and post-October capital losses as arising on January 1, 2013:

Fund	Late-Year Ordinary Losses		Post-October Capital Losses
Columbia Acorn Fund	$	—	$	8,243,176
Columbia Acorn International		—		422,226
Columbia Acorn International Select		3,455,583		—
Columbia Acorn Emerging Markets Fund		—		19,116
Columbia Acorn European Fund		—		1,940

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	%

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	%

119

Columbia Acorn Family of Funds

Notes to Financial Statements, continued

For the year ended December 31, 2012, the effective investment advisory fee rates were as follows:

Fund
Columbia Acorn Fund	0.64	%
Columbia Acorn International	0.76	%
Columbia Acorn USA	0.86	%

Fund
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) exceeding annually each class' average daily net assets as follows:

Fund	Class A			Class B			Class C			Class I			Class R4			Class R5			Class Y			Class Z
Columbia Acorn International Select		1.70	%		2.20	%		2.45	%		1.28	%		1.45	%		1.33	%		1.28	%		1.45	%
Columbia Acorn Select		1.60	%		2.10	%		2.35	%		1.25	%		1.35	%		1.30	%		1.25	%		1.35	%

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

Effective May 1, 2012, for Class A, Class B, Class C and Class Z shares, and effective November 8, 2012 for Class R4, Class R5 and Class Y shares, CWAM has contractually agreed to waive fees and/or reimburse expenses of Columbia Thermostat Fund for one year, so that the ordinary operating expenses (exclusive of brokerage commissions, interest, taxes and extraordinary expenses, but inclusive of custodial charges relating to overdrafts, if any) do not exceed annually each class' average daily net assets as follows:

Fund	Class A			Class B			Class C			Class R4			Class R5			Class Y			Class Z
Columbia Thermostat Fund		0.50	%		1.00	%		1.25	%		0.25	%		0.27	%		0.22	%		0.25	%

There is no guarantee that this agreement will continue thereafter.

Effective May 1, 2012, for Class A, Class B, Class C and Class Z shares, and effective November 8, 2012 for Class R4 and Class R5 shares, CWAM has contractually agreed to waive fees and/or reimburse expenses of Columbia Acorn Emerging Markets Fund and Columbia Acorn European Fund for one year, 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 inclusive of custodial charges relating to overdrafts, if any), do not exceed annually each class' average daily net assets as follows:

Fund	Class A			Class C			Class I			Class R4			Class R5			Class Z
Columbia Acorn Emerging Markets Fund		1.85	%		2.60	%		1.41	%		1.60	%		1.46	%		1.60	%
Columbia Acorn European Fund		1.75	%		2.50	%		1.31	%		—	%		1.36	%		1.50	%

There is no guarantee that this agreement will continue thereafter.

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 agreement will continue thereafter.

Expenses reimbursed by CWAM and its affiliates for the year ended December 31, 2012, were as follows:

Fund	Expenses Reimbursed
Columbia Acorn International	$	414,204
Columbia Thermostat Fund		321,910
Columbia Acorn Emerging Markets Fund		292,249
Columbia Acorn European Fund		242,324

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	%

120

For the year ended December 31, 2012, the 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.

CMID, a wholly owned subsidiary of Ameriprise Financial, is the distributor of the Funds.

For the year ended December 31, 2012, the Funds have been advised that CMID retained underwriting discounts in connection with redemptions of Class A shares and received CDSCs in connection with Class A, Class B and Class C share redemptions as follows:

	Underwriting Discounts		CDSCs
(Unaudited)	Class A		Class A		Class B		Class C
Columbia Acorn Fund	$	1,601,152	$	4,108	$	11,666	$	37,327
Columbia Acorn International		345,764		917		19,023		6,027
Columbia Acorn USA		50,004		—		544		1,839
Columbia Acorn International Select		80,731		145		2,427		415
Columbia Acorn Select		80,837		270		3,544		1,224
Columbia Thermostat Fund		5,056,120		168		2,401		36,807
Columbia Acorn Emerging Markets Fund		12,085		—		—		—
Columbia Acorn European Fund		1,374		—		—		—

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 R4, Class R5, Class Y 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. Each Fund pays CMIS a monthly fee at the annual rate of $18.50 per open account. Prior to May 1, 2012, the annual rate was $17.00 per open account. 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 maintain an omnibus account with a Fund. Such fees are based on the number of sub-accounts comprising the omnibus position.

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. Total transfer agent fees for Class R5 shares are subject to an annual limitation of not more than 0.05% of the average daily net assets attributable to Class R5 shares. Effective November 8, 2012, Class Y shares will not pay transfer agent fees for at least twelve months.

For the year ended December 31, 2012, the Funds' 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 R4			Class R5			Class Z
Columbia Acorn Fund		0.09	%		0.18	%		0.08	%		—	%		0.13	%		0.05	%		0.06	%
Columbia Acorn International		0.16	%		0.38	%		0.14	%		0.15	%		0.13	%		0.02	%		0.05	%
Columbia Acorn USA		0.10	%		0.28	%		0.08	%		—	%		0.13	%		0.05	%		0.11	%
Columbia Acorn International Select		0.12	%		0.24	%		0.15	%		—	%		0.14	%		0.05	%		0.07	%
Columbia Acorn Select		0.11	%		0.20	%		0.11	%		—	%		0.13	%		0.05	%		0.08	%
Columbia Thermostat Fund		0.08	%		0.17	%		0.08	%		—	%		0.13	%		0.05	%		0.06	%
Columbia Acorn Emerging Markets Fund		0.11	%		—	%		0.15	%		—	%		0.13	%		0.05	%		0.05	%
Columbia Acorn European Fund		0.05	%		—	%		0.01	%		—	%		—	%		0.05	%		0.02	%

121

Columbia Acorn Family of Funds

Notes to Financial Statements, continued

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., 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 December 31, 2012, Columbia Acorn International's total potential future obligation over the life of the Guaranty is $121,876. The liability remaining at December 31, 2012 for non-recurring charges associated with the lease amounted to $70,651 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 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 during the year. On December 31, 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, 40, 51, 60, 72 and 75, respectively.

For the year ended December 31, 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
Columbia Acorn Fund	$	800,000	$	—
Columbia Acorn International		3,678,950		—
Columbia Acorn International Select		711,990		—
Columbia Acorn Select		—		1,445,547
Columbia Acorn Emerging Markets Fund		23,583		—

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

Effective July 23, 2012, the Trust participates in a $150 million credit facility with JPMorgan Chase Bank, N.A., along with another Trust managed by CWAM, which was entered into to facilitate portfolio liquidity. Under the facility, interest is charged to each participating fund based on its borrowings at a rate per annum equal to the Federal Funds Rate plus 1.00%. In addition, a commitment fee of 0.08% 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 disclosed as a part of "Other expenses" in the Statements of Operations. The Trust expects to renew this line of credit for

122

one year durations annually in July at then current market rates and terms.

Prior to July 23, 2012, interest was charged at a rate per annum equal to the higher of Federal Funds Rate or Overnight LIBOR plus 1.25%. In addition, the commitment fee was 0.10% per annum of the unutilized line of credit.

Other than as noted below, no Fund had borrowings during the year ended December 31, 2012:

Fund Name	Average Daily Loan Balance Outstanding		Weighted Average Interest Rate
Columbia Acorn USA	$	7,633,333		1.18	%
Columbia Acorn International Select		1,900,000		1.18	%
Columbia Acorn Select		8,500,000		1.49	%

Effective January 11, 2013, the committed line of credit was increased from $150 million to $200 million, under the same terms as disclosed above.

6.  Investment Transactions

The aggregate cost of purchases and proceeds from sales, other than short-term obligations, for the year ended December 31, 2012, were:

	Purchases		Proceeds from Sales
Columbia Acorn Fund	$	2,773,626,402	$	4,265,384,295
Columbia Acorn International		2,155,653,985		1,948,721,278
Columbia Acorn USA		222,195,446		456,536,683
Columbia Acorn International Select		214,235,730		224,470,428
Columbia Acorn Select		169,709,495		722,275,331
Columbia Thermostat Fund		1,167,795,401		517,912,342
Columbia Acorn Emerging Markets Fund		7,743,428		1,827,700
Columbia Acorn European Fund		1,763,030		803,138

7.  Regulatory Settlements with Third Parties

During the years ended December 31, 2012 and 2011, Columbia Acorn International received payments of $107,802 and $107,617, respectively, 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 Statements 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

123

Columbia Acorn Family of Funds

Notes to Financial Statements, continued

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 December 31, 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 these unaffiliated shares were 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		10.9	%		—	%
Columbia Acorn International		3		37.4	%		—	%
Columbia Acorn USA		3		45.6	%		—	%
Columbia Acorn International Select		1		36.6	%		—	%
Columbia Acorn Select		2		27.0	%		—	%
Columbia Thermostat Fund		4		61.2	%		—	%
Columbia Acorn Emerging Markets Fund		1		22.4	%		—	%
Columbia Acorn European Fund		2		32.8	%		31.4	%

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 other than the change in borrowing arrangements (See Note 5) and the following redemption. Between January 14, 2013 and January 15, 2013, a large investor redeemed a total of $185 million from Columbia Acorn USA.

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.

124

Report of Independent Registered Public Accounting Firm

To the Board of Trustees and Shareholders of
Columbia Acorn Trust:

In our opinion, the accompanying statement of assets and liabilities, including the statement of investments, and the related statements of operations and of changes in net assets and the financial highlights present fairly, in all material respects, the financial position of 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 (each a series of the Columbia Acorn Trust, hereinafter referred to as the "Funds") at December 31, 2012, the results of their operations, and the changes in their net assets and the financial highlights for the periods presented, in conformity with accounting principles generally accepted in the United States of America. These financial statements and financial highlights (hereafter referred to as "financial statements") are the responsibility of the

Funds' management; our responsibility is to express an opinion on these financial statements based on our audits. We conducted our audits of these financial statements in accordance with the standards of the Public Company Accounting Oversight Board (United States). Those standards require that we plan and perform the audit to obtain reasonable assurance about whether the financial statements are free of material misstatement. An audit includes examining, on a test basis, evidence supporting the amounts and disclosures in the financial statements, assessing the accounting principles used and significant estimates made by management, and evaluating the overall financial statement presentation. We believe that our audits, which included confirmation of securities at December 31, 2012 by correspondence with the custodian and brokers, provide a reasonable basis for our opinion.

PricewaterhouseCoopers LLP
Chicago, Illinois
February 22, 2013

125

Columbia Acorn Family of Funds

Federal Income Tax Information (Unaudited)

The Funds hereby designate the following tax attributes for the fiscal year ended December 31, 2012. Shareholders will be notified in early 2013 of the amounts for use in preparing 2012 income tax returns.

	Qualified Dividend Income			Dividends Received Deduction			Capital Gain Dividend		Foreign Taxes Paid		Foreign Source Income
Columbia Acorn Fund		100.00	%		100.00	%	$	1,174,543,462	$	—	$	—
Columbia Acorn International		85.98	%		—	%		—		13,137,869		159,180,957
Columbia Acorn USA		100.00	%		100.00	%		126,339,955		—		—
Columbia Acorn International Select		18.07	%		—	%		37,965,361		834,503		11,887,752
Columbia Acorn Select		—	%		—	%		106,967,491		—		—
Columbia Thermostat Fund		34.63	%		22.96	%		—		155,528		1,452,097
Columbia Acorn Emerging Markets Fund		69.87	%		—	%		—		15,164		172,638
Columbia Acorn European Fund		100.00	%		—	%		378		4,833		50,952

Qualified Dividend Income. For taxable, non-corporate shareholders, the percentage of ordinary income dividends paid during the fiscal year that represents qualified dividend income subject to reduced tax rates under the Jobs and Growth Tax Relief Reconciliation Act of 2003.

Dividends Received Deduction. The percentage of ordinary income dividends paid during the fiscal year that qualifies for the corporate dividends received deduction.

Capital Gain Dividend. The Fund designates as a capital gain dividend the amount reflected above, or if subsequently determined to be different, the net capital gain of such fiscal period. The Fund also designates as capital gain dividends, to the extent necessary to fully distribute such capital gains, earnings and profits distributed to shareholders on the redemption of shares.

Foreign Taxes Paid. The Fund makes the election to pass through to shareholders the foreign taxes paid. These taxes, and the corresponding foreign source income, are provided.

126

Board of Trustees and Management of
Columbia Acorn Family of Funds

Each trustee may serve a term of unlimited duration. The Trust's By-laws generally require that a trustee retire at the end of the calendar year in which the trustee attains the age of 75 years. The trustees appoint their own successors, provided that at least two-thirds of the trustees, after such appointment, have been elected by shareholders. Shareholders may remove a trustee, with or without cause, upon the vote of two-thirds of the Trust's outstanding shares at any meeting called for that purpose. A trustee may be removed, with or without cause, upon the vote of a majority of the trustees. The names of the trustees and officers of the Trust, the date each was first elected or appointed to office, their principal business occupations during at least the last five years, the number of portfolios in the fund complex they oversee, and other directorships they hold, are shown below. Each trustee serves in such capacity for each of the eight series of Columbia Acorn Trust and for each of the four series of Wanger Advisors Trust.

The address for the trustees and officers of the Trust is Columbia Wanger Asset Management, LLC, 227 West Monroe Street, Suite 3000, Chicago, Illinois 60606. The Funds' Statement of Additional Information includes additional information about the Funds' trustees and officers. You may obtain a free copy of the Statement of Additional Information by writing or calling toll-free:

Columbia Wanger Asset Management, LLC
Shareholder Services Group
227 W. Monroe, Suite 3000
Chicago IL 60606
1-800-922-6769

Name, Position(s) with Columbia Acorn Trust and Age at December 31, 2012	Year First Elected or Appointed to Office*		Principal Occupation(s) during Past Five Years	Number of Portfolios in Fund Complex Overseen by Trustee/Officer		Other Directorships in addition to Columbia Acorn Trust
Trustees who are not interested persons of Columbia Acorn Trust:
Laura M. Born, 47, Trustee and Chair		2007	Adjunct Assistant Professor of Finance, University of Chicago Booth School of Business; Managing Director – Investment Banking, JP Morgan Chase & Co. (broker/dealer) 2002-2007; prior thereto, associated with JP Morgan as an investment professional since 1991.		12	Wanger Advisors Trust
Michelle L. Collins, 52, Trustee		2008	President, Cambium LLC (financial and business advisory firm) since 2007; Advisory Board Member, Svoboda Capital Partners LLC (private equity firm) since 2007; Managing Director, Svoboda Capital Partners LLC, 1998-2006.		12	Wanger Advisors Trust; Integrys Energy Group, Inc. (public utility); Molex, Inc. (electronics components manufacturer); CDW Corporation (electronics components manufacturer) until October 2007.
Maureen M. Culhane, 64, Trustee		2007	Retired. Formerly, Vice President, Goldman Sachs Asset Management, L.P. (investment adviser), 2005-2007, and Vice President (Consultant) – Strategic Relationship Management, Goldman Sachs & Co., 1999-2005.		12	Wanger Advisors Trust
Margaret M. Eisen, 59, Trustee		2002	Chief Investment Officer, EAM International LLC (corporate finance and asset management) since 2003; Managing Director, CFA Institute, 2005-2008.		12	Wanger Advisors Trust; Antigenics, Inc. (provider of technology products and services) until June 2009.
John C. Heaton, 53, Trustee		2010	Joseph L. Gidwitz Professor of Finance, University of Chicago Booth School of Business since July 2006; James H. Lorie Professor of Finance, University of Chicago Booth School of Business July 2000 – July 2006; financial consultant since 2004.		12	Wanger Advisors Trust
Steven N. Kaplan, 53, Trustee and Vice Chair		1999	Neubauer Family Distinguished Service Professor of Entrepreneurship and Finance, University of Chicago Booth School of Business; faculty member of the University of Chicago Booth School of Business since 1988.		12	Wanger Advisors Trust; Accretive Health, Inc. (healthcare management services provider); Morningstar, Inc. (provider of independent investment research).
David J. Rudis, 59, Trustee		2010	National Checking and Debit Executive, and Illinois President, Bank of America, 2007-2009; President, Consumer Banking Group, LaSalle National Bank, 2004-2007.		12	Wanger Advisors Trust
David B. Small, 56, Trustee		2010	Managing Director, Grosvenor Capital Management, L.P. (investment adviser) since 1994; Adjunct Associate Professor of Finance, University of Chicago Booth School of Business.		12	Wanger Advisors Trust
Trustees who are interested persons of Columbia Acorn Trust:
Charles P. McQuaid, 59, Trustee and President(1)		1992	President and Chief Investment Officer, CWAM or its predecessors, since October 2003; associated with CWAM or its predecessors as an investment professional since 1978.		12	Wanger Advisors Trust

127

Name, Position(s) with Columbia Acorn Trust and Age at December 31, 2012	Year First Elected or Appointed to Office*		Principal Occupation(s) during Past Five Years	Number of Portfolios in Fund Complex Overseen by Trustee/Officer		Other Directorships in addition to Columbia Acorn Trust
Trustee Emeritus
Ralph Wanger, 78, Trustee Emeritus(2)		1970	Founder, CWAM. Formerly, President, Chief Investment Officer and portfolio manager, CWAM or its predecessors, July 1992 – September 2003; Director, Wanger Investment Company PLC; Consultant to CWAM or its predecessors, September 2003 – September 2005.		12	Wanger Advisors Trust
Officers of Columbia Acorn Trust:
Ben Andrews, 46, Vice President		2004	Portfolio manager and/or analyst, CWAM or its predecessors, since 1998; Vice President, Columbia Acorn Trust and Wanger Advisors Trust since 2004.		12	None
Robert A. Chalupnik, 46,Vice President		2011	Portfolio manager and/or analyst, CWAM or its predecessors since 1998; Vice President Columbia Acorn Trust and Wanger Advisors Trust since May 2011.		12	None
Michael G. Clarke, 43, Assistant Treasurer		2004	Vice President, Columbia Management Investment Advisers, LLC since May 2010; Managing Director of Fund Administration, Columbia Management Advisors, LLC, 2004 – 2010; senior officer of Columbia Funds and affiliated funds since 2002.		12	None
Joseph F. DiMaria, 43, Assistant Treasurer		2010	Vice President, Mutual Fund Administration, Columbia Management Investment Advisers, LLC, since May 2010; Director of Fund Administration, Columbia Management Advisors, LLC, 2006 – 2010.		12	None
P. Zachary Egan, 43, Vice President		2003	Director of International Research, CWAM or its predecessors since December 2004; Vice President, Columbia Acorn Trust since 2003 and Wanger Advisors Trust since 2007; portfolio manager and/or analyst, CWAM or its predecessors since 1999.		12	None
Fritz Kaegi, 41,Vice President		2011	Portfolio manager and/or analyst, CWAM or its predecessors since 2004; Vice President Columbia Acorn Trust and Wanger Advisors Trust since September 2011.		12	None
John Kunka, 42, Assistant Treasurer		2006	Director of Accounting and Operations, CWAM since 2006.		12	None
Stephen Kusmierczak, 45, Vice President		2011	Portfolio manager and/or analyst, CWAM or its predecessors since 2001; Vice President Columbia Acorn Trust and Wanger Advisors Trust since September 2011.		12	None
Joseph C. LaPalm, 43, Vice President		2006	Chief Compliance Officer, CWAM since 2005.		12	None
Bruce H. Lauer, 55, Vice President, Secretary and Treasurer		1995	Chief Operating Officer, CWAM or its predecessors since April 2000; Vice President, Secretary and Treasurer, Columbia Acorn Trust and Wanger Advisors Trust since 1995; formerly, Director, Wanger Investment Company PLC; formerly, Director, Banc of America Capital Management (Ireland) Ltd.; and formerly, Director, Bank of America Global Liquidity Funds, PLC.		12	None
Louis J. Mendes III, 48, Vice President		2003	Portfolio manager and/or analyst, CWAM or its predecessors since 2001; Vice President, Columbia Acorn Trust since 2003 and Wanger Advisors Trust since 2005.		12	None

128

Name, Position(s) with Columbia Acorn Trust and Age at December 31, 2012	Year First Elected or Appointed to Office*		Principal Occupation(s) during Past Five Years	Number of Portfolios in Fund Complex Overseen by Trustee/Officer		Other Directorships in addition to Columbia Acorn Trust
Officers of Columbia Acorn Trust: (continued)
Robert A. Mohn, 51, Vice President		1997	Director of Domestic Research, CWAM or its predecessors since March 2004; Vice President, Columbia Acorn Trust and Wanger Advisors Trust since 1997; portfolio manager and/or analyst, CWAM or its predecessors since August 1992.		12	None
Christopher J. Olson, 48, Vice President		2001	Portfolio manager and/or analyst, CWAM or its predecessors since January 2001; Vice President, Columbia Acorn Trust and Wanger Advisors Trust, since 2001.		12	None
Christopher O. Petersen, 43, Assistant Secretary		2010	Vice President and Chief Counsel, Ameriprise Financial since January 2010 (formerly, Vice President and Group Counsel or Counsel, 2004 – 2010); Officer, Columbia Funds and affiliated funds since 2007.		12	None
Scott R. Plummer, 53, Assistant Secretary		2010	Senior Vice President, Chief Legal Officer and Assistant Secretary, Columbia Management Investment Advisers, LLC (or its predecessors) since June 2005; Senior Vice President and Lead Chief Counsel – Asset Management, Ameriprise Financial since February 2012 (previously, Vice President and Lead Chief Counsel – Asset Management, 2010 – 2012, and Vice President and Chief Counsel – Asset Management, 2005 – 2010); Vice President, Chief Counsel and Assistant Secretary, Columbia Management Investment Distributors, Inc. (or its predecessors) since 2008; Vice President, General Counsel and Secretary, Ameriprise Certificate Company since 2005; Chief Counsel, RiverSource Distributors, Inc., 2006 – 2010; Senior Officer, Columbia Funds and affiliated funds since 2006.		12	None
Robert P. Scales, 60, Chief Compliance Officer, Chief Legal Officer, Senior Vice President and General Counsel		2004	Chief Compliance Officer, Chief Legal Officer, Senior Vice President and General Counsel, Columbia Acorn Trust and Wanger Advisors Trust, since 2004.		12	None
Andreas Waldburg-Wolfegg, 46, Vice President		2011	Portfolio Manager and/or analyst of CWAM since 2002; Vice President Columbia Acorn Trust and Wanger Advisors Trust since September 2011		12	None
Linda Roth-Wiszowaty, 43, Assistant Secretary		2006	Business support analyst, CWAM, since April 2007; prior thereto executive administrator, CWAM or its predecessors, and executive assistant to the Chief Operating Officer of CWAM or its predecessors.		12	None

*  Dates prior to April 1992 correspond to the date of first election or appointment as a trustee or officer of The Acorn Fund, Inc., the predecessor to Columbia Acorn Trust.

(1)  Mr. McQuaid is an "interested person" of Columbia Acorn Trust and of CWAM, as defined in the Investment Company Act of 1940, because he is an officer of the Trust and of CWAM.

(2)  As permitted under the Columbia Acorn Trust's By-Laws, Mr. Wanger serves as a non-voting Trustee Emeritus of the Trust.

129

Columbia Acorn Family of Funds Expense Information (Unaudited)

Columbia Acorn Fund	Class A			Class B*			Class C			Class I			Class R			Class R4†			Class R5†			Class Y†			Class Z
Management Fees		0.64	%		0.64	%		0.64	%		0.64	%					0.64	%		0.64	%		0.64	%		0.64	%
Distribution and Service (12b-1) Fees		0.25	%		0.75	%		1.00	%		0.00	%					0.00	%		0.00	%		0.00	%		0.00	%
Other Expenses		0.17	%		0.25	%		0.16	%		0.08	%					0.22	%		0.17	%		0.11	%		0.14	%
Net Expense Ratio		1.06	%		1.64	%		1.80	%		0.72	%					0.86	%		0.81	%		0.75	%		0.78	%
Columbia Acorn International
Management Fees		0.76	%		0.76	%		0.76	%		0.76	%		0.76	%		0.76	%		0.76	%		0.76	%		0.76	%
Distribution and Service (12b-1) Fees		0.25	%		0.75	%		1.00	%		0.00	%		0.50	%		0.00	%		0.00	%		0.00	%		0.00	%
Other Expenses		0.23	%		0.46	%		0.24	%		0.12	%		0.25	%		0.26	%		0.13	%		0.14	%		0.17	%
Net Expense Ratio		1.24	%		1.97	%		2.00	%		0.88	%		1.51	%		1.02	%		0.89	%		0.90	%		0.93	%
Columbia Acorn USA
Management Fees		0.86	%		0.86	%		0.86	%		0.86	%					0.86	%		0.86	%		0.86	%		0.86	%
Distribution and Service (12b-1) Fees		0.25	%		0.75	%		1.00	%		0.00	%					0.00	%		0.00	%		0.00	%		0.00	%
Other Expenses		0.21	%		0.38	%		0.19	%		0.10	%					0.28	%		0.26	%		0.18	%		0.21	%
Net Expense Ratio		1.32	%		1.99	%		2.05	%		0.96	%					1.14	%		1.12	%		1.04	%		1.07	%
Columbia Acorn International Select
Management Fees		0.94	%		0.94	%		0.94	%		0.94	%					0.94	%		0.94	%		0.94	%		0.94	%
Distribution and Service (12b-1) Fees		0.25	%		0.75	%		1.00	%		0.00	%					0.00	%		0.00	%		0.00	%		0.00	%
Other Expenses		0.30	%		0.41	%		0.33	%		0.20	%					0.36	%		0.34	%		0.26	%		0.25	%
Net Expense Ratio		1.49	%		2.10	%		2.27	%		1.14	%					1.30	%		1.28	%		1.20	%		1.19	%
Columbia Acorn Select
Management Fees		0.83	%		0.83	%		0.83	%		0.83	%					0.83	%		0.83	%		0.83	%		0.83	%
Distribution and Service (12b-1) Fees		0.25	%		0.75	%		1.00	%		0.00	%					0.00	%		0.00	%		0.00	%		0.00	%
Other Expenses		0.23	%		0.32	%		0.23	%		0.12	%					0.23	%		0.16	%		0.09	%		0.20	%
Net Expense Ratio		1.31	%		1.90	%		2.06	%		0.95	%					1.06	%		0.99	%		0.92	%		1.03	%
Columbia Thermostat Fund
Management Fees		0.10	%		0.10	%		0.10	%								0.10	%		0.10	%		0.10	%		0.10	%
Distribution and Service (12b-1) Fees		0.25	%		0.75	%		1.00	%								0.00	%		0.00	%		0.00	%		0.00	%
Other Expenses		0.15	%		0.15	%		0.15	%								0.15	%		0.17	%		0.12	%		0.15	%
Net Expense Ratio**		0.50	%		1.00	%		1.25	%								0.25	%		0.27	%		0.22	%		0.25	%
Columbia Acorn Emerging Markets Fund
Management Fees		1.25	%					1.25	%		1.25	%					1.25	%		1.25	%					1.25	%
Distribution and Service (12b-1) Fees		0.25	%					1.00	%		0.00	%					0.00	%		0.00	%					0.00	%
Other Expenses		0.27	%					0.31	%		0.16	%					0.29	%		0.21	%					0.21	%
Net Expense Ratio		1.77	%					2.56	%		1.41	%					1.54	%		1.46	%					1.46	%
Columbia Acorn European Fund
Management Fees		1.19	%					1.19	%		1.19	%								1.19	%					1.19	%
Distribution and Service (12b-1) Fees		0.25	%					1.00	%		0.00	%								0.00	%					0.00	%
Other Expenses		0.17	%					0.13	%		0.12	%								0.17	%					0.14	%
Net Expense Ratio		1.61	%					2.32	%		1.31	%								1.36	%					1.33	%

    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 as of the year ended December 31, 2012. The fees and expenses of Columbia Acorn International Select and Columbia Acorn Select include the effect of the voluntary undertaking by Columbia Wanger Asset Management, LLC (CWAM) to reimburse each Fund for the ordinary operating expenses (exclusive of brokerage commissions, interest, taxes and extraordinary expenses, but inclusive of custodial charges relating to overdrafts, if any), exceeding annually each class' average daily net assets as follows:

Fund	Class A			Class B			Class C			Class I			Class R4			Class R5			Class Y			Class Z
Columbia Acorn International Select		1.70	%		2.20	%		2.45	%		1.28	%		1.45	%		1.33	%		1.28	%		1.45	%
Columbia Acorn Select		1.60	%		2.10	%		2.35	%		1.25	%		1.35	%		1.30	%		1.25	%		1.35	%

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

    The fees and expenses of Columbia Thermostat Fund include the effect of CWAM's contractual undertaking to waive fees and/or reimburse expenses of the Fund so that the ordinary operating expenses (exclusive of brokerage commissions, interest, taxes and extraordinary expenses, but inclusive of custodial charges relating to overdrafts, if any), do not exceed annually the rate of 0.50%, 1.00%, 1.25%, and 0.25% of the Fund's average daily net assets attributable to Class A, Class B, Class C, and Class Z shares, respectively, through April 30, 2013, and 0.25%, 0.27% and 0.22% of the Fund's average daily net assets attributable to Class R4, Class R5 and Class Y shares, respectively, through November 8, 2013. There is no guarantee that this agreement will continue thereafter.

    The fees and expenses of Columbia Acorn Emerging Markets Fund and Columbia Acorn European Fund include the effect of CWAM's contractual undertaking to waive fees and/or reimburse expenses of each Fund 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 inclusive of custodial charges relating to overdrafts, if any) of each Fund's Class A, Class B, Class C and Class Z shares through April 30, 2013, and each Fund's Class R4, Class R5 (if offered) and Class Y shares through November 8, 2013, do not exceed annually each class' average daily net assets as follows:

Fund	Class A			Class C			Class I			Class R4			Class R5			Class Z
Columbia Acorn Emerging Markets Fund		1.85	%		2.60	%		1.41	%		1.60	%		1.46	%		1.60	%
Columbia Acorn European Fund		1.75	%		2.50	%		1.31	%		—	%		1.36	%		1.50	%

    There is no guarantee that this agreement will continue thereafter.

    The fees and expenses of Columbia Acorn International 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 agreement 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 0.60% incurred by the Fund from the underlying portfolio funds in which it invests.

  †  With the exception of Class R5 shares of Columbia Acorn International, noted share classes commenced operations on November 8, 2012, and have limited eligibility. Please see the Funds' prospectuses for details.

130

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 Family of 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.

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, R4, R5, Y and Z Shares

Annual Report, December 31, 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.

© 2013 Columbia Management Investment Advisers, LLC. All rights reserved.

225 Franklin Street, Boston, MA 02110

800.345.6611 www.columbiamanagement.com

C-1446 D (3/13) 152524

Item 2. Code of Ethics.

(a)The registrant has adopted a code of ethics that applies to the registrant’s principal executive officer, principal financial officer, principal accounting officer or controller, or persons performing similar functions, regardless of whether these individuals are employed by the registrant or a third party.

(b)During the period covered by this report, there were not any amendments to a provision of the code of ethics adopted in 2(a) above.

(c)During the period covered by this report, there were no waivers, including any implicit waivers, from a provision of the code of ethics described in 2(a) above that relates to one or more of the items set forth in paragraph (b) of this item’s instructions.

Item 3. Audit Committee Financial Expert.

The registrant’s Board of Trustees has determined that Michelle L. Collins, a member of the registrant’s Board of Trustees and Chair of the Audit Committee, qualifies as an audit committee financial expert.  Ms. Collins is an independent trustee, as defined in paragraph (a)(2) of this item’s instructions.

Item 4. Principal Accountant Fees and Services.

(a) Audit Fees. Aggregate Audit Fees billed by the principal accountant for professional services rendered during the fiscal years ended December 31, 2012 and December 31, 2011 are approximately as follows:

2012		2011
$	296,000	$	286,000

Audit Fees include amounts related to the audit of the registrant’s annual financial statements or services that are normally provided by the accountant in connection with statutory and regulatory filings or engagements for those fiscal years.

(b) Audit-Related Fees. Aggregate Audit-Related Fees billed to the registrant by the principal accountant for professional services rendered during the fiscal years ended December 31, 2012 and December 31, 2011 are approximately as follows:

2012		2011
$	44,900	$	74,100

Audit-Related Fees include amounts for assurance and related services by the principal accountant that are reasonably related to the performance of the audit of the registrant’s financial statements and are not reported in Audit Fees above.  In fiscal years 2012 and 2011, Audit-Related Fees consist of agreed-upon procedures performed for other audit-related additional testing. Fiscal year 2011 also includes Audit-Related Fees for agreed-upon procedures related to a fund merger and agreed-upon procedures for fund accounting and custody conversions.

During the fiscal years ended December 31, 2012 and December 31, 2011, there were no Audit-Related Fees billed by the registrant’s principal accountant to the registrant’s investment adviser (not including any sub-adviser whose role is primarily portfolio management and is subcontracted with or overseen by another investment adviser) and any entity controlling, controlled by, or under common control with the adviser that provides ongoing services to the registrant for an engagement that related directly to the operations and financial reporting of the registrant.

(c) Tax Fees. Aggregate Tax Fees billed by the principal accountant to the registrant for professional services rendered during the fiscal years ended December 31, 2012 and December 31, 2011 are approximately as follows:

2012		2011
$	58,200	$	49,300

Tax Fees incurred in both fiscal years 2012 and 2011 relate to the review of annual tax returns, the review of required shareholder distribution calculations and include amounts for professional services by the principal accountant for tax compliance, tax advice and tax planning.

During the fiscal years ended December 31, 2012 and December 31, 2011, there were no Tax Fees billed by the registrant’s principal accountant to the registrant’s investment adviser (not including any sub-adviser whose role is primarily portfolio management and is subcontracted with or overseen by another investment adviser) and any entity controlling, controlled by, or under common control with the adviser that provides ongoing services to the registrant for an engagement that related directly to the operations and financial reporting of the registrant.

(d) All Other Fees. Aggregate All Other Fees billed by the principal accountant to the registrant for professional services rendered during the fiscal years ended December 31, 2012 and December 31, 2011 are approximately as follows:

2012		2011
$	0	$	0

All Other Fees include amounts for products and services provided by the principal accountant, other than the services reported in paragraphs (a) through (c) above.

Aggregate All Other Fees billed by the registrant’s principal accountant to the registrant’s investment adviser (not including any sub-adviser whose role is primarily portfolio management and is subcontracted with or overseen by another investment adviser) and any entity controlling, controlled by, or under common control with the adviser that provides ongoing services to the registrant for an engagement that related directly to the operations and financial reporting of the registrant during the fiscal years ended December 31, 2012 and December 31, 2011 are approximately as follows:

2012		2011
$	140,000	$	65,000

In both fiscal years 2012 and 2011, All Other Fees consist of professional services rendered for internal control reviews of the registrant’s transfer agent.

(e)(1) Audit Committee Pre-Approval Policies and Procedures

The policy of the registrant’s Audit Committee is to specifically pre-approve (i) all audit and non-audit (including audit related, tax and all other) services provided by the registrant’s independent auditor to the registrant and individual funds (collectively “Fund Services”) and (ii) all non-audit services provided by the registrant’s independent auditor to the funds’ adviser or a control affiliate of the adviser, that relate directly to the funds’ operations and financial reporting (collectively “Fund-related Adviser Services”).  A “control affiliate” is an entity controlling, controlled by, or under common control with the adviser that provides ongoing services to the funds, and the term “adviser” is deemed to exclude any unaffiliated sub-adviser whose role is primarily portfolio management and is sub-contracted or overseen by another investment adviser.

If such Fund Services or Fund-related Adviser Services are required during the period between the Audit Committee’s regularly scheduled meetings, the Chairman of the Audit Committee has the authority to pre-approve the service, with reporting to the full Audit Committee at the next regularly scheduled meeting.

The Audit Committee will waive pre-approval of Fund Services or Fund-related Adviser Services provided that the requirements under paragraph (c)(7)(i)(C) of Rule 2-01 of Regulation S-X are met.

(e)(2) The percentage of services described in paragraphs (b) through (d) of this Item approved pursuant to the “de minimis” exception under paragraph (c)(7)(i)(C) of Rule 2-01 of Regulation S-X during both fiscal years ended December 31, 2012 and December 31, 2011 was zero.

(f) Not applicable.

(g) The aggregate non-audit fees billed by the registrant’s accountant for services rendered to the registrant, and rendered to the registrant’s investment adviser (not including any sub-adviser whose role is primarily portfolio management and is subcontracted with or overseen by another investment adviser), and any entity controlling, controlled by, or under common control with the adviser that provides ongoing services to the registrant for the fiscal years ended December 31, 2012 and December 31, 2011 are approximately as follows:

2012		2011
$	243,100	$	188,400

(h) The registrant’s Audit Committee of the Board of Directors has considered whether the provision of non-audit services that were rendered to the registrant’s adviser (not including any sub-adviser whose role is primarily portfolio management and is subcontracted with or overseen by another investment adviser), and any entity controlling, controlled by, or under common control with the investment adviser that provides ongoing services to the registrant that were not pre-approved pursuant to paragraph (c)(7)(ii) of Rule 2-01 of Regulation S-X, is compatible with maintaining the principal accountant’s independence.

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)During November 2012, the registrant enhanced internal controls over financial reporting relating to the recording of certain last day trades.  These controls include (i) additional analysis of last day security purchase prices, (ii) comparisons of cost and market value for last day trades and (iii) analytical review of per share changes resulting from financial statement adjustments.

Item 12. Exhibits.

(a)(1) Code of ethics required to be disclosed under Item 2 of Form N-CSR attached hereto as Exhibit 99.CODE ETH.

(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	February 22, 2013

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	February 22, 2013

By (Signature and Title)	/s/Bruce H. Lauer
	Bruce H. Lauer, Treasurer
Date	February 22, 2013

EX-99.CODEETH

Exhibit 99.CODEETH

COLUMBIA WANGER ASSET MANAGEMENT ADVISED FUNDS

CODE OF ETHICS FOR PRINCIPAL EXECUTIVE

AND SENIOR FINANCIAL OFFICERS

I.Covered Officers/Purpose of the Code

This Code of Ethics (the “Code”) for the investment companies within the Columbia Wanger Asset Management fund complex (collectively the “Funds” and each, a “Fund”) applies the Funds’ Principal Executive Officer, Principal Financial Officer, and Principal Accounting Officer (the “Covered Officers”) for the purpose of promoting:

·honest and ethical conduct, including the ethical handling of actual or apparent conflicts of interest between personal and professional relationships;

·full, fair, accurate, timely and understandable disclosure in reports and documents that a Fund files with, or submits to, the Securities and Exchange Commission (“SEC”), and in other public communications made by a Fund;

·compliance with applicable laws and governmental rules and regulations;

·the prompt internal reporting of violations of the Code to an appropriate person or persons identified in the Code; and

·accountability for adherence to the Code.

Each Covered Officer shall adhere to a high standard of business ethics and shall be sensitive to situations that may give rise to actual or apparent conflicts of interest.

II.Administration of the Code

The Code shall be administered by the Columbia Wanger Asset Management Compliance Department.  The Boards of Trustees of the Funds (collectively, the “Board”) shall designate an individual to be primarily responsible for the administration of the Code (the “Code Officer”).  In the absence of the Code Officer, his or her designee shall serve as the Code Officer, but only on a temporary basis.

Each Fund has designated a chief legal officer (the “Chief Legal Officer”) for purposes of the Sarbanes-Oxley Act of 2002 and the rules promulgated thereunder.  The Chief Legal Officer shall assist the Code Officer in administration of this Code.  The Chief Legal Officer is responsible for applying this Code to specific situations in which questions are presented under it (in consultation with Fund counsel, where appropriate) and has the authority to interpret this Code in any particular situation.  However, any waivers sought by

a Covered Officer must be approved by each Audit Committee of the Funds (collectively, the “Audit Committee”).

III.Managing Conflicts of Interest

Overview.  A “conflict of interest” occurs when a Covered Officer’s private interest interferes with the interests of, or his/her service to, a Fund. For example, a conflict of interest would arise if a Covered Officer, or a family member, receives improper personal benefits as a result of the Covered Officer’s position with a Fund.

Certain conflicts of interest arise out of the relationships between Covered Officers and a Fund and already are subject to conflict of interest provisions in the Investment Company Act of 1940 (the “Company Act”) and the Investment Advisers Act of 1940 (the “Advisers Act”).  For example, Covered Officers may not individually engage in certain transactions (such as the purchase or sale of securities or other property) with a Fund because of their status as “affiliated persons” of the Fund.  A Fund’s and its investment adviser’s compliance programs and procedures are designed to prevent, or identify and correct, violations of those provisions.  This Code does not, and is not intended to, repeat or replace those programs and procedures, and such conflicts fall outside of the parameters of this Code.

Although typically not presenting an opportunity for improper personal benefit, conflicts may arise from, or as a result of, the contractual relationship between a Fund and its investment adviser, administrator, pricing and bookkeeping agent and/or transfer agent (each, a “Service Provider”) of which the Covered Officers are also officers or employees.  As a result, this Code recognizes that the Covered Officers will, in the normal course of their duties (whether formally for a Fund or for a Service Provider, or for both), be involved in establishing policies and implementing decisions that will have different effects on the Service Provider and a Fund.  The participation of the Covered Officers in such activities is inherent in the contractual relationship between the Fund and the Service Provider and is consistent with the performance by the Covered Officers of their duties as officers of a Fund.  In addition, it is recognized by the Board that the Covered Officers may also be officers or employees of one or more other investment companies covered by this or other codes.

Other conflicts of interest are covered by the Code, even if such conflicts of interest are not subject to provisions of the Company Act and the Advisers Act.  The following list provides examples of conflicts of interest under the Code, but Covered Officers should keep in mind that these examples are not exhaustive.  The overarching principle is that the personal interest of a Covered Officer should not be placed improperly before the interest of a Fund.

Each Covered Officer must:

·not use personal influence or personal relationships to influence investment decisions or financial reporting by a Fund whereby the Covered Officer or a family member would benefit personally to the detriment of a Fund;

·not cause a Fund to take action, or fail to take action, for the individual personal benefit of the Covered Officer or a family member rather than the benefit of the Fund.

There are some conflict of interest situations that must be approved by the Code Officer, after consultation with the Chief Legal Officer.  Those situations include, but are not limited to,:

·service as director on the board of any public or private company;

·the receipt of any gifts in excess of $100 in the aggregate from a third party that does or seeks to do business with the Funds during any 12-month period;

·the receipt of any entertainment from any company with which a Fund has current or prospective business dealings, unless such entertainment is business-related, reasonable in cost, appropriate as to time and place, and not so frequent as to raise any question of impropriety;

·any material ownership interest in, or any consulting or employment relationship with, any Fund service providers, other than its investment adviser, principal underwriter, administrator or any affiliated person thereof;

·a direct or indirect material financial interest in commissions, transaction charges or spreads paid by a Fund for effecting portfolio transactions or for selling or redeeming shares other than an interest arising from the Covered Officer’s employment, such as compensation or equity ownership.

IV.Disclosure and Compliance

Each Covered Officer shall:

·be familiar with the disclosure requirements generally applicable to the Funds;

·not knowingly misrepresent, or cause others to misrepresent, facts about any Fund to others, whether within or outside the Fund, including to the Fund’s trustees and auditors, and to governmental regulators and self-regulatory organizations;

·to the extent appropriate within his/her area of responsibility, consult with other officers and employees of the Funds and the adviser with the goal of promoting full, fair, accurate, timely and understandable

disclosure in the reports and documents the Funds file with, or submit to, the SEC and in other public communications made by the Funds; and

·promote compliance with the standards and restrictions imposed by applicable laws, rules and regulations.

V.Reporting and Accountability

Each Covered Officer must:

·upon adoption of the Code (or after becoming a Covered Officer), affirm in writing to the Board that he/she has received, read and understands the Code;

·annually affirm to the Board compliance with the requirements of the Code;

·not retaliate against any other Covered Officer or any employee of the Funds or their affiliated persons for reports of potential violations that are made in good faith;

·notify the Chief Legal Officer and the Code Officer promptly if he/she knows of any violation of this Code; and

·respond to the trustee and officer questionnaires circulated periodically in connection with the preparation of disclosure documents for the Funds.

The Code Officer shall maintain records of all activities related to this Code.

The Funds will follow the procedures set forth below in investigating and enforcing this Code:

·The Chief Legal Officer and/or the Code Officer will take all appropriate action to investigate any potential violation reported to him/her;

·If, after such investigation, the Chief Legal Officer and the Code Officer believes that no violation has occurred, the Code Officer will notify the person(s) reporting the potential violation, and no further action is required;

·Any matter that the Chief Legal Officer and/or the Code Officer believes is a violation will be reported to the Audit Committee;

·If the Audit Committee concurs that a violation has occurred, it will inform and make a recommendation to the Board, which will consider appropriate action, which may include review of, and appropriate modifications to, applicable policies and procedures; notification to the Chief Executive Officer of Columbia Management Investment Advisers, LLC; or a recommendation to sanction or dismiss the Covered Officer;

·The Audit Committee will be responsible for granting waivers in its sole discretion;

·Any changes to or waivers of this Code will, to the extent required, be disclosed as provided by SEC rules.

The Chief Legal Officer shall:

·report to the Audit Committee quarterly any approvals provided in     accordance with Section II of this Code; and

·report to the Audit Committee quarterly any violations of, or material issues arising under, this Code.

VI.Other Policies and Procedures

This Code shall be the sole code of ethics adopted by the Funds for the purposes of Section 406 of the Sarbanes-Oxley Act and the rules and forms applicable to registered investment companies thereunder.  Insofar as other policies or procedures of the Funds or the Funds’ Service Providers govern or purport to govern the behavior or activities (including, but not limited to, personal trading activities) of the Covered Officers who are subject to this Code, they are superseded by this Code to the extent that they overlap or conflict with the provisions of this Code.  The Funds’ and their investment advisers’ and principal underwriter’s codes of ethics under Rule 17j-1 under the Company Act and any policies and procedures of the Service Providers are separate requirements applicable to the Covered Officers and are not part of this Code.

VII. Amendments

All material amendments to this Code must be approved or ratified by the Board, including a majority of independent directors.

VIII.Confidentiality

All reports and records prepared or maintained pursuant to this Code will be considered confidential and shall be maintained and protected accordingly.  Except as otherwise required by law or this Code, such matters shall not be disclosed to anyone other than the Board, the Covered Officers, the Chief Legal Officer, outside audit firms and legal counsel to the Funds, and senior management of Columbia Management Investment Advisers, LLC.

IX.Internal Use

The Code is intended solely for the internal use by the Funds and does not constitute an admission, by or on behalf of any Fund, as to any fact, circumstance, or legal conclusion.

COLUMBIA WANGER ASSET MANAGEMENT ADVISED FUNDS

CODE OF ETHICS FOR PRINCIPAL EXECUTIVE

AND SENIOR FINANCIAL OFFICERS (“CODE”) — AFFIRMATION

I affirm that:

1.Upon the adoption of the Code, I have received, read and understand the Code and have complied with the Code since its adoption on September 23, 2003.

Signature Date

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:      February 22, 2013	/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:     February 22, 2013	/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 December 31, 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: February 22, 2013	/s/ Charles P. McQuaid
	Charles P. McQuaid, President
Date: February 22, 2013	/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.