N-30B-2 1 a11-28279_5n30b2.htm N-30B-2

Q3 2011

Columbia Acorn Family of Funds

Class Z Shares

Managed by Columbia Wanger Asset Management, LLC

Third Quarter Report

September 30, 2011

n Columbia
Acorn® Fund

n Columbia
Acorn International®

n Columbia
Acorn USA®

n Columbia
Acorn International Select^SM

n Columbia
Acorn Select^SM

n Columbia
Thermostat Fund^SM

n Columbia
Acorn Emerging Markets Fund^SM

n Columbia
Acorn European Fund^SM

Not FDIC insured • No bank guarantee • May lose value

Columbia Acorn Family of Funds

Descriptions of Indexes Included in this Report

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

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

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

• Lipper Indexes include the largest funds tracked by Lipper, Inc. in the named category. Lipper Mid-Cap Growth Funds Index, 30 largest mid-cap growth funds, including Columbia Acorn Fund and Columbia Acorn Select; Lipper International Small/Mid Growth Funds Index, 10 largest non-U.S. small/mid growth funds, including Columbia Acorn International; Lipper Small-Cap Growth Funds Index, 30 largest small-cap growth funds, including Columbia Acorn USA; Lipper International Funds Index, 30 largest non-U.S. funds, excluding non-U.S. small-cap 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.

• Morgan Stanley Capital International Europe, Australasia, Far East (MSCI 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 8% of the total market capitalization of the Russell 3000 Index.

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

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

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

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

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

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

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

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

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

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

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

Columbia Acorn Family of Funds

Table of Contents

Performance At A Glance					2
Chattering Squirrels: 2011 Shareholder Information Meeting Recap					3
Columbia Acorn Fund
In a Nutshell					10
At a Glance					11
Major Portfolio Changes					26
Statement of Investments					29
Columbia Acorn International
In a Nutshell					12
At a Glance					13
Major Portfolio Changes					42
Statement of Investments					46
Portfolio Diversification					55
Columbia Acorn USA
In a Nutshell					14
At a Glance					15
Major Portfolio Changes					56
Statement of Investments					58
Columbia Acorn International Select
In a Nutshell					16
At a Glance					17
Major Portfolio Changes					65
Statement of Investments					66
Portfolio Diversification					70

Columbia Acorn Select
In a Nutshell					18
At a Glance					19
Major Portfolio Changes					71
Statement of Investments					72
Columbia Thermostat Fund
In a Nutshell					20
At a Glance					21
Statement of Investments					78
Columbia Acorn Emerging Markets Fund
In a Nutshell					22
At a Glance					23
Statement of Investments					79
Portfolio Diversification					82
Columbia Acorn European Fund
In a Nutshell					24
At a Glance					25
Statement of Investments					83
Portfolio Diversification					86
Columbia Acorn Family of Funds
Columbia Acorn Family of Funds Information					87

Estimated Year-End Distributions

To help with your tax planning, following are the estimated year-end capital gain distributions for the Columbia Acorn Funds. The expected record date is December 6, 2011, the expected ex-dividend date is December 7, 2011, and the expected payable date is December 7, 2011. Distribution information is not final and should not be considered final until after the record date. The Board of Trustees will determine the actual distributions the Funds will pay.

	Short-term Capital Gains		Long-term Capital Gains
Columbia Acorn Fund		None	$	0.90 - $1.05
Columbia Acorn International		None		None
Columbia Acorn USA		None	$	0.10 - $0.15
Columbia Acorn International Select		None	$	0.40 - $0.50
Columbia Acorn Select		None		None
Columbia Thermostat Fund		None		None
Columbia Acorn Emerging Markets Fund	$	0.00 - $0.05		None
Columbia Acorn European Fund	$	0.00 - $0.05		None

Columbia Acorn Family of Funds

Performance At A Glance Class Z Average Annual Total Returns through 9/30/11

	NAV on 9/30/11		3rd quarter*			Year to date*			1 year			5 years			10 years			Life of Fund
Columbia Acorn Fund (ACRNX) (6/10/70)	$	25.67		-19.66	%		-13.89	%		-1.34	%		1.55	%		9.06	%		14.31	%
Russell 2500 Index				-21.22	%		-14.87	%		-2.22	%		0.19	%		7.08	%		NA
S&P 500 Index**				-13.87	%		-8.68	%		1.14	%		-1.18	%		2.82	%		10.20	%
Lipper Mid-Cap Growth Funds Index				-20.18	%		-14.14	%		-2.18	%		2.41	%		5.29	%		NA
Columbia Acorn International (ACINX) (9/23/92)	$	33.63		-18.23	%		-15.77	%		-8.55	%		2.53	%		11.39	%		10.66	%
S&P Global Ex-U.S. Between $500M and $5B Index				-19.67	%		-17.56	%		-8.84	%		1.77	%		12.15	%		7.96	%
S&P Global Ex-U.S. SmallCap Index				-21.20	%		-18.34	%		-9.65	%		0.20	%		11.18	%		7.14	%
Lipper International Small/Mid Growth Funds Index				-18.96	%		-16.62	%		-6.92	%		0.31	%		9.71	%		NA
Columbia Acorn USA (AUSAX) (9/4/96)	$	24.25		-22.20	%		-15.09	%		-1.14	%		-0.51	%		6.36	%		8.84	%
Russell 2000 Index				-21.87	%		-17.02	%		-3.53	%		-1.02	%		6.12	%		5.84	%
Russell 2500 Index				-21.22	%		-14.87	%		-2.22	%		0.19	%		7.08	%		7.52	%
Lipper Small-Cap Growth Funds Index				-21.54	%		-14.42	%		-1.10	%		0.27	%		4.52	%		4.46	%
Columbia Acorn Int'l Select (ACFFX) (11/23/98)	$	24.73		-14.67	%		-11.47	%		-4.31	%		2.51	%		10.61	%		8.67	%
S&P Developed Ex-U.S. Between $2B and $10B Index				-18.15	%		-14.85	%		-6.54	%		-1.15	%		9.14	%		6.52	%
MSCI EAFE Index				-19.01	%		-14.98	%		-9.36	%		-3.46	%		5.03	%		2.43	%
Lipper International Small/Mid Growth Funds Index				-18.96	%		-16.62	%		-6.92	%		0.31	%		9.71	%		9.10	%
Columbia Acorn Select (ACTWX) (11/23/98)	$	21.60		-23.54	%		-23.52	%		-12.78	%		-0.86	%		6.82	%		8.18	%
S&P MidCap 400 Index				-19.88	%		-13.02	%		-1.28	%		2.20	%		7.50	%		7.72	%
S&P 500 Index**				-13.87	%		-8.68	%		1.14	%		-1.18	%		2.82	%		1.58	%
Lipper Mid-Cap Growth Funds Index				-20.18	%		-14.14	%		-2.18	%		2.41	%		5.29	%		4.86	%
Columbia Thermostat Fund (COTZX) (9/25/02)†	$	11.97		-6.92	%		-2.59	%		4.59	%		3.52	%		—			6.86	%
S&P 500 Index				-13.87	%		-8.68	%		1.14	%		-1.18	%		—			5.73	%
Barclays Capital U.S. Aggregate Bond Index				3.82	%		6.65	%		5.26	%		6.53	%		—			5.36	%
Lipper Flexible Portfolio Funds Index				-11.52	%		-7.00	%		-0.22	%		1.97	%		—			6.59	%
50/50 Blended Benchmark				-5.28	%		-1.12	%		3.48	%		3.04	%		—			5.87	%
Columbia Acorn Emerging Markets Fund (CEFZX) (8/19/11)	$	8.84		—			—			—			—			—			-11.60	%
S&P Emerging Markets Between $500M and $5B Index				—			—			—			—			—			-14.28	%
MSCI Emering Markets Small Cap Index				—			—			—			—			—			-16.10	%
Lipper Emerging Markets Index				—			—			—			—			—			-11.32	%
Columbia Acorn European Fund (CAEZX) (8/19/11)	$	9.41		—			—			—			—			—			-5.90	%
S&P Europe Between $500M and $5B Index				—			—			—			—			—			-7.55	%
HSBC Smaller European Companies Index				—			—			—			—			—			-8.68	%
Lipper European Region Index				—			—			—			—			—			-6.73	%

*Not annualized.

**The comparison to the S&P 500 Index is presented to show performance against a widely recognized market index.

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

Performance results reflect any fee waivers or reimbursements of Fund expenses by the investment adviser and/or any of its affiliates. Absent these fee waivers or expense reimbursement arrangements, performance results would have been lower. Annual operating expense ratios are stated as of each Fund's current prospectus and differences in expense ratios disclosed elsewhere in this report may result from including fee waivers and expense reimbursements as well as different time periods used in calculating the ratios for Class Z shares. Columbia Acorn Fund: 0.76%. Columbia Acorn International: 0.98%. Columbia Acorn USA: 1.01%. Columbia Acorn International Select: 1.16%. Columbia Acorn Select: 0.97%. Columbia Thermostat Fund has a contractual fee waiver and expense reimbursement agreement with CWAM that expires April 30, 2012; expense ratios without and with the contractual waiver/reimbursement, including fees and expenses associated with the Fund's investments in other investment companies are 1.16% and 1.04%, respectively. Columbia Acorn Emerging Markets Fund has a contractual fee waiver and expense reimbursement agreement with CWAM that expires April 30, 2013; expense ratios without and with the contractual waiver/reimbursement are 1.58%. Columbia Acorn European Fund has a contractual fee waiver and expense reimbursement agreement with CWAM that expires April 30, 2013; expense ratios without and with the contractual waiver/reimbursement are 1.51% and 1.50%, respectively.

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

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

Chattering Squirrels: 2011 Shareholder Information Meeting Recap

On September 21, 2011, we held our annual Shareholder Information Meeting in Chicago. Following are highlights from your portfolio managers' presentations. While they did not present at this year's meeting, Columbia Acorn USA portfolio manager Robert Mohn and Columbia Acorn International Select portfolio manager Chris Olson have provided comments to include in this recap. Data quoted in the presentations has been updated through September 30, 2011.

Charles P. McQuaid

Chief Investment Officer and Lead Portfolio Manager of Columbia Acorn Fund and Columbia Thermostat Fund

Over the last year, Columbia Acorn Fund benefited from good stock selection in consumer discretionary and industrial stocks and an underweight in a struggling financial sector. On the downside, some of the Fund's energy stocks took a breather, hurting performance.

Let's look at several Fund holdings. Columbia Acorn Fund's third largest position at the end of September was FMC Technologies, a maker of production systems for oil and gas wells located underwater, including wellheads. The price of oil has been fluctuating, with world demand on the rise and supplies seemingly limited. Deep-water drilling has been booming offshore Brazil and offshore Africa, and is picking up in the Gulf of Mexico. More drilling rigs are being built and, as they are being put to work, we expect that demand for FMC's products should grow.

As mentioned at last year's meeting, we believed industrial stocks Ametek, Mettler Toledo and Donaldson occupied good niches and were reasonably priced. I am pleased to report that all three stocks have performed well. Second quarter 2011 comparable earnings per share were up 38% for Ametek, 22% for Mettler Toledo and 29% for Donaldson. Their stocks have responded favorably to the earnings growth.

Turning our attention to industry weightings, the Fund's largest weight at the end of September was industrials. As noted in the examples above, we have found many stocks in this sector representing what we think are good businesses, at reasonable valuations. In addition, many of their large customers have great balance sheets and need to spend more on industrial equipment in order to remain competitive and accommodate worldwide demand.

The Fund's second largest overweight at the end of the third quarter was in consumer discretionary stocks. We are not particularly bullish on the American consumer but we are bullish on American consumer companies that are pursuing global growth strategies as providers of affordable luxury products. Fund holding Abercrombie & Fitch, for example, has several enormously successful stores overseas. Handbag company Coach derives 30% of its revenues from non-U.S. markets.

Columbia Acorn Fund's largest underweight was in financial services. Most of this underweight was because the Fund has relatively little exposure to real estate investment trusts (REITs). REIT growth has been slower than many other companies, and we don't believe the stocks are cheap. We also have a small underweight in banks, many of which continue to suffer from the real estate collapse while dealing with increased regulations that have hurt profitability.

The Fund's next largest underweight was in utilities. We've maintained a modest exposure in this group because we've found only a handful of companies that we think have good growth opportunities and reasonable stock prices.

Looking at Columbia Acorn Fund's characteristics, the Fund held 375 stocks at the end of September. Acorn has held over 200 stocks since the 1980s and, since 2005, has had between 325 and 425 stocks. The Fund's weighted average market cap was $3.6 billion, somewhat higher than its benchmark, the Russell 2500 Index, because we don't automatically sell winners due to market caps. Fund stocks tend to have modestly higher valuations than benchmark, but have better returns on equity as well. Turnover was 28% last year, a bit higher than our recent average. Some 10% of the Fund was invested in foreign stocks at the end of September, and the range over the last decade has been between 7% and 16%.

Turning to Columbia Thermostat, the Fund has been busy buying stock funds when the market goes down and selling them when the market rises. The Fund went from 50% stocks in April to a peak of 75% stocks in August and

then, with a bit of a market recovery, was at 65% stocks at the end of September. The market has been stuck in a trading range, helping Thermostat performance.

Ben Andrews

Lead Portfolio Manager of Columbia Acorn Select

Columbia Acorn Select underperformed its benchmark, the S&P MidCap 400 Index, for the year ended September 30, 2011. I'd like to stress that I believe in this Fund—its philosophy and its style. The Fund has undergone changes that are intended to help Fund performance going forward. Robert Chalupnik was brought on as a co-portfolio manager of the Fund in May. I've worked closely with Rob over his 10 years as the domestic industrials analyst at Columbia Wanger Asset Management (CWAM) and I feel strongly that his knowledge and ability will be additive to Fund performance.

Fund stocks generally fall into two categories: core holdings and opportunistic holdings. The Fund's core holdings are stocks that we believe are great businesses selling at good prices. They have a sustainable competitive advantage, pricing power, dominant market share and strong cash generation. Some examples of these among the Fund's top 10 are Ametek, Crown Castle and Coach.

The second type, the opportunistic holding, is what we perceive as a good business available at a great price. These are companies that we believe are misunderstood by Wall Street. They could be going through a transition or a turnaround in their business fundamentals. The company could be a spin-off of a smaller business that few analysts appear to be following. Examples of these types of businesses in the top 10 holdings are Hertz and Pacific Rubiales Energy.

This year, many of the Fund's opportunistic holdings have gone down more than the market, regardless of how the company is actually performing. For example, the market is currently pricing Hertz like it's an average cyclical stock that is losing money in a rough recession. In fact, Hertz is not losing money; its earnings are up nicely so far this year. At some point, we expect the market to recognize the changes Hertz has made recently, as well as the changes that have occurred in its industry.

First, Hertz has lengthened its debt maturities, eliminating a lot of refinance risk. Second, we believe there is little risk of the automakers going bankrupt, making it unlikely that Hertz will own cars that become undesireable when it's time to sell them. Third, there are fewer cars being sold in the United States, resulting in higher resale values for Hertz's cars as it rolls over its fleet. Finally, the car rental industry is continuing to consolidate, allowing the remaining players to have more pricing and purchasing power. And, if demand drops, Hertz has the ability to sell the cars in its car inventory, allowing it to adjust quickly to changing economic times.

I'd call Hertz the right stock to own for the long term but, so far this year, it has been the wrong time to own it. I believe the market is currently very one-dimensional, paying up for fast-growth companies. I can't predict when the market will like a stock such as Hertz again, but I believe that as long as the company grows, the market will come around.

When looking at the two types of holdings that Columbia Acorn Select owns, I believe my strength is in finding opportunistic businesses. Looking back over my 13 years at CWAM, I've found many of them, some of which have done quite well over the long run in our Acorn Funds. On the other hand, when I look at what Rob Chalupnik has accomplished at CWAM, I see someone who has done really well at finding businesses with sustainable, competitive advantage, core holdings for Columbia Acorn Select. Bringing our complementary skillsets together to manage Columbia Acorn Select should prove beneficial going forward.

Robert A. Mohn

Director of Domestic Research, Lead Portfolio Manager of Columbia Acorn USA and Co-portfolio Manager of Columbia Acorn Fund

Columbia Acorn USA's results for the 12-month period ended September 30, 2011, were helped by the outperformance of Fund consumer and financial sector stocks. Fund consumer stocks bested the benchmark Russell 2000 Index's consumer sector performance by 9%. Our consumer analyst, Susie Hultquist, has done a masterful job investing in several powerful consumer themes, including "American brands going global" (epitomized by teen retailer Abercrombie & Fitch, whose international business grew 74% in the second

quarter and now comprises 25% of sales), retailers creating new "categories of one" (lululemon athletica, which launched and now dominates the burgeoning premium yoga apparel business), and "internet category killers" (Shutterfly in the photo retailing space).

The Fund is currently overweight the consumer sector, at 16% of Fund assets, 3% greater than the benchmark. On first glance, our outsized position seems to indicate that we believe the U.S. consumer to be on the brink of another spending spree. But this is not the case. We actually anticipate muted growth in U.S. consumer spending going forward. So why the overweight of a group with a tepid, uninspiring outlook? Because we have been able to identify and invest a meaningful amount of money in a fine group of stocks that we believe will benefit from global (as opposed to domestic) consumer spending growth and/or from changing U.S. spending habits (more online shopping and newly developing retail categories). These durable and favorable underlying spending trends trump any concerns we may have about the overall health of the average U.S.-based consumer.

The financials sector is our largest underweight at 14% of Fund assets versus the benchmark's 21% weighting. Our disinterest stems from the basic law of supply and demand. Most financial sectors are suffering from an overabundance of supply (record excess reserves in the banking system, overbuilt suburban office buildings and strip malls) in tandem with a dearth of business demand. High supply plus low demand is a toxic combination. We have been able to identify some select financial companies and sub-sectors with supply/demand working in their favor. Of note are World Acceptance, whose small-loan business is thriving as rival payday lenders get regulated out of business (thus shrinking the overall supply of small loans), and Extra Space Storage, a real estate company bolstered by strong demand for its self-storage units.

Also boosting performance over the past year were our technology stocks, or should I say "stock." IPG Photonics, a top-10 position in the Fund, soared during the 12-month period ended September 30, 2011, gaining 80%. IPG is the dominant provider of fiber lasers, a disruptive technology that essentially marries fiber optics with lasers. Fiber lasers are more efficient and offer better beam quality than standard carbon dioxide gas lasers and recently seem to have reached a positive inflection point in terms of acceptance for new cutting and welding applications. Revenue has grown 81% over the past year.

The telecom sector served as a drag on returns over the past 12 months. The Fund's larger telecom positions continue to increase their cash flow at a robust pace, with cellular tower company SBA Communications enjoying 15% cash flow growth and fiber optic commercial telephone provider tw telecom's cash flow up 8%. However, their stock prices have lagged for the annual period through September 30, 2011, though both were star performers prior to last year's shareholder meeting.

Louis J. Mendes

Co-portfolio Manager of Columbia Acorn International and Columbia Acorn Emerging Markets Fund

With the world at what appears to be an economic crossroads, it is important to understand not only what you are investing in, but why you should continue to hold that investment. Let's look at what you own when you invest in Columbia Acorn International and how it differs from many of its peers.

Columbia Acorn International is invested in nearly all regions of the world outside of the United States but with no one region overwhelming the portfolio. This mitigates the impact of a regional economic or political shock to the Fund. We've been consistent in this diversification. Three years ago the Fund's largest regional weights were, as they are now, Continental Europe, Asia ex-Japan and Japan. Our exposure to Europe has declined a bit, while Asia ex-Japan has increased.

The Fund is also diversified at the corporate level, holding over 200 unique names, each with its own performance drivers. No single investment is responsible for the portfolio's returns on its own. This allows the Fund to have what we believe is a comparatively low volatility relative to its peers. The Fund's top 10 holdings account for no more than 15% of the Fund's assets while many of its peers have 25% or more of their assets in their fund's top 10 names.

United Kingdom, Intertek Group provides testing and certification services to the world of international manufacturing and trade to ensure that products meet international standards in quality and assurance. Vopak is a Dutch manager of oil and natural gas depots around the world. Increased energy demand requires increased energy sourcing from locations far from end markets. As you can see, each of these companies has its own unique set of drivers.

We remain dedicated to small/mid-cap investing with a buy-and-hold philosophy. The Fund's weighted average market cap at the end of September was $3.1 billion, down slightly from $3.2 billion three years ago. The Fund's portfolio turnover in 2010 was 25%, slightly below the 28% level of three years prior and consistently well below industry averages.

We continue to take a team approach to investing. Each member of the investment team is a specialist in his or her particular region or sector. Our emphasis on independent thinking means that we can have contrasting world, country or even sector views, which fuels constructive discourse and helps ensure that we have fully vetted every investment prior to making a portfolio decision. This keeps our focus on stock selection, which has always been the true strength of Acorn investing.

Looking at the bigger economic picture, economies around the world are growing at very different rates and facing very different domestic issues. There is a tug of war going on as some countries wrestle with deflationary fears by creating liquidity, while others enact policies to curtail inflation and its excess liquidity.

The developed markets of the United States and Europe are battling debt/credit crises in the midst of low economic growth and high unemployment. Inflation is not a concern and nominal interest rates are expected to remain historically low for the foreseeable future. Japan has had low interest rates for a long time, as it continues to battle its own deflation problem.

Many of the larger emerging market economies (China, India and Brazil, for example) have been growing too fast in recent years and, in some regions, are at structurally full employment. This has caused excessive inflation in wage rates and contributed to the sharp rise in food demand and prices.

Fritz Kaegi

Lead Portfolio Manager of Columbia Acorn Emerging Markets Fund

Columbia Acorn Emerging Markets Fund invests in small companies (under $5 billion at the time of purchase) in emerging and frontier markets. The hallmark of the Acorn investment approach has always been to buy reasonably priced small companies, with good businesses and prospects, and hold onto them. This approach is well-suited to emerging markets.

Emerging markets are home to much of the growth in the global economy today. The implementation of proven ideas and technologies is increasing living standards and productivity. Improving agricultural practices, for example, are freeing people to pursue jobs in cities, bringing more people to the labor force, especially women. Exposure to international trade and investment is increasing, and local financial systems are getting better at mobilizing capital. Compared to many developed countries, debt levels are modest.

Two other key factors bode well for companies in developing markets. First, they generally have less competition, which is key because revenue growth alone does not necessarily translate into profit growth. Industries with ordinary levels of profitability in advanced markets can have excellent levels of profitability in emerging markets.

Second, emerging market companies with good business franchises often can reinvest capital at high rates of return. Consider U.S. paint company Sherwin Williams and the leader in India, Asian Paints. Both companies earn good returns on capital but it is much harder for Sherwin to reinvest profitability than it is for Asian Paints because the U.S. paint market is saturated and slow-growing, while Indian paint consumption is low and fast-growing. The ability to reinvest at good returns is critical to compounding growth.

Another point to consider is that many of the economic growth drivers and competitive conditions in emerging markets arise from local, not global, conditions. While performance has been somewhat correlated in recent years, we believe that unique, local economic circumstances should, over longer periods, result in outcomes that are different from our developed market stock holdings.

Looking more specifically at Columbia Acorn Emerging Markets Fund, it differs from many other emerging

market funds because it is focused on small companies. Most emerging market funds focus on the same group of giant companies that are driven by macroeconomic factors. A small-company focus offers an investable universe of thousands of companies and, within that universe, locally exposed niche businesses, such as those in the consumer discretionary, health care and industrials sectors, play a notably bigger role. If an investor is interested in emerging markets for growth and diversification potential, we think it makes more sense to look at smaller companies.

For example, looking at the top 10 stocks in the MSCI Emerging Markets Index, a large-cap emerging market benchmark, Petrobras, the state-owned oil company of Brazil, is largely driven by oil prices, providing little diversification for an investor who already owns Exxon or Total. Samsung is a Korean global technology company included in the index but the forces that move the business are not Korean, or even Asian. It largely depends on developed country revenues, just like Apple or Sony.

Now consider a top holding in our Fund. Localiza Rent A Car is a dominant rental car company in Brazil. As the largest single purchaser of cars in Brazil, it extracts favorable pricing for its fleet on acquisition. When combined with a large, in-house network of used car dealerships, it has better cost control and operating margins than any of its peers and the industry is growing twice as fast as the overall economy.

Another Fund holding, Rand Merchant Insurance (RMI), is a South African property and casualty insurer selling directly to customers, a trail blazed successfully in the United States by GEICO. RMI's distribution model gives it a cost advantage—shown in high underwriting margins—even as South African home and car ownership continues to grow.

Many of us on the Columbia Acorn Emerging Markets Fund team have lived and worked in emerging markets and have been traveling to these countries for years as investors. We are delighted to be managing an emerging market fund that employs the classic Acorn focus and process.

Andreas Waldburg-Wolfegg

Lead Portfolio Manager of Columbia Acorn European Fund

We at CWAM have built a broad knowledge of Europe, as a large portion of Columbia Acorn International is invested there. Back in 1997, management decided to use this knowledge to launch a European fund, which is domiciled in Ireland and distributed in select European countries. Throughout its long involvement in Europe, CWAM has built lasting and deep relationships with company managers, as well as their customers. We think we know Europe and we think we know it well.

What an odd time though, you might say, to launch a European fund. Isn't the area in deep trouble? Aren't British and Irish consumers facing tough times? What about Greece and the future of the euro? We share some of these concerns, but we don't struggle to answer these questions. Instead, we focus on what we do best at CWAM: picking stocks. We believe that despite the current macroeconomic challenges, well-financed companies with a global footprint and strong market share will continue to see opportunities where others see threats. This will be no different in the future than it was in the past. At the beginning of the last decade when the media dubbed Germany the "sick man of Europe," we made various successful investments there, some of which we still hold today. More recently, we've had success investing in Next, a British retailer, despite the morose consumer environment in the United Kingdom. Clearly, not all of our European investments have been winners, but we would argue that when we get it right (or wrong) it's more likely due to company-specifics than macroeconomics.

With $15 trillion of world GDP in 2010, Europe not only is the world's largest economic block, it is also the most densely populated and among its most diverse. Most importantly to us, however, is that it is home to some of what we believe to be the best smaller companies.

European companies hold dominant positions in key growth segments, ranging from machine tools to luxury goods, which offer products and services utilized the world over. For example, Italy's Ansaldo STS, a holding in Columbia Acorn International, provides key technology that is being used in the expansion of the Chinese high-speed rail network, while leather goods manufacturer Tod's delivers

a sense of Italian luxury that the Chinese consumer is craving. Tod's is held by Columbia Acorn European Fund and Columbia Acorn International.

The opening of the Iron Curtain in 1989 presented Europeans with many challenges and opportunities. Today, Central and Eastern Europe are peppered with infrastructure projects, a large portion of which are being financed by the European Union. Central and Eastern Europe had an affordable and well-trained workforce that has helped to develop a sturdy and competitive industrial landscape between Gdansk and Budapest. Dutch portfolio holding Aalberts Industries, for example, grasped the opportunity this change provided 20 years ago and today has enviable market share in metal hardening, valves and other industrial applications in Poland and the Czech Republic.

Another reason to launch this fund is that there are few European funds available to U.S. investors that have a smaller company focus. Columbia Acorn European Fund is a more concentrated fund. It provides an alternative exposure to a developed economy that is different from its more diversified big brother, Columbia Acorn International.

The team at CWAM is not only one of the largest teams looking at smaller European companies on either side of the Atlantic, it is also, we believe, one of the most experienced. We think that we have the skills needed to deliver superior investment returns by relying on the time-proven CWAM approach that concentrates on fundamentals and invests for the long run.

Christopher J. Olson

Lead Portfolio Manager of Columbia Acorn International Select

Since we normally discuss quarterly or yearly performance in our reports to shareholders, I thought it might be helpful to take a look at the Fund's performance and investment style over the past five years. Since September of 2006, we have experienced a number of different markets, from the last portion of the previous bull market (2006-2008), a global equity market collapse (2008-2009), a major global equity market rally (2009-2011) and an increasing period of uncertainty regarding what comes next (2011 to the present). Over this period, Class Z shares of the Fund returned on average a positive 2.51% per year,* outperforming its benchmark, the S&P Developed Ex-U.S. Between $2B and $10B Index, which dropped 1.15% on average per year. Large-cap international stocks, as measured by the MSCI EAFE Index, were off 3.46% per year and the broader Lipper International Funds Index was down 2.61% per year. At the same time, the Fund has generated this performance with risk measures (a beta of 0.87 and standard deviation of 21%) below its benchmark and the vast majority of its peers.

We attribute this positive performance to a consistent application of the CWAM investment style, which emphasizes careful stock selection and a fundamental analysis of the risks and potential returns of each stock. As we have discussed before, we pay strict attention to company business models, quality of earnings, competence of management and strength of balance sheets. In a concentrated fund with large weights in individual stocks, stock selection is usually the primary driver of performance. While also spending time looking for great stocks, it is very important to focus on the downside risks that are inherent in every business. It is one thing to make profits from investing; it is another to keep them throughout the various economic and market cycles.

This attention to the downside risks in Fund holdings led me to begin reducing the Fund's weighting in financials in the second half of 2007 and, by the time the crisis hit in 2008, it had a 2% weight in the sector versus 20% in its benchmark. While valuations looked reasonable for the sector, investors were missing the inherent risks on the banks' balance sheets and entirely inappropriate funding structure. The risk to the downside, and potential loss of shareholder funds, was too great to warrant an investment in the sector. Ironically, this was a sector that had helped drive Fund performance through the last bull market in 2006 and 2007, when the Fund was overweight with a 25% allocation to financials, mainly banks. Every investment has a beginning and an end, and it is just as important to pay attention to the last part. While the Fund was down 42% in 2008, it did outperform its benchmark by 3.5% due to its more conservative positioning.

* Class Z share returns each year at September 30 were: 36.67% in 2007; -26.39% in 2008; -0.35% in 2009; 18.01% in 2010; and -4.31% in 2011.

After an approximately 100% rise in the global equity markets from 2009 to 2011, the Fund found itself in a similar position this year, as valuations did not appear to be adequately discounting risk to company earnings from a still wounded global financial system and an uncertain economic outlook. While the Fund had not gone back into the banking sector after the crash, and so has not needed to reduce risk in that sector, I have taken a more cautious view of investments in general. In fact, past economic woes have weighed heavily on the Fund's overweight position in industrial stocks, which detracted from performance four of the last five years. As a result, the Fund is biased toward less cyclical companies, very strong balance sheets, cash generative operations and strong market positions. In a highly uncertain world, a bias toward high and sustainable dividend yields is also appropriate and the underlying stock portfolio's current yield at September 30, 2011, was approximately 3%.

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

Stocks of small- and mid-cap companies pose special risks, including possible illiquidity and greater price volatility than stocks of larger, more established companies. International investing involves special risks, including foreign taxation, currency risks, risks associated with possible differences in financial standards and other risks associated with future political and economic developments. 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. A fund that maintains a relatively concentrated portfolio may be subject to greater risk than a fund that is more fully diversified.

Columbia Acorn Fund

In a Nutshell



Charles P. McQuaid				Robert A. Mohn

Lead Portfolio Manager				Co-Portfolio Manager

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

Fund's Positions
in Mentioned Holdings

As a percentage of net assets, as of 9/30/11

Alexion Pharmaceuticals	1.8	%
Ametek	1.5	%
Informatica	1.3	%
BioMarin Pharmaceutical	0.9	%
Fugro	0.9	%
Cepheid	0.8	%
IPG Photonics	0.8	%
Polycom	0.5	%
Hexagon	0.4	%
InterMune	0.3	%
WABCO Holdings	0.3	%

During the third quarter of 2011, the stock market appeared to be dominated by concerns about the economic outlook for much of the world, especially Europe and China. Columbia Acorn Fund fell 19.66%, somewhat less than its primary benchmark, the Russell 2500 Index, which plunged 21.22%. Year to date, the Fund was down 13.89% versus a 14.87% drop in its benchmark. Comparisons against other benchmarks are shown on Page 2.

Many portfolio technology stocks were among the hardest hit in the quarter. Data integration software provider Informatica was the Fund's largest dollar loser, off 30%. Fiber laser producer IPG Photonics was the Fund's second largest dollar loser, down 40%. Another significant dollar dropper was video conferencing equipment provider Polycom, which fell over 40%. All three companies had excellent fundamental results and stock returns in the first half of the year, but do have substantial exposure overseas. Furthermore, IPG was involved in patent litigation, since resolved favorably, and Polycom was subject to concerns about increasing competition, which were confirmed after the end of the third quarter.

Several industrial stocks were also discounted due to macroeconomic uncertainties. Aerospace and industrial instruments maker Ametek fell 26%. Design and measurement equipment provider Hexagon fell especially hard, down 47% on fears of its exposure to emerging markets. Both companies had reported fine first half results and, as of press time, we've seen no significant fundamental slowdown for either company. Truck components supplier WABCO Holdings fell 45% despite management's September 8 disclosure of increasing orders and low dealer inventories.

Drug companies accounted for all three top dollar winners in the quarter. Alexion Pharmaceuticals jumped 36%. It announced a surprisingly positive clinical study suggesting that its auto-immune drug, Soliris, is effective in treating a severe neurological condition. Should Soliris be approved for that purpose, we believe its sales potential would double. Orphan drug developer BioMarin Pharmaceutical gained 17% while molecular diagnostic instrument producer Cepheid rose 12%. BioMarin's drug pipeline appeared increasingly positive while Cepheid had good financial results and increased its guidance for the year. On the downside, InterMune plunged 44% as management quashed takeover speculation.

Columbia Acorn Fund's international stocks underperformed the Fund's domestic stocks in the quarter, dropping 24%. Hexagon, mentioned above, was the largest international dollar loser. Following closely was offshore oil service company Fugro, which fell 30% on disappointing results. Demand is somewhat weaker than expected, resulting in underutilization of capacity. Foreign stocks accounted for 10.0% of Columbia Acorn Fund's assets at the end of the quarter, down from 10.8% at end of the half and 12.6% at the end of 2010.

A year ago we discussed concerns about the economy and noted: "Based on what our real-world companies are telling us, our current opinion is that slow growth will persist..." Slow growth did indeed persist. Reports from our companies remain generally, but not universally, positive. Given current stock valuations, if world leaders begin solving economic concerns, we think stocks should perform well.

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

Columbia Acorn Fund (ACRNX)

At a Glance

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

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

through September 30, 2011

*Inception 6/10/70*	Year to date*			1 year			5 years			10 years
Returns before taxes		-13.89	%		-1.34	%		1.55	%		9.06	%
Returns after taxes on distributions		-14.10			-2.01			0.88			8.51
Returns after taxes on distributions and sale of fund shares		-8.80			0.04			1.35			8.04
Russell 2500 Index (pretax)**		-14.87			-2.22			0.19			7.08

All results shown assume reinvestment of distributions.

*Year to date data is not annualized

**The Fund's primary benchmark.

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

The Fund's Class Z annual operating expense ratio, as stated in the current prospectus, is 0.76%.

Columbia Acorn Fund Portfolio Diversification

as a percentage of net assets, as of 9/30/11

Columbia Acorn Fund Top 10 Holdings

as a percentage of net assets, as of 9/30/11

1.	lululemon athletica Premium Active Apparel Retailer	2.4	%
2.	Alexion Pharmaceuticals Biotech Focused on Orphan Diseases	1.8	%
3.	FMC Technologies Oil & Gas Wellhead Manufacturer	1.5	%
4.	Crown Castle International Communications Towers	1.5	%
5.	Donaldson Industrial Air Filtration	1.5	%
6.	Mettler Toledo Laboratory Equipment	1.5	%
7.	Ametek Aerospace/Industrial Instruments	1.5	%
8.	Abercrombie & Fitch Teen Apparel Retailer	1.4	%
9.	Informatica Enterprise Data Integration Software	1.3	%
10.	tw telecom Fiber Optic Telephone/Data Services	1.0	%

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 Fund (Class Z)

June 10, 1970 through September 30, 2011

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

Total Net Assets of the Fund: $15.1 billion

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

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

Columbia Acorn International

In a Nutshell



P. Zachary Egan				Louis J. Mendes III

Co-Portfolio Manager				Co-Portfolio Manager

Fund's Positions
in Mentioned Holdings

As a percentage of net assets, as of 9/30/11

Hexagon	1.0	%
Gree	0.6	%
Rheinmetall	0.6	%
Japan Airport Terminal	0.6	%

Columbia Acorn International was down 18.23% in the third quarter of 2011, which brought the year-to-date return through September to negative 15.77%. The Fund was modestly ahead of its primary benchmark, the S&P Global Ex-U.S. Between $500M and $5B Index, in both periods. Results were strongly shaped by the month of September, during which the Fund fell 13.15% as anxiety about European sovereign debt reached a fever pitch.

Unsurprisingly, continental European holdings led the decline, losing almost one-fourth of their value in the third quarter. Globally, stocks exposed to the industrial cycle—capital goods, automobiles and components, energy and materials—also fared poorly, as investors braced for a possible economic contraction not yet factored into expectations. Swedish measurement equipment manufacturer Hexagon has been a core holding in the Fund for many years, and is reflective of the high-quality businesses that we try to buy at reasonable prices. Its stock fell a stunning 47% during the third quarter, even after reporting solid growth and record profitability in the second quarter of its fiscal year. Rheinmetall, a German automotive supplier and defense contractor, was also down 47%, despite hiking its own earnings targets for the year as recently as July.

Japan was a strong relative outperformer in the quarter, with modest losses buoyed by a strengthening yen. Some Japanese stocks were even up a lot, which demonstrates the advantages of geographic diversification within the portfolio, paying close attention to valuation, and taking reigning macroeconomic views with a grain of salt. Japan Airport Terminal, which operates Tokyo's second largest international airport, returned over 28% on improved international passenger volumes. Gaming company Gree was up 40% after posting higher than expected growth in its most recent quarter. Investors are also excited about the company's ability to shift the business toward internally developed games, and about the potential smartphones have to make these games more fun, which could further drive game penetration and pricing.

We are standing by, along with the rest of the world, waiting for European policymakers to manage the risks of sovereign default. While we appreciate the extremely negative consequences of an uncontained default—first on European banks and then on the global economy—we are convinced that the main architects of the common currency are unlikely to let the situation devolve to that point, as it would put the very existence of the currency at risk. The euro is, in our opinion, foremost a political, not economic, institution and the breakup of the Eurozone would register a reversal of a half century-long project of postwar European integration. We believe that key creditor states will be willing to pay for the mistakes of debtor states to avoid such an outcome. Indeed, in the case of default, creditor states would be obliged to pay for these mistakes anyway through the necessary recapitalization of their own banks, which hold much of the toxic debt. Debtor states, therefore, have considerable leverage, which complicates the protracted negotiation, as does defining new limits in the Eurozone on fiscal sovereignty at the national level, a likely product of the crisis.

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

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

Columbia Acorn International (ACINX)

At a Glance

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

through September 30, 2011

*Inception 9/23/92*	Year to date*			1 year			5 years			10 years
Returns before taxes		-15.77	%		-8.55	%		2.53	%		11.39	%
Returns after taxes on distributions		-16.48			-9.33			1.70			10.80
Returns after taxes on distributions and sale of fund shares		-10.14			-5.14			2.19			10.21
S&P Global Ex-U.S. Between $500M and $5B Index**		-17.56			-8.84			1.77			12.15

All results shown assume reinvestment of distributions.

*Year to date data is not annualized

**The Fund's primary benchmark.

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

Columbia Acorn International Portfolio Diversification

as a percentage of net assets, as of 9/30/11

Columbia Acorn International Top 10 Holdings

as a percentage of net assets, as of 9/30/11

1.	Kansai Paint (Japan) Paint Producer in Japan, India, China & Southeast Asia	1.4	%
2.	Melco Crown Entertainment (Hong Kong) Macau Casino Operator	1.1	%
3.	Zhaojin Mining Industry (China) Gold Mining & Refining in China	1.0	%
4.	Alexion Pharmaceuticals (United States) Biotech Focused on Orphan Diseases	1.0	%
5.	Vopak (Netherlands) World's Largest Operator of Petroleum & Chemical Storage Terminals	1.0	%
6.	Gemalto (France) Smart Card Products & Solutions	1.0	%
7.	Olam International (Singapore) Agriculture Supply Chain Manager	1.0	%
8.	Localiza Rent A Car (Brazil) Car Rental	1.0	%
9.	Imtech (Netherlands) Electromechanical & Information & Communications Technologies Installation & Maintenance	1.0	%
10.	Intertek Group (United Kingdom) Testing, Inspection & Certification Services	1.0	%

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 International (Class Z)

September 23, 1992 through September 30, 2011

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

Total Net Assets of the Fund: $5.5 billion

Columbia Acorn USA

In a Nutshell



Robert A. Mohn

Lead Portfolio Manager

Fund's Positions
in Mentioned Holdings

As a percentage of net assets, as of 9/30/11

Informatica	2.6	%
Ametek	2.2	%
Nordson	2.1	%
Alexion Pharmaceuticals	1.7	%
II-VI	1.5	%
Cepheid	1.2	%
BioMarin Pharmaceutical	1.2	%
Atmel	1.1	%
Polycom	0.6	%
Akorn	0.4	%
Acorn Energy	0.2	%

Columbia Acorn USA fell 22.20% in the third quarter of 2011, performing in line with the 21.87% drop of its primary benchmark, the Russell 2000 Index. Year to date, the Fund was off 15.09% versus a 17.02% drop for its benchmark. Markets tumbled as the U.S. credit rating downgrade and the seemingly never-ending crisis in Europe dominated headlines and fueled investor fears.

The Fund's portfolio got caught up in the general riot of selling, crushing stocks that, for the most part, reported solid numbers during the quarter. For example, Informatica, a provider of enterprise data integration software, announced second quarter revenue growth of 24%. Atmel, a leader in touchscreen microcontrollers, reported revenues up 22%. Ametek, a manufacturer of aerospace and industrial instruments, saw revenue growth of 28%. And how did the market respond to these strong revenue gains? By sending the stocks down 26% to 43%, demonstrating the disconnect between current economic reality and the perception of macroeconomic strain.

Two Fund holdings did decline after announcing weaker than expected sales. Nordson, a producer of dispensing systems for adhesives and coatings, fell 27%. II-VI, a manufacturer of laser optics and specialty materials, fell 32%. While results did not meet expectations, both stocks did have sales growth (12% and 16%, respectively). Polycom, a provider of video conferencing equipment, suffered from concerns that competition was heating up, sending its stock down over 40% for the quarter.

Two groups positively affected Fund performance during the quarter, the first being biotech and life sciences stocks. Alexion Pharmaceuticals gained 36% and BioMarin Pharmaceutical rose 17%. Alexion was boosted by a clinical study indicating that its primary drug, Soliris, is effective in treating a severe neurological condition. BioMarin manufactures a number of drugs that have been effective in treating several rare genetic diseases. Cepheid, a provider of molecular diagnostic equipment, has had strong sales of its automated genetic testing instruments, which helped drive its stock up 12%.

While investing in stocks that contain our favorite moniker is not a Fund theme, we were pleased to see that the other "group" that helped performance was the Acorns. Akorn, with a "k," develops, manufactures and distributes generic drugs. Its stock was up 12% in the quarter. Acorn Energy, a natural gas services provider, gained 15%.

The downdraft in the market has made stocks cheaper, but we have seen very little impact to the long-term earnings power of many of the Fund's companies. Historically, when stock prices unhinge from fundamentals and fall in dramatic fashion, it has been a propitious time to invest.

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.

Columbia Acorn USA (AUSAX)

At a Glance

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

through September 30, 2011

*Inception 9/4/96*	Year to date*			1 year			5 years			10 years
Returns before taxes		-15.09	%		-1.14	%		-0.51	%		6.36	%
Returns after taxes on distributions		-15.09			-1.14			-0.84			6.04
Returns after taxes on distributions and sale of fund shares		-9.81			-0.74			-0.40			5.59
Russell 2000 Index (pretax)**		-17.02			-3.53			-1.02			6.12

All results shown assume reinvestment of distributions.

*Year to date data is not annualized

**The Fund's primary benchmark.

The Fund's Class Z shares annual operating expense ratio, as stated in the current prospectus, is 1.01%.

Columbia Acorn USA Portfolio Diversification

as a percentage of net assets, as of 9/30/11

Columbia Acorn USA Top 10 Holdings

as a percentage of net assets, as of 9/30/11

1.	lululemon athletica Premium Active Apparel Retailer	2.7	%
2.	FMC Technologies Oil & Gas Wellhead Manufacturer	2.6	%
3.	Informatica Enterprise Data Integration Software	2.6	%
4.	Ametek Aerospace/Industrial Instruments	2.2	%
5.	Micros Systems Information Systems for Hotels, Restaurants & Retailers	2.2	%
6.	Nordson Dispensing Systems for Adhesives & Coatings	2.1	%
7.	IPG Photonics Fiber Lasers	2.1	%
8.	Abercrombie & Fitch Teen Apparel Retailer	2.0	%
9.	Atwood Oceanics Offshore Drilling Contractor	1.9	%
10.	tw telecom Fiber Optic Telephone/Data Services	1.9	%

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

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

September 4, 1996 through September 30, 2011

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

Total Net Assets of the Fund: $1.4 billion

Columbia Acorn International Select

In a Nutshell

Christopher J. Olson

Lead Portfolio Manager

Fund's Positions
in Mentioned Holdings

As a percentage of net assets, as of 9/30/11

Kansai Paint	5.5	%
Chemring	3.3	%
NHN	2.7	%
Hexagon	2.3	%
Archipelago Resources	2.0	%
Asahi Diamond Industrial	2.0	%
Gree	1.5	%
Rheinmetall	1.5	%
Israel Chemicals	1.4	%
Ain Pharmaciez	1.3	%

Columbia Acorn International Select ended the third quarter of 2011 down 14.67%, outperforming the 18.15% drop of its primary benchmark, the S&P Developed Ex-U.S. Between $2B and $10B Index. Year to date, the Fund was down 11.47%, while its benchmark fell 14.85%. Concerns about the European debt crisis and a possible double-dip recession in the United States caused markets to drop sharply late in the quarter.

Japanese holdings were, once again, strongly represented among the Fund's top contributors due to strong stock selection. Gree, a mobile social networking game developer, rose 36% in the Fund during the quarter. Gree announced higher than expected growth due to the increasing use of smartphones, greater popularity of social networking sites, and the migration of consumer spending from PC-based gaming to mobile phone gaming. Kansai Paint, a paint producer distributing to Japan, India, China and Southeast Asia, was up 5% in the quarter as it stood out with its strong balance sheet and cheap valuation. Ain Pharmaciez, a Japanese drugstore operator, gained 7% in the quarter based on its more defensive nature and better than expected earnings report.

Outside of Japan, NHN, a South Korean online search engine, gained nearly 9% as it released new online game categories and expanded its geographical reach outside of South Korea. Archipelago Resources, a UK-listed gold miner, rose 8% on the successful opening of its flagship Indonesian mine and the installation of a new, well-respected CEO.

Two big detractors to Fund returns in the quarter were European stocks. Swedish measurement equipment manufacturer Hexagon fell 47%. The company reported solid growth and record profitability but its stock fell along with the European markets. Rheinmetall, a German automotive parts supplier and defense contractor, also declined with investor sentiment toward Europe. Its stock fell 47% despite raising earnings projections. In the United Kingdom, another defense contractor, Chemring, fell 20% on the back of further defense cut fears.

Elsewhere, Israel Chemicals, an Israeli chemical producer, fell 25% due to emerging market outflows, political risk aversion and fears surrounding remediation costs near the company's evaporation ponds. Asahi Diamond Industrial, a Japanese manufacturer of consumable diamond tools, lost its sparkle after last quarter's strong performance, falling 36% on fears of slowing global growth.

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

Columbia Acorn International Select (ACFFX)

At a Glance

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

through September 30, 2011

*Inception 11/23/98*	Year to date*			1 year			5 years			10 years
Returns before taxes		-11.47	%		-4.31	%		2.51	%		10.61	%
Returns after taxes on distributions		-11.90			-4.68			2.12			10.40
Returns after taxes on distributions and sale of fund shares		-7.40			-2.65			2.18			9.55
S&P Developed Ex-U.S. Between $2B and $10B Index (pretax)**		-14.85			-6.54			-1.15			9.14

All results shown assume reinvestment of distributions.

*Year to date data is not annualized

**The Fund's primary benchmark.

The Fund's Class Z shares annual operating expense ratio, as stated in the current prospectus, is 1.16%.

Columbia Acorn International Select Portfolio Diversification

as a percentage of net assets, as of 9/30/11

Columbia Acorn International Select Top 10 Holdings

as a percentage of net assets, as of 9/30/11

1.	Ascendas REIT (Singapore) Singapore Industrial Property Landlord	5.5	%
2.	Kansai Paint (Japan) Paint Producer in Japan, India, China & Southeast Asia	5.5	%
3.	Far Eastone Telecom (Taiwan) Taiwan's Third Largest Mobile Operator	4.5	%
4.	Mapletree Industrial Trust REIT (Singapore) Industrial Property Landlord	4.4	%
5.	Seven Bank (Japan) ATM Processing Services	3.6	%
6.	Chemring (United Kingdom) Defense Manufacturer of Countermeasures & Energetics	3.3	%
7.	Rand Merchant Insurance (South Africa) Directly Sold Property & Casualty Insurance; Holdings in Other Insurers	3.0	%
8.	Zhaojin Mining Industry (China) Gold Mining & Refining in China	2.8	%
9.	JLT Group (United Kingdom) International Business Insurance Broker	2.7	%
10.	NHN (South Korea) South Korea's Largest Online Search Engine	2.7	%

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

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

November 23, 1998 through September 30, 2011

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

Total Net Assets of the Fund: $366.9 million

Columbia Acorn Select

In a Nutshell



Ben Andrews				Robert A. Chalupnik

Lead Portfolio Manager				Co-Portfolio Manager

Fund's Positions
in Mentioned Holdings

As a percentage of net assets, as of 9/30/11

Hertz	5.0	%
CNO Financial Group	4.7	%
WNS	3.8	%
Sanmina-SCI	3.1	%
Skullcandy	0.3	%
Horizon Pharma	0.1	%

Columbia Acorn Select fell 23.54% in the third quarter of 2011 and, year to date, was off 23.52% as of the end of September. The S&P MidCap 400 Index, the Fund's primary benchmark, was down 19.88% in the third quarter and year-to-date performance was off 13.02%. The large-cap S&P 500 Index fell 13.87% in the third quarter and was down 8.68% year to date.

Stock market performance has been very volatile lately, with a percent or more move up or down each day becoming common. The drivers of these movements seem to be the potential fallout from the Eurozone debt crisis, as well as a tremendous amount of uncertainty about the health of our domestic economy. This uncertainty, or fear factor, is affecting certain types of stocks more than others. Unfortunately, the Fund owns a handful of the more-affected stocks.

In 2008, we saw big valuation disparities between different types of stocks as well. The freezing of credit markets in 2008 caused companies with debt to go down much more than companies without it. This time around, it seems that many investors are acting like the United States is going to experience another 2008-type crisis. Investors have pushed down the valuations of groups of stocks that they think will suffer more in a crisis environment.

Looking at a sampling of the Fund's portfolio, we see that its investments in Hertz and Sanmina-SCI, as well as Colombian oil companies, have been drastically slashed by the market. These stocks have traded down much more than the average stock, but at least one thing is different now than in 2008: the fundamentals of these companies have remained relatively strong. We believe that the severe sell-off in their share prices is based on a perceived fear rather than current poor fundamentals. We also believe that these companies have improved their balance sheets and competitive position since 2008. We think this fear is overblown. These stocks are priced as if we are in a rough recession but we don't believe we will have a 2008-type crisis this year or next year. If this is true, then we believe many of the Fund's stocks that are being priced like the world is going to stop revolving could rally back strongly.

Looking at the larger positive and negative drivers in the quarter, WNS added 0.7% to Fund overall performance while Hertz cost the Fund 3%. CNO Financial Group cost the overall portfolio 1.6% and Sanmina-SCI cost it 1.5% in the quarter.

During the quarter we sold out of two positions and purchased two new companies. The sales: Navigant Consulting, whose fundamentals continued to disappoint, and Chemspec, which had a management-led leveraged buyout. On the buy side, we added Horizon Pharma and Skullcandy, two busted IPOs that we deemed to be undervalued with positive fundamentals.

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. The Fund is a non-diversified fund and may, therefore, have a greater risk of loss from a few issuers than a similar fund that invests more broadly. The Fund may not operate as a non-diversified fund at all times. International investments involve greater potential risks, including less regulation, currency fluctuations, economic instability and political developments.

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

Columbia Acorn Select (ACTWX)

At a Glance

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

through September 30, 2011

*Inception 11/23/98*	Year to date*			1 year			5 years			10 years
Returns before taxes		-23.52	%		-12.78	%		-0.86	%		6.82	%
Returns after taxes on distributions		-23.98			-13.29			-1.17			6.54
Returns after taxes on distributions and sale of fund shares		-15.22			-8.23			-0.74			5.99
S&P MidCap 400 Index (pretax)**		-13.02			-1.28			2.20			7.50

All results shown assume reinvestment of distributions.

*Year to date data is not annualized

**The Fund's primary benchmark.

The Fund's Class Z shares annual operating expense ratio, as stated in the current prospectus, is 0.97%.

Columbia Acorn Select Portfolio Diversification

as a percentage of net assets, as of 9/30/11

Columbia Acorn Select Top 10 Holdings

as a percentage of net assets, as of 9/30/11

1.	Discover Financial Services Credit Card Company	6.5	%
2.	Hertz Largest U.S. Rental Car Operator	5.0	%
3.	CNO Financial Group Life, Long-term Care & Medical Supplement Insurance	4.7	%
4.	Abercrombie & Fitch Teen Apparel Retailer	4.4	%
5.	Crown Castle International Communications Towers	4.1	%
6.	Ametek Aerospace/Industrial Instruments	4.1	%
7.	WNS (India) Offshore Business Process Outsourcing Services	3.8	%
8.	Pacific Rubiales Energy (Colombia) Oil Production & Exploration in Colombia	3.6	%
9.	Coach Designer & Retailer of Branded Leather Accessories	3.4	%
10.	Safeway Supermarkets	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)

November 23, 1998 through September 30, 2011

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

Total Net Assets of the Fund: $1.3 billion

Columbia Thermostat Fund

In a Nutshell

Charles P. McQuaid

Lead Portfolio Manager

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 fell 6.92% in the third quarter of 2011, outperforming the 13.87% drop of its primary equity benchmark, the S&P 500 Index, and underperforming the 3.82% increase of the Fund's primary debt benchmark, the Barclays Capital U.S. Aggregate Bond Index. Year to date, the Fund was down 2.59% while the S&P 500 Index was off 8.68% and the Barclays index rose 6.65%.

The Fund hit five reallocation triggers during the third quarter. Three of these movements increased exposure to stock funds, as the Fund bought on the weakness in equities. The largest single increase was from 50% to 70% into stock funds in early August, as the Fund's "31-day Rule" fortuitously prevented the Fund from increasing equities earlier during the market rout.* In September, stocks regained some ground causing the Fund to raise its income exposure. Columbia Thermostat Fund ended the period with a 65% exposure to its underlying stock funds and 35% exposure to its underlying bond funds.

The bond portion of the portfolio outperformed the equity portion in this volatile quarter with a 2.24% weighted average return versus a 16.42% weighted average loss for equities. Columbia U.S. Treasury Index Fund was the top performing holding for the quarter, up 6.40%. Year-to-date results were similar with leading gains coming from the bond portion of the portfolio, while the equity portion showed losses for all stock fund holdings and a weighted loss for the year-to-date period.

Market moves in the third quarter were impacted by investor sentiment as dire headlines caused investors to run for cover. The price ranges and allocation levels used by Columbia Thermostat Fund are designed to remove investor emotion from the investment process and automatically buy stock funds when the market is down and sell when the market rises.

*As stated in the Fund's prospectus, the 31-day Rule prohibits a reversal within 31 days. Because the Fund bought bond funds in early July, it could not add to stock funds until 31 days had passed.

Results of the Funds Owned in Columbia Thermostat Fund as of September 30, 2011

Stock Funds	Weighting			3rd			Year to
Fund	in category			quarter			date
Columbia Acorn International, Class I		20	%		-18.20	%		-15.70	%
Columbia Dividend Income Fund, Class I		20	%		-10.48	%		-5.05	%
Columbia Acorn Fund, Class I		15	%		-19.65	%		-13.85	%
Columbia Marsico Growth Fund, Class I		15	%		-16.20	%		-10.93	%
Columbia Acorn Select, Class I		10	%		-23.43	%		-23.40	%
Columbia Contrarian Core Fund, Class I		10	%		-15.99	%		-11.24	%
Columbia Large Cap Enhanced Core Fund, Class I		10	%		-13.37	%		-6.52	%
*Weighted Average* *Equity Loss*		*100*	%		*-16.42*	%		*-12.06*	%
Bond Funds	Weighting			3rd			Year
Fund	in category			quarter			to date
Columbia Intermediate Bond Fund, Class I		50	%		2.39	%		5.09	%
Columbia U.S. Treasury Index Fund, Class I		30	%		6.40	%		8.56	%
Columbia Income Opportunities Fund, Class I		20	%		-4.23	%		-0.03	%
*Weighted Average* *Income Return*		*100*	%		*2.24*	%		*5.13*	%

Columbia Thermostat Fund
Rebalancing in the Third Quarter

July 8, 2011				50% stocks, 50% bonds
August 8, 2011				70% stocks, 30% bonds
August 9, 2011				75% stocks, 25% bonds
September 9, 2011				70% stocks, 30% bonds
September 16, 2011				65% stocks, 35% bonds

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

Columbia Thermostat Fund (COTZX)

At a Glance

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

through September 30, 2011

*Inception 9/25/02*	Year to date*			1 year			5 years			Life of fund
Returns before taxes		-2.59	%		4.59	%		3.52	%		6.86	%
Returns after taxes on distributions		-3.00			4.05			2.20			5.65
Returns after taxes on distributions and sale of fund shares		-1.67			3.12			2.41			5.44
S&P 500 Index (pretax)**		-8.68			1.14			-1.18			5.73
Barclays Capital U.S. Aggregate Bond Index (pretax)**		6.65			5.26			6.53			5.36
Lipper Flexible Portfolio Funds Index (pretax)		-7.00			-0.22			1.97			6.59

All results shown assume reinvestment of distributions.

*Year to date data is not annualized

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

The Fund's Class Z annual operating expense ratio, as stated in the current prospectus, reflects a contractual fee waiver and expense reimbursement with CWAM that expires April 30, 2012. Expense ratios without and with the contractual waiver/reimbursement, including fees and expenses associated with the Fund's investment in other investment companies, are 1.16% and 1.04%, respectively. Absent the waiver or reimbursement, performance results would have been lower.

Columbia Thermostat Fund Asset Allocation

as a percentage of net assets, as of 9/30/11

Columbia Thermostat Fund Portfolio Weightings

as a percentage of assets in each investment category, as of 9/30/11

Stock Mutual Funds

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

Bond Mutual Funds

Columbia Intermediate Bond Fund, Class I	50	%
Columbia U.S. Treasury Index Fund, Class I	30	%
Columbia Conservative High Yield Fund, Class I	20	%

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

September 25, 2002 through September 30, 2011

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

Total Net Assets of the Fund: $135.0 million

Columbia Acorn Emerging Markets Fund

In a Nutshell



Fritz Kaegi				Stephen Kusmierczak

Lead Portfolio Manager				Lead Portfolio Manager



P. Zachary Egan				Louis J. Mendes

Co-Portfolio Manager				Co-Portfolio Manager

Fund's Positions
in Mentioned Holdings

As a percentage of net assets, as of 9/30/11

Komercni Banka	2.5	%
Kansai Paint	1.4	%
Melco Crown Entertainment	1.3	%
China Yurun Food	0.4	%

As of the 2011 third quarter end, Columbia Acorn Emerging Markets Fund was down 11.60% since its inception on August 19, 2011, outperforming its primary benchmark, the S&P Emerging Markets Between $500M and $5B Index, by 2.7%.

During the Fund's six-week performance period, most of its stocks lost value, although there were a few with positive absolute returns. Kansai Paint, a Japanese paint company making the majority of its profits in emerging markets, was up over 8%. One of the leading banks in the Czech Republic, Komercni Banka, was up about 4% on diminished worries about European credit risk and undercapitalized banks. The Czech Republic has not experienced the credit excesses observed in many developed markets and the bank appears substantially better funded than its EU peers.

Two of the most significant performance detractors were in China. China Yurun Food, an integrated pork producer, is one of the country's top three meat processors. Its shares dropped 54% as the company has been unable to pass on record high hog prices, squeezing margins. Melco Crown Entertainment operates casinos in Macau, a gaming market now estimated to be four times as large as Las Vegas. Melco's shares fell 33% following concerns that China's economy is slowing.

In this first quarterly report, we want to share some information on how we construct the Fund. At CWAM, analysts drive our Funds' stock selection. We want the people closest to our investments to take ownership of their decisions and not feel they have to cater to the prejudices (actual or perceived) of the portfolio managers. We as portfolio managers allocate capital among the analysts, are analysts in our own right, and control the Fund's sector and country weights. CWAM analysts try to avoid short-term macro prognostications, since we believe the insight we can achieve at the company level is a lot better than at the national or global level.

The Fund's portfolio has some notable weighting differences from its benchmark. It is meaningfully overweight in the consumer discretionary sector, so our stocks are more exposed to important, and likely durable, trends creating prosperity in emerging markets: urbanization, better education, more effective capital deployment and increasing labor participation by women. Growing incomes in emerging markets should enable consumers to spend more, which we believe will increase valuations of our portfolio companies. On the other hand, the Fund is underweight financials. We've tried to focus on owning companies with defensible business models and higher quality balance sheets, with a goal to outperform the Fund's benchmark in falling markets and keep up in strong bull markets.

In this period of extreme volatility, we see considerable opportunity in emerging markets. Valuations look reasonable compared to developed market peers and historical prices. We think short-term market disruptions provide an attractive entry point for many emerging market equities.

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

Columbia Acorn Emerging
Markets Fund (CEFZX)

At a Glance

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

through September 30, 2011

*Inception 8/19/11*	Life of fund*
Returns before taxes		-11.60	%
Returns after taxes on distributions		-11.60
Returns after taxes on distributions and sale of fund shares		-7.54
S&P Emerging Markets Between $500M and $5B Index (pretax)**		-14.28

All results shown assume reinvestment of distributions.

*Reflects performance from Fund inception on 8/19/11 through 9/30/11.

**The Fund's primary benchmark.

The Fund's Class Z annual operating expense ratio, as stated in the current prospectus, is 1.58%. Columbia Acorn Emerging Markets Fund has a contractual fee waiver and expense reimbursement agreement with CWAM that expires April 30, 2013; expense ratios without and with the contractual waiver/reimbursement are 1.58%.

Columbia Acorn Emerging Markets Fund Sector Diversification

as a percentage of net assets, as of 9/30/11

Columbia Acorn Emerging Markets Fund Regional Diversification

as a percentage of equity, as of 9/30/11

Columbia Acorn Emerging Markets Fund Top 10 Holdings

as a percentage of net assets, as of 9/30/11

1.	Adcock Ingram Holdings (South Africa) Manufacturer of Pharmaceuticals & Medical Supplies	2.8	%
2.	Archipelago Resources (United Kingdom) Gold Mining Projects in Indonesia, Vietnam & the Philippines	2.6	%
3.	Ace Indonesia (Indonesia) Home Improvement Retailer	2.6	%
4.	Alliance Grain Traders (Canada) Global Leader in Pulse Processing & Distribution	2.6	%
5.	Komercni Banka (Czech Republic) Leading Czech Universal Bank	2.5	%
6.	Coronation Fund Managers (South Africa) South African Fund Manager	2.4	%
7.	Rand Merchant Insurance (South Africa) Directly Sold Property & Casualty Insurance; Holdings in Other Insurers	2.4	%
8.	Grupo Aeroportuario del Sureste (Mexico) Mexican Airport Operator	2.3	%
9.	Dufry Group (Switzerland) Operates Airport Duty Free & Duty Paid Shops	2.3	%
10.	Localiza Rent A Car (Brazil) Car Rental	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.

Total Net Assets of the Fund:
$2.6 million

Columbia Acorn European Fund

In a Nutshell



Andreas Waldburg-Wolfegg				Stephen Kusmierczak

Lead Portfolio Manager				Co-Portfolio Manager

Fund's Positions
in Mentioned Holdings

As a percentage of net assets, as of 9/30/11

Charles Taylor	2.3	%
Vopak	2.3	%
JLT Group	2.1	%
Workspace Group	1.1	%
Elringklinger	1.1	%
Shaftesbury	0.1	%

August 2011 may appear to be an odd time to launch a European fund. As Zach Egan and Louis Mendes point out in the Columbia Acorn International "Nutshell," barely a week after the Fund's launch, European equities saw sharp declines, the sharpest anywhere in the world in that period. It looks as if we kept to the advice attributed to Martin Luther: When everybody predicts the end of the world, go and plant an apple tree.

And plant we did. In assembling Columbia Acorn European Fund, we looked very closely at the stocks that we've been following in other CWAM-advised funds. It may not come as a total surprise that we opted to underweight financials in the Fund versus its primary benchmark, the S&P Europe Between $500M and $5B Index, which has a financials weighting of 21%. The financials the Fund does own—roughly a 9% weighting—are as far removed from "ordinary" finance companies as possible. The five stocks the Fund owns in this segment all operate in niches that we believe will continue to grow throughout the euro crisis, and we don't own a single bank at the moment. The Fund's two largest positions in this segment are JLT Group and Charles Taylor, both based in the United Kingdom. Both companies provide specialized services to the insurance industry worldwide and therefore should only be marginally affected by the vagaries of the euro-area. The Fund also owns two real estate companies with interesting portfolios of assets. Shaftesbury concentrates on prime retail properties in greater London and Workspace Group has a portfolio of affordable, short-term lease properties.

Another large underweight is consumer staples (5% of the benchmark), where we have had a hard time finding both interesting business models and attractive valuations. In the consumer discretionary sector, on the other hand, we've been able to assemble a collection of interesting businesses at very attractive prices and are slightly overweight versus the benchmark. Businesses the Fund owns in this segment include Elringklinger, a German company dominating several niche-like markets in the automotive industry.

The Fund's two largest overweights versus the benchmark are industrials and information technology. Both are the result of stock-specific selections. We would argue, for instance, that Vopak, the Netherlands-based global provider of storage capacities for the oil and gas industry, should not be classified as an industrial, and yet it is. Nevertheless, we believe the companies that we've selected in this segment are well-managed and we have followed them for a number of years.

After only six weeks of trading, the Fund's 5.90% drop outperformed its benchmark, which fell 7.55% for the same period. The Fund's positioning gives us great confidence: a collection of businesses that we believe have strong market share, display above-average operating metrics, and possess business models that we believe should allow them to gain market share in a possible downturn in their respective markets.

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

Columbia Acorn
European Fund (CAEZX)

At a Glance

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

through September 30, 2011

*Inception 8/19/11*	Life of fund*
Returns before taxes		-5.90	%
Returns after taxes on distributions		-5.90
Returns after taxes on distributions and sale of fund shares		-3.84
S&P Europe Between $500M and $5B Index (pretax)**		-7.55

All results shown assume reinvestment of distributions.

*Reflects performance from Fund inception on 8/19/11 through 9/30/11.

**The Fund's primary benchmark.

The Fund's Class Z annual operating expense ratio, as stated in the current prospectus, is 1.50%. Columbia Acorn European Fund has a contractual fee waiver and expense reimbursement agreement with CWAM that expires April 30, 2013; expense ratios without and with the contractual waiver/reimbursement are 1.51% and 1.50%, respectively.

Columbia Acorn European Fund Sector Diversification

as a percentage of net assets, as of 9/30/11

Columbia Acorn European Fund Country Diversification

as a percentage of equity, as of 9/30/11

Columbia Acorn European Fund Top 10 Holdings

as a percentage of net assets, as of 9/30/11

1.	1000mercis (France) Interactive Advertising and Marketing	4.9	%
2.	Geberit (Switzerland) Plumbing Supplies	3.4	%
3.	Gemalto (France) Smart Card Products & Solutions	3.3	%
4.	Chemring (United Kingdom) Defense Manufacturer of Countermeasures & Energetics	3.0	%
5.	Eurofins Scientific (France) Food, Pharmaceuticals & Materials Screening & Testing	2.9	%
6.	Wirecard (Germany) Online Payment Processing & Risk Management	2.8	%
7.	Sweco (Sweden) Engineering Consultants	2.7	%
8.	Neopost (France) Postage Meter Machines	2.7	%
9.	Intertek Group (United Kingdom) Testing, Inspection & Certification Services	2.5	%
10.	Imtech (Netherlands) Electromechanical & Information & Communications Technologies Installation & Maintenance	2.4	%

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.

Total Net Assets of the Fund:
$1.6 million

Columbia Acorn Fund

Major Portfolio Changes in the Third Quarter (Unaudited)

	Number of Shares
	06/30/11		09/30/11
Purchases
Information
Atmel		8,130,000		9,065,000
Boingo Wireless		1,200,000		1,400,000
Carbonite		0		362,577
Constant Contact		1,950,000		2,350,000
Finisar		1,725,000		1,905,000
Gemalto (France)		0		230,000
Genpact		781,635		1,575,000
iGATE		2,900,000		3,307,204
ON Semiconductor		5,117,000		6,202,000
Polycom		2,455,000		4,130,000
RPX		0		505,000
Syntel		580,000		680,000
Tangoe		0		313,100
TIBCO		1,381,600		2,000,000
TriQuint Semiconductor		1,750,000		2,290,000
Verisk Analytics		900,000		1,400,000
WNS - ADR (India)		1,027,147		1,076,353
Consumer Goods & Services
Cavco Industries		415,000		460,000
CTS Eventim (Germany)		173,436		320,000
GLG Life Tech (Canada)		1,200,000		1,750,000
HomeAway		1,289,880		1,400,000
lululemon athletica		3,991,265		7,490,000
New Oriental Education & Technology - ADR (China)		200,000		800,000
Pinnacle Entertainment		3,400,000		3,950,000
PVH		0		1,410,000
Skullcandy		0		975,000
Teavana		0		971,500
Thor Industries		1,980,000		2,180,000
Vail Resorts		1,250,000		1,470,000
Industrial Goods & Services
Acorn Energy		0		1,336,001
Albemarle		1,650,000		1,750,000
Chicago Bridge & Iron		0		1,725,000
Clean Harbors		280,000		560,000
FMC Corporation		650,000		760,000
Generac		1,600,000		1,667,021
GrafTech International		2,340,000		4,000,000
Kennametal		2,900,000		3,200,000
Waste Connections		1,672,500		2,400,000
Energy & Minerals
Black Diamond Group (Canada)		528,300		1,056,600
Celtic Exploration (Canada)		175,400		631,000
Crew Energy (Canada)		484,500		847,000

	Number of Shares
	06/30/11		09/30/11
Duluth Exploration - Special Warrants (Canada)		0		500,000
Duluth Metals (Canada)		3,816,400		7,500,000
Mongolian Mining (Hong Kong)		5,215,500		12,000,000
Finance
Artio Global Investors		0		1,000,000
City National		1,145,000		1,275,000
CNO Financial Group		9,400,000		11,900,000
Delphi Financial Group		1,000,000		1,200,000
Eaton Vance		3,391,000		3,700,000
Enstar Group		33,746		150,000
First Busey		4,056,427		4,299,507
H & E Equipment Services		3,000,000		3,400,000
TrustCo Bank		0		779,305
Wright Express		0		100,000
Health Care
Adcock Ingram Holdings (South Africa)		2,393,955		2,859,820
Akorn		4,000,000		4,788,400
Alimera Sciences		1,818,154		2,040,000
eResearch Technology		4,250,000		4,900,000
Gen-Probe		700,000		860,000
HealthSouth		0		1,725,000
Hill-Rom Holdings		0		625,100
HMS Holdings		400,000		850,000
Horizon Pharma		0		870,000
Mednax		0		665,000
Raptor Pharmaceutical		0		3,455,000
Seattle Genetics		4,181,000		4,200,000
Other Industries
Associated Estates Realty		2,700,000		3,000,000
St. Joe		699,701		1,000,000
Summit Hotel Properties		1,481,994		1,500,000

	Number of Shares
	06/30/11		09/30/11
Sales
Information
Actuate		1,500,000		0
Acxiom		1,560,000		0
Applied Micro Circuits		1,650,000		0
Blackboard		1,700,000		0
Blue Coat Systems		313,300		0
Crown Castle International		6,000,000		5,700,000
Dolby Laboratories		815,000		605,000
Entegris		5,000,000		4,000,000
FLIR Systems		600,000		0
Hong Kong Exchanges and Clearing (Hong Kong)		750,000		0
IMAX (Canada)		1,400,000		1,250,000
MetroPCS Communications		1,000,000		600,000
Navigant Consulting		3,100,000		3,000,000
Paetec Holding		9,600,000		9,000,000
Salem Communications		1,541,000		1,533,400
Spanish Broadcasting System		2,400,000		177,700
SRA International		1,583,750		0
Supertex		935,000		644,280
TheStreet.com		1,000,000		656,585
Tyler Technologies		2,000,000		1,700,000
WMS Industries		2,100,000		1,741,367
Consumer Goods & Services
Avis Budget Group		4,600,000		4,000,000
Blue Nile		62,784		0
Chico's FAS		1,933,750		0
Crocs		1,400,000		580,000
Diamond Foods		1,170,000		1,050,000
Expedia		3,900,000		3,100,000
Guess?		1,980,000		1,455,000
Hansen Natural		1,900,000		1,780,000
Herman Miller		2,800,000		2,250,000
ITT Educational Services		350,000		300,000
P.F. Chang's China Bistro		480,000		0
Penn National Gaming		1,590,000		1,100,000
Phillips-Van Heusen		1,410,000		0
Talbots		828,500		0
True Religion Apparel		2,047,000		1,747,000
Universal Technical Institute		1,700,000		1,400,000
Zuoan Fashion (China)		100,197		36,037
Industrial Goods & Services
Albany International		1,100,000		900,000
Clarcor		2,565,000		2,325,000
Greif		350,000		0
Hutchison Port Holdings Trust (Hong Kong)		10,000,000		0

	Number of Shares
	06/30/11		09/30/11
Ibiden (Japan)		600,000		0
Jain Irrigation Systems (India)		3,500,000		3,450,000
Mersen (France)		524,000		495,086
Mine Safety Appliances		1,300,000		926,962
Nalco		831,000		0
Neopost (France)		287,000		265,907
Novozymes (Denmark)		340,000		305,000
Oshkosh Corporation		3,650,000		2,675,000
Republic Services		1,000,000		0
Sika (Switzerland)		10,000		8,000
Simpson Manufacturing		360,073		0
TrueBlue		1,050,000		0
UTI Worldwide		1,000,000		750,000
Watsco		100,000		0
WW Grainger		900,000		605,000
Energy & Minerals
Carrizo Oil & Gas		293,000		0
Core Labs (Netherlands)		641,000		545,000
Houston American Energy		1,200,000		1,143,800
PetroMagdalena Energy (Colombia)		42,580,500		6,866,628
Primary Petroleum (Canada)		2,245,000		0
ShaMaran Petroleum (Iraq)		27,063,400		27,000,000
Southwestern Energy		1,650,000		1,389,000
Tahoe Resources (Canada)		236,400		0
Tuscany International Drilling (Colombia)		9,519,200		8,870,000
Ultra Petroleum		910,000		383,000
Union Agriculture Group (Argentina)		6,818,182		1,136,364
Finance
Alliance Data Systems		400,000		350,000
Associated Banc-Corp		5,413,800		4,487,800
BOK Financial		2,800,000		2,738,000
GATX		90,020		0
Green Bankshares		583,872		158,389
Investment Technology Group		629,493		0
McGrath Rentcorp		2,350,000		2,150,000
Shinsei Bank (Japan)		3,764,300		0
SVB Financial Group		1,160,000		910,000
Symetra Financial		1,600,000		694,343
TCF Financial		3,613,000		3,000,000
Valley National Bancorp		6,304,320		5,700,000
ViewPoint Financial		1,024,069		700,000

Columbia Acorn Fund

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

	Number of Shares
	06/30/11		09/30/11
Sales (continued)
Health Care
Array Biopharma		3,500,000		0
Community Health Systems		1,655,000		1,625,000
Edwards Lifesciences		1,000,000		340,000
Idenix Pharmaceuticals		2,300,000		0
Idexx Laboratories		500,000		0
Isis Pharmaceuticals		4,500,000		3,430,000
Kindred Healthcare		1,450,000		0
Nabi Biopharmaceuticals		3,300,000		0
Onyx Pharmaceuticals		1,450,000		1,170,000
Owens & Minor		200,000		0
United Therapeutics		780,000		142,825
Other Industries
Corporate Office Properties		900,000		0
Genesee & Wyoming		400,000		300,000
JB Hunt Transport Services		1,730,000		1,275,000
Terna (Italy)		3,333,000		0

Columbia Acorn Fund

Statement of Investments (Unaudited), September 30, 2011

Number of Shares			Value (000)
			Equities: 95.8%
Information 25.8%
		> Business Software 6.9%
	4,700,000	Informatica (a)	$	192,465
		Enterprise Data Integration Software
	2,550,000	ANSYS (a)		125,052
		Simulation Software for Engineers and Designers
	2,700,000	Micros Systems (a)		118,557
		Information Systems for Hotels, Restaurants and Retailers
	1,100,000	Quality Systems (b)		106,700
		IT Systems for Medical Groups & Ambulatory Care Centers
	5,164,999	Hexagon (Sweden)		67,162
		Design, Measurement and Visualization Software and Equipment
	1,480,000	Concur Technologies (a)		55,086
		Web Enabled Cost & Expense Management Software
	2,250,000	Blackbaud (c)		50,107
		Software & Services for Non-Profits
	2,000,000	TIBCO (a)		44,780
		Datacenter Software
	1,700,000	Tyler Technologies (a)(c)		42,976
		Financial, Tax, Court, & Document Mgmt Systems for Local Governments
	2,350,000	Constant Contact (a)(c)		40,631
		Email & Other Marketing Campaign Mgmt Systems Delivered Over the Web
	1,450,000	NetSuite (a)(b)		39,164
		End to End IT Systems Solution Delivered Over the Web
	850,000	Red Hat (a)		35,921
		Maintenance & Support for Opensource OS & Middleware
	1,200,000	Ariba (a)		33,252
		Cost Management Software
	2,025,000	Kenexa (a)(c)		31,671
		Recruiting and Workforce Management Solutions
	920,000	Jack Henry & Associates		26,662
		Systems Financial Institutions
	900,000	SPS Commerce (a)(c)		14,661
		Supply Chain Management Software Delivered via the Web
	690,000	Advent Software (a)		14,387
		Asset Management & Trading Systems
	550,000	Intralinks (a)		4,131
		Collaboration Software
	313,100	Tangoe (a)		3,541
		Software Solution for Managing Communication Expense & Devices
	1,000,000	InContact (a)		3,450
		Call Center Systems Delivered Via the Web & Telco Services
				1,050,356
		> Instrumentation 2.8%
	1,600,000	Mettler Toledo (a)(c)		223,936
		Laboratory Equipment
	2,780,000	IPG Photonics (a)(c)		120,763
		Fiber Lasers

Number of Shares			Value (000)
	2,035,000	Trimble Navigation (a)	$	68,274
		GPS-based Instruments
	400,000	Hamamatsu Photonics (Japan)		16,123
		Optical Sensors for Medical & Industrial Applications
				429,096
		> Computer Hardware & Related Equipment 2.4%
	3,565,000	Amphenol		145,345
		Electronic Connectors
	4,550,000	II-VI (a)(c)		79,625
		Laser Optics and Specialty Materials
	1,605,000	Zebra Technologies (a)		49,659
		Bar Code Printers
	1,200,000	Netgear (a)		31,068
		Networking Products for Small Business & Home
	800,000	Nice Systems - ADR (Israel) (a)		24,280
		Audio & Video Recording Solutions
	605,000	Dolby Laboratories (a)		16,601
		Audio Technology for Consumer Electronics
	605,000	Stratasys (a)		11,217
		Rapid Prototyping Systems
	230,000	Gemalto (France)		10,937
		Digital Security Solutions
				368,732
		> Mobile Communications 2.3%
	5,700,000	Crown Castle International (a)		231,819
		Communications Towers
	3,150,000	SBA Communications (a)		108,612
		Communications Towers
	600,000	MetroPCS Communications (a)		5,226
		Discount Cellular Telephone Services
	1,500,000	Globalstar (a)(b)		614
		Satellite Mobile Voice & Data Carrier
				346,271
		> Telephone and Data Services 2.2%
	9,500,000	tw telecom (a)(c)		156,940
		Fiber Optic Telephone/Data Services
	1,200,000	AboveNet		64,320
		Metropolitan Fiber Communications Services
	9,000,000	PAETEC Holding (a)(c)		47,610
		Telephone/Data Services for Business
	2,520,000	Cogent Communications (a)(c)		33,894
		Internet Data Pipelines
	2,000,000	General Communications (a)		16,400
		Commercial Comm & Consumer CATV, Web & Phone in Alaska
	1,400,000	Boingo Wireless (a)(b)		10,010
		Wholesale and Retail WiFi Networks
				329,174
		> Semiconductors & Related Equipment 1.8%
	9,065,000	Atmel (a)		73,154
		Microcontrollers, RF, and Memory Semiconductors
	6,202,000	ON Semiconductor (a)		44,468
		Mixed Signal & Power Management Semiconductors

Columbia Acorn Fund

Statement of Investments (Unaudited), continued

Number of Shares			Value (000)
		> Semiconductors & Related Equipment—continued
	2,345,000	Microsemi (a)	$	37,473
		Analog/Mixed Signal Semiconductors
	4,000,000	Entegris (a)		25,520
		Semiconductor Materials Management Products
	1,900,000	IXYS (a)(c)		20,672
		Power Semiconductors
	500,000	Littelfuse		20,105
		Little Fuses
	1,765,000	Pericom Semiconductor (a)(c)		13,079
		Interface ICs & Frequency Control Products
	2,290,000	TriQuint Semiconductor (a)		11,496
		RF Semiconductors
	644,280	Supertex (a)(c)		11,146
		Analog/Mixed Signal Semiconductors
	800,000	Monolithic Power Systems (a)		8,144
		High Performance Analog & Mixed Signal ICs
				265,257
		> Telecommunications Equipment 1.3%
	4,130,000	Polycom (a)		75,868
		Video Conferencing Equipment
	685,000	F5 Networks (a)		48,669
		Internet Traffic Management Equipment
	1,905,000	Finisar (a)		33,414
		Optical Subsystems and Components
	2,030,000	Ixia (a)		15,570
		Telecom Network Test Equipment
	1,925,000	Infinera (a)		14,861
		Optical Networking Equipment
				188,382
		> Computer Services 1.1%
	3,307,204	iGATE (c)		38,165
		IT & Business Process Outsourcing Services
	680,000	Syntel		29,369
		Offshore I/T Services
	2,125,000	Virtusa (a)(c)		28,050
		Offshore I/T Outsourcing
	1,145,000	ExlService Holdings (a)		25,190
		Business Process Outsourcing
	1,575,000	Genpact (a)		22,664
		Business Process Outsourcing
	4,500,000	Hackett Group (a)(c)		16,785
		IT Integration & Best Practice Research
	1,076,353	WNS - ADR (India) (a)		12,863
		Offshore BPO (Business Process Outsourcing) Services
				173,086
		> CATV 1.1%
	3,000,000	Discovery Communications, Series C (a)		105,450
		CATV programming
	1,250,000	Liberty Global, Series A (a)		45,225
		Cable TV Franchises Outside the USA
	17,770	Jupiter Telecommunications (Japan)		19,227
		Largest Cable Service Provider in Japan
				169,902

Number of Shares			Value (000)
		> Gaming Equipment & Services 0.9%
	3,725,000	Bally Technologies (a)(c)	$	100,500
		Slot Machines & Software
	1,741,367	WMS Industries (a)		30,631
		Slot Machine Provider
				131,131
		> Financial Processors 0.8%
	2,429,000	Global Payments		98,107
		Credit Card Processor
	5,000,000	Singapore Exchange (Singapore)		25,133
		Singapore Equity & Derivatives Market Operator
				123,240
		> Business Information & Marketing Services 0.8%
	1,400,000	Verisk Analytics (a)		48,678
		Risk & Decision Analytics
	900,000	FTI Consulting (a)		33,129
		Financial Consulting Firm
	3,000,000	Navigant Consulting (a)(c)		27,810
		Financial Consulting Firm
	505,000	RPX (a)		10,459
		Patent Aggregation and Defensive Patent Consulting
				120,076
		> Electronics Distribution 0.5%
	3,125,000	Avnet (a)		81,500
		Electronic Components Distribution
				81,500
		> Internet Related 0.4%
	435,000	Equinix (a)		38,641
		Network Neutral Data Centers
	464,305	Mail.ru - GDR (Russia) (a)(h)		13,444
		Internet Social Networking and Games for Russian Speakers
	656,585	TheStreet.com		1,300
		Financial Information Websites
				53,385
		> Contract Manufacturing 0.3%
	1,210,000	Plexus (a)		27,370
		Electronic Manufacturing Services
	2,800,000	Sanmina-SCI (a)		18,704
		Electronic Manufacturing Services
				46,074
		> Entertainment Programming 0.1%
	1,250,000	IMAX (Canada) (a)		18,100
		IMAX Movies, Theatre Equipment and Theatre Joint Ventures
				18,100
		> Radio 0.1%
	164,991	Saga Communications (a)		4,869
		Radio Stations in Small & Mid-sized Cities
	1,533,400	Salem Communications (c)		3,511
		Radio Stations for Religious Programming
	177,700	Spanish Broadcasting System (a)		295
		Spanish Language Radio Stations
				8,675

Number of Shares			Value (000)
		> TV Broadcasting —%
	1,750,000	Gray Television (a)	$	2,730
		Mid Market Affiliated TV Stations
	2,500,000	Entravision Communications (a)		2,550
		Spanish Language TV & Radio Stations
				5,280
		> Consumer Software —%
	362,577	Carbonite (a)(b)		4,365
		Online file storage
				4,365
		> Advertising —%
	1,500,000	VisionChina Media - ADR (China) (a)(b)		2,745
		Advertising on Digital Screens in China's Mass Transit System
				2,745
Information: Total				3,914,827
Consumer Goods & Services 18.3%
		> Retail 5.4%
	7,490,000	lululemon athletica (a)(c)		364,388
		Premium Active Apparel Retailer
	3,510,000	Abercrombie & Fitch		216,076
		Teen Apparel Retailer
	2,300,000	Shutterfly (a)(c)		94,714
		Internet Photo-Centric Retailer
	5,600,000	Pier 1 Imports (a)		54,768
		Home Furnishing Retailer
	5,225,000	Saks (a)(b)		45,719
		Luxury Department Store Retailer
	525,000	DSW		24,244
		Branded Footwear Retailer
	971,500	Teavana (a)(b)		19,760
		Specialty Tea Retailer
	1,371,366	Gaiam (c)		4,649
		Healthy Living Catalogs & E-Commerce
	66,000	The Fresh Market (a)(b)		2,519
		Specialty Food Retailer
				826,837
		> Apparel 3.6%
	2,100,000	Coach		108,843
		Designer & Retailer of Branded Leather Accessories
	1,120,000	Deckers Outdoor (a)		104,451
		Fashion Footwear Wholesaler
	2,190,000	Warnaco Group (a)(c)		100,937
		Global Branded Apparel Manufacturer
	1,410,000	PVH		82,118
		Apparel Wholesaler and Retailer
	1,747,000	True Religion Apparel (a)(c)		47,099
		Premium Denim
	1,455,000	Guess?		41,453
		Branded Apparel + Accessories + Licensor
	1,000,000	Hanesbrands (a)		25,010
		Apparel Wholesaler
	600,000	Steven Madden (a)		18,060
		Wholesaler/Retailer of Fashion Footwear

Number of Shares			Value (000)
	580,000	Crocs (a)	$	13,729
		Branded Footwear Wholesaler & Retailer
	36,037	Zuoan Fashion (China) (a)(b)		99
		Men's Apparel Provider in China
				541,799
		> Travel 2.5%
	3,100,000	Expedia		79,825
		Online Travel Services Company
	3,850,000	Gaylord Entertainment (a)(c)		74,459
		Convention Hotels
	1,470,000	Vail Resorts		55,551
		Ski Resort Operator & Developer
	1,400,000	HomeAway (a)(b)		47,068
		Vacation Rental Online Marketplace
	4,000,000	Avis Budget Group (a)		38,680
		Second Largest Car Rental Company
	970,000	Choice Hotels		28,829
		Franchisor Of Budget Hotel Brands
	3,000,000	Hertz (a)		26,700
		Largest U.S. Rental Car Operator
	2,000,000	Localiza Rent A Car (Brazil)		26,390
		Car Rental
				377,502
		> Food & Beverage 2.0%
	1,780,000	Hansen Natural (a)		155,376
		Alternative Beverages
	1,050,000	Diamond Foods (b)		83,779
		Snack Foods and Culinary Ingredients
	32,896,000	Olam International (Singapore)		56,057
		Agriculture Supply Chain Manager
	1,750,000	GLG Life Tech (Canada) (a)(c)		6,160
		Produce an All-Natural Sweetener Extracted from the Stevia Plant
	240,000	Lance		5,004
		Snack Foods
				306,376
		> Other Consumer Services 0.8%
	2,190,000	Lifetime Fitness (a)(c)		80,701
		Sport & Fitness Club Operator
	14,000,000	Lifestyle International (Hong Kong)		35,518
		Mid to High-End Department Store Operator in Hong Kong & China
	4,250,000	Move (a)		6,162
		Real Estate Internet Websites
	1,325,000	IFM Investments (Century 21 China RE) - ADR (China) (a)		1,524
		Provide Real Estate Services in China
				123,905
		> Casinos & Gaming 0.7%
	1,100,000	Penn National Gaming (a)		36,619
		Regional Casino Operator
	3,950,000	Pinnacle Entertainment (a)(c)		35,866
		Regional Casino Operator
	3,000,000	Melco Crown Entertainment - ADR (Hong Kong) (a)(b)		24,930
		Macau Casino Operator
	12,000,000	MGM China Holdings (Hong Kong) (a)		15,903
		Macau Casino Operator
				113,318

Columbia Acorn Fund

Statement of Investments (Unaudited), continued

Number of Shares			Value (000)
		> Furniture & Textiles 0.7%
	4,000,000	Knoll (c)	$	54,800
		Office Furniture
	2,250,000	Herman Miller		40,185
		Office Furniture
	1,000,000	Interface		11,860
		Modular & Broadloom Carpet
				106,845
		> Educational Services 0.6%
	2,800,000	Career Education (a)		36,540
		Postsecondary Education
	1,400,000	Universal Technical Institute (a)(c)		19,026
		Vocational Training
	800,000	New Oriental Education & Technology - ADR (China) (a)		18,376
		Education Service Provider
	300,000	ITT Educational Services (a)(b)		17,274
		Postsecondary Degree Services
	2,000,000	Voyager Learning, Contingent Value Rights (a)(d)(f)		180
		Education Services for the K-12 Market
				91,396
		> Other Durable Goods 0.5%
	1,720,000	Jarden		48,607
		Branded Household Products
	460,000	Cavco Industries (a)(c)		15,843
		Manufactured Homes
	400,000	Tesla Motors (a)(b)		9,756
		Design, Manufacture and Sell High Performance Electric Vehicles
				74,206
		> Leisure Products 0.4%
	2,180,000	Thor Industries		48,287
		RV & Bus Manufacturer
	975,000	Skullcandy (a)(b)		13,777
		Lifestyle Branded Headphones
				62,064
		> Consumer Goods Distribution 0.4%
	2,100,000	Pool		54,978
		Distributor of Swimming Pool Supplies & Equipment
				54,978
		> Restaurants 0.3%
	2,000,000	AFC Enterprises (a)(c)		23,660
		Popeye's Restaurants
	675,000	Bravo Brio Restaurant Group (a)		11,232
		Upscale Casual Italian Restaurants
	450,000	Cheesecake Factory (a)		11,092
		Casual Dining Restaurants
				45,984
		> Nondurables 0.3%
	1,600,000	Helen of Troy (a)(c)		40,192
		Hair Dryers & Curling Irons
				40,192

Number of Shares			Value (000)
		> Other Entertainment 0.1%
	320,000	CTS Eventim (Germany)	$	9,533
		Event Ticket Sales
				9,533
Consumer Goods & Services: Total				2,774,935
Industrial Goods & Services 17.6%
		> Machinery 9.7%
	4,200,000	Donaldson (c)		230,160
		Industrial Air Filtration
	6,750,000	Ametek		222,547
		Aerospace/Industrial Instruments
	3,000,000	Nordson		119,220
		Dispensing Systems for Adhesives & Coatings
	3,535,000	Pentair		113,155
		Pumps & Water Treatment
	3,200,000	Kennametal		104,768
		Consumable Cutting Tools
	2,325,000	Clarcor		96,208
		Mobile & Industrial Filters
	1,800,000	Pall		76,320
		Filtration & Fluids Clarification
	2,250,000	HEICO (c)		75,735
		FAA Approved Aircraft Replacement Parts
	2,050,000	MOOG (a)		66,871
		Motion Control Products for Aerospace, Defense & Industrial Markets
	2,200,000	ESCO Technologies (c)		56,100
		Automatic Electric Meter Readers
	1,150,000	WABCO Holdings (a)		43,539
		Truck & Bus Component Supplier
	2,675,000	Oshkosh Corporation (a)		42,105
		Specialty Truck Manufacturer
	805,000	Toro		39,662
		Turf Maintenance Equipment
	1,300,000	Kaydon		37,284
		Specialized Friction & Motion Control Products
	600,000	Wabtec		31,722
		Freight & Transit Component Supplier
	1,667,021	Generac (a)		31,357
		Standby Power Generators
	926,962	Mine Safety Appliances		24,991
		Safety Equipment
	265,907	Neopost (France)		19,498
		Postage Meter Machines
	3,450,000	Jain Irrigation Systems (India)		10,685
		Agricultural Micro-Irrigation Systems & Food Processing
	10,000,000	Marel (Iceland) (a)		9,943
		Largest Manufacturer of Poultry and Fish Processing Equipment
	100,000	Valmont Industries		7,794
		Center Pivot Irrigation Systems & Utility Poles
	1,250,000	Spartan Motors		5,163
		Specialty Truck & Chassis Manufacturer
				1,464,827

Number of Shares			Value (000)
		> Industrial Materials & Specialty Chemicals 2.1%
	1,750,000	Albemarle	$	70,700
		Refinery Catalysts and Other Specialty Chemicals
	760,000	FMC Corporation		52,562
		Niche Specialty Chemicals
	305,000	Novozymes (Denmark)		43,365
		Industrial Enzymes
	673,000	Sociedad Quimica y Minera de Chile - ADR (Chile) (b)		32,176
		Producer of Specialty Fertilizers, Lithium and Iodine
	1,260,000	Drew Industries (c)		25,175
		RV & Manufactured Home Components
	2,218,700	Kansai Paint (Japan)		21,261
		Paint Producer in Japan, India, China and Southeast Asia
	495,086	Mersen (France)		19,594
		Advanced Industrial Materials
	900,000	Albany International		16,425
		Paper Machine Clothing and Advanced Textiles
	400,000	Silgan Holdings		14,696
		Metal & Plastic Packaging
	8,000	Sika (Switzerland)		14,164
		Chemicals for Construction & Industrial Applications
				310,118
		> Other Industrial Services 1.9%
	3,200,000	Expeditors International of Washington		129,760
		International Freight Forwarder
	1,767,165	Imtech (Netherlands)		49,709
		Electromechanical and ICT Installation and Maintenance
	1,300,000	Forward Air		33,085
		Freight Transportation Between Airports
	1,600,000	Mobile Mini (a)		26,304
		Portable Storage Units Leasing
	900,000	LKQ (a)		21,744
		Alternative Auto Parts Distribution
	626,524	Arcadis (Netherlands)		11,437
		Engineering Consultants
	750,000	UTI Worldwide		9,780
		Freight Forwarding & Logistics
	1,336,001	Acorn Energy (a)(c)		7,107
		Frac Well Exploration/Monitoring Device, Sonar Security, Electric Grid Monitoring
				288,926
		> Industrial Distribution 0.8%
	605,000	WW Grainger		90,472
		Industrial Distribution
	2,600,000	Interline Brands (a)(c)		33,462
		Industrial Distribution
				123,934
		> Waste Management 0.7%
	2,400,000	Waste Connections		81,168
		Solid Waste Management
	560,000	Clean Harbors (a)		28,728
		Hazardous Waste Services & Disposal
				109,896

Number of Shares			Value (000)
		> Construction 0.7%
	1,725,000	Chicago Bridge & Iron	$	49,387
		Engineering & Construction for LNG & Petrochemicals
	66,000	NVR (a)		39,863
		DC Homebuilder
	1,800,000	Mills Estruturas e Servicos de Engenharia (Brazil)		16,858
		Civil Engineering & Construction
				106,108
		> Outsourcing Services 0.6%
	2,800,000	Quanta Services (a)		52,612
		Electrical & Telecom Construction Services
	1,210,000	Insperity		26,922
		Professional Employer Organization
	600,000	GP Strategies (a)		5,994
		Training Programs
				85,528
		> Electrical Components 0.6%
	1,440,000	Acuity Brands		51,898
		Commercial Lighting Fixtures
	1,500,000	Ushio (Japan)		22,836
		Industrial Light Sources
	351,000	Saft (France)		9,426
		Niche Battery Manufacturer
				84,160
		> Steel 0.3%
	4,000,000	GrafTech International (a)		50,800
		Industrial Graphite Materials Producer
				50,800
		> Conglomerates 0.2%
	2,263,654	Aalberts Industries (Netherlands)		33,655
		Flow Control and Heat Treatment
				33,655
		> Water —%
	649,000	Mueller Water Products		1,610
		Fire Hydrants, Valves & Ductile Iron Pipes
				1,610
Industrial Goods & Services: Total				2,659,562
Health Care 9.5%
		> Medical Equipment & Devices 3.3%
	4,200,000	Alexion Pharmaceuticals (a)		269,052
		Biotech Focused on Orphan Diseases
	1,800,000	Sirona Dental Systems (a)		76,338
		Manufacturer of Dental Equipment
	860,000	Gen-Probe (a)		49,235
		Molecular In-Vitro Diagnostics
	550,000	Haemonetics (a)		32,164
		Blood & Plasma Collection Equipment
	340,000	Edwards Lifesciences (a)		24,235
		Heart Valves
	570,000	Orthofix International (a)		19,671
		Bone Fixation & Stimulation Devices
	625,100	Hill-Rom Holdings		18,766
		Hospital Beds/Patient Handling

Columbia Acorn Fund

Statement of Investments (Unaudited), continued

Number of Shares			Value (000)
		> Medical Equipment & Devices—continued
	1,650,000	Pacific Biosciences of California (a)(b)	$	5,296
		Genome Sequencing
				494,757
		> Biotechnology & Drug Delivery 3.0%
	4,315,000	BioMarin Pharmaceutical (a)		137,519
		Biotech Focused on Orphan Diseases
	4,200,000	Seattle Genetics (a)(b)		80,052
		Antibody-Based Therapies for Cancer
	2,226,000	InterMune (a)		44,965
		Drugs for Pulmonary Fibrosis & Hepatitis C
	2,400,000	Auxilium Pharmaceuticals (a)(c)		35,976
		Biotech Focused on Niche Disease Areas
	1,170,000	Onyx Pharmaceuticals (a)		35,112
		Commercial-Stage Biotech Focused on Cancer
	4,500,000	NPS Pharmaceuticals (a)(c)		29,295
		Orphan Drugs & Healthy Royalties
	5,500,000	Micromet (a)(b)(c)		26,400
		Next-generation Antibody Technology
	3,430,000	Isis Pharmaceuticals (a)		23,255
		Biotech Pioneer in Antisense Drugs
	4,549,900	Chelsea Therapeutics (a)(c)		16,607
		Biotech Focused on Rare Diseases
	3,455,000	Raptor Pharmaceutical (a)(b)(c)		15,582
		Orphan Drug Company
	1,740,000	Anthera Pharmaceuticals (a)		8,300
		Biotech Focused on Cardiovascular, Cancer & Immunology
	142,825	United Therapeutics (a)		5,355
		Biotech Focused on Rare Diseases
	359,944	MicroDose Technologies (a)(d)(f)		299
		Drug Inhaler Development
	94,715	Locus Pharmaceuticals (a)(d)(e)(f)		—
		High Throughput Rational Drug Design
				458,717
		> Medical Supplies 1.6%
	3,200,000	Cepheid (a)(c)		124,256
		Molecular Diagnostics
	2,126,000	Patterson Companies		60,867
		Dental/Vet/Med Distributor
	650,000	Henry Schein (a)		40,307
		Largest Distributor of Healthcare Products
	325,200	Neogen (a)		11,291
		Food and Animal Safety Products
				236,721
		> Health Care Services 1.1%
	665,000	Mednax (a)		41,656
		Physician Mgmt for Pediatric and Anesthesia Practices
	1,625,000	Community Health Systems (a)		27,040
		Non-Urban Hospitals
	3,800,000	Health Management Associates (a)		26,296
		Non-Urban Hospitals
	1,725,000	HealthSouth (a)		25,754
		Inpatient Rehabalitation Facilities
	4,900,000	eResearch Technology (a)(c)		21,854
		Clinical Research Services

Number of Shares			Value (000)
	850,000	HMS Holdings (a)	$	20,731
		Cost Containment Services
	700,000	Allscripts Healthcare Solutions (a)		12,614
		IT for Physician Offices and Hospitals
				175,945
		> Pharmaceuticals 0.5%
	4,788,400	Akorn (a)(c)		37,397
		Develops, Manufactures & Sells Specialty Generic Drugs
	2,859,820	Adcock Ingram Holdings (South Africa)		21,208
		Manufacturer of Pharmaceuticals and Medical Supplies
	2,040,000	Alimera Sciences (a)(b)(c)		16,320
		Ophthalmology-Focused Pharmaceutical Company
	870,000	Horizon Pharma (a)		6,081
		Specialty Pharma Company
				81,006
Health Care: Total				1,447,146
Energy & Minerals 9.3%
		> Oil Services 3.8%
	6,200,000	FMC Technologies (a)		233,120
		Oil and Gas Well Head Manufacturer
	2,641,054	Fugro (Netherlands)		133,192
		Sub-sea Oilfield Services
	2,399,000	Atwood Oceanics (a)		82,430
		Offshore Drilling Contractor
	1,670,000	ShawCor (Canada)		38,774
		Oil and Gas Pipeline Products
	743,000	Oil States International (a)		37,834
		Diversified North American Oil Service Provider
	375,000	Bristow		15,911
		Largest Provider of Helicopter Services to Offshore Oil and Gas Producers
	1,056,600	Black Diamond Group (Canada)		13,662
		Provides Accommodations/Equipment for Oil Sands Development
	500,000	Hornbeck Offshore (a)		12,455
		Supply Vessel Operator in U.S. Gulf of Mexico
	2,890,900	Horizon North Logistics (Canada)		10,842
		Provides Diversified Oil Service Offering in Northern Canada
	8,870,000	Tuscany International Drilling (Colombia) (a)		4,909
	1,040,000	Tuscany International Drilling - Warrants (Colombia) (a)		5
		South America Based Drilling Rig Contractor
				583,134
		> Oil & Gas Producers 3.4%
	4,810,550	Pacific Rubiales Energy (Colombia) (b)		101,913
		Oil Production & Exploration in Colombia
	2,400,000	Tullow Oil (United Kingdom)		48,538
		Oil and Gas Producer
	1,389,000	Southwestern Energy (a)		46,295
		Oil and Gas Producer
	715,000	SM Energy		43,365
		Oil and Gas Producer

Number of Shares			Value (000)
		> Oil & Gas Producers—continued
	695,000	Range Resources	$	40,630
		Oil and Gas Producer
	974,000	Rosetta Resources (a)		33,330
		Oil and Gas Producer Exploring in South Texas and Montana
	2,700,000	Denbury Resources (a)		31,050
		Oil Producer Using Co2 Injection
	650,000	Baytex (Canada) (a)(b)		27,175
		Oil and Gas Producer in Canada
	850,000	Northern Oil And Gas (a)(b)		16,481
		Small E & P Company in North Dakota Bakken
	1,143,800	Houston American Energy (b)		15,739
		Oil and Gas Exploration/Production in Colombia
	250,000	Cabot Oil and Gas		15,477
		Large Natural Gas Producer in Appalachia and Gulf Coast
	631,000	Celtic Exploration (Canada) (a)		13,591
		Canadian Oil and Gas Producer
	550,000	Swift Energy (a)		13,387
		Oil and Gas Exploration and Production
	27,000,000	ShaMaran Petroleum (a)		10,693
		Oil Exploration in Kurdistan
	383,000	Ultra Petroleum (a)		10,617
		Oil and Gas Producer
	847,000	Crew Energy (Canada) (a)		7,501
		Canadian Oil and Gas Producer
	6,866,628	PetroMagdalena Energy (Colombia) (a)(b)		6,553
		Oil & Gas Exploration/Production in Colombia
	228,200	Oasis Petroleum (a)(b)		5,096
		Oil Producer in North Dakota
	575,000	Venoco (a)		5,066
		Oil and Gas Producer in California and Texas
	37,500,000	Petromanas (Canada) (a)(c)		4,473
	18,750,000	Petromanas - Warrants (Canada) (a)(d)		263
		Exploring for Oil in Albania
	26,000,000	Petrodorado (Colombia) (a)(c)		4,218
	24,000,000	Petrodorado - Warrants (Colombia) (a)(d)(f)		499
		Oil & Gas Exploration/Production in Columbia, Peru & Paraguay
	6,300,000	Canacol Energy (Colombia) (a)		3,848
		Oil Producer in South America
	30,275,000	Petroamerica (Colombia) (a)(c)		3,322
		Oil Exploration & Production in Colombia
	1,198,100	Pan Orient (Canada) (a)		2,664
		Growth Oriented, Return Focused Asian Explorer
	8,400,000	Canadian Overseas Petroleum (United Kingdom) (a)(d)		2,474
	4,200,000	Canadian Overseas Petroleum - Warrants (United Kingdom) (a)(d)(f)		232
		Oil & Gas Exploration/Production in the North Sea
	41,100,000	Quetzal Energy (Colombia) (a)(c)(d)		1,694
		Explores for Oil & Gas in Latin America

Number of Shares			Value (000)
	8,900,000	Quetzal Energy (Colombia) (a)(c)	$	382
		Explores for Oil & Gas in Latin America
				516,566
		> Mining 1.6%
	1,950,000	Silver Wheaton (Canada)		57,428
		Silver Mining Royalty Company
	545,000	Core Laboratories (Netherlands)		48,957
		Oil and Gas Reservoir Consulting
	15,000,000	Zhaojin Mining Industry (China)		24,952
		Gold Mining and Refining in China
	2,800,000	Alexco Resource (a)		18,984
		Mining, Exploration & Environmental Services
	4,432,000	Northam Platinum (South Africa)		17,971
		Platinum Mining in South Africa
	7,500,000	Duluth Metals (Canada) (a)(c)		16,533
		Copper & Nickel Miner
	900,000	Silver Standard Resources (a)		16,515
		Silver Mining
	1,150,000	Ivanhoe Mines (Canada) (a)		15,858
		Copper Mine Project in Mongolia
	12,000,000	Mongolian Mining (Hong Kong) (a)		10,609
		Coking Coal Mining in Mongolia
	5,000,000	Orko Silver (Canada) (a)(b)		8,970
		Silver Exploration & Development
	800,000	Augusta Resource (a)(b)		2,456
		U.S. Copper/Molybdenum Mine
	4,000,000	Wolverine Minerals (Canada) (a)(c)(d)(f)		1,299
	2,000,000	Wolverine Minerals - Warrants (Canada) (a)(d)(f)		57
		Gold Miner
	500,000	Duluth Exploration - Special Warrants (Canada) (a)(d)(f)		95
		Copper & Nickel Miner
				240,684
		> Oil Refining, Marketing & Distribution 0.2%
	600,000	Vopak (Netherlands)		28,677
		World's Largest Operator of Petroleum and Chemical Storage Terminals
				28,677
		> Alternative Energy 0.2%
	3,000,000	GT Solar International (a)		21,060
		Largest Manufacturer of Furnaces & Reactors to Produce & Cast Polysilicon
	500,000	STR Holdings (a)(b)		4,055
		Makes Encapsulant for Solar Power Modules/Provides Quality Assurance
	1,210,300	Synthesis Energy Systems (China) (a)(b)		2,094
		Owner/Operator of Gasification Plants
				27,209
		> Agricultural Commodities 0.1%
	1,136,364	Union Agriculture Group (Argentina) (a)(d)(f)		12,113
		Farmland Operator in Uruguay
				12,113
Energy & Minerals: Total				1,408,383

Columbia Acorn Fund

Statement of Investments (Unaudited), continued

Number of Shares			Value (000)
Finance 9.3%
		> Banks 3.7%
	2,738,000	BOK Financial	$	128,385
		Tulsa Based S.W. Bank
	2,337,313	Hancock Holding		62,593
		Gulf Coast Bank
	5,700,000	Valley National Bancorp (b)		60,363
		New Jersey/New York Bank
	1,275,000	City National		48,144
		Bank & Asset Manager
	2,860,000	MB Financial (c)		42,099
		Chicago Bank
	4,487,800	Associated Banc-Corp		41,737
		Midwest Bank
	910,000	SVB Financial Group (a)		33,670
		Bank to Venture Capitalists
	4,300,000	CVB Financial (b)		33,067
		Inland Empire Business Bank
	3,000,000	TCF Financial		27,480
		Great Lakes Bank
	4,299,507	First Busey		18,703
		Illinois Bank
	1,350,000	TriCo Bancshares (c)		16,564
		California Central Valley Bank
	1,121,188	Sandy Spring Bancorp		16,403
		Baltimore, D.C. Bank
	772,632	Hudson Valley		13,467
		Metro New York City Bank
	706,559	Eagle Bancorp (a)		8,316
		Metro D.C. Bank
	779,305	TrustCo Bank		3,476
		New York State Bank
	246,505	Pacific Continental		1,748
		Pacific N.W. Bank
	158,389	Green Bankshares (a)(b)		201
		Tennessee Bank
				556,416
		> Insurance 2.3%
	11,900,000	CNO Financial Group (a)		64,379
		Life, Long Term Care & Medical Supplement Insurance
	2,820,000	Leucadia National		63,958
		Insurance Holding Company
	1,320,000	Hanover Insurance Group		46,860
		Personal & Commercial Lines Insurance
	1,200,000	HCC Insurance Holdings		32,460
		Specialty Insurance
	832,000	Willis Group (Ireland)		28,596
		Insurance Broker
	1,225,000	Tower Group		28,003
		Commercial & Personal Lines Insurance
	1,200,000	Delphi Financial Group		25,824
		Workers Comp & Group Employee Benefit Products & Services
	1,420,000	Selective Insurance Group		18,531
		Commercial & Personal Lines Insurance
	900,000	Brown & Brown		16,020
		Insurance Broker

Number of Shares			Value (000)
	150,000	Enstar Group (a)	$	14,284
		Insurance/Reinsurance & Related Services
	694,343	Symetra Financial		5,659
		Life Insurance
	300,000	Assured Guaranty		3,297
		Global Muni Bond Insurance
				347,871
		> Finance Companies 1.6%
	1,505,202	World Acceptance (a)(c)		84,216
		Personal Loans
	2,300,000	Aaron's		58,075
		Rent to Own
	2,150,000	McGrath Rentcorp (c)		51,149
		Temporary Space & IT Rentals
	3,400,000	H&E Equipment Services (a)(c)		28,050
		Heavy Equipment Leasing
	1,123,400	CAI International (a)(c)		13,166
		International Container Leasing
	1,091,000	Marlin Business Services (a)(c)		11,565
		Small Equipment Leasing
	78,500	Textainer Group Holdings		1,592
		Top International Container Leasor
				247,813
		> Brokerage & Money Management 1.3%
	6,198,000	SEI Investments		95,325
		Mutual Fund Administration & Investment Management
	3,700,000	Eaton Vance		82,399
		Specialty Mutual Funds
	1,000,000	Artio Global Investors		7,960
		International Asset Manager
	400,000	Financial Engines (a)		7,244
		Asset Management for 401k Plans
				192,928
		> Credit Cards 0.3%
	350,000	Alliance Data Systems (a)(b)		32,445
		Diversified Credit Card Provider
	100,000	Wright Express (a)		3,804
		Pay Card Processor
				36,249
		> Savings & Loans 0.1%
	700,000	ViewPoint Financial		8,015
		Texas Thrift
	1,010,000	Provident New York Bancorp		5,878
		New York State Thrift
	452,146	Kaiser Federal Financial Group		5,335
		Los Angeles Savings & Loan
	65,991	Berkshire Hills Bancorp		1,219
		Northeast Thrift
				20,447
Finance: Total				1,401,724

Number of Shares			Value (000)
Other Industries 6.0%
		> Real Estate 3.7%
	4,575,000	Biomed Realty Trust	$	75,808
		Life Science-focused Office Buildings
	840,000	Federal Realty Investment Trust		69,224
		Shopping Centers
	3,000,000	Associated Estates Realty (c)		46,380
		Multifamily Properties
	2,200,000	Dupont Fabros Technology (b)		43,318
		Technology-focused Office Buildings
	720,000	Digital Realty Trust (b)		39,715
		Technology-focused Office Buildings
	1,120,000	Kilroy Realty		35,056
		West Coast Office and Industrial Properties
	1,850,000	Extra Space Storage		34,465
		Self Storage Facilities
	975,000	Post Properties		33,871
		Multifamily Properties
	43,000,000	Mapletree Logistics Trust (Singapore)		27,852
		Industrial Property Landlord
	3,000,000	Education Realty Trust		25,770
		Student Housing
	15,000,000	Ascendas REIT (Singapore)		23,131
		Industrial Property Landlord
	530,000	Macerich		22,594
		Regional Shopping Malls
	700,000	Washington REIT		19,726
		Washington, D.C. Diversified Properties
	3,750,000	DCT Industrial Trust		16,462
		Industrial Properties
	1,000,000	St. Joe (a)(b)		14,990
		Florida Panhandle Landowner
	2,800	Orix JREIT (Japan)		12,867
		Diversified REIT
	3,050,000	Kite Realty Group		11,163
		Community Shopping Centers
	1,500,000	Summit Hotel Properties (c)		10,590
		Owner of Select Service Hotels
	37,407	Security Capital European Realty (Luxembourg) (a)(d)(e)(f)		—
		Self Storage Properties
				562,982
		> Transportation 1.2%
	1,275,000	JB Hunt Transport Services		46,053
		Truck & Intermodal Carrier
	1,260,000	World Fuel Services		41,139
		Global Fuel Broker
	2,800,000	Rush Enterprises, Class A (a)(c)		39,648
	550,000	Rush Enterprises, Class B (a)(c)		6,418
		Truck Sales and Service
	2,730,000	Heartland Express		37,019
		Regional Trucker
	300,000	Genesee & Wyoming (a)		13,956
		Short-line Operator
				184,233

Number of Shares			Value (000)
		> Regulated Utilities 1.1%
	2,000,000	Northeast Utilities	$	67,300
		Regulated Electric Utility
	1,800,000	Wisconsin Energy		56,322
		Wisconsin Utility
	500,000	ALLETE		18,315
		Regulated Electric Utility - Minnesota
	333,000	Red Eléctrica de España (Spain)		15,175
		Spanish Power Transmission
				157,112
Other Industries: Total				904,327
Total Equities: 95.8% (Cost: $10,915,844)				14,510,904
Securities Lending Collateral 2.2%
	333,232,511	Dreyfus Government Cash Management Fund (g) (7 day yield of 0.00%)		333,233
Total Securities Lending Collateral: (Cost: $333,233)				333,233
Total Investments: 98.0% (Cost: $11,249,077)(i)(j)				14,844,137
Obligation to Return Collateral for Securities Loaned: (2.2)%				(333,233	)
Cash and Other Assets Less Liabilities: 4.2%				630,688
Total Net Assets: 100.0%			$	15,141,592

ADR = American Depositary Receipts

GDR = Global Depositary Receipts

Columbia Acorn Fund

Statement of Investments (Unaudited), continued

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

(a) Non-income producing security.

(b) All or a portion of this security was on loan at September 30, 2011. The total market value of securities on loan at September 30, 2011 was $319,697,071.

(c) An affiliated person of the Fund may include any company in which the Fund owns five percent or more of its outstanding voting shares. Holdings and transactions in these affiliated companies during the nine months ended September 30, 2011, are as follows:

Affiliates	Balance of Shares Held 12/31/10		Purchases/ Additions		Sales/ Reductions		Balance of Shares Held 9/30/11		Value		Dividend
Acorn Energy		-		1,336,001		-		1,336,001	$	7,107	$	-
AFC Enterprises		2,000,000		-		-		2,000,000		23,660		-
Akorn		2,659,068		2,129,332		-		4,788,400		37,397		-
Allos Therapeutics*		7,035,000		-		7,035,000		-		-		-
Alimera Sciences		361,450		1,678,550		-		2,040,000		16,320		-
Anthera Pharmaceuticals*		1,450,000		290,000		-		1,740,000		8,300		-
Array Biopharma*		3,500,000		-		3,500,000		-		-		-
Art Technology Group*		9,000,000		-		9,000,000		-		-		-
Associated Estates Realty		2,200,000		800,000		-		3,000,000		46,380		1,207
Auxilium Pharmaceuticals		1,200,000		1,200,000		-		2,400,000		35,976		-
Bally Technologies		3,725,000		-		-		3,725,000		100,500		-
Blackbaud		2,250,000		-		-		2,250,000		50,107		540
CAI International		1,650,000		-		526,600		1,123,400		13,166		-
Cavco Industries		180,000		280,000		-		460,000		15,843		-
Cepheid		2,415,000		785,000		-		3,200,000		124,256		-
Chelsea Therapeutics		3,449,900		1,100,000		-		4,549,900		16,607		-
Clarcor*		2,565,000		-		240,000		2,325,000		96,208		1,077
Cogent Communications		2,800,000		-		280,000		2,520,000		33,894		-
Constant Contact		1,400,000		950,000		-		2,350,000		40,631		-
Diamond Foods*		1,300,000		-		250,000		1,050,000		83,779		170
Donaldson		4,200,000		-		-		4,200,000		230,160		1,176
Drew Industries		1,260,000		-		-		1,260,000		25,175		-
Duluth Metals		3,154,000		4,346,000		-		7,500,000		16,533
Education Realty Trust*		3,000,000		-		-		3,000,000		25,770		300
eResearch Technology		4,250,000		650,000		-		4,900,000		21,854		-
ESCO Technologies		2,200,000		-		-		2,200,000		56,100		528
Gaiam		1,371,366		-		-		1,371,366		4,649		-
Gaylord Entertainment		3,850,000		-		-		3,850,000		74,459		-
GLG Life Tech		1,200,000		550,000		-		1,750,000		6,160		-
H&E Equipment Services		3,000,000		400,000		-		3,400,000		28,050		-
Hackett Group		4,500,000		-		-		4,500,000		16,785		-
HEICO+		1,700,000		550,000		-		2,250,000		75,735		237
Helen of Troy		1,600,000		-		-		1,600,000		40,192		-
iGate		2,913,065		407,204		13,065		3,307,204		38,165		-
II-VI+		2,225,000		2,325,000		-		4,550,000		79,625		-
Informatica*		5,200,000		-		500,000		4,700,000		192,465		-
Interline Brands		2,600,000		-		-		2,600,000		33,462		-
IPG Photonics		2,710,000		70,000		-		2,780,000		120,763		-
IXYS		1,900,000		-		-		1,900,000		20,672		-
Kenexa		2,025,000		-		-		2,025,000		31,671		-
Knoll		4,000,000		-		-		4,000,000		54,800		640
Lifetime Fitness		2,190,000		-		-		2,190,000		80,701		-
lululemon athletica+		4,035,000		3,950,000		495,000		7,490,000		364,388		-
Marlin Business Services		1,091,000		-		-		1,091,000		11,565		-
MB Financial		2,860,000		-		-		2,860,000		42,099		57
McGrath Rentcorp		2,350,000		-		200,000		2,150,000		51,149		1,610
Mettler Toledo		1,600,000		-		-		1,600,000		223,936
Micromet		5,500,000		-		-		5,500,000		26,400		-
Nabi Biopharmaceuticals*		1,383,454		1,916,546		3,300,000		-		-		-
Nanosphere*		1,480,056		-		1,480,056		-		-		-
Navigant Consulting		3,100,000		-		100,000		3,000,000		27,810		-
NPS Pharmaceuticals		3,200,000		1,300,000		-		4,500,000		29,295		-
Orko Silver*		10,000,000		-		5,000,000		5,000,000		8,970		-
Orthofix International*		1,150,000		-		580,000		570,000		19,671		-
PAETEC Holding		9,600,000		-		600,000		9,000,000		47,610		-
Pericom Semiconductor		1,765,000		-		-		1,765,000		13,079		-
Petroamerica		30,275,000		-		-		30,275,000		3,322		-

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

Affiliates	Balance of Shares Held 12/31/10		Purchases/ Additions		Sales/ Reductions		Balance of Shares Held 9/30/11		Value		Dividend
Petrodorado		24,000,000		2,000,000		-		26,000,000	$	4,218	$	-
Petrolifera Petroleum*		13,950,000		-		13,950,000		-		-		-
Petromanas		37,500,000		-		-		37,500,000		4,473		-
Pinnacle Entertainment		3,400,000		550,000		-		3,950,000		35,866		-
Quetzal Energy		-		50,000,000		-		50,000,000		2,076		-
Raptor Pharmaceutical		-		3,455,000		-		3,455,000		15,582		-
Rush Enterprises		3,350,000		-		-		3,350,000		46,066		-
Salem Communications		1,541,000		-		7,600		1,533,400		3,511		-
Shutterfly		1,700,000		600,000		-		2,300,000		94,714		-
Spanish Broadcasting System*+		2,400,000		240,000		2,462,300		177,700		295		-
SPS Commerce		856,429		43,571		-		900,000		14,661		-
Summit Hotel Properties		-		1,500,000		-		1,500,000		10,590		230
Supertex		1,035,000		-		390,720		644,280		11,146		-
Talbots*		4,150,000		-		4,150,000		-		-		-
THQ*		3,567,000		-		3,567,000		-		-		-
TriCo Bancshares		1,350,000		-		-		1,350,000		16,564		243
True Religion Apparel		2,047,000		-		300,000		1,747,000		47,099		-
Tuscany International Drilling*		10,719,200		-		1,849,200		8,870,000		4,909		-
tw telecom		9,500,000		-		-		9,500,000		156,940		-
Tyler Technologies		2,000,000		-		300,000		1,700,000		42,976		-
Universal Technical Institute		1,700,000		-		300,000		1,400,000		19,026		-
Virtusa		2,000,000		125,000		-		2,125,000		28,050		-
Warnaco Group		2,190,000		-		-		2,190,000		100,937		-
Wolverine Minerals		-		4,000,000		-		4,000,000		1,299		-
World Acceptance		1,505,202		-		-		1,505,202		84,216		-
Total of Affiliated Transactions		322,039,190		89,527,204		60,376,541		351,189,853	$	3,638,585	$	8,015

* At September 30, 2011, the Fund owned less than five percent of the company's outstanding voting shares.

+ Includes the effects of a stock split.

The aggregate cost and value of these companies at September 30, 2011, were $2,461,969 and $3,198,218 respectively. Investments in affiliate companies represent 21.12% of total net assets at September 30, 2011.

(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 September 30, 2011, the market value of these securities (in thousands) amounted to $19,205 which represented 0.13% of total net assets.

Additional information on these securities is as follows:

Security	Acquisition Dates	Shares		Cost		Value
Union Agriculture Group	12/08/10		1,136,364	$	15,000	$	12,113
Canadian Overseas Petroleum	11/24/10		8,400,000		3,591		2,474
Quetzal Energy	1/14/11		41,100,000		5,193		1,694
Wolverine Minerals	6/03/11		4,000,000		2,005		1,299
Petrodorado - Warrants	11/20/09		24,000,000		2,965		499
MicroDose Technologies	11/24/00		359,944		2,005		299
Petromanas - Warrants	5/20/10		18,750,000		1,086		263
Canadian Overseas Petroleum - Warrants	11/24/10		4,200,000		526		232
Voyager Learning, Contingent Value Rights	12/24/09		2,000,000		-		180
Duluth Exploration - Special Warrants	8/19/11		500,000		-		95
Wolverine Minerals - Warrants	6/03/11		2,000,000		243		57
Locus Pharmaceuticals	9/05/01-2/08/07		94,715		7,780		-
Security Capital European Realty	8/20/98-7/20/99		37,407		205		-
				$	40,599	$	19,205

(e) Security has no value.

(f) Illiquid security.

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

(h) Security exempt from registration under Section 4(2) of the Securities Act of 1933. This security may only be resold in exempt transactions to qualified buyers. Private resales of this security to qualified institutional buyers are also exempt from registration pursuant to Rule 144A under the Securities Act of 1933. At September 30, 2011, this security had an aggregate value of $13,444, which represented 0.09% of total net assets.

(i) At September 30, 2011, for federal income tax purposes the cost of investments was $11,249,077 and net unrealized appreciation was $3,595,060 consisting of gross unrealized appreciation of $4,942,760 and gross unrealized depreciation of $1,347,700.

Columbia Acorn Fund

Statement of Investments (Unaudited), continued

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

(j) On September 30, 2011, the market value of foreign securities represented 9.95% of total net assets. The Fund's foreign portfolio was diversified as follows:

	Value			Percentage of Net Assets
Netherlands	$	305,627			2.02
Canada		246,767			1.63
Singapore		132,171			0.87
Columbia		124,021			0.82
Japan		92,314			0.61
Hong Kong		86,960			0.57
Sweden		67,162			0.44
France		59,455			0.39
United Kingdom		51,244			0.34
China		49,790			0.33
Denmark		43,364			0.29
Brazil		43,249			0.29
South Africa		39,179			0.26
	Value			Percentage of Net Assets
Chile	$	32,176			0.21
Israel		24,280			0.16
India		23,547			0.16
Spain		15,174			0.10
Switzerland		14,164			0.09
Russia		13,444			0.09
Argentina		12,114			0.08
Iraq		10,693			0.07
Iceland		9,943			0.07
Germany		9,533			0.06
Luxembourg		-	*		-
Total Foreign Portfolio	$	1,506,371			9.95

* Rounds to less than $500.

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

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

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

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

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

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

The following table summarizes the inputs used, as of September 30, 2011, 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	$	3,762,802	$	152,025	$	-	$	3,914,827
Consumer Goods & Services		2,657,746		117,009		180		2,774,935
Industrial Goods & Services		2,393,988		265,573		-		2,659,561
Health Care		1,425,640		21,208		299		1,447,147
Energy & Minerals		1,125,717		270,457		12,209		1,408,383
Finance		1,401,724		-		-		1,401,724
Other Industries		825,304		79,023		-		904,327
Total Equities		13,592,921		905,295		12,688		14,510,904
Total Securities Lending Collateral		333,233		-		-		333,233
Total Investments	$	13,926,154	$	905,295	$	12,688	$	14,844,137

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 sales price on the foreign exchange or market on which they trade. The Fund may use a systematic fair valuation model 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 adviser'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.

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

The Fund's assets assigned to the Level 3 input category are valued at fair value as determined in good faith under consistently applied procedures established by and under the general supervision of the Board of Trustees. To determine fair value, management will utilize the valuation technique that they deem the most appropriate in the circumstances. Securities for which no market exists are valued based upon the market approach using some unobservable inputs which may include, but are not limited to, projected earnings, available cash, line of business, multiples, and consideration of the prioritization of the equity in a company's capital structure.

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

Transfers In				Tranfers Out
Level 1		Level 2		Level 1		Level 2
$	91,474	$	16,715	$	16,715	$	91,474

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

Financial assets were transferred from Level 2 to Level 1 as resale restrictions expired.

Foreign exchange-traded financial assets were transferred from Level 1 to Level 2.

The following table reconciles asset balances for the nine months ending September 30, 2011, in which significant unobservable inputs (Level 3) were used in determining value:

Investments in Securities	Balance as of December 31, 2010		Realized Gain/(Loss)		Change in Unrealized Appreciation (Depreciation)			Purchases		Sales		Transfers into Level 3		Transfers out of Level 3		Balance as of September 30, 2011
Equities
Consumer Goods & Services	$	262	$	-	$	(82	)	$	-	$	-	$	-	$	-	$	180
Energy & Minerals		15,000		-		(2,887	)		96		-		-		-		12,209
Health Care		103		-		196			-		-		-		-		299
	$	15,365	$	-	$	(2,773	)	$	96	$	-	$	-	$	-	$	12,688

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

The change in unrealized depreciation attributed to securities owned at September 30, 2011, which were valued using significant unobservable inputs (Level 3) amounted to $2,773.

Columbia Acorn International

Major Portfolio Changes in the Third Quarter (Unaudited)

	Number of Shares
	06/30/11		09/30/11
Purchases
Asia
> Japan
Advance Residence Investment		15,300		16,005
Aeon Delight		1,846,000		1,995,438
Ain Pharmaciez		707,000		751,792
Asahi Diamond Industrial		1,360,000		1,851,900
Daiseki		1,181,200		1,277,429
Fukuoka REIT		2,850		2,874
Glory		977,000		1,055,562
Hamamatsu Photonics		710,000		765,554
Hoshizaki Electric		1,563,000		1,697,200
Ibiden		819,000		883,144
Icom		675,780		732,108
Japan Airport Terminal		1,666,700		2,052,572
Jupiter Telecommunications		24,022		25,979
Kakaku.com		2,870		530,500
Kansai Paint		7,568,400		8,187,600
Kintetsu World Express		868,000		937,651
Kuraray		1,974,000		2,129,100
Misumi Group		0		772,000
Miura		587,800		636,250
Mori Hills REIT Investment		4,458		5,540
Nakanishi		274,000		295,762
Osaka Securities Exchange		5,100		5,531
Park24		0		736,600
Pigeon		439,800		469,500
Seven Bank		21,000		22,694
Shimadzu		2,400,000		2,600,000
Shinsei Bank		23,908,800		25,769,649
Sintokogio		1,794,000		1,940,200
Torishima Pump Manufacturing		1,250,500		1,346,963
Tsumura		789,000		855,604
Ushio		1,292,500		1,405,739
Wacom		23,500		25,380
> Taiwan
Advantech		0		3,458,700
Chroma Ate		0		7,025,500
CTCI Corp		0		9,315,800
Far Eastone Telecom		21,429,000		33,118,800
Formosa International Hotels		1,142,620		1,580,717
Lung Yen		0		510,800
President Chain Store		5,665,000		7,017,009
Radiant Opto-Electronics		0		5,910,000
St. Shine Optical		1,511,000		2,240,000
Taiwan Hon Chuan		6,911,000		11,315,800
Tripod Technologies		0		5,613,270
> Singapore
Ascendas REIT		22,000,000		23,489,149
Goodpack Limited		13,000,000		15,000,000

	Number of Shares
	06/30/11		09/30/11
Mapletree Commercial Trust		30,000,000		32,300,000
Mapletree Industrial Trust REIT		37,010,000		42,675,997
Mapletree Logistics Trust		50,000,000		53,383,000
> Hong Kong
Hutchison Port Holdings Trust		30,000,000		32,000,000
L'Occitane International		8,077,000		15,000,000
Melco International		0		7,419,000
MGM China Holdings		12,000,000		12,500,000
Mongolian Mining		23,335,500		35,923,500
Nagacorp		0		40,438,400
Sasa International		35,000,000		37,703,800
> China
51job - ADR		247,000		263,700
AMVIG Holdings		0		25,695,600
China Yurun Food		10,764,600		12,047,000
Digital China		0		11,165,300
Jiangsu Expressway		23,146,000		23,596,000
Netease.com		0		401,000
New Oriental Education & Technology - ADR		230,000		965,387
Noah Holdings - ADR		432,790		800,000
Want Want		7,143,600		19,410,400
Zhaojin Mining Industry		32,276,000		34,745,554
> India
Asian Paints		320,000		341,652
Infrastructure Development Finance		3,550,000		3,807,700
Jain Irrigation Systems		8,587,418		11,163,303
Manappuram Finance		11,814,746		14,381,649
Mundra Port & Special Economic Zone		7,496,953		8,052,053
REI Agro		30,574,905		32,642,905
S. Kumars Nationwide		9,600,000		10,249,300
Shriram Transport Finance		715,000		767,100
United Breweries		367,138		1,203,445
> South Korea
MegaStudy		121,132		129,332
NHN		150,000		160,150
Woongjin Coway		1,157,000		1,242,590
> Philipines
Int'l Container Terminal		0		7,931,700
Manila Water Company		0		14,299,600
SM Prime Holdings		0		63,272,200
> Thailand
Home Product Center		80,000,000		104,039,000
> Indonesia
Ace Indonesia		6,898,100		8,306,300

	Number of Shares
	06/30/11		09/30/11
Purchases (continued)
Europe
> United Kingdom
Abcam		2,752,210		2,950,000
Archipelago Resources		26,712,371		29,063,787
Chemring		5,437,000		5,700,000
Cobham		5,385,000		5,804,000
Domino's Pizza United Kingdom & Ireland		0		2,497,000
FlyBe		1,376,083		1,499,183
GlobeOp Financial Services		3,758,000		4,155,200
JLT Group		2,868,800		3,644,400
Kesa Electricals		8,346,000		9,009,000
Petropavlovsk		1,976,000		2,109,700
Premier Oil		2,432,000		2,636,932
PureCircle		3,889,000		4,163,948
Rotork		680,000		730,000
Shaftesbury		859,200		1,691,711
Smith and Nephew		1,630,000		1,761,742
Sterling Resources		2,600,000		2,840,000
Tullow Oil		690,000		740,581
> Netherlands
Aalberts Industries		2,296,992		2,479,123
Arcadis		1,164,669		1,252,514
Fugro		784,111		844,967
Imtech		1,841,280		1,955,311
Koninklijke TenCate		1,272,365		1,371,573
Unit 4 Aggresso		1,476,800		1,591,702
Vopak		1,104,200		1,189,424
> France
Eurofins Scientific		489,287		554,800
Gemalto		799,000		1,193,000
Hi-Media		1,689,100		1,831,204
Mersen		541,500		556,874
Neopost		610,000		631,797
Norbert Dentressangle		213,800		232,400
Pierre & Vacances		322,200		322,605
Rubis		274,100		376,131
Saft		902,900		971,800
Teleperformance		1,078,000		1,158,000
> Switzerland
Bank Sarasin & Cie		720,000		773,707
Dufry Group		190,000		286,300
Geberit		185,000		225,650
Kuehne & Nagel		325,000		350,445
Partners Group		235,000		265,000
> Germany
CTS Eventim		403,286		819,889
Deutsche Beteiligungs		312,500		338,886
Dürr		237,511		636,800

	Number of Shares
	06/30/11		09/30/11
Elringklinger		515,000		555,700
Rational		137,500		148,295
Rheinmetall		630,000		679,600
Rhoen-Klinikum		1,460,000		1,600,000
Wirecard		2,120,000		2,286,441
> Sweden
Hexagon		3,799,000		4,056,007
Sweco		3,887,000		4,150,024
Unibet		607,000		658,700
> Italy
Ansaldo STS		2,083,000		2,621,149
CIR		9,796,000		13,547,300
Geox		3,573,000		4,973,000
> Denmark
Novozymes		306,000		329,760
SimCorp		156,000		168,042
> Ireland
Aryzta		297,000		395,008
United Drug		9,669,485		9,700,000
> Czech Republic
Komercni Banka		121,268		130,682
> Portugal
Redes Energéticas Nacionais		7,278,105		7,770,405
> Finland
Stockmann		967,777		1,039,429
> Norway
Atea		2,045,964		2,403,664
> Belgium
EVS Broadcast Equipment		145,031		332,977
> Greece
Intralot		6,475,300		6,954,400
Other Countries
> Canada
AG Growth		540,000		582,942
Alliance Grain Traders		501,700		754,800
Baytex		574,000		615,857
Black Diamond Group		546,500		1,189,576
CCL Industries		1,301,612		1,403,772
Celtic Exploration		146,200		505,000
Crew Energy		367,600		678,000
DeeThree Exploration		3,738,877		4,061,377
Eacom Timber		12,500,000		13,000,000
Horizon North Logistics		2,214,100		2,411,514
Ivanhoe Mines		1,833,100		1,964,621
Onex Capital		605,000		653,200

Columbia Acorn International

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

	Number of Shares
	06/30/11		09/30/11
Purchases (continued)
Other Countries—continued
> Canada—continued
Pan Orient		1,480,610		1,607,306
ShawCor		1,710,000		1,790,397
Southern Arc Minerals		5,737,500		6,217,500
Tahoe Resources		872,700		963,600
> United States
Alexion Pharmaceuticals		822,000		887,431
Atwood Oceanics		1,273,000		1,373,080
BioMarin Pharmaceutical		1,145,000		1,229,871
Bristow		391,000		421,732
FMC Technologies		658,000		707,213
Oil States International		250,000		270,000
Textainer Group Holdings		568,000		838,297
World Fuel Services		918,000		987,228
> South Africa
Adcock Ingram Holdings		4,625,000		4,992,200
Coronation Fund Managers		8,723,060		10,271,492
Massmart Holdings		0		1,019,988
Naspers		1,096,000		1,170,188
Northam Platinum		5,780,900		6,463,160
Rand Merchant Insurance		17,625,208		19,098,300
> Autstralia
Cochlear		467,000		498,560
UGL		2,482,000		2,653,389
> Israel
Israel Chemicals		2,890,000		3,085,527
> Senegal
Sonatel		43,000		45,237
Latin America
> Brazil
Mills Estruturas e Servicos de Engenharia		3,000,000		3,184,900
MRV Engenharia		3,400,000		3,634,800
Multiplus		1,100,000		1,179,000
Suzano - Preferred		5,937,000		6,344,043
> Mexico
Grupo Aeroportuario del Surest - ADR		580,000		624,168
> Chile
Sociedad Quimica y Minera de Chile - ADR		340,000		362,996
> Argentina
Madalena Ventures		5,400,000		5,940,000
> Colombia
Canacol Energy		8,240,000		8,893,869
Gulf United		20,718,000		22,525,000

	Number of Shares
	06/30/11		09/30/11
Sales
Asia
> Japan
Aeon Mall		906,000		880,474
Asics		3,650,000		2,116,900
Gree		1,355,000		1,139,000
Kamigumi		3,283,000		634,794
Makita		509,000		0
Nippon Sheet Glass		7,174,000		6,107,300
Start Today		1,275,000		938,400
> Taiwan
China Steel Chemical		4,192,000		2,748,000
Everlight Electronics		7,206,000		0
Simplo Technology		5,821,000		3,678,530
Sinyi Realty		2,211,000		1,211,280
> Singapore
CDL Hospitality Trust		23,000,000		21,890,000
Olam International		35,981,000		33,000,000
Singapore Exchange		4,000,000		3,500,000
> Hong Kong
Hong Kong Exchanges and Clearing		750,000		0
Lifestyle International		18,000,000		17,000,000
> China
China Communication Services		41,959,300		0
ENN Energy		6,000,000		5,000,000
RexLot Holdings		240,000,000		239,160,800
Shandong Weigao		11,286,200		0
Wasion Group		24,244,400		8,479,200
Zuoan Fashion		680,503		265,146
Europe
> United Kingdom
Intertek Group		2,000,000		1,853,000
Next		582,000		446,300
Serco		3,513,800		3,305,000
Workspace Group		56,093,000		8,028,385
> Netherlands
Core Laboratories		249,000		228,095
USG People		1,093,994		454,772
> Switzerland
Sika		22,300		19,251
> Germany
Vossloh		165,000		0
> Sweden
Orc Software		708,342		140,068

	Number of Shares
	06/30/11		09/30/11
Sales (continued)
Europe—continued
> Italy
Credito Emiliano		4,311,600		0
Terna		4,111,000		0
Tod's		257,200		155,200
> Ireland
Paddy Power		359,000		350,000
> Spain
Red Eléctrica de España		579,000		494,320
> Portugal
Banco Comercial Português		22,568,987		0
> Finland
Poyry		410,523		409,248
> Russia
Mail.ru - GDR		764,506		629,642
> Poland
Central European Distribution		893,900		0
Other Countries
> Canada
Guyana Goldfields		1,291,135		0
> South Africa
Mr. Price		4,600,000		3,722,083
> Autstralia
SAI Global		6,281,896		5,806,600
Seek		1,000,000		0
> Egypt
Paints & Chemical Industries (Pachin)		235,342		0
Latin America
> Brazil
Localiza Rent A Car		4,300,000		4,200,000
Natura		1,300,000		0
PDG Realty		4,400,000		0

Columbia Acorn International

Statement of Investments (Unaudited), September 30, 2011

Number of Shares			Value (000)
			Equities: 96.4%
Asia 41.6%
		> Japan 18.6%
	8,187,600	Kansai Paint	$	78,460
		Paint Producer in Japan, India, China and Southeast Asia
	22,694	Seven Bank		44,294
		ATM Processing Services
	1,995,438	Aeon Delight		42,826
		Facility Maintenance & Management
	1,697,200	Hoshizaki Electric		41,348
		Commercial Kitchen Equipment
	7,780	Orix JREIT		35,750
		Diversified REIT
	1,139,000	Gree		34,736
		Mobile Social Networking Game Developer/Platform
	751,792	Ain Pharmaciez		33,127
		Dispensing Pharmacy/Drugstore Operator
	765,554	Hamamatsu Photonics		30,857
		Optical Sensors for Medical & Industrial Applications
	2,052,572	Japan Airport Terminal		30,534
		Airport Terminal Operator at Haneda
	25,380	Wacom (a)		29,747
		Computer Graphic Illustration Devices
	2,129,100	Kuraray		29,037
		Special Resin, Fine Chemical, Fibers & Textures
	16,005	Advance Residence Investment		28,992
		Residential REIT
	25,769,649	Shinsei Bank		28,965
		Commercial Bank
	2,116,900	Asics		28,905
		Footwear and Apparel
	25,979	Jupiter Telecommunications		28,110
		Largest Cable Service Provider in Japan
	855,604	Tsumura		27,280
		Traditional Chinese/Japanese Herbal Rx Drugs (Kampo)
	295,762	Nakanishi		26,991
		Dental Tools & Machinery
	937,651	Kintetsu World Express		26,818
		Airfreight Logistics
	1,851,900	Asahi Diamond Industrial		25,760
		Consumable Diamond Tools
	5,531	Osaka Securities Exchange (b)		25,348
		Osaka Securities Exchange
	1,277,429	Daiseki		25,279
		Waste Disposal and Recycling
	1,055,562	Glory		24,813
		Currency Handling Systems & Related Equipment
	2,600,000	Shimadzu		21,932
		Analytical Instrument, Medical & Industrial Equipment
	530,500	Kakaku.com		21,776
		Online Price Comparison Services for Consumers

Number of Shares			Value (000)
	1,405,739	Ushio	$	21,401
		Industrial Light Sources
	938,400	Start Today		20,333
		Online Japanese Apparel Retailer
	880,474	Aeon Mall		20,112
		Suburban Shopping Mall Developer, Owner & Operator
	469,500	Pigeon		19,247
		Baby Care Products
	1,940,200	Sintokogio		18,987
		Automated Casting Machines, Surface Treatment System and Consumables
	1,346,963	Torishima Pump Manufacturing (b)		18,918
		Industrial Pump for Power Generation and Water Supply Systems
	732,108	Icom		18,767
		Two Way Radio Communication Equipment
	2,874	Fukuoka REIT		18,677
		Diversified REIT in Fukuoka
	883,144	Ibiden		18,663
		Electronic Parts & Ceramics
	5,540	Mori Hills REIT Investment		18,639
		Tokyo-centric Diversified REIT
	636,250	Miura		18,629
		Industrial Boiler
	772,000	Misumi Group		17,156
		Industrial Components Distributor
	6,107,300	Nippon Sheet Glass		13,664
		Sheet Glass for Building and Automotive Use
	736,600	Park24		9,155
		Parking Lot Operator
	634,794	Kamigumi		5,666
		Port Cargo Handling & Logistics
				1,029,699
		> Taiwan 4.8%
	33,118,800	Far Eastone Telecom		48,967
		Taiwan's 3rd Largest Mobile Operator
	7,017,009	President Chain Store		39,519
		Taiwan's Number One Convenience Chain Store Operator
	2,240,000	St. Shine Optical		27,343
		World's Leading Disposable Contact Lens OEM
	11,315,800	Taiwan Hon Chuan		24,014
		Beverage Packaging (bottles, caps, labels) Manufacturer
	3,678,530	Simplo Technology		22,593
		Battery Packs for Notebook & Tablet PCs
	1,580,717	Formosa International Hotels		21,529
		Hotel, Food & Beverage Operation & Hospitality Management Services
	5,910,000	Radiant Opto-Electronics		16,578
		LCD Back Light Modules
	5,613,270	Tripod Technologies		14,622
		Printed Circuit Boards
	7,025,500	Chroma Ate		14,396
		Automatic Test Systems, Testing & Measurement Instruments

Number of Shares			Value (000)
		> Taiwan—continued
	2,748,000	China Steel Chemical	$	11,403
		Sole Coal Chemical Producer in Taiwan
	9,315,800	CTCI Corp		11,144
		International Engineering Firm
	3,458,700	Advantech		9,085
		Industrial PC & Components
	1,211,280	Sinyi Realty		1,560
		Taiwanese Realty Company
	510,800	Lung Yen		1,224
		Funeral Services and Columbaria
				263,977
		> Singapore 4.4%
	33,000,000	Olam International		56,234
		Agriculture Supply Chain Manager
	23,489,149	Ascendas REIT		36,221
		Industrial Property Landlord
	42,675,997	Mapletree Industrial Trust REIT		35,113
		Industrial Property Landlord
	53,383,000	Mapletree Logistics Trust		34,577
		Industrial Property Landlord
	21,890,000	CDL Hospitality Trust		25,144
		Hotel Owner/Operator
	32,300,000	Mapletree Commercial Trust		19,994
		Retail and Office Property Landlord
	3,500,000	Singapore Exchange		17,593
		Singapore Equity & Derivatives Market Operator
	15,000,000	Goodpack Limited		17,312
		International Bulk Container Leasing
				242,188
		> Hong Kong 4.3%
	7,000,000	Melco Crown Entertainment - ADR (c)		58,170
		Macau Casino Operator
	17,000,000	Lifestyle International		43,129
		Mid to High-End Department Store Operator in Hong Kong & China
	35,923,500	Mongolian Mining (c)		31,761
		Coking Coal Mining in Mongolia
	15,000,000	L'Occitane International (c)		30,213
		Skin Care and Cosmetics Producer
	37,703,800	Sasa International		22,358
		Cosmetics Retailer
	32,000,000	Hutchison Port Holdings Trust		21,360
		Southern China Container Ports
	12,500,000	MGM China Holdings (c)		16,565
		Macau Casino Operator
	40,438,400	Nagacorp		8,629
		Casino/Entertainment Complex in Cambodia
	7,419,000	Melco International		4,857
		Macau Casino Operator
				237,042
		> China 4.0%
	34,745,554	Zhaojin Mining Industry		57,798
		Gold Mining and Refining in China
	965,387	New Oriental Education & Technology - ADR (c)		22,175
		Education Service Provider

Number of Shares			Value (000)
	23,596,000	Jiangsu Expressway	$	17,821
		Chinese Toll Road Operator
	19,410,400	Want Want		17,579
		Chinese Branded Consumer Food Company
	5,000,000	ENN Energy		16,175
		China's Largest Private Gas Operator
	401,000	Netease.com		15,302
		Chinese Online Gaming Services
	11,165,300	Digital China		14,615
		IT Distribution & Systems Integration Services
	25,695,600	AMVIG Holdings		14,483
		Chinese Tobacco Packaging Material Supplier
	239,160,800	RexLot Holdings		14,216
		Lottery Equipment Supplier in China
	12,047,000	China Yurun Food		12,742
		Meat Processor in China
	263,700	51job - ADR (b)(c)		10,522
		Integrated Human Resource Services
	800,000	Noah Holdings - ADR (b)		7,360
		Wealth Management Product Distributor in China
	8,479,200	Wasion Group		2,449
		Electronic Power Meter Total Solution Provider
	265,146	Zuoan Fashion (b)(c)		729
		Men's Apparel Provider in China
				223,966
		> India 2.7%
	11,163,303	Jain Irrigation Systems		34,573
		Agricultural Micro-Irrigation Systems & Food Processing
	8,052,053	Mundra Port & Special Economic Zone		26,906
		Indian West Coast Shipping Port
	341,652	Asian Paints		21,990
		India's Largest Paint Company
	32,642,905	REI Agro		16,480
		Basmati Rice Processing
	14,381,649	Manappuram Finance		15,262
		Short-term Lending Collateralized by Household Gold
	767,100	Shriram Transport Finance		9,529
		Used Truck Finance
	1,203,445	United Breweries (c)		9,150
		India's Largest Brewer
	10,249,300	S. Kumars Nationwide		8,711
		Textiles, Clothing & Retail
	3,807,700	Infrastructure Development Finance		8,552
		Infrastructure Finance in India
				151,153
		> South Korea 1.5%
	1,242,590	Woongjin Coway		40,009
		South Korean Household Appliance Rental Service Provider
	160,150	NHN (c)		30,511
		Korean Online Search Services
	129,332	MegaStudy		12,973
		Education Service Provider
				83,493

Columbia Acorn International

Statement of Investments (Unaudited), continued

Number of Shares			Value (000)
		> Philipines 0.6%
	63,272,200	SM Prime Holdings	$	17,578
		Shopping Mall Operator
	7,931,700	Int'l Container Terminal		8,415
		Container Handling Terminals & Port Management
	14,299,600	Manila Water Company		6,190
		Water Utility Company in the Philippines
				32,183
		> Thailand 0.6%
	104,039,000	Home Product Center		31,099
		Home Improvement Retailer
				31,099
		> Indonesia 0.1%
	8,306,300	Ace Indonesia		3,105
		Home Improvement Retailer
				3,105
Asia: Total				2,297,905
Europe 35.3%
		> United Kingdom 7.7%
	1,853,000	Intertek Group		53,294
		Testing, Inspection, Certification Services
	5,700,000	Chemring		46,669
		Defense Manufacturer of Countermeasures and Energetics
	3,644,400	JLT Group (b)		35,688
		International Business Insurance Broker
	29,063,787	Archipelago Resources (a)(c)		31,066
		Gold Mining Projects in Indonesia, Vietnam, and the Philippines
	8,028,385	Workspace Group (a)		26,965
		United Kingdom Real Estate
	3,305,000	Serco		26,146
		Facilities Management
	2,109,700	Petropavlovsk		19,401
		Gold and Iron Ore Mining in Russia
	4,155,200	GlobeOp Financial Services		18,726
		Hedge Fund Administrator
	730,000	Rotork		17,570
		Valve Actuators for Oil & Water Pipelines
	446,300	Next		17,497
		Clothes and Home Retailer in the United Kingdom
	2,497,000	Domino's Pizza United Kingdom & Ireland		17,216
		Pizza Delivery in United Kingdom, Ireland and Germany
	2,950,000	Abcam (c)		16,676
		Online Sales of Antibodies
	1,761,742	Smith and Nephew		15,848
		Medical Equipment & Supplies
	5,804,000	Cobham		15,711
		Aerospace Components
	740,581	Tullow Oil		14,978
		Oil and Gas Producer
	2,636,932	Premier Oil (c)		14,176
		Oil and Gas Producer in Europe, Pakistan and Asia

Number of Shares			Value (000)
	1,691,711	Shaftesbury	$	12,221
		London Prime Retail REIT
	9,009,000	Kesa Electricals		11,704
		Europe's Leading Electricals Retailers
	4,163,948	PureCircle (c)		5,790
		Natural Sweeteners
	1,650,000	SKIL Ports and Logistics (c)		3,782
		Indian Container Port Project
	1,499,183	FlyBe (c)		2,665
		Largest European Regional Airline
	1,692,525	Sterling Resources (c)		1,599
	1,147,475	Sterling Resources (c)(d)		1,062
		Oil & Gas Exploration - Europe
				426,450
		> Netherlands 5.8%
	1,189,424	Vopak		56,848
		World's Largest Operator of Petroleum and Chemical Storage Terminals
	1,955,311	Imtech		55,001
		Electromechanical and ICT Installation and Maintenance
	844,967	Fugro		42,613
		Sub-sea Oilfield Services
	1,371,573	Koninklijke TenCate (a)		42,153
		Advanced Textiles and Industrial Fabrics
	1,591,702	Unit 4 Aggresso (a)		38,867
		Business Software Development
	2,479,123	Aalberts Industries		36,859
		Flow Control and Heat Treatment
	1,252,514	Arcadis		22,864
		Engineering Consultants
	228,095	Core Laboratories (b)		20,490
		Oil and Gas Reservoir Consulting
	454,772	USG People		3,766
		Temporary Staffing Services
				319,461
		> France 5.0%
	1,193,000	Gemalto		56,731
		Digital Security Solutions
	631,797	Neopost		46,327
		Postage Meter Machines
	554,800	Eurofins Scientific		41,935
		Food, Pharmaceuticals and Materials Screening and Testing
	971,800	Saft		26,097
		Niche Battery Manufacturer
	1,158,000	Teleperformance		24,600
		Call Center Operator
	556,874	Mersen		22,040
		Advanced Industrial Materials
	376,131	Rubis		18,947
		Tank Storage and LPG Distribution
	232,400	Norbert Dentressangle		17,861
		Leading European Logistics and Transport Group
	322,605	Pierre & Vacances		12,839
		Vacation Apartment Lets

Number of Shares			Value (000)
		> France—continued
	1,831,204	Hi-Media (b)(c)	$	5,935
		Online Advertiser in Europe
				273,312
		> Switzerland 3.8%
	265,000	Partners Group		43,634
		Private Markets Asset Management
	225,650	Geberit (c)		41,664
		Plumbing Supplies
	350,445	Kuehne & Nagel		39,331
		Freight Forwarding/Logistics
	19,251	Sika		34,085
		Chemicals for Construction & Industrial Applications
	286,300	Dufry Group (c)		25,029
		Operates Airport Duty Free and Duty Paid Shops
	773,707	Bank Sarasin & Cie		23,657
		Private Banking
				207,400
		> Germany 3.6%
	2,286,441	Wirecard		34,980
		Online Payment Processing & Risk Management
	148,295	Rational		33,290
		Commercial Ovens
	1,600,000	Rhoen-Klinikum		32,400
		Health Care Services
	679,600	Rheinmetall		31,877
		Defense & Automotive
	819,889	CTS Eventim		24,424
		Event Ticket Sales
	636,800	Dürr		20,520
		Automotive Plant Engineering & Associated Capital Equipment
	555,700	Elringklinger (b)		12,992
		Automobile Components
	338,886	Deutsche Beteiligungs		6,753
		Private Equity Investment Management
				197,236
		> Sweden 1.9%
	4,056,007	Hexagon		52,741
		Design, Measurement and Visualization Software and Equipment
	4,150,024	Sweco (a)		34,311
		Engineering Consultants
	658,700	Unibet (c)		12,388
		European Online Gaming Operator
	905,452	East Capital Explorer		6,920
		Sweden-Based RUS/CEE Investment Fund
	140,068	Orc Software (b)		941
		Software for Securities Trading, Analysis and Risk Management
				107,301
		> Italy 1.5%
	2,621,149	Ansaldo STS		26,050
		Railway Systems Integrator
	13,547,300	CIR		25,470
		Italian Holding Company

Number of Shares			Value (000)
	4,973,000	Geox	$	18,105
		Apparel and Shoe Maker
	155,200	Tod's		13,093
		Leather Shoes and Bags
				82,718
		> Denmark 1.3%
	329,760	Novozymes		46,885
		Industrial Enzymes
	168,042	SimCorp		24,107
		Software for Investment Managers
				70,992
		> Ireland 1.2%
	9,700,000	United Drug		29,701
		Irish Pharmaceutical Wholesaler & Outsourcer
	350,000	Paddy Power		18,020
		Irish Betting Services
	395,008	Aryzta		16,743
		Baked Goods
				64,464
		> Iceland 0.7%
	35,982,499	Marel (c)		35,777
		Largest Manufacturer of Poultry and Fish Processing Equipment
				35,777
		> Czech Republic 0.4%
	130,682	Komercni Banka		24,237
		Leading Czech Universal Bank
				24,237
		> Spain 0.4%
	494,320	Red Eléctrica de España		22,525
		Spanish Power Transmission
				22,525
		> Portugal 0.4%
	7,770,405	Redes Energéticas Nacionais		21,838
		Portuguese Power Transmission and Gas Transportation
				21,838
		> Finland 0.4%
	1,039,429	Stockmann (b)		17,483
		Department Store and Fashion Retailer in Scandinavia and Russia
	409,248	Poyry		3,206
		Engineering Consultants
				20,689
		> Norway 0.3%
	2,403,664	Atea		19,065
		Leading Nordic IT Hardware/Software Reseller and Installation Company
				19,065
		> Russia 0.3%
	629,642	Mail.ru - GDR (c)(f)		18,231
		Internet Social Networking and Games for Russian Speakers
				18,231

Columbia Acorn International

Statement of Investments (Unaudited), continued

Number of Shares			Value (000)
		> Belgium 0.3%
	332,977	EVS Broadcast Equipment	$	17,220
		Digital Live Mobile Production Software and Systems
				17,220
		> Kazakhstan 0.2%
	1,770,000	Halyk Savings Bank of Kazakhstan (c)		10,976
		Largest Retail Bank and Insurer in Kazakhstan
				10,976
		> Greece 0.1%
	6,954,400	Intralot		7,993
		Lottery and Gaming Systems and Services
				7,993
Europe: Total				1,947,885
Other Countries 15.5%
		> Canada 4.8%
	1,790,397	ShawCor		41,569
		Oil and Gas Pipeline Products
	1,403,772	CCL Industries		37,415
		Leading Global Label Manufacturer
	615,857	Baytex (b)(c)		25,747
		Oil and Gas Producer in Canada
	582,942	AG Growth		20,844
		Leading Manufacturer of Augers and Grain Handling Equipment
	653,200	Onex Capital		20,358
		Private Equity
	754,800	Alliance Grain Traders		16,063
		Global Leader in Pulse Processing and Distribution
	1,189,576	Black Diamond Group		15,382
		Provides Accommodations/Equipment for Oil Sands Development
	1,049,943	Ivanhoe Mines (c)		14,478
	914,678	Ivanhoe Mines (c)(g)		12,531
		Copper Mine Project in Mongolia
	963,600	Tahoe Resources (c)		13,885
		Silver Project in Guatemala
	505,000	Celtic Exploration (c)		10,877
		Canadian Oil and Gas Producer
	2,411,514	Horizon North Logistics		9,044
		Provides Diversified Oil Service Offering in Northern Canada
	2,919,000	DeeThree Exploration (a)(c)(d)		6,251
	1,142,377	DeeThree Exploration (a)(c)		2,497
		Canadian Oil and Gas Producer
	678,000	Crew Energy (c)		6,004
		Canadian Oil and Gas Producer
	6,217,500	Southern Arc Minerals (a)(c)(d)		5,350
		Gold and Copper Exploration in Indonesia
	1,607,306	Pan Orient (c)		3,574
		Pan Orient is Growth Oriented, Return Focused Asian Explorer
	12,500,000	Petromanas (c)		1,491
	6,250,000	Petromanas - Warrants (c)(d)		88
		Exploring for Oil in Albania

Number of Shares			Value (000)
	13,000,000	Eacom Timber (c)	$	1,241
		Canadian Lumber Producer
				264,689
		> United States 4.6%
	887,431	Alexion Pharmaceuticals (c)		56,849
		Biotech Focused on Orphan Diseases
	1,373,080	Atwood Oceanics (c)		47,179
		Offshore Drilling Contractor
	1,229,871	BioMarin Pharmaceutical (c)		39,196
		Biotech Focused on Orphan Diseases
	987,228	World Fuel Services		32,233
		Global Fuel Broker
	707,213	FMC Technologies (c)		26,591
		Oil and Gas Well Head Manufacturer
	421,732	Bristow		17,894
		Largest Provider of Helicopter Services to Offshore Oil and Gas Producers
	838,297	Textainer Group Holdings		17,001
		Top International Container Leasor
	270,000	Oil States International (c)		13,748
		Diversified North American Oil Service Provider
				250,691
		> South Africa 3.9%
	1,170,188	Naspers		50,535
		Media in Africa, China, Russia, and Other Emerging Markets
	4,992,200	Adcock Ingram Holdings		37,021
		Manufacturer of Pharmaceuticals and Medical Supplies
	3,722,083	Mr. Price		30,847
		South African Retailer of Apparel, Household and Sporting Goods
	19,098,300	Rand Merchant Insurance		29,575
		Directly Sold Property and Casualty Insurance; Holdings in Other Insurers
	6,463,160	Northam Platinum		26,207
		Platinum Mining in South Africa
	10,271,492	Coronation Fund Managers		25,354
		South African Fund Manager
	1,019,988	Massmart Holdings		17,460
		General Merchandise, Food, and Home Improvement Stores; Wal-Mart Subsidiary
				216,999
		> Australia 1.4%
	2,653,389	UGL		29,009
		Engineering and Facilities Management
	5,806,600	SAI Global		26,419
		Publishing, Certification, Compliance Services
	498,560	Cochlear		22,101
		Cochlear Implants
				77,529
		> Israel 0.6%
	3,085,527	Israel Chemicals		35,139
		Producer of Potash, Phosphates, Bromine, and Specialty Chemicals
				35,139

Number of Shares			Value (000)
		> Senegal 0.2%
	45,237	Sonatel	$	11,272
		Leading Telecoms Operator in Western Africa
				11,272
Other Countries: Total				856,319
Latin America 4.0%
		> Brazil 2.7%
	4,200,000	Localiza Rent A Car		55,419
		Car Rental
	3,184,900	Mills Estruturas e Servicos de Engenharia		29,829
		Civil Engineering & Construction
	6,344,043	Suzano - Preferred		28,578
		Brazilian Pulp and Paper Producer
	3,634,800	MRV Engenharia		18,520
		Brazilan Property Developer
	1,179,000	Multiplus		17,018
		Loyalty Program Operator in Brazil
				149,364
		> Mexico 0.5%
	624,168	Grupo Aeroportuario del Sureste - ADR		31,034
		Mexican Airport Operator
				31,034
		> Chile 0.3%
	362,996	Sociedad Quimica y Minera de Chile - ADR		17,355
		Producer of Specialty Fertilizers, Lithium and Iodine
				17,355
		> Argentina 0.3%
	1,136,364	Union Agriculture Group (c)(d)(e)		12,114
		Farmland Operator in Uruguay
	5,940,000	Madalena Ventures (c)(d)		2,666
		Oil and Gas Exploration in Argentina
				14,780
		> Colombia 0.2%
	8,893,869	Canacol Energy (c)		5,432
		Oil Producer in South America
	22,525,000	Gulf United (c)(d)		4,973
		Prospecting for Oil Alongside Large Producers in Colombia
				10,405
Latin America: Total				222,938
Total Equities: 96.4% (Cost: $4,746,140)				5,325,047

Number of Shares			Value (000)
Securities Lending Collateral 0.9%
	47,260,372	Dreyfus Government Cash Management Fund (h) (7 day yield of 0.00%)	$	47,260
Total Securities Lending Collateral: (Cost: $47,260)				47,260
Total Investments: 97.3% (Cost: $4,793,400)(i)(j)				5,372,307
Obligation to Return Collateral for Securities Loaned: (0.9)%				(47,260	)
Cash and Other Assets Less Liabilities: 3.6%				198,718
Total Net Assets: 100.0%			$	5,523,765

ADR = American Depositary Receipts

GDR = Global Depositary Receipts

Columbia Acorn International

Statement of Investments (Unaudited), continued

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

(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 nine months ended September 30, 2011, are as follows:

Affiliates	Balance of Shares Held 12/31/10		Purchases/ Additions		Sales/ Reductions		Balance of Shares Held 9/30/11		Value		Dividend
Archipelago Resources		24,346,593		4,717,194		-		29,063,787	$	31,066	$	-
DeeThree Exploration		2,392,877		1,668,500		-		4,061,377		8,748		-
Gulf United*		-		22,525,000		-		22,525,000		4,973		-
Koninklijke TenCate		1,240,557		131,016		-		1,371,573		42,153		-
Southern Arc Minerals		-		6,217,500		-		6,217,500		5,350		-
Sweco		3,887,000		263,024		-		4,150,024		34,311		1,617
Unit 4 Aggresso		1,476,800		114,902		-		1,591,702		38,867		450
United Drug*		12,110,000		737,752		3,147,752		9,700,000		29,701		1,371
Wacom		20,900		4,480		-		25,380		29,747		721
Workspace Group+		60,304,000		640,600		52,916,215		8,028,385		26,965		522
Total of Affiliated Transactions		105,778,727		37,019,968		56,063,967		86,734,728	$	251,881	$	4,681

* At September 30, 2011, the Fund owned less than five percent of the company's outstanding voting shares.

+ Includes the effects of a corporate action.

The aggregate cost and value of these companies at September 30, 2011, were $181,558 and $217,207, respectively. Investments in affiliated companies represented 3.93% of the Fund's total net assets at September 30, 2011.

(b) All or a portion of this security was on loan at September 30, 2011. The total market value of securities on loan at September 30, 2011 was $43,849,295.

(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 September 30, 2011, the market value of these securities (in thousands) amounted to $32,504 which represented 0.59% of total net assets.

Additional information on these securities is as follows:

Security	Acquisition Dates	Shares		Cost		Value
Union Agriculture Group	12/08/10		1,136,364	$	15,000	$	12,114
DeeThree Exploration	9/07/10-3/08/11		2,919,000		10,228		6,251
Southern Arc Minerals	2/16/11		6,217,500		10,087		5,350
Gulf United Energy	2/11/11		22,525,000		6,758		4,973
Madalena Ventures	10/21/10		5,940,000		3,764		2,666
Sterling Resources	12/02/10		1,147,475		3,425		1,062
Petromanas - Warrants	5/20/10		6,250,000		362		88
				$	49,624	$	32,504

(e) Illiquid security.

(f) Security exempt from registration under Section 4(2) of the Securities Act of 1933. This security may only be resold in exempt transactions to qualified buyers. Private resales of this security to qualified institutional buyers are also exempt from registration pursuant to Rule 144A under the Securities Act of 1933. At September 30, 2011, this security had an aggregate value of $18,231, which represented 0.33% of total net assets.

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

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

(i) At September 30, 2011, for federal income tax purposes, the cost of investments was $4,793,400 and net unrealized appreciation was $578,907 consisting of gross unrealized appreciation of $1,122,711 and gross unrealized depreciation of $543,804.

(j) On September 30, 2011, the Fund's total investments were denominated in currencies as follows:

Currency	Value		Percentage of Net Assets
Japanese Yen	$	1,029,699		18.6
Euro		1,006,966		18.2
U.S. Dollar		514,013		9.3
British Pound		423,789		7.7
Hong Kong Dollar		325,390		5.9
Other currencies less
than 5% of total net assets		2,072,450		40.3
	$	5,372,307		100.0

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

At September 30, 2011, the Fund had entered into the following forward foreign currency exchange contracts:

Forward Foreign Currency Exchange Contracts to Buy	Forward Foreign Currency Exchange Contracts to Sell	Principal Amount in Foreign Currency		Principal Amount in U.S. Dollar		Settlement Date	Unrealized Depreciation
USD	EUR		56,462	$	79,721	10/14/11	$	4,082
USD	EUR		55,878		79,551	11/15/11		4,708
USD	EUR		58,431		80,000	12/15/11		1,742
AUD	USD		33,213		35,227	10/14/11		(3,130	)
AUD	USD		4,379		4,500	10/14/11		(268	)
AUD	USD		38,997		39,936	11/15/11		(2,405	)
AUD	USD		39,571		40,000	12/15/11		(2,045	)
CAD	USD		38,103		39,646	10/14/11		(3,294	)
CAD	USD		39,685		39,996	11/15/11		(2,164	)
CAD	USD		39,741		40,000	12/15/11		(2,136	)
				$	478,577		$	(4,910	)

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

AUD = Australian Dollar

CAD = Canadian Dollar

EUR = Euro

USD = United States Dollar

• 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)

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

The following table summarizes the inputs used, as of September 30, 2011, 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	$	114,258	$	2,183,647		$	-	$	2,297,905
Europe		22,089		1,925,796			-		1,947,885
Other Countries		503,692		352,627			-		856,319
Latin America		203,185		7,639			12,114		222,938
Total Equities		843,224		4,469,709			12,114		5,325,047
Total Securities Lending Collateral		47,260		-			-		47,260
Total Investments	$	890,484	$	4,469,709		$	12,114	$	5,372,307
Unrealized Appreciation on Forward Foreign Currency Contracts		-		10,532			-		10,532
Unrealized Depreciation on Forward Foreign Currency Contracts		-		(15,442	)		-		(15,442	)
Total	$	890,484	$	4,464,799		$	12,114	$	5,367,397

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 sales price on the foreign exchange or market on which they trade. The Fund may use a systematic fair valuation model 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 adviser's experience with similar securities or situations. Factors may include, but

Columbia Acorn International

Statement of Investments (Unaudited), continued

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

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
$	214,727	$	22,667	$	22,667	$	214,727

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

Financial assets were transferred from Level 2 to Level 1 as resale restrictions expired.

Foreign exchange-traded financial assets were transferred from Level 1 to Level 2.

The following table reconciles asset balances for the nine months ending September 30, 2011, in which significant unobservable inputs (Level 3) were used in determining value:

Investments in Securities	Balance as of December 31, 2010		Realized Gain/(Loss)			Change in Unrealized Appreciation (Depreciation)			Purchases		Sales		Transfers into Level 3		Transfers out of Level 3		Balance as of September 30, 2011
Equities
Asia	$	79	$	(38,558	)	$	38,479		$	-	$	-	$	-	$	-	$	-
Latin America		15,000		-			(2,886	)		-		-		-		-		12,114
	$	15,079	$	(38,558	)	$	35,593		$	-	$	-	$	-	$	-	$	12,114

The change in unrealized depreciation attributed to securities owned at September 30, 2011, which were valued using significant unobservable inputs (Level 3) amounted to $2,886.

Columbia Acorn International

Portfolio Diversification (Unaudited)

At September 30, 2011, the Fund's portfolio investments as a percentage of net assets were diversified as follows:

	Value (000)		Percentage of Net Assets
> Industrial Goods & Services
Other Industrial Services	$	513,117		9.3
Industrial Materials & Specialty Chemicals		403,700		7.3
Machinery		391,682		7.1
Electrical Components		109,878		2.0
Construction		82,637		1.5
Conglomerates		80,992		1.5
Outsourcing Services		29,912		0.5
Industrial Distribution		17,312		0.3
		1,629,230		29.5
> Consumer Goods & Services
Retail		260,486		4.7
Food & Beverage		151,736		2.8
Casinos & Gaming		140,838		2.6
Nondurables		99,968		1.8
Other Consumer Services		96,444		1.7
Apparel		73,933		1.3
Travel		70,923		1.3
Other Entertainment		45,953		0.8
Educational Services		35,148		0.6
Restaurants		17,216		0.3
Consumer Goods Distribution		11,704		0.2
		1,004,349		18.1
> Information
Computer Hardware & Related Equipment		149,356		2.7
Internet Related		136,355		2.5
Business Software		132,935		2.4
Mobile Communications		67,734		1.2
Instrumentation		67,185		1.2
Financial Processors		52,573		1.0
Telephone and Data Services		35,872		0.6
Gaming Equipment & Services		34,736		0.6
CATV		28,110		0.5
Computer Services		20,006		0.4
Electronics Distribution		14,615		0.3
Advertising		5,935		0.1
		745,412		13.5

	Value (000)			Percentage of Net Assets
> Energy & Minerals
Mining	$	232,967			4.2
Oil Services		214,020			3.9
Oil & Gas Producers		101,415			1.8
Oil Refining, Marketing & Distribution		75,795			1.4
Agricultural Commodities		57,996			1.1
		682,193			12.4
> Other Industries
Real Estate		328,391			6.0
Transportation		135,149			2.4
Regulated Utilities		66,728			1.2
		530,268			9.6
> Finance
Brokerage & Money Management		125,044			2.3
Banks		117,024			2.1
Finance Companies		94,858			1.7
Insurance		65,263			1.2
		402,189			7.3
> Health Care
Medical Equipment & Devices		121,789			2.2
Pharmaceuticals		94,002			1.7
Medical Supplies		44,019			0.8
Biotechnology & Drug Delivery		39,196			0.7
Health Care Services		32,400			0.6
		331,406			6.0
Total Equities:		5,325,047			96.4
Securities Lending Collateral:		47,260			0.9
Total Investments:		5,372,307			97.3
Obligation to Return Collateral for Securities Loaned:		(47,260	)		(0.9	)
Cash and Other Assets Less Liabilities:		198,718			3.6
Net Assets:	$	5,523,765			100.0

Columbia Acorn USA

Major Portfolio Changes in the Third Quarter (Unaudited)

	Number of Shares
	06/30/11		09/30/11
Purchases
Information
AboveNet		168,800		192,800
Carbonite		0		62,597
ExlService Holdings		428,000		556,000
NetSuite		129,000		184,000
Polycom		386,000		460,000
Tangoe		0		57,400
Consumer Goods & Services
Cavco Industries		161,000		206,000
HomeAway		30,000		140,000
lululemon athletica		390,000		780,000
Pinnacle Entertainment		645,000		775,000
Shutterfly		254,000		289,000
Skullcandy		0		140,000
Teavana		0		161,500
Warnaco Group		192,000		222,000
Industrial Goods & Services
Acorn Energy		0		600,000
Albany International		135,000		187,000
Clean Harbors		0		65,000
GrafTech International		486,000		686,000
Kennametal		177,000		226,000
Toro		71,800		136,800
Finance
CAI International		230,000		330,000
City National		0		70,000
Financial Engines		0		173,000
Textainer Group Holdings		285,000		345,000
TrustCo Bank		245,300		595,300
Health Care
Akorn		725,000		796,500
Alimera Sciences		108,512		133,180
Gen-Probe		124,000		140,000
HealthSouth		0		205,000
Hill-Rom Holdings		0		84,007
Horizon Pharma		0		150,000
Sirona Dental Systems		184,000		224,000

	Number of Shares
	06/30/11		09/30/11
Sales
Information
Amphenol		196,000		159,000
Applied Micro Circuits		448,000		0
Blackbaud		333,000		300,000
Blackboard		247,000		0
Entegris		675,000		0
FLIR Systems		130,000		0
Global Payments		188,000		170,000
IMAX (Canada)		145,000		0
Informatica		985,000		910,000
Nice Systems - ADR (Israel)		280,000		252,000
PAETEC Holding		2,030,000		0
Plexus		261,000		236,000
SBA Communications		650,000		560,000
Spanish Broadcasting System		71,718		0
TheStreet.com		343,000		225,100
Consumer Goods & Services
Chico's FAS		481,000		0
Herman Miller		260,000		164,000
Penn National Gaming		270,000		69,000
Saks		875,000		790,000
Talbots		480,000		0
True Religion Apparel		241,530		181,000
Universal Technical Institute		165,000		0
Industrial Goods & Services
Albemarle		54,000		0
Kaydon		50,000		0
WABCO Holdings		100,000		0
Finance
Associated Banc-Corp		692,400		623,000
GATX		42,400		0
McGrath Rentcorp		335,418		210,000
Pacific Continental		527,700		513,755
TCF Financial		659,800		594,000
Valley National Bancorp		931,000		675,000
ViewPoint Financial		756,000		602,487
Health Care
Array Biopharma		450,000		0
Health Management Associates		1,038,900		738,900
Idexx Laboratories		53,000		0
Isis Pharmaceuticals		850,000		643,000
Kindred Healthcare		150,000		0
Nabi Biopharmaceuticals		455,000		0
Onyx Pharmaceuticals		232,000		178,000
United Therapeutics		102,000		18,675

	Number of Shares
	06/30/11		09/30/11
Sales (continued)
Energy & Minerals
Carrizo Oil & Gas		73,000		0
Core Laboratories (Netherlands)		100,000		85,000
Houston American Energy		386,000		368,200
Other Industries
Biomed Realty Trust		995,200		739,200
Corporate Office Properties		246,000		0
Heartland Express		310,000		0
Macerich Company		98,619		0
Summit Hotel Properties		208,000		0

Columbia Acorn USA

Statement of Investments (Unaudited), September 30, 2011

Number of Shares			Value (000)
			Equities: 99.0%
Information 31.1%
		> Business Software 9.6%
	910,000	Informatica (a)	$	37,265
		Enterprise Data Integration Software
	698,000	Micros Systems (a)		30,649
		Information Systems for Hotels, Restaurants and Retailers
	375,000	ANSYS (a)		18,390
		Simulation Software for Engineers and Designers
	408,000	Ariba (a)		11,306
		Cost Management Software
	243,000	Concur Technologies (a)		9,045
		Web Enabled Cost & Expense Management Software
	300,000	Blackbaud		6,681
		Software & Services for Non-Profits
	322,000	SPS Commerce (a)		5,245
		Supply Chain Management Software Delivered via the Web
	52,000	Quality Systems		5,044
		IT Systems for Medical Groups & Ambulatory Care Centers
	184,000	NetSuite (a)		4,970
		End to End IT Systems Solution Delivered Over the Web
	220,000	Advent Software (a)		4,587
		Asset Management & Trading Systems
	198,000	Constant Contact (a)		3,423
		E-mail & Other Marketing Campaign Mgmt Systems Delivered Over the Web
	57,400	Tangoe (a)		649
		Software Solution for Managing Communication Expense & Devices
				137,254
		> Instrumentation 4.2%
	678,000	IPG Photonics (a)		29,452
		Fiber Lasers
	180,000	Mettler Toledo (a)		25,193
		Laboratory Equipment
	168,000	Trimble Navigation (a)		5,637
		GPS-based Instruments
				60,282
		> Computer Hardware & Related Equipment 3.6%
	1,238,000	II-VI (a)		21,665
		Laser Optics and Specialty Materials
	324,000	Zebra Technologies (a)		10,025
		Bar Code Printers
	252,000	Nice Systems - ADR (Israel) (a)(g)		7,648
		Audio & Video Recording Solutions
	159,000	Amphenol		6,482
		Electronic Connectors
	196,000	Netgear (a)		5,075
		Networking Products for Small Business & Home
				50,895

Number of Shares			Value (000)
		> Semiconductors & Related Equipment 3.3%
	1,958,000	Atmel (a)	$	15,801
		Microcontrollers, RF, and Memory Semiconductors
	760,000	Microsemi (a)		12,145
		Analog/Mixed Signal Semiconductors
	1,061,750	ON Semiconductor (a)		7,613
		Mixed Signal & Power Management Semiconductors
	1,075,000	TriQuint Semiconductor (a)		5,397
		RF Semiconductors
	346,000	Monolithic Power Systems (a)		3,522
		High Performance Analog & Mixed Signal ICs
	430,000	Pericom Semiconductor (a)		3,186
		Interface ICs & Frequency Control Products
				47,664
		> Telephone and Data Services 2.6%
	1,617,000	tw telecom (a)		26,713
		Fiber Optic Telephone/Data Services
	192,800	AboveNet		10,334
		Metropolitan Fiber Communications Services
				37,047
		> Telecommunications Equipment 2.4%
	732,000	Finisar (a)		12,839
		Optical Subsystems and Components
	460,000	Polycom (a)		8,450
		Video Conferencing Equipment
	903,000	Ixia (a)		6,926
		Telecom Network Test Equipment
	752,000	Infinera (a)		5,806
		Optical Networking Equipment
				34,021
		> Gaming Equipment & Services 1.5%
	660,000	Bally Technologies (a)		17,807
		Slot Machines & Software
	235,000	WMS Industries (a)		4,133
		Slot Machine Provider
				21,940
		> Mobile Communications 1.4%
	560,000	SBA Communications (a)		19,309
		Communications Towers
				19,309
		> Computer Services 1.3%
	556,000	ExlService Holdings (a)		12,232
		Business Process Outsourcing
	1,005,500	Hackett Group (a)		3,750
		IT Integration & Best Practice Research
	710,000	RCM Technologies (a)(b)		3,188
		Technology & Engineering Services
				19,170
		> Financial Processors 0.5%
	170,000	Global Payments		6,866
		Credit Card Processor
				6,866

Number of Shares			Value (000)
		> Contract Manufacturing 0.4%
	236,000	Plexus (a)	$	5,338
		Electronic Manufacturing Services
				5,338
		> Radio 0.1%
	511,100	Salem Communications		1,170
		Radio Stations for Religious Programming
				1,170
		> TV Broadcasting 0.1%
	975,000	Entravision Communications (a)		994
		Spanish Language TV & Radio Stations
				994
		> Consumer Software 0.1%
	62,597	Carbonite (a)(c)		754
		Online File Storage
				754
		> Internet Related —%
	225,100	TheStreet.com		446
		Financial Information Websites
				446
Information: Total				443,150
Consumer Goods & Services 17.6%
		> Retail 6.8%
	780,000	lululemon athletica (a)		37,947
		Premium Active Apparel Retailer
	468,500	Abercrombie & Fitch		28,841
		Teen Apparel Retailer
	289,000	Shutterfly (a)		11,901
		Internet Photo-Centric Retailer
	805,000	Pier 1 Imports (a)		7,873
		Home Furnishing Retailer
	790,000	Saks (a)		6,913
		Luxury Department Store Retailer
	161,500	Teavana (a)(c)		3,285
		Specialty Tea Retailer
	9,000	The Fresh Market (a)		343
		Specialty Food Retailer
				97,103
		> Travel 2.9%
	849,700	Gaylord Entertainment (a)		16,433
		Convention Hotels
	1,175,950	Avis Budget Group (a)		11,371
		Second Largest Car Rental Company
	750,000	Hertz (a)		6,675
		Largest U.S. Rental Car Operator
	140,000	HomeAway (a)(c)		4,707
		Vacation Rental Online Marketplace
	71,000	Vail Resorts		2,683
		Ski Resort Operator & Developer
				41,869
		> Apparel 1.6%
	222,000	Warnaco Group (a)		10,232
		Global Branded Apparel Manufacturer

Number of Shares			Value (000)
	90,000	Deckers Outdoor (a)	$	8,393
		Fashion Footwear Wholesaler
	181,000	True Religion Apparel (a)		4,880
		Premium Denim
				23,505
		> Furniture & Textiles 1.5%
	880,000	Knoll		12,056
		Office Furniture
	540,000	Interface		6,404
		Modular & Broadloom Carpet
	164,000	Herman Miller		2,929
		Office Furniture
				21,389
		> Food & Beverage 1.1%
	197,000	Diamond Foods (c)		15,719
		Snack Foods and Culinary Ingredients
				15,719
		> Consumer Goods Distribution 0.9%
	472,000	Pool		12,357
		Distributor of Swimming Pool Supplies & Equipment
				12,357
		> Other Durable Goods 0.8%
	206,000	Cavco Industries (a)		7,095
		Manufactured Homes
	140,000	Jarden		3,956
		Branded Household Products
				11,051
		> Other Consumer Services 0.7%
	259,000	Lifetime Fitness (a)		9,544
		Sport & Fitness Club Operator
				9,544
		> Casinos & Gaming 0.7%
	775,000	Pinnacle Entertainment (a)		7,037
		Regional Casino Operator
	69,000	Penn National Gaming (a)		2,297
		Regional Casino Operator
				9,334
		> Leisure Products 0.4%
	162,000	Thor Industries		3,588
		RV & Bus Manufacturer
	140,000	Skullcandy (a)(c)		1,978
		Lifestyle Branded Headphones
				5,566
		> Educational Services 0.2%
	37,350	ITT Educational Services (a)(c)		2,151
		Postsecondary Degree Services
				2,151
		> Restaurants —%
	26,600	Bravo Brio Restaurant Group (a)		443
		Upscale Casual Italian Restaurants
				443
Consumer Goods & Services: Total				250,031

Columbia Acorn USA

Statement of Investments (Unaudited), continued

Number of Shares			Value (000)
Industrial Goods & Services 15.8%
		> Machinery 11.8%
	941,250	Ametek	$	31,033
		Aerospace/Industrial Instruments
	747,200	Nordson		29,694
		Dispensing Systems for Adhesives & Coatings
	445,000	Donaldson		24,386
		Industrial Air Filtration
	835,000	ESCO Technologies		21,292
		Automatic Electric Meter Readers
	585,000	Pentair		18,726
		Pumps & Water Treatment
	504,665	HEICO		16,987
		FAA Approved Aircraft Replacement Parts
	280,000	MOOG (a)		9,134
		Motion Control Products for Aerospace, Defense & Industrial Markets
	226,000	Kennametal		7,399
		Consumable Cutting Tools
	136,800	Toro		6,740
		Turf Maintenance Equipment
	162,000	Oshkosh Corporation (a)		2,550
		Specialty Truck Manufacturer
				167,941
		> Industrial Materials & Specialty Chemicals 1.0%
	496,000	Drew Industries		9,910
		RV & Manufactured Home Components
	187,000	Albany International		3,413
		Paper Machine Clothing and Advanced Textiles
				13,323
		> Electrical Components 0.7%
	280,000	Acuity Brands		10,091
		Commercial Lighting Fixtures
				10,091
		> Waste Management 0.7%
	195,000	Waste Connections		6,595
		Solid Waste Management
	65,000	Clean Harbors (a)		3,334
		Hazardous Waste Services & Disposal
				9,929
		> Other Industrial Services 0.6%
	600,000	Acorn Energy (a)		3,192
		Frac Well Exploration/Monitoring Device, Sonar Security,Electric Grid Monitoring
	265,000	TrueBlue (a)		3,003
		Temporary Manual Labor
	109,000	Forward Air		2,774
		Freight Transportation Between Airports
				8,969
		> Steel 0.6%
	686,000	GrafTech International (a)		8,712
		Industrial Graphite Materials Producer
				8,712
		> Industrial Distribution 0.3%
	350,000	Interline Brands (a)		4,505
		Industrial Distribution
				4,505

Number of Shares			Value (000)
		> Water 0.1%
	204,200	Mueller Water Products	$	506
		Fire Hydrants, Valves & Ductile Iron Pipes
				506
Industrial Goods & Services: Total				223,976
Finance 10.4%
		> Banks 5.1%
	431,597	Lakeland Financial		8,917
		Indiana Bank
	278,678	Hancock Holding		7,463
		Gulf Coast Bank
	675,000	Valley National Bancorp (c)		7,148
		New Jersey/New York Bank
	480,000	MB Financial		7,066
		Chicago Bank
	1,478,200	First Busey		6,430
		Illinois Bank
	170,000	SVB Financial Group (a)		6,290
		Bank to Venture Capitalists
	623,000	Associated Banc-Corp		5,794
		Midwest Bank
	594,000	TCF Financial		5,441
		Great Lakes Bank
	513,755	Pacific Continental		3,643
		Pacific N.W. Bank
	269,600	Eagle Bancorp (a)		3,173
		Metro D.C. Bank
	595,300	TrustCo Bank		2,655
		New York State Bank
	70,000	City National		2,643
		Bank & Asset Manager
	178,826	Sandy Spring Bancorp		2,616
		Baltimore, D.C. Bank
	210,000	CVB Financial		1,615
		Inland Empire Business Bank
	90,000	TriCo Bancshares		1,104
		California Central Valley Bank
	851,247	Guaranty Bancorp (a)		1,022
		Colorado Bank
				73,020
		> Finance Companies 3.4%
	345,000	World Acceptance (a)		19,303
		Personal Loans
	412,500	Aaron's		10,416
		Rent to Own
	345,000	Textainer Group Holdings		6,996
		Top International Container Leasor
	210,000	McGrath Rentcorp		4,996
		Temporary Space & IT Rentals
	330,000	CAI International (a)		3,868
		International Container Leasing
	201,000	H&E Equipment Services (a)		1,658
		Heavy Equipment Leasing
	99,200	Marlin Business Services (a)		1,051
		Small Equipment Leasing
				48,288

Number of Shares			Value (000)
		> Savings & Loans 0.9%
	602,487	ViewPoint Financial	$	6,899
		Texas Thrift
	215,000	Berkshire Hills Bancorp		3,971
		Northeast Thrift
	173,073	Kaiser Federal Financial Group		2,042
		Los Angeles Savings & Loan
				12,912
		> Brokerage & Money Management 0.7%
	209,500	Eaton Vance		4,665
		Specialty Mutual Funds
	173,000	Financial Engines (a)		3,133
		Asset Management for 401k Plans
	675,000	MF Global (a)		2,788
		Futures Broker
				10,586
		> Insurance 0.3%
	39,000	Enstar Group (a)		3,714
		Insurance/Reinsurance & Related Services
				3,714
Finance: Total				148,520
Health Care 10.0%
		> Biotechnology & Drug Delivery 4.2%
	520,000	BioMarin Pharmaceutical (a)		16,572
		Biotech Focused on Orphan Diseases
	495,000	Seattle Genetics (a)(c)		9,435
		Antibody-Based Therapies for Cancer
	375,000	Auxilium Pharmaceuticals (a)		5,621
		Biotech Focused on Niche Disease Areas
	840,000	NPS Pharmaceuticals (a)		5,468
		Orphan Drugs & Healthy Royalties
	178,000	Onyx Pharmaceuticals (a)		5,342
		Commercial-Stage Biotech Focused on Cancer
	643,000	Isis Pharmaceuticals (a)		4,360
		Biotech Pioneer in Antisense Drugs
	196,000	InterMune (a)		3,959
		Drugs for Pulmonary Fibrosis & Hepatitis C
	810,000	Micromet (a)		3,888
		Next-generation Antibody Technology
	790,000	Chelsea Therapeutics (a)		2,884
		Biotech Focused on Rare Diseases
	265,000	Anthera Pharmaceuticals (a)		1,264
		Biotech Focused on Cardiovascular, Cancer & Immunology
	243,000	Savient Pharmaceuticals (a)(c)		996
		Biotech Company Focused on Severe Gout
	18,675	United Therapeutics (a)		700
		Biotech Focused on Rare Diseases
	18,181	Metabolex, Series A-1 (a)(d)(e)		18
		Diabetes Drug Development
	738,060	Medicure - Warrants (a)(d)(e)		—
		Cardiovascular Biotech Company
	37,500	Locus Pharmaceuticals, Series A-1, Pfd. (a)(d)(e)		—
		High Throughput Rational Drug Design

Number of Shares			Value (000)
	19,329	Locus Pharmaceuticals, Series B-1, Pfd. (a)(d)(e)	$	—
		High Throughput Rational Drug Design
				60,507
		> Medical Equipment & Devices 3.1%
	370,000	Alexion Pharmaceuticals (a)		23,702
		Biotech Focused on Orphan Diseases
	224,000	Sirona Dental Systems (a)		9,500
		Manufacturer of Dental Equipment
	140,000	Gen-Probe (a)		8,015
		Molecular In-Vitro Diagnostics
	84,007	Hill-Rom Holdings		2,522
		Hospital Beds/Patient Handling
	155,000	Pacific Biosciences of California (a)(c)		498
		Genome Sequencing
				44,237
		> Medical Supplies 1.3%
	439,600	Cepheid (a)		17,070
		Molecular Diagnostics
	49,000	Neogen (a)		1,701
		Food and Animal Safety Products
				18,771
		> Health Care Services 0.8%
	738,900	Health Management Associates (a)		5,113
		Non-Urban Hospitals
	205,000	HealthSouth (a)		3,061
		Inpatient Rehabalitation Facilities
	151,000	Community Health Systems (a)		2,512
		Non-Urban Hospitals
				10,686
		> Pharmaceuticals 0.6%
	796,500	Akorn (a)		6,221
		Develops, Manufactures & Sells Specialty Generic Drugs
	133,180	Alimera Sciences (a)(c)		1,065
		Ophthalmology-Focused Pharmaceutical Company
	150,000	Horizon Pharma (a)(c)		1,049
		Specialty Pharma Company
				8,335
Health Care: Total				142,536
Energy & Minerals 8.2%
		> Oil Services 4.8%
	1,000,000	FMC Technologies (a)		37,600
		Oil and Gas Well Head Manufacturer
	803,000	Atwood Oceanics (a)		27,591
		Offshore Drilling Contractor
	86,000	Bristow		3,649
		Largest Provider of Helicopter Services to Offshore Oil and Gas Producers
				68,840
		> Oil & Gas Producers 2.5%
	1,135,000	Quicksilver Resources (a)(c)		8,603
		Natural Gas and Coal Seam Gas Producer
	133,000	SM Energy		8,067
		Oil and Gas Producer

Columbia Acorn USA

Statement of Investments (Unaudited), continued

Number of Shares			Value (000)
		> Oil & Gas Producers—continued
	368,200	Houston American Energy (c)	$	5,066
		Oil and Gas Exploration/Production in Colombia
	143,000	Rosetta Resources (a)		4,894
		Oil and Gas Producer Exploring in South Texas and Montana
	230,000	Northern Oil And Gas (a)(c)		4,460
		Small E&P Company in North Dakota Bakken
	168,000	Swift Energy (a)		4,089
		Oil and Gas Exploration and Production
	22,800	Oasis Petroleum (a)		509
		Oil Producer in North Dakota
				35,688
		> Mining 0.9%
	85,000	Core Laboratories (Netherlands) (g)		7,635
		Oil and Gas Reservoir Consulting
	600,000	Alexco Resource (a)		4,068
		Mining, Exploration & Environmental Services
	180,000	Augusta Resource (a)(c)		553
		U.S. Copper/Molybdenum Mine
				12,256
Energy & Minerals: Total				116,784
Other Industries 5.9%
		> Real Estate 4.8%
	915,000	Extra Space Storage		17,046
		Self Storage Facilities
	739,200	Biomed Realty Trust		12,249
		Life Science-focused Office Buildings
	600,000	Associated Estates Realty		9,276
		Multifamily Properties
	870,000	Education Realty Trust		7,473
		Student Housing
	177,000	Kilroy Realty		5,540
		West Coast Office and Industrial Properties
	1,380,000	Kite Realty Group		5,051
		Community Shopping Centers
	1,058,000	DCT Industrial Trust		4,645
		Industrial Properties
	191,000	Dupont Fabros Technology (c)		3,761
		Technology-focused Office Buildings
	100,000	Post Properties		3,474
		Multifamily Properties
				68,515
		> Transportation 1.1%
	256,000	World Fuel Services		8,358
		Global Fuel Broker
	410,091	Rush Enterprises, Class A (a)		5,807
	115,000	Rush Enterprises, Class B (a)		1,342
		Truck Sales and Service
				15,507
Other Industries: Total				84,022
Total Equities: 99.0% (Cost: $1,167,960)				1,409,019

Number of Shares			Value (000)
Securities Lending Collateral 3.2%
	45,915,875	Dreyfus Government Cash Management Fund (f) (7 day yield of 0.00%)	$	45,916
Total Securities Lending Collateral: (Cost: $45,916)				45,916
Total Investments: 102.2% (Cost: $1,213,876)(g)(h)				1,454,935
Obligation to Return Collateral for Securities Loaned: (3.2)%				(45,916	)
Cash and Other Assets Less Liabilities: 1.0%				14,590
Total Net Assets: 100.0%			$	1,423,609

ADR = American Depositary Receipts

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

(a) Non-income producing security.

(b) An affiliated person of the Fund may include any company in which the Fund owns five percent or more of its outstanding voting shares. Holdings and transactions in these affiliated companies during the nine months ended September 30, 2011, are as follows:

Affiliates	Balance of Shares Held 12/31/10		Purchases/ Additions		Sales/ Reductions		Balance of Shares Held 9/30/11		Value		Dividend
RCM Technologies		710,000		-		-		710,000	$	3,188	$	-
Total of Affiliated Transactions		710,000		-		-		710,000	$	3,188	$	-

The aggregate cost and value of these companies at September 30, 2011, were $4,479 and $3,188, respectively. Investments in affiliated companies represented 0.22% of the Fund's total net assets at September 30, 2011.

(c) All or a portion of this security was on loan at September 30, 2011. The total market value of securities on loan at September 30, 2011 was $43,598,480.

(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 September 30, 2011, the market value of these securities (in thousands) amounted to $18 which represented less than 0.01% of total net assets.

Security	Acquisition Dates	Shares		Cost		Value
Metabolex, Series A-1	2/11/00		18,181	$	2,000	$	18
Locus Pharmaceuticals, Series A-1 Pfd.	9/05/01		37,500		1,500		-
Locus Pharmaceuticals, Series B-1 Pfd.	2/08/07		19,329		56		-
Medicure - Warrants	12/22/06		738,060		-		-
				$	3,556	$	18

(e) Illiquid security.

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

(g) On September 30, 2011, the market value of foreign securities represents 1.08% of total net assets. The Fund's foreign portfolio was diversified as follows:

	Value		Percent
Israel	$	7,648		0.54
Netherlands		7,635		0.54
Total Foreign Portfolio	$	15,283		1.08

(h) At September 30, 2011, for federal income tax purposes, the cost of investments was $1,213,876 and net unrealized appreciation was $241,059 consisting of gross unrealized appreciation of $406,760 and gross unrealized depreciation of $165,701.

• 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)

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

Columbia Acorn USA

Statement of Investments (Unaudited), continued

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

The following table summarizes the inputs used, as of September 30, 2011, 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	$	443,150	$	-		$	-	$	443,150
Consumer Goods & Services		250,031		-			-		250,031
Industrial Goods & Services		223,976		-			-		223,976
Finance		148,520		-			-		148,520
Health Care		142,518		-	*		18		142,536
Energy & Minerals		116,784		-			-		116,784
Other Industries		84,022		-			-		84,022
Total Equities		1,409,001		-	*		18		1,409,019
Total Securities Lending Collateral		45,916		-			-		45,916
Total Investments	$	1,454,917	$	-	*	$	18	$	1,454,935

* Rounds to less than $500.

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

The following table reconciles asset balances for the nine months ending September 30, 2011, in which significant unobservable inputs (Level 3) were used in determining value:

Investments in Securities	Balance as of December 31, 2010		Realized Gain/(Loss)		Change in Unrealized Appreciation (Depreciation)			Purchases		Sales		Transfers into Level 3		Transfers out of Level 3		Balance as of September 30, 2011
Equities
Health Care	$	20	$	-	$	(2	)	$	-	$	-	$	-	$	-	$	18
	$	20	$	-	$	(2	)	$	-	$	-	$	-	$	-	$	18

The change in unrealized depreciation attributed to securities owned at September 30, 2011, which were valued using significant unobservable inputs (Level 3) amounted to $2.

Columbia Acorn International Select

Major Portfolio Changes in the Third Quarter (Unaudited)

	Number of Shares
	06/30/11		09/30/11
Purchases
Asia
> Japan
Asahi Diamond Industrial		480,000		528,000
Seven Bank		4,450		6,753
> Singapore
Mapletree Industrial Trust REIT		14,601,100		19,420,000
> China
Netease.com		0		84,000
Want Want		1,655,000		3,764,000
Zhaojin Mining Industry		2,649,400		6,276,000
> Taiwan
Far Eastone Telecom		0		11,208,400
Europe
> United Kingdom
Archipelago Resources		4,472,797		6,886,399
JLT Group		881,100		1,014,600
Shaftesbury		226,800		423,820
> Belgium
EVS Broadcast Equipment		33,800		74,000
Other Countries
> Israel
Israel Chemicals		310,000		460,000
> South Africa
Adcock Ingram Holdings		1,152,200		1,220,200
Rand Merchant Insurance		4,902,152		7,209,798

	Number of Shares
	06/30/11		09/30/11
Sales
Asia
> Japan
Gree		280,000		181,000
Kansai Paint		2,115,000		2,100,000
> China
Jiangsu Expressway		6,727,000		4,170,000
> South Korea
NHN		79,266		52,000
Woongjin Coway		151,000		111,000
Europe
> United Kingdom
Chemring		1,609,133		1,480,000
Intertek Group		400,000		312,000
Serco		985,000		850,000
Workspace Group		9,710,000		1,304,000
> Netherlands
Core Laboratories		45,000		38,000
Fugro		117,121		115,821
> Switzerland
Kuehne & Nagel		51,000		49,000
> Germany
Rhoen-Klinikum		297,000		270,000
Wirecard		672,000		630,000
> Ireland
United Drug		2,377,800		1,930,000
> France
Neopost		48,000		32,657
Other Countries
> South Africa
Naspers		122,700		88,700
> United States
SM Energy		67,000		52,000
> Australia
UGL		540,000		—

Columbia Acorn International Select

Statement of Investments (Unaudited), September 30, 2011

Number of Shares			Value (000)
			Equities: 95.3%
Asia 42.0%
		> Japan 16.5%
	2,100,000	Kansai Paint	$	20,124
		Paint Producer in Japan, India, China and Southeast Asia
	6,753	Seven Bank		13,180
		ATM Processing Services
	8,970	Jupiter Telecommunications		9,706
		Largest Cable Service Provider in Japan
	528,000	Asahi Diamond Industrial		7,344
		Consumable Diamond Tools
	181,000	Gree		5,520
		Mobile Social Networking Game Developer/Platform
	110,000	Ain Pharmaciez		4,847
		Dispensing Pharmacy/Drugstore Operator
				60,721
		> Singapore 11.8%
	13,130,000	Ascendas REIT		20,247
		Industrial Property Landlord
	19,420,000	Mapletree Industrial Trust REIT		15,978
		Industrial Property Landlord
	11,142,000	Mapletree Logistics Trust		7,217
		Industrial Property Landlord
				43,442
		> China 5.5%
	6,276,000	Zhaojin Mining Industry		10,440
		Gold Mining and Refining in China
	3,764,000	Want Want		3,409
		Chinese Branded Consumer Food Company
	84,000	Netease.com		3,205
		Chinese Online Gaming Services
	4,170,000	Jiangsu Expressway		3,150
		Chinese Toll Road Operator
				20,204
		> Taiwan 4.5%
	11,208,400	Far Eastone Telecom		16,572
		Taiwan's 3rd Largest Mobile Operator
				16,572
		> South Korea 3.7%
	52,000	NHN (a)		9,907
		Korean Online Search Services
	111,000	Woongjin Coway		3,574
		South Korean Household Appliance Rental Service Provider
				13,481
Asia: Total				154,420
Europe 38.3%
		> United Kingdom 14.8%
	1,480,000	Chemring		12,118
		Defense Manufacturer of Countermeasures and Energetics
	1,014,600	JLT Group (b)		9,936
		International Business Insurance Broker

Number of Shares			Value (000)
	312,000	Intertek Group	$	8,973
		Testing, Inspection, Certification Services
	6,886,399	Archipelago Resources (a)		7,361
		Gold Mining Projects in Indonesia, Vietnam, and the Philippines
	850,000	Serco		6,724
		Facilities Management
	1,304,000	Workspace Group		4,380
		United Kingdom Real Estate
	423,820	Shaftesbury		3,062
		London Prime Retail REIT
	616,000	Cobham		1,667
		Aerospace Components
				54,221
		> Netherlands 7.3%
	166,000	AkzoNobel		7,325
		Largest Global Supplier of Protective Paints and Coatings
	235,519	Imtech		6,625
		Electromechanical and ICT Installation and Maintenance
	115,821	Fugro		5,841
		Sub-sea Oilfield Services
	242,103	Aalberts Industries		3,599
		Flow Control and Heat Treatment
	38,000	Core Laboratories (b)		3,414
		Oil and Gas Reservoir Consulting
				26,804
		> Germany 5.6%
	630,000	Wirecard		9,638
		Online Payment Processing & Risk Management
	270,000	Rhoen-Klinikum		5,467
		Health Care Services
	115,500	Rheinmetall		5,418
		Defense & Automotive
				20,523
		> Switzerland 2.6%
	49,000	Kuehne & Nagel		5,499
		Freight Forwarding/Logistics
	24,000	Partners Group		3,952
		Private Markets Asset Management
				9,451
		> Sweden 2.3%
	658,666	Hexagon		8,565
		Design, Measurement and Visualization Software and Equipment
				8,565
		> Ireland 1.6%
	1,930,000	United Drug		5,909
		Irish Pharmaceutical Wholesaler & Outsourcer
				5,909
		> Iceland 1.3%
	4,800,000	Marel (a)		4,773
		Largest Manufacturer of Poultry and Fish Processing Equipment
				4,773

Number of Shares			Value (000)
		> Denmark 1.1%
	29,000	Novozymes	$	4,123
		Industrial Enzymes
				4,123
		> Belgium 1.0%
	74,000	EVS Broadcast Equipment		3,827
		Digital Live Mobile Production Software and Systems
				3,827
		> France 0.7%
	32,657	Neopost		2,395
		Postage Meter Machines
				2,395
Europe: Total				140,591
Other Countries 12.7%
		> South Africa 6.6%
	7,209,798	Rand Merchant Insurance		11,165
		Directly Sold Property and Casualty Insurance; Holdings in Other Insurers
	1,220,200	Adcock Ingram Holdings		9,049
		Manufacturer of Pharmaceuticals and Medical Supplies
	88,700	Naspers		3,830
		Media in Africa, China, Russia, and Other Emerging Markets
				24,044
		> Canada 2.8%
	210,400	CCL Industries		5,608
		Leading Global Label Manufacturer
	125,000	AG Growth		4,469
		Leading Manufacturer of Augers and Grain Handling Equipment
				10,077
		> United States 1.9%
	112,000	Atwood Oceanics (a)		3,848
		Offshore Drilling Contractor
	52,000	SM Energy		3,154
		Oil and Gas Producer
				7,002
		> Israel 1.4%
	460,000	Israel Chemicals		5,239
		Producer of Potash, Phosphates, Bromine, and Specialty Chemicals
				5,239
Other Countries: Total				46,362
Latin America 2.2%
		> Colombia 1.7%
	260,000	Pacific Rubiales Energy		5,508
		Oil Production & Exploration in Colombia
	18,800,000	Quetzal Energy (a)(c)		775
		Explores for Oil & Gas in Latin America
				6,283

Number of Shares			Value (000)
		> Argentina 0.5%
	166,667	Union Agriculture Group (a)(c)(f)	$	1,777
		Farmland Operator in Uruguay
				1,777
Latin America: Total				8,060
Total Equities: 95.2% (Cost: $321,163)				349,433
Securities Lending Collateral 1.1%
	3,965,250	Dreyfus Government Cash Management Fund (d) (7 day yield of 0.00%)		3,965
Total Securities Lending Collateral: (Cost: $3,965)				3,965
Total Investments: 96.3% (Cost: $325,128)(e)(g)				353,398
Obligation to Return Collateral for Securities Loaned: (1.1)%				(3,965	)
Cash and Other Assets Less Liabilities: 4.8%				17,494
Total Net Assets: 100.0%			$	366,927

Columbia Acorn International Select

Statement of Investments (Unaudited), continued

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

(a) Non-income producing security.

(b) All or a portion of this security was on loan at September 30, 2011. The total market value of securities on loan at September 30, 2011 was $3,742,527.

(c) 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 September 30, 2011, the market value of these securities (in thousands) amounted to $2,552 which represented 0.70% of total net assets.

Additional information on these securities is as follows:

Security	Acquisition Dates	Shares		Cost		Value
Union Agriculture Group	12/8/10		166,667	$	2,200	$	1,777
Quetzal Energy	1/14/11		18,800,000		2,376		775
				$	4,576	$	2,552

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

(e) At September 30, 2011, for federal income tax purposes, the cost of investments was $353,605 and net unrealized appreciation was $28,270 consisting of gross unrealized appreciation of $54,463 and gross unrealized depreciation of $26,193.

(f) Illiquid security.

(g) On September 30, 2011, the Fund's total investments were denominated in currencies as follows:

Currency	Value		Percentage of Net Assets
Japanese Yen	$	60,721		16.5
Euro		56,045		15.3
Pound Sterling		54,221		14.8
US Dollar		47,839		13.0
Singapore Dollar		43,442		11.8
South African Rand		24,044		6.6
Other currencies less than 5% of total net assets		95,563		26.0
	$	381,875		104.0

• 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)

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

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

The following table summarizes the inputs used, as of September 30, 2011, 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	$	3,205	$	151,215	$	-	$	154,420
Europe		3,414		137,177		-		140,591
Other Countries		17,079		29,283		-		46,362
Latin America		5,508		775		1,777		8,060
Total Equities		29,206		318,450		1,777		349,433
Total Securities Lending Collateral		3,965		-		-		3,965
Total Investments	$	33,171	$	318,450	$	1,777	$	353,398

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

The following table reconciles asset balances for the nine months ending September 30, 2011, in which significant unobservable inputs (Level 3) were used in determining value:

Investments in Securities	Balance as of December 31, 2010		Realized Gain/(Loss)		Change in Unrealized Appreciation (Depreciation)			Purchases		Sales		Transfers into Level 3		Transfers out of Level 3		Balance as of September 30, 2011
Latin America
Argentina	$	2,200	$	-	$	(423	)	$	-	$	-	$	-	$	-	$	1,777
	$	2,200	$	-	$	(423	)	$	-	$	-	$	-	$	-	$	1,777

The change in unrealized depreciation attributed to securities owned at September 30, 2011, which were valued using significant unobservable inputs (Level 3) amounted to $423.

Columbia Acorn International Select

Portfolio Diversification (Unaudited)

At September 30, 2011, the Fund's portfolio investments as a percentage of net assets were diversified as follows:

	Value (000)		Percentage of Net Assets
> Industrial Goods & Services
Industrial Materials & Specialty Chemicals	$	36,811		10.0
Machinery		24,399		6.6
Other Industrial Services		21,098		5.8
Electrical Components		13,785		3.8
Outsourcing Services		6,724		1.8
Conglomerates		3,599		1.0
		106,416		29.0
> Information
Internet Related		16,943		4.6
Mobile Communications		16,572		4.5
Business Software		12,392		3.4
CATV		9,706		2.7
Financial Processors		9,638		2.6
Gaming Equipment & Services		5,520		1.5
		70,771		19.3
> Other Industries
Real Estate		50,883		13.9
Transportation		3,149		0.8
		54,032		14.7
> Energy & Minerals
Mining		21,214		5.8
Oil Services		9,689		2.6
Oil & Gas Producers		9,437		2.6
Agricultural Commodities		1,777		0.5
		42,117		11.5
> Finance
Insurance		21,101		5.7
Banks		13,180		3.6
Brokerage & Money Management		3,952		1.1
		38,233		10.4
> Health Care
Pharmaceuticals		14,958		4.1
Health Care Services		5,468		1.5
		20,426		5.6

	Value (000)			Percentage of Net Assets
> Consumer Goods & Services
Nondurables	$	5,608			1.4
Retail		4,847			1.3
Other Consumer Services		3,574			1.0
Food & Beverage		3,409			1.0
		17,438			4.7
Total Equities:		349,433			95.2
Securities Lending Collateral:		3,965			1.1
Total Investments:		353,398			96.3
Obligation to Return Collateral for Securities Loaned:		(3,965	)		(1.1	)
Cash and Other Assets Less Liabilities:		17,494			4.8
Net Assets:	$	366,927			100.0

Columbia Acorn Select

Major Portfolio Changes in the Third Quarter (Unaudited)

	Number of Shares
	06/30/11		09/30/11
Purchases
Consumer Goods & Services
Gaylord Entertainment		860,000		1,060,000
lululemon athletica		350,000		565,000
Skullcandy		0		266,300
GLG Life Tech (Canada)		1,000,000		1,850,000
IFM Investments (Century 21 China RE) - ADR (China)		2,300,000		2,946,537
Industrial Goods & Services
Quanta Services		1,400,000		1,500,000
Kennametal		885,000		1,085,000
Information
WNS - ADR (India)		4,227,186		4,276,336
Energy & Minerals
Petromanas (Canada)		5,000,000		18,125,000
Canacol Energy (Colombia)		30,530,000		33,500,000
Health Care
Horizon Pharma		0		195,000
NPS Pharmaceuticals		2,000,000		2,200,000
Akorn		2,250,000		2,500,000

	Number of Shares
	06/30/11		09/30/11
Sales
Consumer Goods & Services
Abercrombie & Fitch		1,100,000		950,000
Coach		1,025,000		875,000
Hertz		8,400,000		7,525,000
ITT Educational Services		325,000		315,000
RexLot Holdings (China)		335,000,000		315,000,000
Safeway		3,000,000		2,625,000
Tiffany & Co.		250,000		240,000
Industrial Goods & Services
Ametek		1,830,000		1,660,000
ChemSpec International - ADR (China)		1,500,000		0
Donaldson		785,000		735,000
Expeditors International of Washington		750,000		685,000
Oshkosh Corporation		650,000		325,000
Pall		840,000		790,000
Waste Management		1,200,000		650,000
WW Grainger		220,000		170,000
Information
Amphenol		750,000		700,000
Crown Castle International		1,510,000		1,360,000
Globalstar		15,000,000		12,000,000
Mettler Toledo		120,000		115,000
Navigant Consulting		813,073		0
Sanmina-SCI		6,950,000		6,275,000
SBA Communications		755,000		730,000
VisionChina Media - ADR (China)		3,573,400		2,573,400
Finance
CNO Financial Group		12,300,000		11,650,000
Discover Financial Services		5,050,000		3,800,000
MF Global		5,550,000		4,900,000
SEI Investments		1,100,000		1,050,000
Energy & Minerals
Canadian Solar (China)		3,300,000		2,700,000
Houston American Energy		1,450,000		1,309,500
Kirkland Lake Gold (Canada)		1,000,000		950,000
Pacific Rubiales Energy (Colombia)		2,500,000		2,255,000
Petromanas (Canada)		13,125,000		6,562,500
ShaMaran Petroleum (Iraq)		38,343,900		36,500,000
Synthesis Energy Systems (China)		3,850,372		3,050,372
Other Industries
Biomed Realty Trust		1,900,000		1,800,000
JB Hunt Transport Services		1,275,000		1,140,000
Wisconsin Energy		500,000		475,000

Columbia Acorn Select

Statement of Investments (Unaudited), September 30, 2011

Number of Shares			Value (000)
			Equities: 98.5%
Consumer Goods & Services 24.4%
		> Retail 10.7%
	950,000	Abercrombie & Fitch	$	58,482
		Teen Apparel Retailer
	2,625,000	Safeway		43,654
		Supermarkets
	565,000	lululemon athletica (a)		27,487
		Premium Active Apparel Retailer
	240,000	Tiffany & Co.		14,597
		Luxury Good Retailer
				144,220
		> Travel 6.5%
	7,525,000	Hertz (a)		66,973
		Largest U.S. Rental Car Operator
	1,060,000	Gaylord Entertainment (a)(b)		20,500
		Convention Hotels
				87,473
		> Apparel 3.4%
	875,000	Coach		45,351
		Designer & Retailer of Branded Leather Accessories
				45,351
		> Casinos & Gaming 1.4%
	315,000,000	RexLot Holdings (China)		18,724
		Lottery Equipment Supplier in China
				18,724
		> Educational Services 1.3%
	315,000	ITT Educational Services (a)(b)		18,138
		Post-secondary Degree Services
				18,138
		> Food & Beverage 0.5%
	1,850,000	GLG Life Tech (Canada) (a)(b)(c)		6,512
		Produce an All-Natural Sweetener Extracted from the Stevia Plant
				6,512
		> Leisure Products 0.3%
	266,300	Skullcandy (a)(b)		3,763
		Lifestyle Branded Headphones
				3,763
		> Other Consumer Services 0.3%
	2,946,537	IFM Investments (Century 21 China RE) - ADR (China) (a)(c)		3,388
		Provide Real Estate Services in China
				3,388
Consumer Goods & Services: Total				327,569
Industrial Goods & Services 20.2%
		> Machinery 12.6%
	1,660,000	Ametek		54,730
		Aerospace/Industrial Instruments
	735,000	Donaldson		40,278
		Industrial Air Filtration
	1,085,000	Kennametal		35,523
		Consumable Cutting Tools

Number of Shares			Value (000)
	790,000	Pall	$	33,496
		Filtration & Fluids Clarification
	325,000	Oshkosh Corporation (a)		5,115
		Specialty Truck Manufacturer
				169,142
		> Outsourcing Services 2.1%
	1,500,000	Quanta Services (a)		28,185
		Electrical & Telecom Construction Services
				28,185
		> Other Industrial Services 2.0%
	685,000	Expeditors International of Washington		27,777
		International Freight Forwarder
				27,777
		> Industrial Distribution 1.9%
	170,000	WW Grainger		25,422
		Industrial Distribution
				25,422
		> Waste Management 1.6%
	650,000	Waste Management		21,164
		U.S. Garbage Collection & Disposal
				21,164
Industrial Goods & Services: Total				271,690
Information 17.9%
		> Mobile Communications 6.4%
	1,360,000	Crown Castle International (a)		55,311
		Communications Towers
	730,000	SBA Communications (a)		25,171
		Communications Towers
	12,000,000	Globalstar (a)(b)		4,908
		Satellite Mobile Voice & Data Carrier
				85,390
		> Computer Services 3.8%
	4,276,336	WNS - ADR (India) (a)(c)		51,102
		Offshore BPO (Business Process Outsourcing) Services
				51,102
		> Contract Manufacturing 3.1%
	6,275,000	Sanmina-SCI (a)(c)		41,917
		Electronic Manufacturing Services
				41,917
		> Computer Hardware & Related Equipment 2.1%
	700,000	Amphenol		28,539
		Electronic Connectors
				28,539
		> Instrumentation 1.2%
	115,000	Mettler Toledo (a)		16,096
		Laboratory Equipment
				16,096
		> Business Software 0.5%
	182,000	Concur Technologies (a)		6,774
		Web Enabled Cost & Expense Management Software
				6,774

Number of Shares			Value (000)
		> Telecommunications Equipment 0.4%
	324,000	Finisar (a)	$	5,683
		Optical Subsystems and Components
				5,683
		> Advertising 0.4%
	2,573,400	VisionChina Media - ADR (China) (a)(b)		4,709
		Advertising on Digital Screens in China's Mass Transit System
				4,709
Information: Total				240,210
Finance 13.9%
		> Credit Cards 6.5%
	3,800,000	Discover Financial Services		87,172
		Credit Card Company
				87,172
		> Insurance 4.7%
	11,650,000	CNO Financial Group (a)		63,026
		Life, Long-term Care & Medical Supplement Insurance
				63,026
		> Brokerage & Money Management 2.7%
	4,900,000	MF Global (a)		20,237
		Futures Broker
	1,050,000	SEI Investments		16,149
		Mutual Fund Administration & Investment Management
				36,386
Finance: Total				186,584
Energy & Minerals 13.1%
		> Oil & Gas Producers 8.7%
	2,255,000	Pacific Rubiales Energy (Colombia)		47,773
		Oil Production & Exploration in Colombia
	33,500,000	Canacol Energy (Colombia) (a)(c)		20,460
		Oil Producer in South America
	1,309,500	Houston American Energy (b)		18,019
		Oil and Gas Exploration/Production in Colombia
	36,500,000	ShaMaran Petroleum (Iraq) (a)(c)		14,455
		Oil Exploration in Kurdistan
	24,000,000	Canadian Overseas Petroleum (United Kingdom) (a)(c)(d)		7,070
	12,000,000	Canadian Overseas Petroleum - Warrants (United Kingdom) (a)(d)(e)		662
		Oil & Gas Exploration/Production in the North Sea
	34,856,000	Petrodorado (Colombia) (a)(c)		5,655
	17,144,000	Petrodorado - Warrants (Colombia) (a)(d)(e)		356
		Oil & Gas Exploration/Production in Columbia, Peru & Paraguay
	18,125,000	Petromanas (Canada) (a)		2,162
	6,562,500	Petromanas - Warrants (Canada) (a)(d)		92
		Exploring for Oil in Albania
				116,704

Number of Shares			Value (000)
		> Agricultural Commodities 1.5%
	1,515,152	Union Agriculture Group (Argentina) (a)(d)(e)	$	16,152
		Farmland Operator in Uruguay
	38,000,000	Eacom Timber (Canada) (a)(c)		3,626
		Canadian Lumber Producer
				19,778
		> Alternative Energy 1.4%
	2,700,000	Canadian Solar (China) (a)(b)(c)		9,936
		Solar Cell & Module Manufacturer
	3,050,372	Synthesis Energy Systems (China) (a)(b)(c)		5,277
		Owner/Operator of Gasification Plants
	1,600,000	Real Goods Solar (a)(c)		2,912
		Residential Solar Energy Installer
				18,125
		> Mining 1.1%
	950,000	Kirkland Lake Gold (Canada) (a)		15,402
		Gold Mining
				15,402
		> Oil Services 0.4%
	10,885,700	Tuscany International Drilling (Colombia) (a)		6,025
	760,000	Tuscany International Drilling - Warrants (Colombia) (a)		4
		South America Based Drilling Rig Contractor
				6,029
Energy & Minerals: Total				176,038
Other Industries 6.4%
		> Transportation 3.1%
	1,140,000	JB Hunt Transport Services		41,177
		Truck & Intermodal Carrier
				41,177
		> Real Estate 2.2%
	1,800,000	Biomed Realty Trust		29,826
		Life Science-focused Office Buildings
				29,826
		> Regulated Utilities 1.1%
	475,000	Wisconsin Energy		14,863
		Wisconsin Utility
				14,863
Other Industries: Total				85,866
Health Care 2.6%
		> Pharmaceuticals 1.5%
	2,500,000	Akorn (a)		19,525
		Develops, Manufactures & Sells Specialty Generic Drugs
	195,000	Horizon Pharma (a)(b)		1,363
		Specialty Pharma Company
				20,888

Columbia Acorn Select

Statement of Investments (Unaudited), continued

Number of Shares			Value (000)
		> Biotechnology & Drug Delivery 1.1%
	2,200,000	NPS Pharmaceuticals (a)	$	14,322
		Orphan Drugs & Healthy Royalties
				14,322
Health Care: Total				35,210
Total Equities: 98.5% (Cost: $1,276,242)				1,323,167
Securities Lending Collateral 2.4%
	32,441,695	Dreyfus Government Cash Management Fund (f) (7 day yield of 0.00%)		32,442
Total Securities Lending Collateral: (Cost: $32,442)				32,442
Total Investments: 100.9% (Cost: $1,308,684)(g)(h)				1,355,609
Obligation to Return Collateral for Securities Loaned: (2.4)%				(32,442	)
Cash and Other Assets Less Liabilities: 1.5%				20,166
Total Net Assets: 100.0%			$	1,343,333

ADR = American Depositary Receipts

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

(a) Non-income producing security.

(b) All or a portion of this security was on loan at September 30, 2011. The total market value of securities on loan at September 30, 2011 was $29,941,439.

Affiliates	Balance of Shares Held 12/31/10		Purchases/ Additions		Sales/ Reductions		Balance of Shares Held 9/30/11		Value		Dividend
Canacol Energy		36,240,000		-		2,740,000		33,500,000	$	20,460	$	-
Canadian Overseas Petroleum*		16,800,000		7,200,000		-		24,000,000		7,070		-
Canadian Solar		3,200,000		100,000		600,000		2,700,000		9,936		-
Eacom Timber		38,000,000		-		-		38,000,000		3,626		-
GLG Life Tech		1,000,000		850,000		-		1,850,000		6,512		-
Globalstar*		15,000,000		-		3,000,000		12,000,000		4,908		-
IFM Investments (Century 21 China RE) - ADR		2,300,000		646,537		-		2,946,537		3,388		-
Petrodorado		28,400,000		6,456,000		-		34,856,000		5,655		-
Real Goods Solar		1,500,000		100,000		-		1,600,000		2,912		-
Sanmina-SCI		7,100,000		-		825,000		6,275,000		41,917		-
ShaMaran Petroleum		35,950,000		550,000		-		36,500,000		14,455		-
Synthesis Energy Systems		4,500,000		-		1,449,628		3,050,372		5,277		-
Tuscany International Drilling*		11,324,000		-		438,300		10,885,700		6,025
VisionChina Media - ADR*		3,675,000		-		1,101,600		2,573,400		4,709		-
WNS - ADR		4,200,000		76,336		-		4,276,336		51,102		-
Total of Affiliated Transactions		209,189,000		15,978,873		10,154,528		215,013,345	$	187,952	$	-

* At September 30, 2011, the Fund owned less than five percent of the company's outstanding voting shares.

The aggregate cost and value of these companies at September 30, 2011, were $264,476 and $165,240, respectively. Investments in affiliated companies represented 12.30% of the Fund's total net assets at September 30, 2011.

(d) Denotes a restricted security, which is subject to restrictions on resale under federal securities laws. These securities are valued in good faith by the Board of Trustees. At September 30, 2011, these securities (in thousands) amounted to $24,333, which represented 1.81% of total net assets.

Security	Acquisition Dates	Shares		Cost		Value
Union Agriculture Group	12/08/10		1,515,152	$	20,000	$	16,152
Canadian Overseas Petroleum	11/24/10		24,000,000		10,260		7,070
Canadian Overseas Petroleum - Warrants	11/24/10		12,000,000		1,502		662
Petrodorado - Warrants	11/20/09		17,144,000		2,118		357
Petromanas - Warrants	5/20/10		6,562,500		380		92
				$	34,260	$	24,333

(e) Illiquid security.

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

(g) On September 30, 2011, the market value of foreign securities represents 17.83% of total net assets. The Fund's foreign portfolio was diversified as follows:

	Value		Percent
Colombia	$	80,273		5.98
India		51,102		3.80
China		42,034		3.13
Canada		27,794		2.07
Argentina		16,152		1.20
Iraq		14,455		1.07
United Kingdom		7,732		0.58
Total Foreign Portfolio	$	239,542		17.83

(h) At Setpember 30, 2011, for federal income tax purposes, the cost of investments was $1,308,684 and net unrealized appreciation was $46,925 consisting of gross unrealized appreciation of $324,355 and gross unrealized depreciation of $277,430.

Columbia Acorn Select

Statement of Investments (Unaudited), continued

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

• 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)

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

The following table summarizes the inputs used, as of September 30, 2011, 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
Consumer Goods & Services	$	308,845	$	18,724	$	-	$	327,569
Industrial Goods & Services		271,690		-		-		271,690
Information		240,210		-		-		240,210
Finance		186,584		-		-		186,584
Energy & Minerals		151,706		8,180		16,152		176,038
Other Industries		85,866		-		-		85,866
Health Care		35,210		-		-		35,210
Total Equities		1,280,111		26,904		16,152		1,323,167
Total Securities Lending Collateral		32,442		-		-		32,442
Total Investments	$	1,312,553	$	26,904	$	16,152	$	1,355,609

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
$	50,762	$	-	$	-	$	50,762

Financial assets were transferred from Level 2 to Level 1 as resale restrictions expired.

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

The following table reconciles asset balances for the nine months ending September 30, 2011, in which significant unobservable inputs (Level 3) were used in determining value:

Investments in Securities	Balance as of December 31, 2010		Realized Gain/(Loss)		Change in Unrealized Appreciation (Depreciation)			Purchases		Sales		Transfers into Level 3		Transfers out of Level 3		Balance as of September 30, 2011
Equities
Energy & Minerals	$	20,000	$	-	$	(3,848	)	$	-	$	-	$	-	$	-	$	16,152
	$	20,000	$	-	$	(3,848	)	$	-	$	-	$	-	$	-	$	16,152

The change in unrealized depreciation attributed to securities owned at September 30, 2011, which were valued using significant unobservable inputs (Level 3) amounted to $3,848.

Columbia Thermostat Fund

Statement of Investments (Unaudited), September 30, 2011

Number of Shares			Value (000)
		> Affiliated Stock Funds: 63.7%
	1,437,902	Columbia Dividend Income Fund, Class I	$	17,514
	512,910	Columbia Acorn International Fund, Class I		17,264
	501,194	Columbia Acorn Fund, Class I		12,871
	682,892	Columbia Marsico Growth Fund, Class I		12,572
	769,451	Columbia Large Cap Enhanced Core Fund, Class I		8,625
	677,414	Columbia Contrarian Core Fund, Class I		8,610
	395,830	Columbia Acorn Select Fund, Class I		8,562
Total Stock Funds: (Cost: $79,231)				86,018

Number of Shares			Value (000)
		> Affiliated Bond Funds: 35.8%
	2,623,446	Columbia Intermediate Bond Fund, Class I	$	24,215
	1,233,832	Columbia U.S. Treasury Index Fund, Class I		14,633
	1,040,371	Columbia Income Opportunities Fund, Class I		9,457
Total Bond Funds: (Cost: $47,009)				48,305
Total Investments: 99.5% (Cost: $126,240)(a)				134,323
Cash and Other Assets Less Liabilities: 0.5%				725
Total Net Assets: 100.0%			$	135,048

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

(a) At September 30, 2011, for federal income tax purposes, the cost of investments was $126,240 and net unrealized appreciation was $8,083 consisting of gross unrealized appreciation of $8,137 and gross unrealized depreciation of $54.

• 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)

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

The following table summarizes the inputs used, as of September 30, 2011, in valuing the Fund's assets:

Investment Type	Quoted Prices (Level 1)		Other Significant Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)		Total
Total Stock Funds	$	86,018	$	-	$	-	$	86,018
Total Bond Funds		48,305		-		-		48,305
Total Investments	$	134,323	$	-	$	-	$	134,323

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

Columbia Acorn Emerging Markets Fund

Statement of Investments (Unaudited), September 30, 2011

Number of Shares			Value (000)
			Equities: 87.4%
Asia 43.5%
		> Taiwan 12.9%
	26,990	Chroma Ate	$	55
		Automatic Test Systems, Testing & Measurement Instruments
	4,000	St. Shine Optical		49
		World's Leading Disposable Contact Lens OEM
	7,730	Simplo Technology		47
		Battery Packs for Notebook & Tablet PCs
	25,902	Far Eastone Telecom		38
		Taiwan's 3rd Largest Mobile Operator
	2,449	Formosa International Hotels		33
		Hotel, Food & Beverage Operation & Hospitality Management Services
	5,000	President Chain Store		28
		Taiwan's Number One Convenience Chain Store Operator
	9,277	Radiant Opto-Electronics		26
		LCD Back Light Modules
	11,085	Taiwan Hon Chuan		24
		Beverage Packaging (bottles, caps, labels) Manufacturer
	13,900	CTCI Corp		17
		International Engineering Firm
	4,800	Advantech		13
		Industrial PC & Components
	1,200	Lung Yen		3
		Funeral Services and Columbaria
				333
		> China 10.5%
	83,166	AMVIG Holdings		47
		Chinese Tobacco Packaging Material Supplier
	33,251	Digital China		43
		IT Distribution & Systems Integration Services
	1,000	Netease.com		38
		Chinese Online Gaming Services
	37,812	Jiangsu Expressway		29
		Chinese Toll Road Operator
	3,000	Noah Holdings - ADR		28
		Wealth Management Product Distributor in China
	451,892	RexLot Holdings		27
		Lottery Equipment Supplier in China
	7,538	ENN Energy		24
		China's Largest Private Gas Operator
	579	51job - ADR		23
		Integrated Human Resource Services
	10,727	China Yurun Food		11
		Meat Processor in China
				270
		> Hong Kong 8.9%
	219,935	Nagacorp		47
		Casino/Entertainment Complex in Cambodia
	48,909	Mongolian Mining (a)		43
		Coking Coal Mining in Mongolia
	16,865	Lifestyle International		43
		Mid to High-End Department Store Operator in Hong Kong & China

Number of Shares			Value (000)
	65,652	Sasa International	$	39
		Cosmetics Retailer
	4,137	Melco Crown Entertainment - ADR		34
		Macau Casino Operator
	33,000	Melco International		22
		Macau Casino Operator
				228
		> Philipines 4.6%
	189,156	SM Prime Holdings		53
		Shopping Mall Operator
	88,382	Manila Water Company		38
		Water Utility Company in the Philippines
	25,567	Int'l Container Terminal		27
		Container Handling Terminals & Port Management
				118
		> Indonesia 2.6%
	178,989	Ace Indonesia		67
		Home Improvement Retailer
				67
		> Japan 1.4%
	3,860	Kansai Paint		37
		Paint Producer in Japan, India, China and Southeast Asia
				37
		> Thailand 1.4%
	117,555	Home Product Center		35
		Home Improvement Retailer
				35
		> Singapore 1.2%
	27,403	Goodpack Limited		32
		International Bulk Container Leasing
				32
Asia: Total				1,120
Other Countries 17.8%
		> South Africa 12.3%
	9,580	Adcock Ingram Holdings		71
		Manufacturer of Pharmaceuticals and Medical Supplies
	24,626	Coronation Fund Managers		61
		South African Fund Manager
	39,175	Rand Merchant Insurance		61
		Directly Sold Property and Casualty Insurance; Holdings in Other Insurers
	11,354	Northam Platinum		46
		Platinum Mining in South Africa
	5,370	Mr. Price		44
		South African Retailer of Apparel, Household and Sporting Goods
	1,945	Massmart Holdings		33
		General Merchandise, Food, and Home Improvement Stores; Wal-Mart Subsidiary
				316
		> United States 3.0%
	645	Bristow		28
		Largest Provider of Helicopter Services to Offshore Oil and Gas Producers

Columbia Acorn Emerging Markets Fund

Statement of Investments (Unaudited), continued

Number of Shares			Value (000)
		> United States—continued
	752	Atwood Oceanics	$	26
		Offshore Drilling Contractor
	1,200	Textainer Group Holdings		24
		Top International Container Leasor
				78
		> Canada 2.5%
	3,100	Alliance Grain Traders		66
		Global Leader in Pulse Processing and Distribution
				66
Other Countries: Total				460
Europe 14.3%
		> Sweden 3.3%
	3,498	Hexagon		46
		Design, Measurement and Visualization Software and Equipment
	4,972	East Capital Explorer		38
		Sweden-Based RUS/CEE Investment Fund
				84
		> United Kingdom 2.6%
	62,959	Archipelago Resources (a)		67
		Gold Mining Projects in Indonesia, Vietnam, and the Philippines
				67
		> Czech Republic 2.5%
	352	Komercni Banka		65
		Leading Czech Universal Bank
				65
		> Switzerland 2.3%
	675	Dufry Group (a)		59
		Operates Airport Duty Free and Duty Paid Shops
				59
		> France 1.5%
	780	Rubis		39
		Tank Storage and LPG Distribution
				39
		> Kazakhstan 1.1%
	4,332	Halyk Savings Bank of Kazakhstan (a)		27
		Largest Retail Bank and Insurer in Kazakhstan
				27
		> Germany 1.0%
	824	Dürr		27
		Automotive Plant Engineering & Associated Capital Equipment
				27
Europe: Total				368
Latin America 11.8%
		> Brazil 8.5%
	4,436	Localiza Rent A Car		59
		Car Rental
	11,121	MRV Engenharia		57
		Brazilan Property Developer

Number of Shares			Value (000)
	4,617	Mills Estruturas e Servicos de Engenharia	$	43
		Civil Engineering & Construction
	7,431	Suzano - Preferred		33
		Brazilian Pulp and Paper Producer
	1,884	Multiplus		27
		Loyalty Program Operator in Brazil
				219
		> Mexico 2.3%
	1,203	Grupo Aeroportuario del Sureste - ADR		59
		Mexican Airport Operator
				59
		> Argentina 1.0%
	56,433	Madalena Ventures (a)		26
		Oil and Gas Exploration in Argentina
				26
Latin America: Total				304
Total Equities: 87.4% (Cost: $2,555)				2,252
			Exchange Traded Funds: 5.2%
India 5.2%
	3,065	EGShares India Small Cap ETF		45
	2,444	Wisdomtree India Earnings Index ETF		45
	3,649	Market Vectors India Small Cap Index ETF		43
India: Total				133
Total Exchange Traded Funds: 5.2% (Cost: $144)				133
Total Investments: 92.6% (Cost: $2,699)(b)(c)				2,385
Cash and Other Assets Less Liabilities: 7.4%				192
Total Net Assets: 100.0%			$	2,577

ADR = American Depositary Receipts

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

(a) Non-income producing security.

(b) At September 30, 2011, for federal income tax purposes the cost of investments was $2,699 and net unrealized depreciation was $314 consisting of gross unrealized appreciation of $6 and gross unrealized depreciation of $320.

Currency	Value		Percentage of Net Assets
U.S. Dollar	$	420		16.3
Hong Kong Dollar		375		14.6
Taiwan Dollar		333		12.9
South African Rand		316		12.3
Brazilian Real		219		8.5
Other currencies less than 5% of total net assets		722		28.0
	$	2,385		92.6

• 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)

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

The following table summarizes the inputs used, as of September 30, 2011, 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	$	123	$	997	$	-	$	1,120
Other Countries		144		316		-		460
Europe		-		368		-		368
Latin America		304		-		-		304
Total Equities		571		1,681		-		2,252
Exchange Traded Funds
Asia		133		-		-		133
Total Exchange Traded Funds		133		-		-		133
Total Investments	$	704	$	1,681	$	-	$	2,385

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

Columbia Acorn Emerging Markets

Portfolio Diversification (Unaudited)

At September 30, 2011, the Fund's portfolio investments as a percentage of net assets were diversified as follows:

	Value (000)		Percentage of Net Assets
> Consumer Goods & Services
Retail	$	306		11.9
Casinos & Gaming		130		5.0
Other Consumer Services		69		2.6
Travel		59		2.3
Food & Beverage		38		1.5
Other Entertainment		33		1.3
		635		24.6
> Energy & Minerals
Mining		157		6.1
Agricultural Commodities		99		3.8
Oil Services		53		2.1
Oil Refining, Marketing & Distribution		39		1.5
Oil & Gas Producers		26		1.0
		374		14.5
> Information
Computer Hardware & Related Equipment		86		3.3
Instrumentation		56		2.1
Business Software		45		1.8
Electronics Distribution		44		1.7
Mobile Communications		38		1.5
Internet Related		38		1.5
		307		11.9
> Finance
Brokerage & Money Management		99		3.8
Banks		92		3.6
Insurance		60		2.4
Finance Companies		52		2.0
		303		11.8

	Value (000)		Percentage of Net Assets
> Other Industries
Real Estate	$	109		4.2
Transportation		88		3.4
Regulated Utilities		63		2.5
		260		10.1
> Industrial Goods & Services
Industrial Materials & Specialty Chemicals		107		4.2
Construction		60		2.3
Industrial Distribution		32		1.2
Other Industrial Services		27		1.1
Machinery		27		1.0
		253		9.8
> Health Care
Pharmaceuticals		71		2.8
Medical Supplies		49		1.9
		120		4.7
Total Equities:		2,252		87.4
Exchange Traded Funds:		133		5.2
Total Investments:		2,385		92.6
Cash and Other Assets Less Liabilities:		192		7.4
Net Assets:	$	2,577		100.0

Columbia Acorn European Fund

Statement of Investments (Unaudited), September 30, 2011

Number of Shares			Value (000)
			Equities: 92.7%
Europe 92.7%
		> France 22.2%
	1,580	1000mercis	$	78
		Interactive Advertising and Marketing
	1,100	Gemalto		52
		Digital Security Solutions
	600	Eurofins Scientific		46
		Food, Pharmaceuticals and Materials Screening and Testing
	590	Neopost		43
		Postage Meter Machines
	360	Norbert Dentressangle		28
		Leading European Logistics and Transport Group
	1,050	Teleperformance		22
		Call Center Operator
	420	Rubis		21
		Tank Storage and LPG Distribution
	720	Saft		20
		Niche Battery Manufacturer
	460	Mersen		18
		Advanced Industrial Materials
	4,670	Hi-Media (a)		15
		Online Advertiser in Europe
	220	Pierre & Vacances		9
		Vacation Apartment Lets
				352
		> United Kingdom 18.7%
	5,800	Chemring		47
		Defense Manufacturer of Countermeasures and Energetics
	1,400	Intertek Group		40
		Testing, Inspection, Certification Services
	17,220	Charles Taylor		37
		Insurance Services
	3,450	JLT Group		34
		International Business Insurance Broker
	5,430	GlobeOp Financial Services		24
		Hedge Fund Administrator
	3,000	Domino's Pizza United Kingdom & Ireland		21
		Pizza Delivery In UK, Ireland and Germany
	2,140	Serco		17
		Facilities Management
	5,020	Workspace Group		17
		UK Real Estate
	2,790	Abcam (a)		16
		Online Sales of Antibodies
	620	Rotork		15
		Valve Actuators for Oil & Water Pipelines
	2,540	Premier Oil (a)		14
		Oil and Gas Producer in Europe, Pakistan and Asia
	4,850	Cobham		13
		Aerospace Components
	160	Shaftesbury		1
		London Prime Retail REIT
				296

Number of Shares			Value (000)
		> Netherlands 16.8%
	1,340	Imtech	$	38
		Electromechanical and ICT Installation and Maintenance
	1,530	Unit 4 Aggresso		37
		Business Software Development
	770	Vopak		37
		World's Largest Operator of Petroleum and Chemical Storage Terminals
	2,420	Aalberts Industries		36
		Flow Control and Heat Treatment
	390	Core Laboratories		35
		Oil and Gas Reservoir Consulting
	1,910	Arcadis		35
		Engineering Consultants
	1,020	Koninklijke TenCate		31
		Advanced Textiles and Industrial Fabrics
	340	Fugro		17
		Sub-sea Oilfield Services
				266
		> Germany 10.6%
	2,880	Wirecard		44
		Online Payment Processing & Risk Management
	140	Rational		32
		Commercial Ovens
	560	Rheinmetall		26
		Defense & Automotive
	720	Elringklinger		17
		Automobile Components
	520	Dürr		17
		Automotive Plant Engineering & Associated Capital Equipment
	550	CTS Eventim		16
		Event Ticket Sales
	800	Rhoen-Klinikum		16
		Health Care Services
				168
		> Switzerland 7.7%
	290	Geberit (a)		53
		Plumbing Supplies
	15	Sika		27
		Chemicals for Construction & Industrial Applications
	160	Partners Group		26
		Private Markets Asset Management
	170	Dufry Group (a)		15
		Operates Airport Duty Free and Duty Paid Shops
				121
		> Sweden 4.8%
	5,250	Sweco		43
		Engineering Consultants
	2,460	Hexagon		32
		Design, Measurement and Visualization Software and Equipment
				75
		> Italy 2.8%
	10,650	CIR		20
		Italian Holding Company
	3,640	Geox		13
		Apparel and Shoe Maker
	130	Tod's		11
		Leather Shoes and Bags
				44

Columbia Acorn European Fund

Statement of Investments (Unaudited), continued

Number of Shares			Value (000)
		> Ireland 2.7%
	8,700	United Drug	$	27
		Irish Pharmaceutical Wholesaler & Outsourcer
	300	Paddy Power		15
		Irish Betting Services
				42
		> Portugal 2.0%
	11,230	Redes Energéticas Nacionais		32
		Portuguese Power Transmission and Gas Transportation
				32
		> Russia 1.6%
	860	Mail.ru - GDR (a)(b)		25
		Internet Social Networking and Games for Russian Speakers
				25
		> Belgium 1.0%
	300	EVS Broadcast Equipment		16
		Digital Live Mobile Production Software and Systems
				16
		> Norway 0.9%
	1,900	Atea		15
		Leading Nordic IT Hardware/Software Reseller and Installation Company
				15

Number of Shares			Value (000)
		> Greece 0.9%
	12,800	Intralot	$	15
		Lottery and Gaming Systems and Services
				15
		> Iceland —%
	400	Marel (a)		—
		Largest Manufacturer of Poultry and Fish Processing Equipment
				—
Europe: Total				1,467
Total Equities: 92.7% (Cost: $1,566)				1,467
Total Investments: 92.7% (Cost: $1,566)(c)(d)				1,467
Cash and Other Assets Less Liabilities: 7.3%				115
Total Net Assets: 100.0%			$	1,582

GDR = Global Depositary Receipts

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

(a) Non-income producing security.

(b) Security exempt from registration under Section 4(2) of the Securities Act of 1933. This security may only be resold in exempt transactions to qualified buyers. Private resales of this security to qualified institutional buyers are also exempt from registration pursuant to Rule 144A under the Securities Act of 1933. At September 30, 2011, this security had an aggregate value of $25, which represented 1.58% of total net assets.

(c) At September 30, 2011 for federal income tax purposes the cost of investments was $1,566 and net unrealized depreciation was $99 consisting of gross unrealized appreciation of $13 and gross unrealized depreciation of $112.

(d) On September 30, 2011, the Fund's total investments were denominated in currencies as follows:

Currency	Value		Percentage of Net Assets
Euro	$	899		56.8
Pound Sterling		296		18.7
Swiss Franc		121		7.7
Other currencies less than 5% of total net assets		151		9.5
	$	1,467		92.7

• 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)

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

The following table summarizes the inputs used, as of September 30, 2011, 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	$	35	$	1,432	$	-	$	1,467
Total Equities		35		1,432		-		1,467
Total Investments	$	35	$	1,432	$	-	$	1,467

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

Columbia Acorn European Fund

Portfolio Diversification (Unaudited)

At September 30, 2011, the Fund's portfolio investments as a percentage of net assets were diversified as follows:

	Value (000)		Percentage of Net Assets
> Industrial Goods & Services
Other Industrial Services	$	201		12.7
Machinery		133		8.4
Industrial Machinery & Specialty Chemicals		93		5.9
Electrical Components		80		5.1
Conglomerates		56		3.5
Construction		54		3.4
Outsourcing Services		17		1.1
		634		40.1
> Information
Business Software		85		5.4
Business Information & Marketing Services		78		4.9
Computer Hardware & Related Equipment		52		3.3
Financial Processors		44		2.8
Internet Related		25		1.6
Telephone & Data Services		22		1.4
Advertising		15		0.9
Computer Services		15		0.9
		336		21.2
> Energy & Minerals
Oil Refining, Marketing & Distribution		58		3.7
Mining		35		2.2
Oil Services		17		1.1
Oil & Gas Producers		14		0.8
		124		7.8
> Finance
Insurance		71		4.5
Brokerage & Money Management		51		3.2
		122		7.7

	Value (000)		Percentage of Net Assets
> Consumer Goods & Services
Casinos & Gaming	$	30		1.9
Restaurants		21		1.4
Other Entertainment		16		1.0
Retail		15		0.9
Apparel		13		0.8
Nondurables		11		0.7
Travel		9		0.6
		115		7.3
> Other Industries
Regulated Utilities		31		2.0
Transportation		28		1.8
Real Estate		18		1.1
		77		4.9
> Health Care
Pharmaceuticals		27		1.7
Health Care Services		16		1.0
Medical Supplies		16		1.0
		59		3.7
Total Equities:		1,467		92.7
Total Investments:		1,467		92.7
Cash and Other Assets Less Liabilities:		115		7.3
Net Assets:	$	1,582		100.0

Columbia Acorn Family of Funds

Third Quarter Class Z Share Information (Unaudited)

Minimum Initial Investment in
all Funds:				$0 to $2,000,
				available only to
				certain eligible
				investors
Exchange Fee:				None

Columbia Acorn Fund	ACRNX
Management Fee		0.64	%
12b-1 Fee		None
Other Expenses		0.12	%
Net Expense Ratio		0.76	%
Columbia Acorn International	ACINX
Management Fee		0.76	%
12b-1 Fee		None
Other Expenses		0.20	%
Net Expense Ratio		0.96	%
Columbia Acorn USA	AUSAX
Management Fee		0.86	%
12b-1 Fee		None
Other Expenses		0.13	%
Net Expense Ratio		0.99	%
Columbia Acorn International Select	ACFFX
Management Fee		0.94	%
12b-1 Fee		None
Other Expenses		0.21	%
Net Expense Ratio		1.15	%
Columbia Acorn Select	ACTWX
Management Fee		0.81	%
12b-1 Fee		None
Other Expenses		0.16	%
Net Expense Ratio		0.97	%
Columbia Thermostat Fund	COTZX
Management Fee		0.10	%
12b-1 Fee		None
Other Expenses		0.15	%*
Net Expense Ratio		0.25	%*
Columbia Acorn Emerging Markets Fund	CEFZX
Management Fee		1.25	%
12b-1 Fee		None
Other Expenses		0.35	%
Net Expense Ratio		1.60	%
Columbia Acorn European Fund	CAEZX
Management Fee		1.19	%
12b-1 Fee		None
Other Expenses		0.31	%
Net Expense Ratio		1.50	%

Fees and expenses are for the nine months ended September 30, 2011. Some share classes of Columbia Acorn Select and Columbia Acorn International Select include the effect of the voluntary undertaking by Columbia Wanger Asset Management, LLC (CWAM) to waive fees and/or reimburse the Funds for any ordinary operating expenses (exclusive of brokerage commissions, interest, taxes and extraordinary expenses, but inclusive of custodian charges relating to overdrafts, if any), after giving effect to any balance credits from the Funds' custodian, in excess of the annual rate of the Funds as follows:

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

These arrangements may be modified or terminated by either the Funds or CWAM upon 30 days notice. Columbia Thermostat Fund's fees and expenses include the effect of CWAM's contractual undertaking to waive fees and/or reimburse the Fund for any ordinary operating expenses (exclusive of distribution and service fees, interest and fees on borrowings and expenses associated with the Fund's investments in other investment companies, but including custodian charges relating to overdrafts, if any), after giving effect to any balance credits from the Fund's custodian, in excess of the annual rate of 0.25% of the average daily net assets. Columbia Thermostat Fund's waiver/reimbursement arrangement is contractual through April 30, 2012. There is no guarantee that this arrangement will continue thereafter. CWAM has contractually undertaken to waive fees and/or reimburse Columbia Acorn Emerging Markets Fund so that the Fund's ordinary operating expenses (excluding interest and fees on borrowings and expenses associated with the Fund's investment in other investment companies, if any) do not exceed the annual rate of 1.60% of the Fund's average daily net assets attributable to Class Z shares, through April 30, 2013. There is no guarantee that this arrangement will continue thereafter. Columbia Acorn European Fund's fees and expenses include the effect of CWAM's contractual undertaking to waive fees and/or reimburse the Fund so that its ordinary operating expenses (excluding interest and fees on borrowings and expenses associated with the Fund's investment in other investment companies, if any) do not exceed the annual rate of 1.50% of the Fund's average daily net assets attributable to Class Z shares, through April 30, 2013. There is no guarantee that this arrangement will continue thereafter.

* Does not include estimated fees and expenses of 0.65% incurred by the Fund from the underlying portfolio funds in which it invests.

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

Allan B. Muchin

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 Adviser

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.

Investors should consider the investment objectives, risks, charges and expenses of a mutual fund carefully before investing. For a free prospectus, which contains this and other important information about the funds, visit www.columbiamanagement.com. Read the prospectus carefully before investing.

Columbia Acorn Funds are distributed by Columbia Management Investment Distributors, Inc., member FINRA and managed by Columbia Wanger Asset Management, LLC.

Find out what's new – visit our web site at:

www.columbiamanagement.com

Our e-mail address is:

ServiceInquiries@ColumbiaManagement.com

Shareholders should not include personal information such as account numbers, Social Security numbers or taxpayer identification numbers in e-mail. We are unable to accept account transactions sent via e-mail.

PRESORTED

FIRST-CLASS MAIL

U.S. POSTAGE PAID

HOLLISTON, MA

PERMIT NO. 20

Columbia Management^®

Columbia Acorn Family of Funds
Class Z Shares

Third Quarter Report, September 30, 2011

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.

225 Franklin Street, Boston, MA 02110

800.345.6611 www.columbiamanagement.com

C-1562 A (11/11) 127908

Columbia Management^®

Columbia Acorn Family of Funds
Class Z Shares

Third Quarter Report, September 30, 2011

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

Prospectuses and the Statement of Additional Information (SAI)

Information Provided by the SEC

The investment company registration number of Columbia Acorn Trust, of which each of these Funds is a series, is 811-01829.

225 Franklin Street, Boston, MA 02110

800.345.6611 www.columbiamanagement.com

C-1562 A (11/11) 127908

Columbia Management^®

Columbia Acorn Family of Funds
Class Z Shares

Third Quarter Report, September 30, 2011

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

Prospectuses and the Statement of Additional Information (SAI)

Information Provided by the SEC

The investment company registration number of Columbia Acorn Trust, of which each of these Funds is a series, is 811-01829.

C-1562 A (11/11) 127908

Q3 2011

Columbia Acorn Family of Funds

Class A, B, C, I, R and R5 Shares

Managed by Columbia Wanger Asset Management, LLC

Third Quarter Report

September 30, 2011

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

Descriptions of Indexes Included in this Report

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

Columbia Acorn Family of Funds

Table of Contents

Share Class Performance					2
Fund Performance vs. Benchmark					4
Chattering Squirrels: 2011 Shareholder Information Meeting Recap					5
Columbia Acorn Fund
In a Nutshell					12
At a Glance					13
Major Portfolio Changes					28
Statement of Investments					31
Columbia Acorn International
In a Nutshell					14
At a Glance					15
Major Portfolio Changes					44
Statement of Investments					48
Portfolio Diversification					57
Columbia Acorn USA
In a Nutshell					16
At a Glance					17
Major Portfolio Changes					58
Statement of Investments					60

Columbia Acorn International Select
In a Nutshell					18
At a Glance					19
Major Portfolio Changes					67
Statement of Investments					68
Portfolio Diversification					72
Columbia Acorn Select
In a Nutshell					20
At a Glance					21
Major Portfolio Changes					73
Statement of Investments					74
Columbia Thermostat Fund
In a Nutshell					22
At a Glance					23
Statement of Investments					80
Columbia Acorn Emerging Markets Fund
In a Nutshell					24
At a Glance					25
Statement of Investments					81
Portfolio Diversification					84
Columbia Acorn European Fund
In a Nutshell					26
At a Glance					27
Statement of Investments					85
Portfolio Diversification					88
Columbia Acorn Family of Funds
Columbia Acorn Family of Funds Expense Information					91

Estimated Year-End Distributions

	Short-term Capital Gains		Long-term Capital Gains
Columbia Acorn Fund		None	$	0.90 - $1.05
Columbia Acorn International		None		None
Columbia Acorn USA		None	$	0.10 - $0.15
Columbia Acorn International Select		None	$	0.40 - $0.50
Columbia Acorn Select		None		None
Columbia Thermostat Fund		None		None
Columbia Acorn Emerging Markets Fund	$	0.00 - $0.05		None
Columbia Acorn European Fund	$	0.00 - $0.05		None

Columbia Acorn Funds

Share Class Performance Average Annual Total Returns through 9/30/11

	Class A						Class B*						Class C						Class I†			Class R††			Class R5††
	Without Sales Charge			With Sales Charge			Without Sales Charge			With Sales Charge			Without Sales Charge			With Sales Charge			Without Sales Charge			Without Sales Charge**			Without Sales Charge**
Columbia Acorn Fund (10/16/00)
3 months**		–19.68	%		–24.30	%		–19.85	%		–23.85	%		–19.86	%		–20.66	%		–19.65	%		NA			NA
Year to date**		–14.06	%		–18.99	%		–14.53	%		–18.76	%		–14.58	%		–15.42	%		–13.85	%		NA			NA
1 year		–1.62	%		–7.26	%		–2.26	%		–6.95	%		–2.41	%		–3.34	%		–1.30	%		NA			NA
5 years		1.25	%		0.07	%		0.61	%		0.29	%		0.45	%		0.45	%		NA			NA			NA
10 years		8.67	%		8.03	%		7.95	%		7.95	%		7.85	%		7.85	%		NA			NA			NA
Life of fund		7.37	%		6.79	%		6.67	%		6.67	%		6.58	%		6.58	%		–0.12	%		NA			NA
Columbia Acorn International (10/16/00)
3 months**		–18.31	%		–23.00	%		–18.44	%		–22.52	%		–18.43	%		–19.25	%		–18.20	%		NA			NA
Year to date**		–15.98	%		–20.80	%		–16.38	%		–20.46	%		–16.43	%		–17.25	%		–15.70	%		NA			NA
1 year		–8.86	%		–14.10	%		–9.42	%		–13.84	%		–9.52	%		–10.41	%		–8.44	%		NA			NA
5 years		2.17	%		0.97	%		1.54	%		1.21	%		1.39	%		1.39	%		NA			NA			NA
10 years		10.94	%		10.29	%		10.22	%		10.22	%		10.13	%		10.13	%		NA			NA			NA
Life of fund		5.89	%		5.32	%		5.20	%		5.20	%		5.12	%		5.12	%		–7.63	%		–16.48	%		–16.43	%
Columbia Acorn USA (10/16/00)
3 months**		–22.26	%		–26.73	%		–22.38	%		–26.26	%		–22.42	%		–23.19	%		–22.19	%		NA			NA
Year to date**		–15.29	%		–20.16	%		–15.74	%		–19.96	%		–15.75	%		–16.60	%		–15.06	%		NA			NA
1 year		–1.44	%		–7.09	%		–2.09	%		–6.98	%		–2.19	%		–3.17	%		–1.10	%		NA			NA
5 years		–0.79	%		–1.96	%		–1.44	%		–1.80	%		–1.57	%		–1.57	%		NA			NA			NA
10 years		5.97	%		5.34	%		5.26	%		5.26	%		5.18	%		5.18	%		NA			NA			NA
Life of fund		6.67	%		6.09	%		5.97	%		5.97	%		5.89	%		5.89	%		0.08	%		NA			NA
Columbia Acorn International Select (10/16/00)
3 months**		–14.74	%		–19.65	%		14.88	%		–19.14	%		–14.91	%		–15.76	%		–14.66	%		NA			NA
Year to date**		–11.72	%		–16.80	%		12.15	%		–16.51	%		–12.26	%		–13.13	%		–11.38	%		NA			NA
1 year		–4.71	%		–10.18	%		5.31	%		–10.01	%		–5.47	%		–6.41	%		–4.22	%		NA			NA
5 years		2.15	%		0.95	%		1.49	%		1.11	%		1.33	%		1.33	%		NA			NA			NA
10 years		10.23	%		9.57	%		9.51	%		9.51	%		9.40	%		9.40	%		NA			NA			NA
Life of fund		4.21	%		3.65	%		3.52	%		3.52	%		3.44	%		3.44	%		–3.82	%		NA			NA
Columbia Acorn Select (10/16/00)
3 months**		–23.60	%		–28.00	%		–23.70	%		–27.51	%		–23.73	%		–24.50	%		–23.43	%		NA			NA
Year to date**		–23.69	%		–28.07	%		–24.05	%		–27.81	%		–24.14	%		–24.89	%		–23.40	%		NA			NA
1 year		–13.05	%		–18.06	%		–13.56	%		–17.85	%		–13.72	%		–14.58	%		–12.64	%		NA			NA
5 years		–1.16	%		–2.32	%		–1.78	%		–2.15	%		–1.94	%		–1.94	%		NA			NA			NA
10 years		6.47	%		5.84	%		5.75	%		5.75	%		5.66	%		5.66	%		NA			NA			NA
Life of fund		5.63	%		5.06	%		4.93	%		4.93	%		4.84	%		4.84	%		–10.94	%		NA			NA
Columbia Thermostat Fund (3/3/03) †††
3 months**		–6.93	%		–12.27	%		–7.06	%		–11.70	%		–7.07	%		–8.00	%		NA			NA			NA
Year to date**		–2.80	%		–8.40	%		–3.08	%		–7.87	%		–3.29	%		–4.25	%		NA			NA			NA
1 year		4.40	%		–1.63	%		3.91	%		–1.09	%		3.60	%		2.60	%		NA			NA			NA
5 years		3.26	%		2.05	%		2.74	%		2.40	%		2.49	%		2.49	%		NA			NA			NA
Life of fund		6.81	%		6.07	%		6.22	%		6.22	%		6.02	%		6.02	%		NA			NA			NA
Columbia Acorn Emerging Markets Fund (8/19/11)
Life of fund**		–11.60	%		–16.68	%		NA			NA			–11.70	%		–12.58	%		–11.60	%		NA			NA
Columbia Acorn European Fund (8/19/11)
Life of fund**		–5.90	%		–11.31	%		NA			NA			–6.00	%		–6.94	%		–5.90	%		NA			NA

Columbia Acorn Funds

Share Class Performance, continued

Net Asset Value Per Share as of 09/30/11

	Class A		Class B		Class C		Class I		Class R		Class R5
Columbia Acorn Fund	$	24.86	$	22.94	$	22.68	$	25.68		NA		NA
Columbia Acorn International	$	33.51	$	32.60	$	32.48	$	33.66	$	33.50	$	33.63
Columbia Acorn USA	$	23.33	$	21.57	$	21.39	$	24.26		NA		NA
Columbia Acorn International Select	$	24.46	$	23.34	$	23.22	$	24.75		NA		NA
Columbia Acorn Select	$	21.01	$	19.61	$	19.44	$	21.63		NA		NA
Columbia Thermostat Fund	$	12.08	$	12.12	$	12.10		NA		NA		NA
Columbia Acorn Emerging Markets Fund	$	8.84		NA	$	8.83	$	8.84		NA		NA
Columbia Acorn European Fund	$	9.41		NA	$	9.40	$	9.41		NA		NA

*The Funds no longer accept investments from new or existing shareholders in Class B shares.

**Not annualized.

†Class I shares are offered at net asset value without sales charge and are available only to qualifying institutional investors.

††Class R and Class R5 shares of Columbia Acorn International commenced operations on August 15, 2011 in connection with the completed merger of two series of RiverSource International Managers Series, Inc. into Columbia Acorn International.

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

The "with sales charge" returns include the maximum initial sales charge of 5.75% for Class A shares, the applicable contingent deferred sales charge (CDSC) for Class B shares (5%, 4%, 3%, 3%, 2%, 1%, 0% for the first through seventh years after purchase, respectively), and the maximum CDSC of 1.00% of Class C shares during the first year after purchase.

Annual operating expense ratios are as stated in each Fund's current prospectus and differences in expense ratios disclosed elsewhere in this report may result from including fee waivers and expense reimbursements as well as different time periods used in calculating the ratios. Columbia Acorn Fund: Class A: 1.07%; Class B: 1.69%; Class C: 1.85%; Class I: 0.72%. Columbia Acorn International: Class A: 1.35%; Class B: 1.96%; Class C: 2.11%; Class I: 0.93%; Class R: 1.60%; Class R5: 0.98%. Effective August 12, 2011, the Funds' transfer agent contractually agreed, through August 14, 2013, to waive a portion of total annual Fund operating expenses attributable to transfer agency fees 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. Columbia Acorn USA: Class A: 1.30%; Class B: 1.98%; Class C: 2.08%; Class I: 0.95%. Columbia Acorn International Select: Class A: 1.56%; Class B: 2.24%; Class C: 2.36%; Class I: 1.13%. Columbia Acorn Select: Class A: 1.28%; Class B: 1.93%; Class C: 2.08%; Class I: 0.92%. Columbia Thermostat Fund has a contractual fee waiver and expense reimbursement agreement with CWAM that expires April 30, 2012; expense ratios without and with the contractual waiver/reimbursement, including fees and expenses associated with the Fund's investments in other investment companies are, respectively: Class A: 1.52% and 1.29%; Class B: 2.07% and 1.79%; Class C: 2.28% and 2.04%. Columbia Acorn Emerging Markets Fund has a contractual fee waiver and expense reimbursement agreement with CWAM that expires April 30, 2013; expense ratios without and with the contractual waiver/reimbursement are, respectively: Class A: 1.96% and 1.85%; Class C: 2.73% and 2.60%; Class I: 1.52% and 1.41%. Columbia Acorn European Fund has a contractual fee waiver and expense reimbursement agreement with CWAM that expires April 30, 2013; expense ratios without and with the contractual waiver/reimbursement are, respectively: Class A: 1.89% and 1.75%; Class C: 2.66% and 2.50%; Class I: 1.45% and 1.31%.

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

All results shown assume reinvestment of distributions and do not reflect the deduction of taxes that a shareholder would pay on fund distributions or on the redemption of fund shares.

Columbia Acorn Family of Funds

Fund Performance vs. Benchmarks Average Annual Total Returns through 9/30/11

Class A Shares, without sales charge	3rd quarter*			Year to date*			1 year			5 years			10 years			Life of Fund
Columbia Acorn Fund (LACAX) (10/16/00)		-19.68	%		-14.06	%		-1.62	%		1.25	%		8.67	%		7.37	%
Russell 2500 Index		-21.22	%		-14.87	%		-2.22	%		0.19	%		7.08	%		5.11	%
S&P 500 Index**		-13.87	%		-8.68	%		1.14	%		-1.18	%		2.82	%		0.11	%
Lipper Mid-Cap Growth Funds Index		-20.18	%		-14.14	%		-2.18	%		2.41	%		5.29	%		-0.44	%
Columbia Acorn International (LAIAX) (10/16/00)		-18.31	%		-15.98	%		-8.86	%		2.17	%		10.94	%		5.89	%
S&P Global Ex-U.S. Between $500M and $5B Index		-19.67	%		-17.56	%		-8.84	%		1.77	%		12.15	%		8.63	%
S&P Global Ex-U.S. SmallCap Index		-21.20	%		-18.34	%		-9.65	%		0.20	%		11.18	%		7.63	%
Lipper International Small/Mid Growth Funds Index		-18.96	%		-16.62	%		-6.92	%		0.31	%		9.71	%		4.46	%
Columbia Acorn USA (LAUAX) (10/16/00)		-22.26	%		-15.29	%		-1.44	%		-0.79	%		5.97	%		6.67	%
Russell 2000 Index		-21.87	%		-17.02	%		-3.53	%		-1.02	%		6.12	%		4.07	%
Russell 2500 Index		-21.22	%		-14.87	%		-2.22	%		0.19	%		7.08	%		5.11	%
Lipper Small-Cap Growth Funds Index		-21.54	%		-14.42	%		-1.10	%		0.27	%		4.52	%		0.15	%
Columbia Acorn Int'l Select (LAFAX) (10/16/00)		-14.74	%		-11.72	%		-4.71	%		2.15	%		10.23	%		4.21	%
S&P Developed Ex-U.S. Between $2B and $10B Index		-18.15	%		-14.85	%		-6.54	%		-1.15	%		9.14	%		6.22	%
MSCI EAFE Index		-19.01	%		-14.98	%		-9.36	%		-3.46	%		5.03	%		1.78	%
Lipper International Small/Mid Growth Funds Index		-18.96	%		-16.62	%		-6.92	%		0.31	%		9.71	%		4.46	%
Columbia Acorn Select (LATFX) (10/16/00)		-23.60	%		-23.69	%		-13.05	%		-1.16	%		6.47	%		5.63	%
S&P MidCap 400 Index		-19.88	%		-13.02	%		-1.28	%		2.20	%		7.50	%		5.48	%
S&P 500 Index**		-13.87	%		-8.68	%		1.14	%		-1.18	%		2.82	%		0.11	%
Lipper Mid-Cap Growth Funds Index		-20.18	%		-14.14	%		-2.18	%		2.41	%		5.29	%		-0.44	%
Columbia Thermostat Fund (CTFAX) (3/3/03)†		-6.93	%		-2.80	%		4.40	%		3.26	%		—			6.81	%
S&P 500 Index		-13.87	%		-8.68	%		1.14	%		-1.18	%		—			5.60	%
Barclays Capital U.S. Aggregate Bond Index		3.82	%		6.65	%		5.26	%		6.53	%		—			5.24	%
Lipper Flexible Portfolio Funds Index		-11.52	%		-7.00	%		-0.22	%		1.97	%		—			6.57	%
50/50 Blended Benchmark		-5.28	%		-1.12	%		3.48	%		3.04	%		—			5.73	%
Columbia Acorn Emerging Markets Fund (CAGAX) (8/19/11)		—			—			—			—			—			-11.60	%
S&P Emerging Markets Between $500M and $5B Index		—			—			—			—			—			-14.28	%
MSCI Emering Markets Small Cap Index		—			—			—			—			—			-16.10	%
Lipper Emerging Markets Index		—			—			—			—			—			-11.32	%
Columbia Acorn European Fund (CAEAX) (8/19/11)		—			—			—			—			—			-5.90	%
S&P Europe Between $500M and $5B Index		—			—			—			—			—			-7.55	%
HSBC Smaller European Companies Index		—			—			—			—			—			-8.68	%
Lipper European Region Index		—			—			—			—			—			-6.73	%

*Not annualized.

**The comparison to the S&P 500 Index is presented to show performance against a widely recognized market index.

Performance results reflect any fee waivers or reimbursements of Fund expenses by the investment adviser and/or its affiliates. Please see Page 91 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. Absent these fee waivers or expense reimbursement arrangements, performance results would have been lower. Annual operating expense ratios are stated as of each Fund's current prospectus and differences in expense ratios disclosed elsewhere in this report may result from application of any fee waivers/expense reimbursements as well as different time periods used in calculating the ratios. Columbia Acorn Fund: Class A: 1.07%; Class B: 1.69%; Class C: 1.85%; Class I: 0.72%. Columbia Acorn International: Class A: 1.35%; Class B: 1.96%; Class C: 2.11%; Class I: 0.93%; Class R: 1.60%; Class R5: 0.98%. Columbia Acorn USA: Class A: 1.30%; Class B: 1.98%; Class C: 2.08%; Class I: 0.95%. Columbia Acorn International Select: Class A: 1.56%; Class B: 2.24%; Class C: 2.36%; Class I: 1.13%. Columbia Acorn Select: Class A: 1.28%; Class B: 1.93%; Class C: 2.08%; Class I: 0.92%. Columbia Thermostat Fund: Class A: 1.29%; Class B: 1.79%; Class C: 2.04%. Columbia Acorn Emerging Markets Fund Class A: 1.85%; Class C: 2.60%; Class I: 1.41%. Columbia Acorn European Fund Class A: 1.75%; Class C: 2.50%; Class I: 1.31%.

Chattering Squirrels: 2011 Shareholder Information Meeting Recap

Charles P. McQuaid

Chief Investment Officer and Lead Portfolio Manager of Columbia Acorn Fund and Columbia Thermostat Fund

Turning our attention to industry weightings, the Fund's largest overweight at the end of September was industrials. As noted in the examples above, we have found many stocks in this sector representing what we think are good businesses, at reasonable valuations. In addition, many of their large customers have great balance sheets and need to spend more on industrial equipment in order to remain competitive and accommodate worldwide demand.

then, with a bit of a market recovery, was at 65% stocks at the end of September. The market has been stuck in a trading range, helping Thermostat performance.

Ben Andrews

Lead Portfolio Manager of Columbia Acorn Select

Robert A. Mohn

Director of Domestic Research, Lead Portfolio Manager of Columbia Acorn USA and Co-portfolio Manager of Columbia Acorn Fund

Abercrombie & Fitch, whose international business grew 74% in the second quarter and now comprises 25% of sales), retailers creating new "categories of one" (lululemon athletica, which launched and now dominates the burgeoning premium yoga apparel business), and "internet category killers" (Shutterfly in the photo retailing space).

Louis J. Mendes

Co-portfolio Manager of Columbia Acorn International and Columbia Acorn Emerging Markets Fund

A quick look at a few of the Fund's top holdings provides an example of the diversity of ideas. Melco Crown Entertainment is a Macau casino operator that, in only a few short years, has risen to dwarf Las Vegas's gambling revenues, as it caters to the newly minted wealth of Asia. In the United Kingdom, Intertek Group provides testing and certification services to the world of international manufacturing and trade to ensure that products meet international standards in quality and assurance. Vopak is a Dutch manager of oil and natural gas depots around the world. Increased energy demand requires increased energy sourcing from locations far from end markets. As you can see, each of these companies has its own unique set of drivers.

Fritz Kaegi

Lead Portfolio Manager of Columbia Acorn Emerging Markets Fund

Looking more specifically at Columbia Acorn Emerging Markets Fund, it differs from many other emerging market funds because it is focused on small companies. Most emerging market funds focus on the same group of giant companies that are driven by macroeconomic factors. A small-company focus offers an investable universe of thousands of companies and, within that universe, locally exposed niche businesses, such as those in the consumer discretionary, health care and industrials sectors, play a notably bigger role. If an investor is interested in emerging markets for growth and diversification potential, we think it makes more sense to look at smaller companies.

Andreas Waldburg-Wolfegg

Lead Portfolio Manager of Columbia Acorn European Fund

Christopher J. Olson

Lead Portfolio Manager of Columbia Acorn International Select

Since we normally discuss quarterly or yearly performance in our reports to shareholders, I thought it might be helpful to take a look at Columbia Acorn International Select's performance and investment style over the past five years. Since September of 2006, we have experienced a number of different markets, from the last portion of the previous bull market (2006-2008), a global equity market collapse (2008-2009), a major global equity market rally (2009-2011) and an increasing period of uncertainty regarding what comes next (2011 to the present). Over this period, Class Z shares of the Fund returned on average a positive 2.51% per year,* outperforming its benchmark, the S&P Developed Ex-U.S. Between $2B and $10B Index, which dropped 1.15% on average per year. Large-cap international stocks, as measured by the MSCI EAFE Index, were off 3.46% per year and the broader Lipper International Funds Index was down 2.6% per year. At the same time, the Fund has generated this performance with risk measures (a beta of 0.87 and standard deviation of 21%) below its benchmark and the vast majority of its peers.

a beginning and an end, and it is just as important to pay attention to the last part. While the Fund was down 42% in 2008, it did outperform its benchmark by 3.5% due to its more conservative positioning.

* Class Z share returns each year at September 30 were: 36.67% in 2007; -26.39% in 2008; -0.35% in 2009; 18.01% in 2010; and -4.31% in 2011.

Columbia Acorn Fund

In a Nutshell



Charles P. McQuaid				Robert A. Mohn

Lead Portfolio Manager				Co-Portfolio Manager

Fund's Positions
in Mentioned Holdings

As a percentage of net assets, as of 9/30/11

Alexion Pharmaceuticals	1.8	%
Ametek	1.5	%
Informatica	1.3	%
BioMarin Pharmaceutical	0.9	%
Fugro	0.9	%
Cepheid	0.8	%
IPG Photonics	0.8	%
Polycom	0.5	%
Hexagon	0.4	%
InterMune	0.3	%
WABCO Holdings	0.3	%

During the third quarter of 2011, the stock market appeared to be dominated by concerns about the economic outlook for much of the world, especially Europe and China. Columbia Acorn Fund fell 19.68% (Class A shares, without sales charge), somewhat less than its primary benchmark, the Russell 2500 Index, which plunged 21.22%. Year to date, the Fund was down 14.06% versus a 14.87% drop in its benchmark. Comparisons against other benchmarks are shown on Page 4.

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

Columbia Acorn Fund

At a Glance (Class A Shares - LACAX)

Pretax and After-tax Average Annual Total Returns (Based on Class A Share Returns)

through September 30, 2011

Inception 10/16/00		Year to date*			1 year			5 years			10 years
Returns before taxes	NAV POP		-14.06 -18.99	%		-1.62 -7.26	%		1.25 0.07	%		8.67 8.03	%
Returns after taxes on distributions	NAV POP		-14.20 -19.13			-2.20 -7.81			0.62 -0.56			8.15 7.51
Returns after taxes on distributions and sale of fund shares	NAV POP		-8.91 -12.13			-0.12 -3.84			1.12 0.11			7.69 7.11
Russell 2500 Index**(pretax)			-14.87			-2.22			0.19			7.08

All results shown assume reinvestment of distributions.

*Year to date data is not annualized.

**The Fund's primary benchmark.

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

Public offering price (POP) returns include the maximum sales charge of 5.75% for Class A shares. Net asset value (NAV) returns do not include sales charges or contingent deferred sales charges (CDSC).

The Fund's Class A shares annual operating expense ratio, as stated in the current prospectus, is 1.07%.

Columbia Acorn Fund Portfolio Diversification

as a percentage of net assets, as of 9/30/11

Columbia Acorn Fund Top 10 Holdings

as a percentage of net assets, as of 9/30/11

1.	lululemon athletica Premium Active Apparel Retailer	2.4	%
2.	Alexion Pharmaceuticals Biotech Focused on Orphan Diseases	1.8	%
3.	FMC Technologies Oil & Gas Wellhead Manufacturer	1.5	%
4.	Crown Castle International Communications Towers	1.5	%
5.	Donaldson Industrial Air Filtration	1.5	%
6.	Mettler Toledo Laboratory Equipment	1.5	%
7.	Ametek Aerospace/Industrial Instruments	1.5	%
8.	Abercrombie & Fitch Teen Apparel Retailer	1.4	%
9.	Informatica Enterprise Data Integration Software	1.3	%
10.	tw telecom Fiber Optic Telephone/Data Services	1.0	%

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 Fund (Class A)

October 16, 2000 through September 30, 2011

Illustration is based on a hypothetical $10,000 investment from inception in Class A shares of the Fund, which includes a 5.75% maximum initial sales charge. The Russell 2500 Index is unmanaged and returns for both the index and the Fund include reinvested dividends and capital gains. Although the index is provided for use in assessing the Fund's performance, the Fund's holdings may differ significantly from those in the index. It is not possible to invest directly in an index. The graph does not reflect taxes that a shareholder may pay on Fund distributions or on a sale of Fund shares.

Total Net Assets of the Fund: $15.1 billion

Columbia Acorn International

In a Nutshell



P. Zachary Egan				Louis J. Mendes III

Co-Portfolio Manager				Co-Portfolio Manager

Fund's Positions
in Mentioned Holdings

As a percentage of net assets, as of 9/30/11

Hexagon	1.0	%
Gree	0.6	%
Rheinmetall	0.6	%
Japan Airport Terminal	0.6	%

Columbia Acorn International was down 18.31% (Class A shares, without sales charge) in the third quarter of 2011, which brought the year-to-date return through September to negative 15.98%. The Fund was modestly ahead of its primary benchmark, the S&P Global Ex-U.S. Between $500M and $5B Index, in both periods. Results were strongly shaped by the month of September, during which the Fund fell 13.16% as anxiety about European sovereign debt reached a fever pitch.

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

Columbia Acorn International

At a Glance (Class A Shares - LAIAX)

Pretax and After-tax Average Annual Total Returns (Based on Class A Share Returns)

through September 30, 2011

Inception 10/16/00		Year to date*			1 year			5 years			10 years
Returns before taxes	NAV POP		-15.98 -20.80	%		-8.86 -14.10	%		2.17 0.97	%		10.94 10.29	%
Returns after taxes on distributions	NAV POP		-16.69 -21.47			-9.59 -14.79			1.41 0.22			10.45 9.80
Returns after taxes on distributions and sale of fund shares	NAV POP		-10.28 -13.42			-5.42 -8.84			1.88 0.85			9.84 9.23
S&P Global Ex-US Between $500M and $5B Index** (pretax)			-17.56			-8.84			1.77			12.15

All results shown assume reinvestment of distributions.

*Year to date data is not annualized.

**The Fund's primary benchmark.

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

The Fund's Class A shares annual operating expense ratio, as stated in the current prospectus, is 1.35%. Effective August 12, 2011, the Funds' transfer agent contractually agreed, through August 14, 2013, to waive a portion of total annual Fund operating expenses attributable to transfer agency fees incurred by Class A shares of Columbia Acorn International such that total annual Fund operating expenses will be reduced by 0.04% for Class A shares of the Fund.

Columbia Acorn International Portfolio Diversification

as a percentage of net assets, as of 9/30/11

Columbia Acorn International Top 10 Holdings

as a percentage of net assets, as of 9/30/11

1.	Kansai Paint (Japan) Paint Producer in Japan, India, China & Southeast Asia	1.4	%
2.	Melco Crown Entertainment (Hong Kong) Macau Casino Operator	1.1	%
3.	Zhaojin Mining Industry (China) Gold Mining & Refining in China	1.0	%
4.	Alexion Pharmaceuticals (United States) Biotech Focused on Orphan Diseases	1.0	%
5.	Vopak (Netherlands) World's Largest Operator of Petroleum & Chemical Storage Terminals	1.0	%
6.	Gemalto (France) Smart Card Products & Solutions	1.0	%
7.	Olam International (Singapore) Agriculture Supply Chain Manager	1.0	%
8.	Localiza Rent A Car (Brazil) Car Rental	1.0	%
9.	Imtech (Netherlands) Electromechanical & Information & Communications Technologies Installation & Maintenance	1.0	%
10.	Intertek Group (United Kingdom) Testing, Inspection & Certification Services	1.0	%

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 International (Class A)

October 16, 2000 through September 30, 2011

Illustration is based on a hypothetical $10,000 investment from inception in Class A shares of the Fund, which includes a 5.75% maximum initial sales charge. The S&P Global Ex-U.S. Between $500M and $5B Index is unmanaged and returns for both the index and the Fund include reinvested dividends and capital gains. Although the index is provided for use in assessing the Fund's performance, the Fund's holdings may differ significantly from those in the index. It is not possible to invest directly in an index. The graph does not reflect taxes that a shareholder may pay on Fund distributions or on a sale of Fund shares.

Total Net Assets of the Fund: $5.5 billion

Columbia Acorn USA

In a Nutshell



Robert A. Mohn

Lead Portfolio Manager

Fund's Positions
in Mentioned Holdings

As a percentage of net assets, as of 9/30/11

Informatica	2.6	%
Ametek	2.2	%
Nordson	2.1	%
Alexion Pharmaceuticals	1.7	%
II-VI	1.5	%
Cepheid	1.2	%
BioMarin Pharmaceutical	1.2	%
Atmel	1.1	%
Polycom	0.6	%
Akorn	0.4	%
Acorn Energy	0.2	%

Columbia Acorn USA fell 22.26% (Class A shares, without sales charge) in the third quarter of 2011, performing in line with the 21.87% drop of its primary benchmark, the Russell 2000 Index. Year to date, the Fund was off 15.29% versus a 17.02% drop for its benchmark. Markets tumbled as the U.S. credit rating downgrade and the seemingly never-ending crisis in Europe dominated headlines and fueled investor fears.

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.

Columbia Acorn USA

At a Glance (Class A Shares - LAUAX)

Pretax and After-tax Average Annual Total Returns (Based on Class A Share Returns)

through September 30, 2011

Inception 10/16/00		Year to date*			1 year			5 years			10 years
Returns before taxes	NAV POP		-15.29 -20.16	%		-1.44 -7.09	%		-0.79 -1.96	%		5.97 5.34	%
Returns after taxes on distributions	NAV POP		-15.29 -20.16			-1.44 -7.09			-1.13 -2.29			5.67 5.04
Returns after taxes on distributions and sale of fund shares	NAV POP		-9.94 -13.10			-0.93 -4.61			-0.64 -1.62			5.25 4.68
Russell 2000 Index**(pretax)			-17.02			-3.53			-1.02			6.12

All results shown assume reinvestment of distributions.

*Year to date data is not annualized.

**The Fund's primary benchmark.

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

The Fund's Class A shares annual operating expense ratio, as stated in the current prospectus, is 1.30%.

Columbia Acorn USA Portfolio Diversification

as a percentage of net assets, as of 9/30/11

Columbia Acorn USA Top 10 Holdings

as a percentage of net assets, as of 9/30/11

1.	lululemon athletica Premium Active Apparel Retailer	2.7	%
2.	FMC Technologies Oil & Gas Wellhead Manufacturer	2.6	%
3.	Informatica Enterprise Data Integration Software	2.6	%
4.	Ametek Aerospace/Industrial Instruments	2.2	%
5.	Micros Systems Information Systems for Hotels, Restaurants & Retailers	2.2	%
6.	Nordson Dispensing Systems for Adhesives & Coatings	2.1	%
7.	IPG Photonics Fiber Lasers	2.1	%
8.	Abercrombie & Fitch Teen Apparel Retailer	2.0	%
9.	Atwood Oceanics Offshore Drilling Contractor	1.9	%
10.	tw telecom Fiber Optic Telephone/Data Services	1.9	%

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

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

October 16, 2000 through September 30, 2011

Illustration is based on a hypothetical $10,000 investment from inception in Class A shares of the Fund, which includes a 5.75% maximum initial sales charge. The Russell 2000 Index is unmanaged and returns for both the index and the Fund include reinvested dividends and capital gains. Although the index is provided for use in assessing the Fund's performance, the Fund's holdings may differ significantly from those in the index. It is not possible to invest directly in an index. The graph does not reflect taxes that a shareholder may pay on Fund distributions or on a sale of Fund shares.

Total Net Assets of the Fund: $1.4 billion

Columbia Acorn International Select

In a Nutshell

Christopher J. Olson

Lead Portfolio Manager

Fund's Positions
in Mentioned Holdings

As a percentage of net assets, as of 9/30/11

Kansai Paint	5.5	%
Chemring	3.3	%
NHN	2.7	%
Hexagon	2.3	%
Archipelago Resources	2.0	%
Asahi Diamond Industrial	2.0	%
Gree	1.5	%
Rheinmetall	1.5	%
Israel Chemicals	1.4	%
Ain Pharmaciez	1.3	%

Columbia Acorn International Select ended the third quarter of 2011 down 14.74% (Class A shares, without sales charge), outperforming the 18.15% drop of its primary benchmark, the S&P Developed Ex-U.S. Between $2B and $10B Index. Year to date, the Fund was down 11.72%, while its benchmark fell 14.85%. Concerns about the European debt crisis and a possible double-dip recession in the United States caused markets to drop sharply late in the quarter.

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

Columbia Acorn International Select

At a Glance (Class A Shares - LAFAX)

Pretax and After-tax Average Annual Total Returns (Based on Class A Share Returns)

through September 30, 2011

Inception 10/16/00		Year to date*			1 year			5 years			10 years
Returns before taxes	NAV POP		-11.72 -16.80	%		-4.71 -10.18	%		2.15 0.95	%		10.23 9.57	%
Returns after taxes on distributions	NAV POP		-12.05 -17.11			-4.98 -10.43			1.83 0.63			10.07 9.42
Returns after taxes on distributions and sale of fund shares	NAV POP		-7.58 -10.88			-2.92 -6.48			1.89 0.86			9.21 8.61
S&P Developed Ex-US Between $2B and $10B Index** (pretax)			-14.85			-6.54			-1.15			9.14

All results shown assume reinvestment of distributions.

*Year to date data is not annualized.

**The Fund's primary benchmark.

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

The Fund's Class A shares annual operating expense ratio, as stated in the current prospectus, is 1.56%.

Columbia Acorn International Select Portfolio Diversification

as a percentage of net assets, as of 9/30/11

Columbia Acorn International Select Top 10 Holdings

as a percentage of net assets, as of 9/30/11

1.	Ascendas REIT (Singapore) Singapore Industrial Property Landlord	5.5	%
2.	Kansai Paint (Japan) Paint Producer in Japan, India, China & Southeast Asia	5.5	%
3.	Far Eastone Telecom (Taiwan) Taiwan's Third Largest Mobile Operator	4.5	%
4.	Mapletree Industrial Trust REIT (Singapore) Industrial Property Landlord	4.4	%
5.	Seven Bank (Japan) ATM Processing Services	3.6	%
6.	Chemring (United Kingdom) Defense Manufacturer of Countermeasures & Energetics	3.3	%
7.	Rand Merchant Insurance (South Africa) Directly Sold Property & Casualty Insurance; Holdings in Other Insurers	3.0	%
8.	Zhaojin Mining Industry (China) Gold Mining & Refining in China	2.8	%
9.	JLT Group (United Kingdom) International Business Insurance Broker	2.7	%
10.	NHN (South Korea) South Korea's Largest Online Search Engine	2.7	%

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 A)

October 16, 2000 through September 30, 2011

Illustration is based on a hypothetical $10,000 investment from inception in Class A shares of the Fund, which includes a 5.75% maximum initial sales charge. The S&P Developed Ex-U.S. Between $2B and $10B Index is unmanaged and returns for both the index and the Fund include reinvested dividends and capital gains. Although the index is provided for use in assessing the Fund's performance, the Fund's holdings may differ significantly from those in the index. It is not possible to invest directly in an index. The graph does not reflect taxes that a shareholder may pay on Fund distributions or on a sale of Fund shares.

Total Net Assets of the Fund: $366.9 million

Columbia Acorn Select

In a Nutshell



Ben Andrews				Robert A. Chalupnik

Lead Portfolio Manager				Co-Portfolio Manager

Fund's Positions
in Mentioned Holdings

As a percentage of net assets, as of 9/30/11

Hertz	5.0	%
CNO Financial Group	4.7	%
WNS	3.8	%
Sanmina-SCI	3.1	%
Skullcandy	0.3	%
Horizon Pharma	0.1	%

Columbia Acorn Select fell 23.60% (Class A shares, without sales charge) in the third quarter of 2011 and, year to date, was off 23.69% as of the end of September. The S&P MidCap 400 Index, the Fund's primary benchmark, was down 19.88% in the third quarter and year-to-date performance was off 13.02%. The large-cap S&P 500 Index fell 13.87% in the third quarter and was down 8.68% year to date.

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

Columbia Acorn Select

At a Glance (Class A Shares - LTFAX)

Pretax and After-tax Average Annual Total Returns (Based on Class A Share Returns)

through September 30, 2011

*Inception 10/16/00*		Year to date*			1 year			5 years			10 years
Returns before taxes	NAV POP		-23.69 -28.07	%		-13.05 -18.06	%		-1.16 -2.32	%		6.47 5.84	%
Returns after taxes on distributions	NAV POP		-24.08 -28.44			-13.49 -18.48			-1.46 -2.62			6.21 5.58
Returns after taxes on distributions and sale of fund shares	NAV POP		-15.34 -18.19			-8.41 -11.68			-0.98 -1.96			5.68 5.11
S&P MidCap 400 Index** (pretax)			13.02			-1.28			2.20			7.50

All results shown assume reinvestment of distributions.

*Year to date data is not annualized.

**The Fund's primary benchmark.

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

The Fund's Class A shares annual operating expense ratio, as stated in the current prospectus, is 1.28%.

Columbia Acorn Select Portfolio Diversification

as a percentage of net assets, as of 9/30/11

Columbia Acorn Select Top 10 Holdings

as a percentage of net assets, as of 9/30/11

1.	Discover Financial Services Credit Card Company	6.5	%
2.	Hertz Largest U.S. Rental Car Operator	5.0	%
3.	CNO Financial Group Life, Long-term Care & Medical Supplement Insurance	4.7	%
4.	Abercrombie & Fitch Teen Apparel Retailer	4.4	%
5.	Crown Castle International Communications Towers	4.1	%
6.	Ametek Aerospace/Industrial Instruments	4.1	%
7.	WNS (India) Offshore Business Process Outsourcing Services	3.8	%
8.	Pacific Rubiales Energy (Colombia) Oil Production & Exploration in Colombia	3.6	%
9.	Coach Designer & Retailer of Branded Leather Accessories	3.4	%
10.	Safeway Supermarkets	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 A)

October 16, 2000 through September 30, 2011

Illustration is based on a hypothetical $10,000 investment from inception in Class A shares of the Fund, which includes a 5.75% maximum initial sales charge. The S&P MidCap 400 Index is unmanaged and returns for both the index and the Fund include reinvested dividends and capital gains. Although the index is provided for use in assessing the Fund's performance, the Fund's holdings may differ significantly from those in the index. It is not possible to invest directly in an index. The graph does not reflect taxes that a shareholder may pay on Fund distributions or on a sale of Fund shares.

Total Net Assets of the Fund: $1.3 billion

Columbia Thermostat Fund

In a Nutshell

Charles P. McQuaid

Lead Portfolio Manager

Columbia Thermostat Fund fell 6.93% (Class A shares, without sales charge) in the third quarter of 2011, outperforming the 13.87% drop of its primary equity benchmark, the S&P 500 Index, and underperforming the 3.82% increase of the Fund's primary debt benchmark, the Barclays Capital U.S. Aggregate Bond Index. Year to date, the Fund was down 2.80% while the S&P 500 Index was off 8.68% and the Barclays index rose 6.65%.

The Fund hit five reallocation triggers during the third quarter. Two of these movements increased exposure to stock funds, as the Fund bought on the weakness in equities. The largest single increase was from 50% to 70% into stock funds in early August, as the Fund's "31-day Rule" fortuitously prevented the Fund from increasing equities earlier during the market rout.* In September, stocks regained some ground causing the Fund to raise its income exposure. Columbia Thermostat Fund ended the period with a 65% exposure to its underlying stock funds and 35% exposure to its underlying bond funds.

*As stated in the Fund's prospectus, the 31-day Rule prohibits a reversal within 31 days. Because the Fund bought bond funds in early July, it could not add to stock funds until 31 days had passed.

Results of the Funds Owned in Columbia Thermostat Fund as of September 30, 2011

Stock Funds	Weighting			3rd			Year to
Fund	in category			quarter			date
Columbia Acorn International, Class I		20	%		-18.20	%		-15.70	%
Columbia Dividend Income Fund, Class I		20	%		-10.48	%		-5.05	%
Columbia Acorn Fund, Class I		15	%		-19.65	%		-13.85	%
Columbia Marsico Growth Fund, Class I		15	%		-16.20	%		-10.93	%
Columbia Acorn Select, Class I		10	%		-23.43	%		-23.40	%
Columbia Contrarian Core Fund, Class I		10	%		-15.99	%		-11.24	%
Columbia Large Cap Enhanced Core Fund, Class I		10	%		-13.37	%		-6.52	%
*Weighted Average* *Equity Loss*		*100*	%		*-16.42*	%		*-12.06*	%
Bond Funds	Weighting			3rd			Year
Fund	in category			quarter			to date
Columbia Intermediate Bond Fund, Class I		50	%		2.39	%		5.09	%
Columbia U.S. Treasury Index Fund, Class I		30	%		6.40	%		8.56	%
Columbia Income Opportunities Fund, Class I		20	%		-4.23	%		-0.03	%
*Weighted Average* *Income Return*		*100*	%		*2.24*	%		*5.13*	%

Columbia Thermostat Fund
Rebalancing in the Third Quarter

July 8, 2011				50% stocks, 50% bonds
August 8, 2011				70% stocks, 30% bonds
August 9, 2011				75% stocks, 25% bonds
September 9, 2011				70% stocks, 30% bonds
September 16, 2011				65% stocks, 35% bonds

Columbia Thermostat Fund

At a Glance (Class A Shares - CTFAX)

Pretax and After-tax Average Annual Total Returns (Based on Class A Share Returns)

through September 30, 2011

*Inception 3/3/03*		Year to date*			1 year			5 years			Life of fund
Returns before taxes	NAV POP		-2.80 -8.40	%		4.40 -1.63	%		3.26 2.05	%		6.81 6.07	%
Returns after taxes on distributions	NAV POP		-3.21 -8.79			3.90 -2.10			2.04 0.85			5.64 4.91
Returns after taxes on distributions and sale of fund shares	NAV POP		-1.80 -5.45			2.94 -0.98			2.23 1.20			5.42 4.76
S&P 500 Index** (pretax)			-8.68			1.14			-1.18			5.60
Barclays Capital U.S. Aggregate Bond Index** (pretax)			6.65			5.26			6.53			5.24
Lipper Flexible Portfolio Funds Index (pretax)			-7.00			-0.22			1.97			6.57

All results shown assume reinvestment of distributions.

*Year to date data is not annualized.

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

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

The Fund's annual operating expense ratio, as stated in the current prospectus, reflects a contractual fee waiver and expense reimbursement with CWAM that expires April 30, 2012. Class A expense ratios without and with the contractual waiver/reimbursement, including fees and expenses associated with the Fund's investment in other investment companies, are 1.52% and 1.29%, respectively. Absent the waiver or reimbursement, performance results would have been lower.

Columbia Thermostat Fund Asset Allocation

as a percentage of net assets, as of 9/30/11

Columbia Thermostat Fund Portfolio Weightings

as a percentage of assets in each investment category, as of 9/30/11

Stock Mutual Funds

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

Bond Mutual Funds

Columbia Intermediate Bond Fund, Class I	50	%
Columbia U.S. Treasury Index Fund, Class I	30	%
Columbia Conservative High Yield Fund, Class I	20	%

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

March 3, 2003 through September 30, 2011

Illustration is based on a hypothetical $10,000 investment from inception in Class A shares of the Fund, which includes a 5.75% maximum initial sales charge. The indexes are unmanaged and returns for both the indexes and the Fund include reinvested dividends and capital gains. Although the indexes are provided for use in assessing the Fund's performance, the Fund's holdings may differ significantly from those in the index. It is not possible to invest directly in an index. The graph does not reflect taxes that a shareholder may pay on Fund distributions or on a sale of Fund shares.

Total Net Assets of the Fund: $135.0 million

Columbia Acorn Emerging Markets Fund

In a Nutshell



Fritz Kaegi				Stephen Kusmierczak

Lead Portfolio Manager				Lead Portfolio Manager



P. Zachary Egan				Louis J. Mendes

Co-Portfolio Manager				Co-Portfolio Manager

Fund's Positions
in Mentioned Holdings

As a percentage of net assets, as of 9/30/11

Komercni Banka	2.5	%
Kansai Paint	1.4	%
Melco Crown Entertainment	1.3	%
China Yurun Food	0.4	%

As of the 2011 third quarter end, Columbia Acorn Emerging Markets Fund was down 11.60% (Class A shares, without sales charge) since its inception on August 19, 2011, outperforming its primary benchmark, the S&P Emerging Markets Between $500M and $5B Index, by 2.68%.

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

Columbia Acorn Emerging
Markets Fund

At a Glance (Class A Shares - CAGAX)

Pretax and After-tax Average Annual Total Returns (Based on Class A Share Returns)

through September 30, 2011

*Inception 8/19/11*		Life of fund*
Returns before taxes	NAV POP		-11.60 -16.68	%
Returns after taxes on distributions	NAV POP		-11.60 -16.68
Returns after taxes on distributions and sale of fund shares	NAV POP		-7.54 -10.84
S&P Emerging Markets Between $500M and $5B Index (pretax)**			-14.28

All results shown assume reinvestment of distributions.

*Reflects performance from Fund inception on 8/19/11 through 9/30/11.

**The Fund's primary benchmark.

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

The Fund's annual operating expense ratio, as stated in the current prospectus, reflects a contractual fee waiver and expense reimbursement agreement with CWAM that expires April 30, 2013; Class A share expense ratios without and with the contractual waiver/reimbursement are 1.96% and 1.85%, respectively.

Columbia Acorn Emerging Markets Fund Portfolio Diversification

as a percentage of net assets, as of 9/30/11

Columbia Acorn Emerging Markets Fund Regional Diversification

as a percentage of equity, as of 9/30/11

Columbia Acorn Emerging Markets Fund Top 10 Holdings

as a percentage of net assets, as of 9/30/11

1.	Adcock Ingram Holdings (South Africa) Manufacturer of Pharmaceuticals & Medical Supplies	2.8	%
2.	Archipelago Resources (United Kingdom) Gold Mining Projects in Indonesia, Vietnam & the Philippines	2.6	%
3.	Ace Indonesia (Indonesia) Home Improvement Retailer	2.6	%
4.	Alliance Grain Traders (Canada) Global Leader in Pulse Processing & Distribution	2.6	%
5.	Komercni Banka (Czech Republic) Leading Czech Universal Bank	2.5	%
6.	Coronation Fund Managers (South Africa) South African Fund Manager	2.4	%
7.	Rand Merchant Insurance (South Africa) Directly Sold Property & Casualty Insurance; Holdings in Other Insurers	2.4	%
8.	Grupo Aeroportuario del Sureste (Mexico) Mexican Airport Operator	2.3	%
9.	Dufry Group (Switzerland) Operates Airport Duty Free & Duty Paid Shops	2.3	%
10.	Localiza Rent A Car (Brazil) Car Rental	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.

Total Net Assets of the Fund:
$2.6 million

Columbia Acorn European Fund

In a Nutshell



Andreas Waldburg-Wolfegg				Stephen Kusmierczak

Lead Portfolio Manager				Co-Portfolio Manager

Fund's Positions
in Mentioned Holdings

As a percentage of net assets, as of 9/30/11

Charles Taylor	2.3	%
Vopak	2.3	%
JLT Group	2.1	%
Workspace Group	1.1	%
Elringklinger	1.1	%
Shaftesbury	0.1	%

After only six weeks of trading, the Fund's 5.90% (Class A shares, without sales charge) drop outperformed its benchmark, which fell 7.55% for the same period. The Fund's positioning gives us great confidence: a collection of businesses that we believe have strong market share, display above-average operating metrics, and possess business models that we believe should allow them to gain market share in a possible downturn in their respective markets.

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

Columbia Acorn
European Fund

At a Glance (Class A Shares - CAEAX)

Pretax and After-tax Average Annual Total Returns (Based on Class A Share Returns)

through September 30, 2011

*Inception 8/19/11*		Life of fund*
Returns before taxes	NAV POP		-5.90 -11.31	%
Returns after taxes on distributions	NAV POP		-5.90 -11.31
Returns after taxes on distributions and sale of fund shares	NAV POP		-3.84 -7.35
S&P Europe Between $500M and $5B Index (pretax)**			-7.55

All results shown assume reinvestment of distributions.

*Reflects performance from Fund inception on 8/19/11 through 9/30/11.

**The Fund's primary benchmark.

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

Columbia Acorn European Fund Portfolio Diversification

as a percentage of net assets, as of 9/30/11

Columbia Acorn European Fund Country Diversification

as a percentage of equity, as of 9/30/11

Columbia Acorn European Fund Top 10 Holdings

as a percentage of net assets, as of 9/30/11

1.	1000mercis (France) Interactive Advertising and Marketing	4.9	%
2.	Geberit (Switzerland) Plumbing Supplies	3.4	%
3.	Gemalto (France) Smart Card Products & Solutions	3.3	%
4.	Chemring (United Kingdom) Defense Manufacturer of Countermeasures & Energetics	3.0	%
5.	Eurofins Scientific (France) Food, Pharmaceuticals & Materials Screening & Testing	2.9	%
6.	Wirecard (Germany) Online Payment Processing & Risk Management	2.8	%
7.	Sweco (Sweden) Engineering Consultants	2.7	%
8.	Neopost (France) Postage Meter Machines	2.7	%
9.	Intertek Group (United Kingdom) Testing, Inspection & Certification Services	2.5	%
10.	Imtech (Netherlands) Electromechanical & Information & Communications Technologies Installation & Maintenance	2.4	%

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.

Total Net Assets of the Fund:
$1.6 million

Columbia Acorn Fund

Major Portfolio Changes in the Third Quarter (Unaudited)

	Number of Shares
	06/30/11		09/30/11
Purchases
Information
Atmel		8,130,000		9,065,000
Boingo Wireless		1,200,000		1,400,000
Carbonite		0		362,577
Constant Contact		1,950,000		2,350,000
Finisar		1,725,000		1,905,000
Gemalto (France)		0		230,000
Genpact		781,635		1,575,000
iGATE		2,900,000		3,307,204
ON Semiconductor		5,117,000		6,202,000
Polycom		2,455,000		4,130,000
RPX		0		505,000
Syntel		580,000		680,000
Tangoe		0		313,100
TIBCO		1,381,600		2,000,000
TriQuint Semiconductor		1,750,000		2,290,000
Verisk Analytics		900,000		1,400,000
WNS - ADR (India)		1,027,147		1,076,353
Consumer Goods & Services
Cavco Industries		415,000		460,000
CTS Eventim (Germany)		173,436		320,000
GLG Life Tech (Canada)		1,200,000		1,750,000
HomeAway		1,289,880		1,400,000
lululemon athletica		3,991,265		7,490,000
New Oriental Education & Technology - ADR (China)		200,000		800,000
Pinnacle Entertainment		3,400,000		3,950,000
PVH		0		1,410,000
Skullcandy		0		975,000
Teavana		0		971,500
Thor Industries		1,980,000		2,180,000
Vail Resorts		1,250,000		1,470,000
Industrial Goods & Services
Acorn Energy		0		1,336,001
Albemarle		1,650,000		1,750,000
Chicago Bridge & Iron		0		1,725,000
Clean Harbors		280,000		560,000
FMC Corporation		650,000		760,000
Generac		1,600,000		1,667,021
GrafTech International		2,340,000		4,000,000
Kennametal		2,900,000		3,200,000
Waste Connections		1,672,500		2,400,000
Energy & Minerals
Black Diamond Group (Canada)		528,300		1,056,600
Celtic Exploration (Canada)		175,400		631,000
Crew Energy (Canada)		484,500		847,000

	Number of Shares
	06/30/11		09/30/11
Duluth Exploration - Special Warrants (Canada)		0		500,000
Duluth Metals (Canada)		3,816,400		7,500,000
Mongolian Mining (Hong Kong)		5,215,500		12,000,000
Finance
Artio Global Investors		0		1,000,000
City National		1,145,000		1,275,000
CNO Financial Group		9,400,000		11,900,000
Delphi Financial Group		1,000,000		1,200,000
Eaton Vance		3,391,000		3,700,000
Enstar Group		33,746		150,000
First Busey		4,056,427		4,299,507
H & E Equipment Services		3,000,000		3,400,000
TrustCo Bank		0		779,305
Wright Express		0		100,000
Health Care
Adcock Ingram Holdings (South Africa)		2,393,955		2,859,820
Akorn		4,000,000		4,788,400
Alimera Sciences		1,818,154		2,040,000
eResearch Technology		4,250,000		4,900,000
Gen-Probe		700,000		860,000
HealthSouth		0		1,725,000
Hill-Rom Holdings		0		625,100
HMS Holdings		400,000		850,000
Horizon Pharma		0		870,000
Mednax		0		665,000
Raptor Pharmaceutical		0		3,455,000
Seattle Genetics		4,181,000		4,200,000
Other Industries
Associated Estates Realty		2,700,000		3,000,000
St. Joe		699,701		1,000,000
Summit Hotel Properties		1,481,994		1,500,000

	Number of Shares
	06/30/11		09/30/11
Sales
Information
Actuate		1,500,000		0
Acxiom		1,560,000		0
Applied Micro Circuits		1,650,000		0
Blackboard		1,700,000		0
Blue Coat Systems		313,300		0
Crown Castle International		6,000,000		5,700,000
Dolby Laboratories		815,000		605,000
Entegris		5,000,000		4,000,000
FLIR Systems		600,000		0
Hong Kong Exchanges and Clearing (Hong Kong)		750,000		0
IMAX (Canada)		1,400,000		1,250,000
MetroPCS Communications		1,000,000		600,000
Navigant Consulting		3,100,000		3,000,000
Paetec Holding		9,600,000		9,000,000
Salem Communications		1,541,000		1,533,400
Spanish Broadcasting System		2,400,000		177,700
SRA International		1,583,750		0
Supertex		935,000		644,280
TheStreet.com		1,000,000		656,585
Tyler Technologies		2,000,000		1,700,000
WMS Industries		2,100,000		1,741,367
Consumer Goods & Services
Avis Budget Group		4,600,000		4,000,000
Blue Nile		62,784		0
Chico's FAS		1,933,750		0
Crocs		1,400,000		580,000
Diamond Foods		1,170,000		1,050,000
Expedia		3,900,000		3,100,000
Guess?		1,980,000		1,455,000
Hansen Natural		1,900,000		1,780,000
Herman Miller		2,800,000		2,250,000
ITT Educational Services		350,000		300,000
P.F. Chang's China Bistro		480,000		0
Penn National Gaming		1,590,000		1,100,000
Phillips-Van Heusen		1,410,000		0
Talbots		828,500		0
True Religion Apparel		2,047,000		1,747,000
Universal Technical Institute		1,700,000		1,400,000
Zuoan Fashion (China)		100,197		36,037
Industrial Goods & Services
Albany International		1,100,000		900,000
Clarcor		2,565,000		2,325,000
Greif		350,000		0
Hutchison Port Holdings Trust (Hong Kong)		10,000,000		0

	Number of Shares
	06/30/11		09/30/11
Ibiden (Japan)		600,000		0
Jain Irrigation Systems (India)		3,500,000		3,450,000
Mersen (France)		524,000		495,086
Mine Safety Appliances		1,300,000		926,962
Nalco		831,000		0
Neopost (France)		287,000		265,907
Novozymes (Denmark)		340,000		305,000
Oshkosh Corporation		3,650,000		2,675,000
Republic Services		1,000,000		0
Sika (Switzerland)		10,000		8,000
Simpson Manufacturing		360,073		0
TrueBlue		1,050,000		0
UTI Worldwide		1,000,000		750,000
Watsco		100,000		0
WW Grainger		900,000		605,000
Energy & Minerals
Carrizo Oil & Gas		293,000		0
Core Labs (Netherlands)		641,000		545,000
Houston American Energy		1,200,000		1,143,800
PetroMagdalena Energy (Colombia)		42,580,500		6,866,628
Primary Petroleum (Canada)		2,245,000		0
ShaMaran Petroleum (Iraq)		27,063,400		27,000,000
Southwestern Energy		1,650,000		1,389,000
Tahoe Resources (Canada)		236,400		0
Tuscany International Drilling (Colombia)		9,519,200		8,870,000
Ultra Petroleum		910,000		383,000
Union Agriculture Group (Argentina)		6,818,182		1,136,364
Finance
Alliance Data Systems		400,000		350,000
Associated Banc-Corp		5,413,800		4,487,800
BOK Financial		2,800,000		2,738,000
GATX		90,020		0
Green Bankshares		583,872		158,389
Investment Technology Group		629,493		0
McGrath Rentcorp		2,350,000		2,150,000
Shinsei Bank (Japan)		3,764,300		0
SVB Financial Group		1,160,000		910,000
Symetra Financial		1,600,000		694,343
TCF Financial		3,613,000		3,000,000
Valley National Bancorp		6,304,320		5,700,000
ViewPoint Financial		1,024,069		700,000

Columbia Acorn Fund

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

	Number of Shares
	06/30/11		09/30/11
Sales (continued)
Health Care
Array Biopharma		3,500,000		0
Community Health Systems		1,655,000		1,625,000
Edwards Lifesciences		1,000,000		340,000
Idenix Pharmaceuticals		2,300,000		0
Idexx Laboratories		500,000		0
Isis Pharmaceuticals		4,500,000		3,430,000
Kindred Healthcare		1,450,000		0
Nabi Biopharmaceuticals		3,300,000		0
Onyx Pharmaceuticals		1,450,000		1,170,000
Owens & Minor		200,000		0
United Therapeutics		780,000		142,825
Other Industries
Corporate Office Properties		900,000		0
Genesee & Wyoming		400,000		300,000
JB Hunt Transport Services		1,730,000		1,275,000
Terna (Italy)		3,333,000		0

Columbia Acorn Fund

Statement of Investments (Unaudited), September 30, 2011

Number of Shares			Value (000)
			Equities: 95.8%
Information 25.8%
		> Business Software 6.9%
	4,700,000	Informatica (a)	$	192,465
		Enterprise Data Integration Software
	2,550,000	ANSYS (a)		125,052
		Simulation Software for Engineers and Designers
	2,700,000	Micros Systems (a)		118,557
		Information Systems for Hotels, Restaurants and Retailers
	1,100,000	Quality Systems (b)		106,700
		IT Systems for Medical Groups & Ambulatory Care Centers
	5,164,999	Hexagon (Sweden)		67,162
		Design, Measurement and Visualization Software and Equipment
	1,480,000	Concur Technologies (a)		55,086
		Web Enabled Cost & Expense Management Software
	2,250,000	Blackbaud (c)		50,107
		Software & Services for Non-Profits
	2,000,000	TIBCO (a)		44,780
		Datacenter Software
	1,700,000	Tyler Technologies (a)(c)		42,976
		Financial, Tax, Court, & Document Mgmt Systems for Local Governments
	2,350,000	Constant Contact (a)(c)		40,631
		Email & Other Marketing Campaign Mgmt Systems Delivered Over the Web
	1,450,000	NetSuite (a)(b)		39,164
		End to End IT Systems Solution Delivered Over the Web
	850,000	Red Hat (a)		35,921
		Maintenance & Support for Opensource OS & Middleware
	1,200,000	Ariba (a)		33,252
		Cost Management Software
	2,025,000	Kenexa (a)(c)		31,671
		Recruiting and Workforce Management Solutions
	920,000	Jack Henry & Associates		26,662
		Systems Financial Institutions
	900,000	SPS Commerce (a)(c)		14,661
		Supply Chain Management Software Delivered via the Web
	690,000	Advent Software (a)		14,387
		Asset Management & Trading Systems
	550,000	Intralinks (a)		4,131
		Collaboration Software
	313,100	Tangoe (a)		3,541
		Software Solution for Managing Communication Expense & Devices
	1,000,000	InContact (a)		3,450
		Call Center Systems Delivered Via the Web & Telco Services
				1,050,356
		> Instrumentation 2.8%
	1,600,000	Mettler Toledo (a)(c)		223,936
		Laboratory Equipment
	2,780,000	IPG Photonics (a)(c)		120,763
		Fiber Lasers

Number of Shares			Value (000)
	2,035,000	Trimble Navigation (a)	$	68,274
		GPS-based Instruments
	400,000	Hamamatsu Photonics (Japan)		16,123
		Optical Sensors for Medical & Industrial Applications
				429,096
		> Computer Hardware & Related Equipment 2.4%
	3,565,000	Amphenol		145,345
		Electronic Connectors
	4,550,000	II-VI (a)(c)		79,625
		Laser Optics and Specialty Materials
	1,605,000	Zebra Technologies (a)		49,659
		Bar Code Printers
	1,200,000	Netgear (a)		31,068
		Networking Products for Small Business & Home
	800,000	Nice Systems - ADR (Israel) (a)		24,280
		Audio & Video Recording Solutions
	605,000	Dolby Laboratories (a)		16,601
		Audio Technology for Consumer Electronics
	605,000	Stratasys (a)		11,217
		Rapid Prototyping Systems
	230,000	Gemalto (France)		10,937
		Digital Security Solutions
				368,732
		> Mobile Communications 2.3%
	5,700,000	Crown Castle International (a)		231,819
		Communications Towers
	3,150,000	SBA Communications (a)		108,612
		Communications Towers
	600,000	MetroPCS Communications (a)		5,226
		Discount Cellular Telephone Services
	1,500,000	Globalstar (a)(b)		614
		Satellite Mobile Voice & Data Carrier
				346,271
		> Telephone and Data Services 2.2%
	9,500,000	tw telecom (a)(c)		156,940
		Fiber Optic Telephone/Data Services
	1,200,000	AboveNet		64,320
		Metropolitan Fiber Communications Services
	9,000,000	PAETEC Holding (a)(c)		47,610
		Telephone/Data Services for Business
	2,520,000	Cogent Communications (a)(c)		33,894
		Internet Data Pipelines
	2,000,000	General Communications (a)		16,400
		Commercial Comm & Consumer CATV, Web & Phone in Alaska
	1,400,000	Boingo Wireless (a)(b)		10,010
		Wholesale and Retail WiFi Networks
				329,174
		> Semiconductors & Related Equipment 1.8%
	9,065,000	Atmel (a)		73,154
		Microcontrollers, RF, and Memory Semiconductors
	6,202,000	ON Semiconductor (a)		44,468
		Mixed Signal & Power Management Semiconductors

Columbia Acorn Fund

Statement of Investments (Unaudited), continued

Number of Shares			Value (000)
		> Semiconductors & Related Equipment—continued
	2,345,000	Microsemi (a)	$	37,473
		Analog/Mixed Signal Semiconductors
	4,000,000	Entegris (a)		25,520
		Semiconductor Materials Management Products
	1,900,000	IXYS (a)(c)		20,672
		Power Semiconductors
	500,000	Littelfuse		20,105
		Little Fuses
	1,765,000	Pericom Semiconductor (a)(c)		13,079
		Interface ICs & Frequency Control Products
	2,290,000	TriQuint Semiconductor (a)		11,496
		RF Semiconductors
	644,280	Supertex (a)(c)		11,146
		Analog/Mixed Signal Semiconductors
	800,000	Monolithic Power Systems (a)		8,144
		High Performance Analog & Mixed Signal ICs
				265,257
		> Telecommunications Equipment 1.3%
	4,130,000	Polycom (a)		75,868
		Video Conferencing Equipment
	685,000	F5 Networks (a)		48,669
		Internet Traffic Management Equipment
	1,905,000	Finisar (a)		33,414
		Optical Subsystems and Components
	2,030,000	Ixia (a)		15,570
		Telecom Network Test Equipment
	1,925,000	Infinera (a)		14,861
		Optical Networking Equipment
				188,382
		> Computer Services 1.1%
	3,307,204	iGATE (c)		38,165
		IT & Business Process Outsourcing Services
	680,000	Syntel		29,369
		Offshore I/T Services
	2,125,000	Virtusa (a)(c)		28,050
		Offshore I/T Outsourcing
	1,145,000	ExlService Holdings (a)		25,190
		Business Process Outsourcing
	1,575,000	Genpact (a)		22,664
		Business Process Outsourcing
	4,500,000	Hackett Group (a)(c)		16,785
		IT Integration & Best Practice Research
	1,076,353	WNS - ADR (India) (a)		12,863
		Offshore BPO (Business Process Outsourcing) Services
				173,086
		> CATV 1.1%
	3,000,000	Discovery Communications, Series C (a)		105,450
		CATV programming
	1,250,000	Liberty Global, Series A (a)		45,225
		Cable TV Franchises Outside the USA
	17,770	Jupiter Telecommunications (Japan)		19,227
		Largest Cable Service Provider in Japan
				169,902

Number of Shares			Value (000)
		> Gaming Equipment & Services 0.9%
	3,725,000	Bally Technologies (a)(c)	$	100,500
		Slot Machines & Software
	1,741,367	WMS Industries (a)		30,631
		Slot Machine Provider
				131,131
		> Financial Processors 0.8%
	2,429,000	Global Payments		98,107
		Credit Card Processor
	5,000,000	Singapore Exchange (Singapore)		25,133
		Singapore Equity & Derivatives Market Operator
				123,240
		> Business Information & Marketing Services 0.8%
	1,400,000	Verisk Analytics (a)		48,678
		Risk & Decision Analytics
	900,000	FTI Consulting (a)		33,129
		Financial Consulting Firm
	3,000,000	Navigant Consulting (a)(c)		27,810
		Financial Consulting Firm
	505,000	RPX (a)		10,459
		Patent Aggregation and Defensive Patent Consulting
				120,076
		> Electronics Distribution 0.5%
	3,125,000	Avnet (a)		81,500
		Electronic Components Distribution
				81,500
		> Internet Related 0.4%
	435,000	Equinix (a)		38,641
		Network Neutral Data Centers
	464,305	Mail.ru - GDR (Russia) (a)(h)		13,444
		Internet Social Networking and Games for Russian Speakers
	656,585	TheStreet.com		1,300
		Financial Information Websites
				53,385
		> Contract Manufacturing 0.3%
	1,210,000	Plexus (a)		27,370
		Electronic Manufacturing Services
	2,800,000	Sanmina-SCI (a)		18,704
		Electronic Manufacturing Services
				46,074
		> Entertainment Programming 0.1%
	1,250,000	IMAX (Canada) (a)		18,100
		IMAX Movies, Theatre Equipment and Theatre Joint Ventures
				18,100
		> Radio 0.1%
	164,991	Saga Communications (a)		4,869
		Radio Stations in Small & Mid-sized Cities
	1,533,400	Salem Communications (c)		3,511
		Radio Stations for Religious Programming
	177,700	Spanish Broadcasting System (a)		295
		Spanish Language Radio Stations
				8,675

Number of Shares			Value (000)
		> TV Broadcasting —%
	1,750,000	Gray Television (a)	$	2,730
		Mid Market Affiliated TV Stations
	2,500,000	Entravision Communications (a)		2,550
		Spanish Language TV & Radio Stations
				5,280
		> Consumer Software —%
	362,577	Carbonite (a)(b)		4,365
		Online file storage
				4,365
		> Advertising —%
	1,500,000	VisionChina Media - ADR (China) (a)(b)		2,745
		Advertising on Digital Screens in China's Mass Transit System
				2,745
Information: Total				3,914,827
Consumer Goods & Services 18.3%
		> Retail 5.4%
	7,490,000	lululemon athletica (a)(c)		364,388
		Premium Active Apparel Retailer
	3,510,000	Abercrombie & Fitch		216,076
		Teen Apparel Retailer
	2,300,000	Shutterfly (a)(c)		94,714
		Internet Photo-Centric Retailer
	5,600,000	Pier 1 Imports (a)		54,768
		Home Furnishing Retailer
	5,225,000	Saks (a)(b)		45,719
		Luxury Department Store Retailer
	525,000	DSW		24,244
		Branded Footwear Retailer
	971,500	Teavana (a)(b)		19,760
		Specialty Tea Retailer
	1,371,366	Gaiam (c)		4,649
		Healthy Living Catalogs & E-Commerce
	66,000	The Fresh Market (a)(b)		2,519
		Specialty Food Retailer
				826,837
		> Apparel 3.6%
	2,100,000	Coach		108,843
		Designer & Retailer of Branded Leather Accessories
	1,120,000	Deckers Outdoor (a)		104,451
		Fashion Footwear Wholesaler
	2,190,000	Warnaco Group (a)(c)		100,937
		Global Branded Apparel Manufacturer
	1,410,000	PVH		82,118
		Apparel Wholesaler and Retailer
	1,747,000	True Religion Apparel (a)(c)		47,099
		Premium Denim
	1,455,000	Guess?		41,453
		Branded Apparel + Accessories + Licensor
	1,000,000	Hanesbrands (a)		25,010
		Apparel Wholesaler
	600,000	Steven Madden (a)		18,060
		Wholesaler/Retailer of Fashion Footwear

Number of Shares			Value (000)
	580,000	Crocs (a)	$	13,729
		Branded Footwear Wholesaler & Retailer
	36,037	Zuoan Fashion (China) (a)(b)		99
		Men's Apparel Provider in China
				541,799
		> Travel 2.5%
	3,100,000	Expedia		79,825
		Online Travel Services Company
	3,850,000	Gaylord Entertainment (a)(c)		74,459
		Convention Hotels
	1,470,000	Vail Resorts		55,551
		Ski Resort Operator & Developer
	1,400,000	HomeAway (a)(b)		47,068
		Vacation Rental Online Marketplace
	4,000,000	Avis Budget Group (a)		38,680
		Second Largest Car Rental Company
	970,000	Choice Hotels		28,829
		Franchisor Of Budget Hotel Brands
	3,000,000	Hertz (a)		26,700
		Largest U.S. Rental Car Operator
	2,000,000	Localiza Rent A Car (Brazil)		26,390
		Car Rental
				377,502
		> Food & Beverage 2.0%
	1,780,000	Hansen Natural (a)		155,376
		Alternative Beverages
	1,050,000	Diamond Foods (b)		83,779
		Snack Foods and Culinary Ingredients
	32,896,000	Olam International (Singapore)		56,057
		Agriculture Supply Chain Manager
	1,750,000	GLG Life Tech (Canada) (a)(c)		6,160
		Produce an All-Natural Sweetener Extracted from the Stevia Plant
	240,000	Lance		5,004
		Snack Foods
				306,376
		> Other Consumer Services 0.8%
	2,190,000	Lifetime Fitness (a)(c)		80,701
		Sport & Fitness Club Operator
	14,000,000	Lifestyle International (Hong Kong)		35,518
		Mid to High-End Department Store Operator in Hong Kong & China
	4,250,000	Move (a)		6,162
		Real Estate Internet Websites
	1,325,000	IFM Investments (Century 21 China RE) - ADR (China) (a)		1,524
		Provide Real Estate Services in China
				123,905
		> Casinos & Gaming 0.7%
	1,100,000	Penn National Gaming (a)		36,619
		Regional Casino Operator
	3,950,000	Pinnacle Entertainment (a)(c)		35,866
		Regional Casino Operator
	3,000,000	Melco Crown Entertainment - ADR (Hong Kong) (a)(b)		24,930
		Macau Casino Operator
	12,000,000	MGM China Holdings (Hong Kong) (a)		15,903
		Macau Casino Operator
				113,318

Columbia Acorn Fund

Statement of Investments (Unaudited), continued

Number of Shares			Value (000)
		> Furniture & Textiles 0.7%
	4,000,000	Knoll (c)	$	54,800
		Office Furniture
	2,250,000	Herman Miller		40,185
		Office Furniture
	1,000,000	Interface		11,860
		Modular & Broadloom Carpet
				106,845
		> Educational Services 0.6%
	2,800,000	Career Education (a)		36,540
		Postsecondary Education
	1,400,000	Universal Technical Institute (a)(c)		19,026
		Vocational Training
	800,000	New Oriental Education & Technology - ADR (China) (a)		18,376
		Education Service Provider
	300,000	ITT Educational Services (a)(b)		17,274
		Postsecondary Degree Services
	2,000,000	Voyager Learning, Contingent Value Rights (a)(d)(f)		180
		Education Services for the K-12 Market
				91,396
		> Other Durable Goods 0.5%
	1,720,000	Jarden		48,607
		Branded Household Products
	460,000	Cavco Industries (a)(c)		15,843
		Manufactured Homes
	400,000	Tesla Motors (a)(b)		9,756
		Design, Manufacture and Sell High Performance Electric Vehicles
				74,206
		> Leisure Products 0.4%
	2,180,000	Thor Industries		48,287
		RV & Bus Manufacturer
	975,000	Skullcandy (a)(b)		13,777
		Lifestyle Branded Headphones
				62,064
		> Consumer Goods Distribution 0.4%
	2,100,000	Pool		54,978
		Distributor of Swimming Pool Supplies & Equipment
				54,978
		> Restaurants 0.3%
	2,000,000	AFC Enterprises (a)(c)		23,660
		Popeye's Restaurants
	675,000	Bravo Brio Restaurant Group (a)		11,232
		Upscale Casual Italian Restaurants
	450,000	Cheesecake Factory (a)		11,092
		Casual Dining Restaurants
				45,984
		> Nondurables 0.3%
	1,600,000	Helen of Troy (a)(c)		40,192
		Hair Dryers & Curling Irons
				40,192

Number of Shares			Value (000)
		> Other Entertainment 0.1%
	320,000	CTS Eventim (Germany)	$	9,533
		Event Ticket Sales
				9,533
Consumer Goods & Services: Total				2,774,935
Industrial Goods & Services 17.6%
		> Machinery 9.7%
	4,200,000	Donaldson (c)		230,160
		Industrial Air Filtration
	6,750,000	Ametek		222,547
		Aerospace/Industrial Instruments
	3,000,000	Nordson		119,220
		Dispensing Systems for Adhesives & Coatings
	3,535,000	Pentair		113,155
		Pumps & Water Treatment
	3,200,000	Kennametal		104,768
		Consumable Cutting Tools
	2,325,000	Clarcor		96,208
		Mobile & Industrial Filters
	1,800,000	Pall		76,320
		Filtration & Fluids Clarification
	2,250,000	HEICO (c)		75,735
		FAA Approved Aircraft Replacement Parts
	2,050,000	MOOG (a)		66,871
		Motion Control Products for Aerospace, Defense & Industrial Markets
	2,200,000	ESCO Technologies (c)		56,100
		Automatic Electric Meter Readers
	1,150,000	WABCO Holdings (a)		43,539
		Truck & Bus Component Supplier
	2,675,000	Oshkosh Corporation (a)		42,105
		Specialty Truck Manufacturer
	805,000	Toro		39,662
		Turf Maintenance Equipment
	1,300,000	Kaydon		37,284
		Specialized Friction & Motion Control Products
	600,000	Wabtec		31,722
		Freight & Transit Component Supplier
	1,667,021	Generac (a)		31,357
		Standby Power Generators
	926,962	Mine Safety Appliances		24,991
		Safety Equipment
	265,907	Neopost (France)		19,498
		Postage Meter Machines
	3,450,000	Jain Irrigation Systems (India)		10,685
		Agricultural Micro-Irrigation Systems & Food Processing
	10,000,000	Marel (Iceland) (a)		9,943
		Largest Manufacturer of Poultry and Fish Processing Equipment
	100,000	Valmont Industries		7,794
		Center Pivot Irrigation Systems & Utility Poles
	1,250,000	Spartan Motors		5,163
		Specialty Truck & Chassis Manufacturer
				1,464,827

Number of Shares			Value (000)
		> Industrial Materials & Specialty Chemicals 2.1%
	1,750,000	Albemarle	$	70,700
		Refinery Catalysts and Other Specialty Chemicals
	760,000	FMC Corporation		52,562
		Niche Specialty Chemicals
	305,000	Novozymes (Denmark)		43,365
		Industrial Enzymes
	673,000	Sociedad Quimica y Minera de Chile - ADR (Chile) (b)		32,176
		Producer of Specialty Fertilizers, Lithium and Iodine
	1,260,000	Drew Industries (c)		25,175
		RV & Manufactured Home Components
	2,218,700	Kansai Paint (Japan)		21,261
		Paint Producer in Japan, India, China and Southeast Asia
	495,086	Mersen (France)		19,594
		Advanced Industrial Materials
	900,000	Albany International		16,425
		Paper Machine Clothing and Advanced Textiles
	400,000	Silgan Holdings		14,696
		Metal & Plastic Packaging
	8,000	Sika (Switzerland)		14,164
		Chemicals for Construction & Industrial Applications
				310,118
		> Other Industrial Services 1.9%
	3,200,000	Expeditors International of Washington		129,760
		International Freight Forwarder
	1,767,165	Imtech (Netherlands)		49,709
		Electromechanical and ICT Installation and Maintenance
	1,300,000	Forward Air		33,085
		Freight Transportation Between Airports
	1,600,000	Mobile Mini (a)		26,304
		Portable Storage Units Leasing
	900,000	LKQ (a)		21,744
		Alternative Auto Parts Distribution
	626,524	Arcadis (Netherlands)		11,437
		Engineering Consultants
	750,000	UTI Worldwide		9,780
		Freight Forwarding & Logistics
	1,336,001	Acorn Energy (a)(c)		7,107
		Frac Well Exploration/Monitoring Device, Sonar Security, Electric Grid Monitoring
				288,926
		> Industrial Distribution 0.8%
	605,000	WW Grainger		90,472
		Industrial Distribution
	2,600,000	Interline Brands (a)(c)		33,462
		Industrial Distribution
				123,934
		> Waste Management 0.7%
	2,400,000	Waste Connections		81,168
		Solid Waste Management
	560,000	Clean Harbors (a)		28,728
		Hazardous Waste Services & Disposal
				109,896

Number of Shares			Value (000)
		> Construction 0.7%
	1,725,000	Chicago Bridge & Iron	$	49,387
		Engineering & Construction for LNG & Petrochemicals
	66,000	NVR (a)		39,863
		DC Homebuilder
	1,800,000	Mills Estruturas e Servicos de Engenharia (Brazil)		16,858
		Civil Engineering & Construction
				106,108
		> Outsourcing Services 0.6%
	2,800,000	Quanta Services (a)		52,612
		Electrical & Telecom Construction Services
	1,210,000	Insperity		26,922
		Professional Employer Organization
	600,000	GP Strategies (a)		5,994
		Training Programs
				85,528
		> Electrical Components 0.6%
	1,440,000	Acuity Brands		51,898
		Commercial Lighting Fixtures
	1,500,000	Ushio (Japan)		22,836
		Industrial Light Sources
	351,000	Saft (France)		9,426
		Niche Battery Manufacturer
				84,160
		> Steel 0.3%
	4,000,000	GrafTech International (a)		50,800
		Industrial Graphite Materials Producer
				50,800
		> Conglomerates 0.2%
	2,263,654	Aalberts Industries (Netherlands)		33,655
		Flow Control and Heat Treatment
				33,655
		> Water —%
	649,000	Mueller Water Products		1,610
		Fire Hydrants, Valves & Ductile Iron Pipes
				1,610
Industrial Goods & Services: Total				2,659,562
Health Care 9.5%
		> Medical Equipment & Devices 3.3%
	4,200,000	Alexion Pharmaceuticals (a)		269,052
		Biotech Focused on Orphan Diseases
	1,800,000	Sirona Dental Systems (a)		76,338
		Manufacturer of Dental Equipment
	860,000	Gen-Probe (a)		49,235
		Molecular In-Vitro Diagnostics
	550,000	Haemonetics (a)		32,164
		Blood & Plasma Collection Equipment
	340,000	Edwards Lifesciences (a)		24,235
		Heart Valves
	570,000	Orthofix International (a)		19,671
		Bone Fixation & Stimulation Devices
	625,100	Hill-Rom Holdings		18,766
		Hospital Beds/Patient Handling

Columbia Acorn Fund

Statement of Investments (Unaudited), continued

Number of Shares			Value (000)
		> Medical Equipment & Devices—continued
	1,650,000	Pacific Biosciences of California (a)(b)	$	5,296
		Genome Sequencing
				494,757
		> Biotechnology & Drug Delivery 3.0%
	4,315,000	BioMarin Pharmaceutical (a)		137,519
		Biotech Focused on Orphan Diseases
	4,200,000	Seattle Genetics (a)(b)		80,052
		Antibody-Based Therapies for Cancer
	2,226,000	InterMune (a)		44,965
		Drugs for Pulmonary Fibrosis & Hepatitis C
	2,400,000	Auxilium Pharmaceuticals (a)(c)		35,976
		Biotech Focused on Niche Disease Areas
	1,170,000	Onyx Pharmaceuticals (a)		35,112
		Commercial-Stage Biotech Focused on Cancer
	4,500,000	NPS Pharmaceuticals (a)(c)		29,295
		Orphan Drugs & Healthy Royalties
	5,500,000	Micromet (a)(b)(c)		26,400
		Next-generation Antibody Technology
	3,430,000	Isis Pharmaceuticals (a)		23,255
		Biotech Pioneer in Antisense Drugs
	4,549,900	Chelsea Therapeutics (a)(c)		16,607
		Biotech Focused on Rare Diseases
	3,455,000	Raptor Pharmaceutical (a)(b)(c)		15,582
		Orphan Drug Company
	1,740,000	Anthera Pharmaceuticals (a)		8,300
		Biotech Focused on Cardiovascular, Cancer & Immunology
	142,825	United Therapeutics (a)		5,355
		Biotech Focused on Rare Diseases
	359,944	MicroDose Technologies (a)(d)(f)		299
		Drug Inhaler Development
	94,715	Locus Pharmaceuticals (a)(d)(e)(f)		—
		High Throughput Rational Drug Design
				458,717
		> Medical Supplies 1.6%
	3,200,000	Cepheid (a)(c)		124,256
		Molecular Diagnostics
	2,126,000	Patterson Companies		60,867
		Dental/Vet/Med Distributor
	650,000	Henry Schein (a)		40,307
		Largest Distributor of Healthcare Products
	325,200	Neogen (a)		11,291
		Food and Animal Safety Products
				236,721
		> Health Care Services 1.1%
	665,000	Mednax (a)		41,656
		Physician Mgmt for Pediatric and Anesthesia Practices
	1,625,000	Community Health Systems (a)		27,040
		Non-Urban Hospitals
	3,800,000	Health Management Associates (a)		26,296
		Non-Urban Hospitals
	1,725,000	HealthSouth (a)		25,754
		Inpatient Rehabalitation Facilities
	4,900,000	eResearch Technology (a)(c)		21,854
		Clinical Research Services

Number of Shares			Value (000)
	850,000	HMS Holdings (a)	$	20,731
		Cost Containment Services
	700,000	Allscripts Healthcare Solutions (a)		12,614
		IT for Physician Offices and Hospitals
				175,945
		> Pharmaceuticals 0.5%
	4,788,400	Akorn (a)(c)		37,397
		Develops, Manufactures & Sells Specialty Generic Drugs
	2,859,820	Adcock Ingram Holdings (South Africa)		21,208
		Manufacturer of Pharmaceuticals and Medical Supplies
	2,040,000	Alimera Sciences (a)(b)(c)		16,320
		Ophthalmology-Focused Pharmaceutical Company
	870,000	Horizon Pharma (a)		6,081
		Specialty Pharma Company
				81,006
Health Care: Total				1,447,146
Energy & Minerals 9.3%
		> Oil Services 3.8%
	6,200,000	FMC Technologies (a)		233,120
		Oil and Gas Well Head Manufacturer
	2,641,054	Fugro (Netherlands)		133,192
		Sub-sea Oilfield Services
	2,399,000	Atwood Oceanics (a)		82,430
		Offshore Drilling Contractor
	1,670,000	ShawCor (Canada)		38,774
		Oil and Gas Pipeline Products
	743,000	Oil States International (a)		37,834
		Diversified North American Oil Service Provider
	375,000	Bristow		15,911
		Largest Provider of Helicopter Services to Offshore Oil and Gas Producers
	1,056,600	Black Diamond Group (Canada)		13,662
		Provides Accommodations/Equipment for Oil Sands Development
	500,000	Hornbeck Offshore (a)		12,455
		Supply Vessel Operator in U.S. Gulf of Mexico
	2,890,900	Horizon North Logistics (Canada)		10,842
		Provides Diversified Oil Service Offering in Northern Canada
	8,870,000	Tuscany International Drilling (Colombia) (a)		4,909
	1,040,000	Tuscany International Drilling - Warrants (Colombia) (a)		5
		South America Based Drilling Rig Contractor
				583,134
		> Oil & Gas Producers 3.4%
	4,810,550	Pacific Rubiales Energy (Colombia) (b)		101,913
		Oil Production & Exploration in Colombia
	2,400,000	Tullow Oil (United Kingdom)		48,538
		Oil and Gas Producer
	1,389,000	Southwestern Energy (a)		46,295
		Oil and Gas Producer
	715,000	SM Energy		43,365
		Oil and Gas Producer

Number of Shares			Value (000)
		> Oil & Gas Producers—continued
	695,000	Range Resources	$	40,630
		Oil and Gas Producer
	974,000	Rosetta Resources (a)		33,330
		Oil and Gas Producer Exploring in South Texas and Montana
	2,700,000	Denbury Resources (a)		31,050
		Oil Producer Using Co2 Injection
	650,000	Baytex (Canada) (a)(b)		27,175
		Oil and Gas Producer in Canada
	850,000	Northern Oil And Gas (a)(b)		16,481
		Small E & P Company in North Dakota Bakken
	1,143,800	Houston American Energy (b)		15,739
		Oil and Gas Exploration/Production in Colombia
	250,000	Cabot Oil and Gas		15,477
		Large Natural Gas Producer in Appalachia and Gulf Coast
	631,000	Celtic Exploration (Canada) (a)		13,591
		Canadian Oil and Gas Producer
	550,000	Swift Energy (a)		13,387
		Oil and Gas Exploration and Production
	27,000,000	ShaMaran Petroleum (a)		10,693
		Oil Exploration in Kurdistan
	383,000	Ultra Petroleum (a)		10,617
		Oil and Gas Producer
	847,000	Crew Energy (Canada) (a)		7,501
		Canadian Oil and Gas Producer
	6,866,628	PetroMagdalena Energy (Colombia) (a)(b)		6,553
		Oil & Gas Exploration/Production in Colombia
	228,200	Oasis Petroleum (a)(b)		5,096
		Oil Producer in North Dakota
	575,000	Venoco (a)		5,066
		Oil and Gas Producer in California and Texas
	37,500,000	Petromanas (Canada) (a)(c)		4,473
	18,750,000	Petromanas - Warrants (Canada) (a)(d)		263
		Exploring for Oil in Albania
	26,000,000	Petrodorado (Colombia) (a)(c)		4,218
	24,000,000	Petrodorado - Warrants (Colombia) (a)(d)(f)		499
		Oil & Gas Exploration/Production in Columbia, Peru & Paraguay
	6,300,000	Canacol Energy (Colombia) (a)		3,848
		Oil Producer in South America
	30,275,000	Petroamerica (Colombia) (a)(c)		3,322
		Oil Exploration & Production in Colombia
	1,198,100	Pan Orient (Canada) (a)		2,664
		Growth Oriented, Return Focused Asian Explorer
	8,400,000	Canadian Overseas Petroleum (United Kingdom) (a)(d)		2,474
	4,200,000	Canadian Overseas Petroleum - Warrants (United Kingdom) (a)(d)(f)		232
		Oil & Gas Exploration/Production in the North Sea
	41,100,000	Quetzal Energy (Colombia) (a)(c)(d)		1,694
		Explores for Oil & Gas in Latin America

Number of Shares			Value (000)
	8,900,000	Quetzal Energy (Colombia) (a)(c)	$	382
		Explores for Oil & Gas in Latin America
				516,566
		> Mining 1.6%
	1,950,000	Silver Wheaton (Canada)		57,428
		Silver Mining Royalty Company
	545,000	Core Laboratories (Netherlands)		48,957
		Oil and Gas Reservoir Consulting
	15,000,000	Zhaojin Mining Industry (China)		24,952
		Gold Mining and Refining in China
	2,800,000	Alexco Resource (a)		18,984
		Mining, Exploration & Environmental Services
	4,432,000	Northam Platinum (South Africa)		17,971
		Platinum Mining in South Africa
	7,500,000	Duluth Metals (Canada) (a)(c)		16,533
		Copper & Nickel Miner
	900,000	Silver Standard Resources (a)		16,515
		Silver Mining
	1,150,000	Ivanhoe Mines (Canada) (a)		15,858
		Copper Mine Project in Mongolia
	12,000,000	Mongolian Mining (Hong Kong) (a)		10,609
		Coking Coal Mining in Mongolia
	5,000,000	Orko Silver (Canada) (a)(b)		8,970
		Silver Exploration & Development
	800,000	Augusta Resource (a)(b)		2,456
		U.S. Copper/Molybdenum Mine
	4,000,000	Wolverine Minerals (Canada) (a)(c)(d)(f)		1,299
	2,000,000	Wolverine Minerals - Warrants (Canada) (a)(d)(f)		57
		Gold Miner
	500,000	Duluth Exploration - Special Warrants (Canada) (a)(d)(f)		95
		Copper & Nickel Miner
				240,684
		> Oil Refining, Marketing & Distribution 0.2%
	600,000	Vopak (Netherlands)		28,677
		World's Largest Operator of Petroleum and Chemical Storage Terminals
				28,677
		> Alternative Energy 0.2%
	3,000,000	GT Solar International (a)		21,060
		Largest Manufacturer of Furnaces & Reactors to Produce & Cast Polysilicon
	500,000	STR Holdings (a)(b)		4,055
		Makes Encapsulant for Solar Power Modules/Provides Quality Assurance
	1,210,300	Synthesis Energy Systems (China) (a)(b)		2,094
		Owner/Operator of Gasification Plants
				27,209
		> Agricultural Commodities 0.1%
	1,136,364	Union Agriculture Group (Argentina) (a)(d)(f)		12,113
		Farmland Operator in Uruguay
				12,113
Energy & Minerals: Total				1,408,383

Columbia Acorn Fund

Statement of Investments (Unaudited), continued

Number of Shares			Value (000)
Finance 9.3%
		> Banks 3.7%
	2,738,000	BOK Financial	$	128,385
		Tulsa Based S.W. Bank
	2,337,313	Hancock Holding		62,593
		Gulf Coast Bank
	5,700,000	Valley National Bancorp (b)		60,363
		New Jersey/New York Bank
	1,275,000	City National		48,144
		Bank & Asset Manager
	2,860,000	MB Financial (c)		42,099
		Chicago Bank
	4,487,800	Associated Banc-Corp		41,737
		Midwest Bank
	910,000	SVB Financial Group (a)		33,670
		Bank to Venture Capitalists
	4,300,000	CVB Financial (b)		33,067
		Inland Empire Business Bank
	3,000,000	TCF Financial		27,480
		Great Lakes Bank
	4,299,507	First Busey		18,703
		Illinois Bank
	1,350,000	TriCo Bancshares (c)		16,564
		California Central Valley Bank
	1,121,188	Sandy Spring Bancorp		16,403
		Baltimore, D.C. Bank
	772,632	Hudson Valley		13,467
		Metro New York City Bank
	706,559	Eagle Bancorp (a)		8,316
		Metro D.C. Bank
	779,305	TrustCo Bank		3,476
		New York State Bank
	246,505	Pacific Continental		1,748
		Pacific N.W. Bank
	158,389	Green Bankshares (a)(b)		201
		Tennessee Bank
				556,416
		> Insurance 2.3%
	11,900,000	CNO Financial Group (a)		64,379
		Life, Long Term Care & Medical Supplement Insurance
	2,820,000	Leucadia National		63,958
		Insurance Holding Company
	1,320,000	Hanover Insurance Group		46,860
		Personal & Commercial Lines Insurance
	1,200,000	HCC Insurance Holdings		32,460
		Specialty Insurance
	832,000	Willis Group (Ireland)		28,596
		Insurance Broker
	1,225,000	Tower Group		28,003
		Commercial & Personal Lines Insurance
	1,200,000	Delphi Financial Group		25,824
		Workers Comp & Group Employee Benefit Products & Services
	1,420,000	Selective Insurance Group		18,531
		Commercial & Personal Lines Insurance
	900,000	Brown & Brown		16,020
		Insurance Broker

Number of Shares			Value (000)
	150,000	Enstar Group (a)	$	14,284
		Insurance/Reinsurance & Related Services
	694,343	Symetra Financial		5,659
		Life Insurance
	300,000	Assured Guaranty		3,297
		Global Muni Bond Insurance
				347,871
		> Finance Companies 1.6%
	1,505,202	World Acceptance (a)(c)		84,216
		Personal Loans
	2,300,000	Aaron's		58,075
		Rent to Own
	2,150,000	McGrath Rentcorp (c)		51,149
		Temporary Space & IT Rentals
	3,400,000	H&E Equipment Services (a)(c)		28,050
		Heavy Equipment Leasing
	1,123,400	CAI International (a)(c)		13,166
		International Container Leasing
	1,091,000	Marlin Business Services (a)(c)		11,565
		Small Equipment Leasing
	78,500	Textainer Group Holdings		1,592
		Top International Container Leasor
				247,813
		> Brokerage & Money Management 1.3%
	6,198,000	SEI Investments		95,325
		Mutual Fund Administration & Investment Management
	3,700,000	Eaton Vance		82,399
		Specialty Mutual Funds
	1,000,000	Artio Global Investors		7,960
		International Asset Manager
	400,000	Financial Engines (a)		7,244
		Asset Management for 401k Plans
				192,928
		> Credit Cards 0.3%
	350,000	Alliance Data Systems (a)(b)		32,445
		Diversified Credit Card Provider
	100,000	Wright Express (a)		3,804
		Pay Card Processor
				36,249
		> Savings & Loans 0.1%
	700,000	ViewPoint Financial		8,015
		Texas Thrift
	1,010,000	Provident New York Bancorp		5,878
		New York State Thrift
	452,146	Kaiser Federal Financial Group		5,335
		Los Angeles Savings & Loan
	65,991	Berkshire Hills Bancorp		1,219
		Northeast Thrift
				20,447
Finance: Total				1,401,724

Number of Shares			Value (000)
Other Industries 6.0%
		> Real Estate 3.7%
	4,575,000	Biomed Realty Trust	$	75,808
		Life Science-focused Office Buildings
	840,000	Federal Realty Investment Trust		69,224
		Shopping Centers
	3,000,000	Associated Estates Realty (c)		46,380
		Multifamily Properties
	2,200,000	Dupont Fabros Technology (b)		43,318
		Technology-focused Office Buildings
	720,000	Digital Realty Trust (b)		39,715
		Technology-focused Office Buildings
	1,120,000	Kilroy Realty		35,056
		West Coast Office and Industrial Properties
	1,850,000	Extra Space Storage		34,465
		Self Storage Facilities
	975,000	Post Properties		33,871
		Multifamily Properties
	43,000,000	Mapletree Logistics Trust (Singapore)		27,852
		Industrial Property Landlord
	3,000,000	Education Realty Trust		25,770
		Student Housing
	15,000,000	Ascendas REIT (Singapore)		23,131
		Industrial Property Landlord
	530,000	Macerich		22,594
		Regional Shopping Malls
	700,000	Washington REIT		19,726
		Washington, D.C. Diversified Properties
	3,750,000	DCT Industrial Trust		16,462
		Industrial Properties
	1,000,000	St. Joe (a)(b)		14,990
		Florida Panhandle Landowner
	2,800	Orix JREIT (Japan)		12,867
		Diversified REIT
	3,050,000	Kite Realty Group		11,163
		Community Shopping Centers
	1,500,000	Summit Hotel Properties (c)		10,590
		Owner of Select Service Hotels
	37,407	Security Capital European Realty (Luxembourg) (a)(d)(e)(f)		—
		Self Storage Properties
				562,982
		> Transportation 1.2%
	1,275,000	JB Hunt Transport Services		46,053
		Truck & Intermodal Carrier
	1,260,000	World Fuel Services		41,139
		Global Fuel Broker
	2,800,000	Rush Enterprises, Class A (a)(c)		39,648
	550,000	Rush Enterprises, Class B (a)(c)		6,418
		Truck Sales and Service
	2,730,000	Heartland Express		37,019
		Regional Trucker
	300,000	Genesee & Wyoming (a)		13,956
		Short-line Operator
				184,233

Number of Shares			Value (000)
		> Regulated Utilities 1.1%
	2,000,000	Northeast Utilities	$	67,300
		Regulated Electric Utility
	1,800,000	Wisconsin Energy		56,322
		Wisconsin Utility
	500,000	ALLETE		18,315
		Regulated Electric Utility - Minnesota
	333,000	Red Eléctrica de España (Spain)		15,175
		Spanish Power Transmission
				157,112
Other Industries: Total				904,327
Total Equities: 95.8% (Cost: $10,915,844)				14,510,904
Securities Lending Collateral 2.2%
	333,232,511	Dreyfus Government Cash Management Fund (g) (7 day yield of 0.00%)		333,233
Total Securities Lending Collateral: (Cost: $333,233)				333,233
Total Investments: 98.0% (Cost: $11,249,077)(i)(j)				14,844,137
Obligation to Return Collateral for Securities Loaned: (2.2)%				(333,233	)
Cash and Other Assets Less Liabilities: 4.2%				630,688
Total Net Assets: 100.0%			$	15,141,592

ADR = American Depositary Receipts

GDR = Global Depositary Receipts

Columbia Acorn Fund

Statement of Investments (Unaudited), continued

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

(a) Non-income producing security.

(b) All or a portion of this security was on loan at September 30, 2011. The total market value of securities on loan at September 30, 2011 was $319,697,071.

Affiliates	Balance of Shares Held 12/31/10		Purchases/ Additions		Sales/ Reductions		Balance of Shares Held 9/30/11		Value		Dividend
Acorn Energy		-		1,336,001		-		1,336,001	$	7,107	$	-
AFC Enterprises		2,000,000		-		-		2,000,000		23,660		-
Akorn		2,659,068		2,129,332		-		4,788,400		37,397		-
Allos Therapeutics*		7,035,000		-		7,035,000		-		-		-
Alimera Sciences		361,450		1,678,550		-		2,040,000		16,320		-
Anthera Pharmaceuticals*		1,450,000		290,000		-		1,740,000		8,300		-
Array Biopharma*		3,500,000		-		3,500,000		-		-		-
Art Technology Group*		9,000,000		-		9,000,000		-		-		-
Associated Estates Realty		2,200,000		800,000		-		3,000,000		46,380		1,207
Auxilium Pharmaceuticals		1,200,000		1,200,000		-		2,400,000		35,976		-
Bally Technologies		3,725,000		-		-		3,725,000		100,500		-
Blackbaud		2,250,000		-		-		2,250,000		50,107		540
CAI International		1,650,000		-		526,600		1,123,400		13,166		-
Cavco Industries		180,000		280,000		-		460,000		15,843		-
Cepheid		2,415,000		785,000		-		3,200,000		124,256		-
Chelsea Therapeutics		3,449,900		1,100,000		-		4,549,900		16,607		-
Clarcor*		2,565,000		-		240,000		2,325,000		96,208		1,077
Cogent Communications		2,800,000		-		280,000		2,520,000		33,894		-
Constant Contact		1,400,000		950,000		-		2,350,000		40,631		-
Diamond Foods*		1,300,000		-		250,000		1,050,000		83,779		170
Donaldson		4,200,000		-		-		4,200,000		230,160		1,176
Drew Industries		1,260,000		-		-		1,260,000		25,175		-
Duluth Metals		3,154,000		4,346,000		-		7,500,000		16,533
Education Realty Trust*		3,000,000		-		-		3,000,000		25,770		300
eResearch Technology		4,250,000		650,000		-		4,900,000		21,854		-
ESCO Technologies		2,200,000		-		-		2,200,000		56,100		528
Gaiam		1,371,366		-		-		1,371,366		4,649		-
Gaylord Entertainment		3,850,000		-		-		3,850,000		74,459		-
GLG Life Tech		1,200,000		550,000		-		1,750,000		6,160		-
H&E Equipment Services		3,000,000		400,000		-		3,400,000		28,050		-
Hackett Group		4,500,000		-		-		4,500,000		16,785		-
HEICO+		1,700,000		550,000		-		2,250,000		75,735		237
Helen of Troy		1,600,000		-		-		1,600,000		40,192		-
iGate		2,913,065		407,204		13,065		3,307,204		38,165		-
II-VI+		2,225,000		2,325,000		-		4,550,000		79,625		-
Informatica*		5,200,000		-		500,000		4,700,000		192,465		-
Interline Brands		2,600,000		-		-		2,600,000		33,462		-
IPG Photonics		2,710,000		70,000		-		2,780,000		120,763		-
IXYS		1,900,000		-		-		1,900,000		20,672		-
Kenexa		2,025,000		-		-		2,025,000		31,671		-
Knoll		4,000,000		-		-		4,000,000		54,800		640
Lifetime Fitness		2,190,000		-		-		2,190,000		80,701		-
lululemon athletica+		4,035,000		3,950,000		495,000		7,490,000		364,388		-
Marlin Business Services		1,091,000		-		-		1,091,000		11,565		-
MB Financial		2,860,000		-		-		2,860,000		42,099		57
McGrath Rentcorp		2,350,000		-		200,000		2,150,000		51,149		1,610
Mettler Toledo		1,600,000		-		-		1,600,000		223,936
Micromet		5,500,000		-		-		5,500,000		26,400		-
Nabi Biopharmaceuticals*		1,383,454		1,916,546		3,300,000		-		-		-
Nanosphere*		1,480,056		-		1,480,056		-		-		-
Navigant Consulting		3,100,000		-		100,000		3,000,000		27,810		-
NPS Pharmaceuticals		3,200,000		1,300,000		-		4,500,000		29,295		-
Orko Silver*		10,000,000		-		5,000,000		5,000,000		8,970		-
Orthofix International*		1,150,000		-		580,000		570,000		19,671		-
PAETEC Holding		9,600,000		-		600,000		9,000,000		47,610		-
Pericom Semiconductor		1,765,000		-		-		1,765,000		13,079		-
Petroamerica		30,275,000		-		-		30,275,000		3,322		-

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

Affiliates	Balance of Shares Held 12/31/10		Purchases/ Additions		Sales/ Reductions		Balance of Shares Held 9/30/11		Value		Dividend
Petrodorado		24,000,000		2,000,000		-		26,000,000	$	4,218	$	-
Petrolifera Petroleum*		13,950,000		-		13,950,000		-		-		-
Petromanas		37,500,000		-		-		37,500,000		4,473		-
Pinnacle Entertainment		3,400,000		550,000		-		3,950,000		35,866		-
Quetzal Energy		-		50,000,000		-		50,000,000		2,076		-
Raptor Pharmaceutical		-		3,455,000		-		3,455,000		15,582		-
Rush Enterprises		3,350,000		-		-		3,350,000		46,066		-
Salem Communications		1,541,000		-		7,600		1,533,400		3,511		-
Shutterfly		1,700,000		600,000		-		2,300,000		94,714		-
Spanish Broadcasting System*+		2,400,000		240,000		2,462,300		177,700		295		-
SPS Commerce		856,429		43,571		-		900,000		14,661		-
Summit Hotel Properties		-		1,500,000		-		1,500,000		10,590		230
Supertex		1,035,000		-		390,720		644,280		11,146		-
Talbots*		4,150,000		-		4,150,000		-		-		-
THQ*		3,567,000		-		3,567,000		-		-		-
TriCo Bancshares		1,350,000		-		-		1,350,000		16,564		243
True Religion Apparel		2,047,000		-		300,000		1,747,000		47,099		-
Tuscany International Drilling*		10,719,200		-		1,849,200		8,870,000		4,909		-
tw telecom		9,500,000		-		-		9,500,000		156,940		-
Tyler Technologies		2,000,000		-		300,000		1,700,000		42,976		-
Universal Technical Institute		1,700,000		-		300,000		1,400,000		19,026		-
Virtusa		2,000,000		125,000		-		2,125,000		28,050		-
Warnaco Group		2,190,000		-		-		2,190,000		100,937		-
Wolverine Minerals		-		4,000,000		-		4,000,000		1,299		-
World Acceptance		1,505,202		-		-		1,505,202		84,216		-
Total of Affiliated Transactions		322,039,190		89,527,204		60,376,541		351,189,853	$	3,638,585	$	8,015

* At September 30, 2011, the Fund owned less than five percent of the company's outstanding voting shares.

+ Includes the effects of a stock split.

Additional information on these securities is as follows:

Security	Acquisition Dates	Shares		Cost		Value
Union Agriculture Group	12/08/10		1,136,364	$	15,000	$	12,113
Canadian Overseas Petroleum	11/24/10		8,400,000		3,591		2,474
Quetzal Energy	1/14/11		41,100,000		5,193		1,694
Wolverine Minerals	6/03/11		4,000,000		2,005		1,299
Petrodorado - Warrants	11/20/09		24,000,000		2,965		499
MicroDose Technologies	11/24/00		359,944		2,005		299
Petromanas - Warrants	5/20/10		18,750,000		1,086		263
Canadian Overseas Petroleum - Warrants	11/24/10		4,200,000		526		232
Voyager Learning, Contingent Value Rights	12/24/09		2,000,000		-		180
Duluth Exploration - Special Warrants	8/19/11		500,000		-		95
Wolverine Minerals - Warrants	6/03/11		2,000,000		243		57
Locus Pharmaceuticals	9/05/01-2/08/07		94,715		7,780		-
Security Capital European Realty	8/20/98-7/20/99		37,407		205		-
				$	40,599	$	19,205

(e) Security has no value.

(f) Illiquid security.

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

Columbia Acorn Fund

Statement of Investments (Unaudited), continued

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

(j) On September 30, 2011, the market value of foreign securities represented 9.95% of total net assets. The Fund's foreign portfolio was diversified as follows:

	Value			Percentage of Net Assets
Netherlands	$	305,627			2.02
Canada		246,767			1.63
Singapore		132,171			0.87
Columbia		124,021			0.82
Japan		92,314			0.61
Hong Kong		86,960			0.57
Sweden		67,162			0.44
France		59,455			0.39
United Kingdom		51,244			0.34
China		49,790			0.33
Denmark		43,364			0.29
Brazil		43,249			0.29
South Africa		39,179			0.26
	Value			Percentage of Net Assets
Chile	$	32,176			0.21
Israel		24,280			0.16
India		23,547			0.16
Spain		15,174			0.10
Switzerland		14,164			0.09
Russia		13,444			0.09
Argentina		12,114			0.08
Iraq		10,693			0.07
Iceland		9,943			0.07
Germany		9,533			0.06
Luxembourg		-	*		-
Total Foreign Portfolio	$	1,506,371			9.95

* Rounds to less than $500.

• 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)

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

The following table summarizes the inputs used, as of September 30, 2011, 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	$	3,762,802	$	152,025	$	-	$	3,914,827
Consumer Goods & Services		2,657,746		117,009		180		2,774,935
Industrial Goods & Services		2,393,988		265,573		-		2,659,561
Health Care		1,425,640		21,208		299		1,447,147
Energy & Minerals		1,125,717		270,457		12,209		1,408,383
Finance		1,401,724		-		-		1,401,724
Other Industries		825,304		79,023		-		904,327
Total Equities		13,592,921		905,295		12,688		14,510,904
Total Securities Lending Collateral		333,233		-		-		333,233
Total Investments	$	13,926,154	$	905,295	$	12,688	$	14,844,137

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

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

Transfers In				Tranfers Out
Level 1		Level 2		Level 1		Level 2
$	91,474	$	16,715	$	16,715	$	91,474

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

Financial assets were transferred from Level 2 to Level 1 as resale restrictions expired.

Foreign exchange-traded financial assets were transferred from Level 1 to Level 2.

The following table reconciles asset balances for the nine months ending September 30, 2011, in which significant unobservable inputs (Level 3) were used in determining value:

Investments in Securities	Balance as of December 31, 2010		Realized Gain/(Loss)		Change in Unrealized Appreciation (Depreciation)			Purchases		Sales		Transfers into Level 3		Transfers out of Level 3		Balance as of September 30, 2011
Equities
Consumer Goods & Services	$	262	$	-	$	(82	)	$	-	$	-	$	-	$	-	$	180
Energy & Minerals		15,000		-		(2,887	)		96		-		-		-		12,209
Health Care		103		-		196			-		-		-		-		299
	$	15,365	$	-	$	(2,773	)	$	96	$	-	$	-	$	-	$	12,688

The change in unrealized depreciation attributed to securities owned at September 30, 2011, which were valued using significant unobservable inputs (Level 3) amounted to $2,773.

Columbia Acorn International

Major Portfolio Changes in the Third Quarter (Unaudited)

	Number of Shares
	06/30/11		09/30/11
Purchases
Asia
> Japan
Advance Residence Investment		15,300		16,005
Aeon Delight		1,846,000		1,995,438
Ain Pharmaciez		707,000		751,792
Asahi Diamond Industrial		1,360,000		1,851,900
Daiseki		1,181,200		1,277,429
Fukuoka REIT		2,850		2,874
Glory		977,000		1,055,562
Hamamatsu Photonics		710,000		765,554
Hoshizaki Electric		1,563,000		1,697,200
Ibiden		819,000		883,144
Icom		675,780		732,108
Japan Airport Terminal		1,666,700		2,052,572
Jupiter Telecommunications		24,022		25,979
Kakaku.com		2,870		530,500
Kansai Paint		7,568,400		8,187,600
Kintetsu World Express		868,000		937,651
Kuraray		1,974,000		2,129,100
Misumi Group		0		772,000
Miura		587,800		636,250
Mori Hills REIT Investment		4,458		5,540
Nakanishi		274,000		295,762
Osaka Securities Exchange		5,100		5,531
Park24		0		736,600
Pigeon		439,800		469,500
Seven Bank		21,000		22,694
Shimadzu		2,400,000		2,600,000
Shinsei Bank		23,908,800		25,769,649
Sintokogio		1,794,000		1,940,200
Torishima Pump Manufacturing		1,250,500		1,346,963
Tsumura		789,000		855,604
Ushio		1,292,500		1,405,739
Wacom		23,500		25,380
> Taiwan
Advantech		0		3,458,700
Chroma Ate		0		7,025,500
CTCI Corp		0		9,315,800
Far Eastone Telecom		21,429,000		33,118,800
Formosa International Hotels		1,142,620		1,580,717
Lung Yen		0		510,800
President Chain Store		5,665,000		7,017,009
Radiant Opto-Electronics		0		5,910,000
St. Shine Optical		1,511,000		2,240,000
Taiwan Hon Chuan		6,911,000		11,315,800
Tripod Technologies		0		5,613,270
> Singapore
Ascendas REIT		22,000,000		23,489,149
Goodpack Limited		13,000,000		15,000,000

	Number of Shares
	06/30/11		09/30/11
Mapletree Commercial Trust		30,000,000		32,300,000
Mapletree Industrial Trust REIT		37,010,000		42,675,997
Mapletree Logistics Trust		50,000,000		53,383,000
> Hong Kong
Hutchison Port Holdings Trust		30,000,000		32,000,000
L'Occitane International		8,077,000		15,000,000
Melco International		0		7,419,000
MGM China Holdings		12,000,000		12,500,000
Mongolian Mining		23,335,500		35,923,500
Nagacorp		0		40,438,400
Sasa International		35,000,000		37,703,800
> China
51job - ADR		247,000		263,700
AMVIG Holdings		0		25,695,600
China Yurun Food		10,764,600		12,047,000
Digital China		0		11,165,300
Jiangsu Expressway		23,146,000		23,596,000
Netease.com		0		401,000
New Oriental Education & Technology - ADR		230,000		965,387
Noah Holdings - ADR		432,790		800,000
Want Want		7,143,600		19,410,400
Zhaojin Mining Industry		32,276,000		34,745,554
> India
Asian Paints		320,000		341,652
Infrastructure Development Finance		3,550,000		3,807,700
Jain Irrigation Systems		8,587,418		11,163,303
Manappuram Finance		11,814,746		14,381,649
Mundra Port & Special Economic Zone		7,496,953		8,052,053
REI Agro		30,574,905		32,642,905
S. Kumars Nationwide		9,600,000		10,249,300
Shriram Transport Finance		715,000		767,100
United Breweries		367,138		1,203,445
> South Korea
MegaStudy		121,132		129,332
NHN		150,000		160,150
Woongjin Coway		1,157,000		1,242,590
> Philipines
Int'l Container Terminal		0		7,931,700
Manila Water Company		0		14,299,600
SM Prime Holdings		0		63,272,200
> Thailand
Home Product Center		80,000,000		104,039,000
> Indonesia
Ace Indonesia		6,898,100		8,306,300

	Number of Shares
	06/30/11		09/30/11
Purchases (continued)
Europe
> United Kingdom
Abcam		2,752,210		2,950,000
Archipelago Resources		26,712,371		29,063,787
Chemring		5,437,000		5,700,000
Cobham		5,385,000		5,804,000
Domino's Pizza United Kingdom & Ireland		0		2,497,000
FlyBe		1,376,083		1,499,183
GlobeOp Financial Services		3,758,000		4,155,200
JLT Group		2,868,800		3,644,400
Kesa Electricals		8,346,000		9,009,000
Petropavlovsk		1,976,000		2,109,700
Premier Oil		2,432,000		2,636,932
PureCircle		3,889,000		4,163,948
Rotork		680,000		730,000
Shaftesbury		859,200		1,691,711
Smith and Nephew		1,630,000		1,761,742
Sterling Resources		2,600,000		2,840,000
Tullow Oil		690,000		740,581
> Netherlands
Aalberts Industries		2,296,992		2,479,123
Arcadis		1,164,669		1,252,514
Fugro		784,111		844,967
Imtech		1,841,280		1,955,311
Koninklijke TenCate		1,272,365		1,371,573
Unit 4 Aggresso		1,476,800		1,591,702
Vopak		1,104,200		1,189,424
> France
Eurofins Scientific		489,287		554,800
Gemalto		799,000		1,193,000
Hi-Media		1,689,100		1,831,204
Mersen		541,500		556,874
Neopost		610,000		631,797
Norbert Dentressangle		213,800		232,400
Pierre & Vacances		322,200		322,605
Rubis		274,100		376,131
Saft		902,900		971,800
Teleperformance		1,078,000		1,158,000
> Switzerland
Bank Sarasin & Cie		720,000		773,707
Dufry Group		190,000		286,300
Geberit		185,000		225,650
Kuehne & Nagel		325,000		350,445
Partners Group		235,000		265,000
> Germany
CTS Eventim		403,286		819,889
Deutsche Beteiligungs		312,500		338,886
Dürr		237,511		636,800

	Number of Shares
	06/30/11		09/30/11
Elringklinger		515,000		555,700
Rational		137,500		148,295
Rheinmetall		630,000		679,600
Rhoen-Klinikum		1,460,000		1,600,000
Wirecard		2,120,000		2,286,441
> Sweden
Hexagon		3,799,000		4,056,007
Sweco		3,887,000		4,150,024
Unibet		607,000		658,700
> Italy
Ansaldo STS		2,083,000		2,621,149
CIR		9,796,000		13,547,300
Geox		3,573,000		4,973,000
> Denmark
Novozymes		306,000		329,760
SimCorp		156,000		168,042
> Ireland
Aryzta		297,000		395,008
United Drug		9,669,485		9,700,000
> Czech Republic
Komercni Banka		121,268		130,682
> Portugal
Redes Energéticas Nacionais		7,278,105		7,770,405
> Finland
Stockmann		967,777		1,039,429
> Norway
Atea		2,045,964		2,403,664
> Belgium
EVS Broadcast Equipment		145,031		332,977
> Greece
Intralot		6,475,300		6,954,400
Other Countries
> Canada
AG Growth		540,000		582,942
Alliance Grain Traders		501,700		754,800
Baytex		574,000		615,857
Black Diamond Group		546,500		1,189,576
CCL Industries		1,301,612		1,403,772
Celtic Exploration		146,200		505,000
Crew Energy		367,600		678,000
DeeThree Exploration		3,738,877		4,061,377
Eacom Timber		12,500,000		13,000,000
Horizon North Logistics		2,214,100		2,411,514
Ivanhoe Mines		1,833,100		1,964,621
Onex Capital		605,000		653,200

Columbia Acorn International

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

	Number of Shares
	06/30/11		09/30/11
Purchases (continued)
Other Countries—continued
> Canada—continued
Pan Orient		1,480,610		1,607,306
ShawCor		1,710,000		1,790,397
Southern Arc Minerals		5,737,500		6,217,500
Tahoe Resources		872,700		963,600
> United States
Alexion Pharmaceuticals		822,000		887,431
Atwood Oceanics		1,273,000		1,373,080
BioMarin Pharmaceutical		1,145,000		1,229,871
Bristow		391,000		421,732
FMC Technologies		658,000		707,213
Oil States International		250,000		270,000
Textainer Group Holdings		568,000		838,297
World Fuel Services		918,000		987,228
> South Africa
Adcock Ingram Holdings		4,625,000		4,992,200
Coronation Fund Managers		8,723,060		10,271,492
Massmart Holdings		0		1,019,988
Naspers		1,096,000		1,170,188
Northam Platinum		5,780,900		6,463,160
Rand Merchant Insurance		17,625,208		19,098,300
> Autstralia
Cochlear		467,000		498,560
UGL		2,482,000		2,653,389
> Israel
Israel Chemicals		2,890,000		3,085,527
> Senegal
Sonatel		43,000		45,237
Latin America
> Brazil
Mills Estruturas e Servicos de Engenharia		3,000,000		3,184,900
MRV Engenharia		3,400,000		3,634,800
Multiplus		1,100,000		1,179,000
Suzano - Preferred		5,937,000		6,344,043
> Mexico
Grupo Aeroportuario del Sureste - ADR		580,000		624,168
> Chile
Sociedad Quimica y Minera de Chile - ADR		340,000		362,996
> Argentina
Madalena Ventures		5,400,000		5,940,000
> Colombia
Canacol Energy		8,240,000		8,893,869
Gulf United		20,718,000		22,525,000

	Number of Shares
	06/30/11		09/30/11
Sales
Asia
> Japan
Aeon Mall		906,000		880,474
Asics		3,650,000		2,116,900
Gree		1,355,000		1,139,000
Kamigumi		3,283,000		634,794
Makita		509,000		0
Nippon Sheet Glass		7,174,000		6,107,300
Start Today		1,275,000		938,400
> Taiwan
China Steel Chemical		4,192,000		2,748,000
Everlight Electronics		7,206,000		0
Simplo Technology		5,821,000		3,678,530
Sinyi Realty		2,211,000		1,211,280
> Singapore
CDL Hospitality Trust		23,000,000		21,890,000
Olam International		35,981,000		33,000,000
Singapore Exchange		4,000,000		3,500,000
> Hong Kong
Hong Kong Exchanges and Clearing		750,000		0
Lifestyle International		18,000,000		17,000,000
> China
China Communication Services		41,959,300		0
ENN Energy		6,000,000		5,000,000
RexLot Holdings		240,000,000		239,160,800
Shandong Weigao		11,286,200		0
Wasion Group		24,244,400		8,479,200
Zuoan Fashion		680,503		265,146
Europe
> United Kingdom
Intertek Group		2,000,000		1,853,000
Next		582,000		446,300
Serco		3,513,800		3,305,000
Workspace Group		56,093,000		8,028,385
> Netherlands
Core Laboratories		249,000		228,095
USG People		1,093,994		454,772
> Switzerland
Sika		22,300		19,251
> Germany
Vossloh		165,000		0
> Sweden
Orc Software		708,342		140,068

	Number of Shares
	06/30/11		09/30/11
Sales (continued)
Europe—continued
> Italy
Credito Emiliano		4,311,600		0
Terna		4,111,000		0
Tod's		257,200		155,200
> Ireland
Paddy Power		359,000		350,000
> Spain
Red Eléctrica de España		579,000		494,320
> Portugal
Banco Comercial Português		22,568,987		0
> Finland
Poyry		410,523		409,248
> Russia
Mail.ru - GDR		764,506		629,642
> Poland
Central European Distribution		893,900		0
Other Countries
> Canada
Guyana Goldfields		1,291,135		0
> South Africa
Mr. Price		4,600,000		3,722,083
> Autstralia
SAI Global		6,281,896		5,806,600
Seek		1,000,000		0
> Egypt
Paints & Chemical Industries (Pachin)		235,342		0
Latin America
> Brazil
Localiza Rent A Car		4,300,000		4,200,000
Natura		1,300,000		0
PDG Realty		4,400,000		0

Columbia Acorn International

Statement of Investments (Unaudited), September 30, 2011

Number of Shares			Value (000)
			Equities: 96.4%
Asia 41.6%
		> Japan 18.6%
	8,187,600	Kansai Paint	$	78,460
		Paint Producer in Japan, India, China and Southeast Asia
	22,694	Seven Bank		44,294
		ATM Processing Services
	1,995,438	Aeon Delight		42,826
		Facility Maintenance & Management
	1,697,200	Hoshizaki Electric		41,348
		Commercial Kitchen Equipment
	7,780	Orix JREIT		35,750
		Diversified REIT
	1,139,000	Gree		34,736
		Mobile Social Networking Game Developer/Platform
	751,792	Ain Pharmaciez		33,127
		Dispensing Pharmacy/Drugstore Operator
	765,554	Hamamatsu Photonics		30,857
		Optical Sensors for Medical & Industrial Applications
	2,052,572	Japan Airport Terminal		30,534
		Airport Terminal Operator at Haneda
	25,380	Wacom (a)		29,747
		Computer Graphic Illustration Devices
	2,129,100	Kuraray		29,037
		Special Resin, Fine Chemical, Fibers & Textures
	16,005	Advance Residence Investment		28,992
		Residential REIT
	25,769,649	Shinsei Bank		28,965
		Commercial Bank
	2,116,900	Asics		28,905
		Footwear and Apparel
	25,979	Jupiter Telecommunications		28,110
		Largest Cable Service Provider in Japan
	855,604	Tsumura		27,280
		Traditional Chinese/Japanese Herbal Rx Drugs (Kampo)
	295,762	Nakanishi		26,991
		Dental Tools & Machinery
	937,651	Kintetsu World Express		26,818
		Airfreight Logistics
	1,851,900	Asahi Diamond Industrial		25,760
		Consumable Diamond Tools
	5,531	Osaka Securities Exchange (b)		25,348
		Osaka Securities Exchange
	1,277,429	Daiseki		25,279
		Waste Disposal and Recycling
	1,055,562	Glory		24,813
		Currency Handling Systems & Related Equipment
	2,600,000	Shimadzu		21,932
		Analytical Instrument, Medical & Industrial Equipment
	530,500	Kakaku.com		21,776
		Online Price Comparison Services for Consumers

Number of Shares			Value (000)
	1,405,739	Ushio	$	21,401
		Industrial Light Sources
	938,400	Start Today		20,333
		Online Japanese Apparel Retailer
	880,474	Aeon Mall		20,112
		Suburban Shopping Mall Developer, Owner & Operator
	469,500	Pigeon		19,247
		Baby Care Products
	1,940,200	Sintokogio		18,987
		Automated Casting Machines, Surface Treatment System and Consumables
	1,346,963	Torishima Pump Manufacturing (b)		18,918
		Industrial Pump for Power Generation and Water Supply Systems
	732,108	Icom		18,767
		Two Way Radio Communication Equipment
	2,874	Fukuoka REIT		18,677
		Diversified REIT in Fukuoka
	883,144	Ibiden		18,663
		Electronic Parts & Ceramics
	5,540	Mori Hills REIT Investment		18,639
		Tokyo-centric Diversified REIT
	636,250	Miura		18,629
		Industrial Boiler
	772,000	Misumi Group		17,156
		Industrial Components Distributor
	6,107,300	Nippon Sheet Glass		13,664
		Sheet Glass for Building and Automotive Use
	736,600	Park24		9,155
		Parking Lot Operator
	634,794	Kamigumi		5,666
		Port Cargo Handling & Logistics
				1,029,699
		> Taiwan 4.8%
	33,118,800	Far Eastone Telecom		48,967
		Taiwan's 3rd Largest Mobile Operator
	7,017,009	President Chain Store		39,519
		Taiwan's Number One Convenience Chain Store Operator
	2,240,000	St. Shine Optical		27,343
		World's Leading Disposable Contact Lens OEM
	11,315,800	Taiwan Hon Chuan		24,014
		Beverage Packaging (bottles, caps, labels) Manufacturer
	3,678,530	Simplo Technology		22,593
		Battery Packs for Notebook & Tablet PCs
	1,580,717	Formosa International Hotels		21,529
		Hotel, Food & Beverage Operation & Hospitality Management Services
	5,910,000	Radiant Opto-Electronics		16,578
		LCD Back Light Modules
	5,613,270	Tripod Technologies		14,622
		Printed Circuit Boards
	7,025,500	Chroma Ate		14,396
		Automatic Test Systems, Testing & Measurement Instruments

Number of Shares			Value (000)
		> Taiwan—continued
	2,748,000	China Steel Chemical	$	11,403
		Sole Coal Chemical Producer in Taiwan
	9,315,800	CTCI Corp		11,144
		International Engineering Firm
	3,458,700	Advantech		9,085
		Industrial PC & Components
	1,211,280	Sinyi Realty		1,560
		Taiwanese Realty Company
	510,800	Lung Yen		1,224
		Funeral Services and Columbaria
				263,977
		> Singapore 4.4%
	33,000,000	Olam International		56,234
		Agriculture Supply Chain Manager
	23,489,149	Ascendas REIT		36,221
		Industrial Property Landlord
	42,675,997	Mapletree Industrial Trust REIT		35,113
		Industrial Property Landlord
	53,383,000	Mapletree Logistics Trust		34,577
		Industrial Property Landlord
	21,890,000	CDL Hospitality Trust		25,144
		Hotel Owner/Operator
	32,300,000	Mapletree Commercial Trust		19,994
		Retail and Office Property Landlord
	3,500,000	Singapore Exchange		17,593
		Singapore Equity & Derivatives Market Operator
	15,000,000	Goodpack Limited		17,312
		International Bulk Container Leasing
				242,188
		> Hong Kong 4.3%
	7,000,000	Melco Crown Entertainment - ADR (c)		58,170
		Macau Casino Operator
	17,000,000	Lifestyle International		43,129
		Mid to High-End Department Store Operator in Hong Kong & China
	35,923,500	Mongolian Mining (c)		31,761
		Coking Coal Mining in Mongolia
	15,000,000	L'Occitane International (c)		30,213
		Skin Care and Cosmetics Producer
	37,703,800	Sasa International		22,358
		Cosmetics Retailer
	32,000,000	Hutchison Port Holdings Trust		21,360
		Southern China Container Ports
	12,500,000	MGM China Holdings (c)		16,565
		Macau Casino Operator
	40,438,400	Nagacorp		8,629
		Casino/Entertainment Complex in Cambodia
	7,419,000	Melco International		4,857
		Macau Casino Operator
				237,042
		> China 4.0%
	34,745,554	Zhaojin Mining Industry		57,798
		Gold Mining and Refining in China
	965,387	New Oriental Education & Technology - ADR (c)		22,175
		Education Service Provider

Number of Shares			Value (000)
	23,596,000	Jiangsu Expressway	$	17,821
		Chinese Toll Road Operator
	19,410,400	Want Want		17,579
		Chinese Branded Consumer Food Company
	5,000,000	ENN Energy		16,175
		China's Largest Private Gas Operator
	401,000	Netease.com		15,302
		Chinese Online Gaming Services
	11,165,300	Digital China		14,615
		IT Distribution & Systems Integration Services
	25,695,600	AMVIG Holdings		14,483
		Chinese Tobacco Packaging Material Supplier
	239,160,800	RexLot Holdings		14,216
		Lottery Equipment Supplier in China
	12,047,000	China Yurun Food		12,742
		Meat Processor in China
	263,700	51job - ADR (b)(c)		10,522
		Integrated Human Resource Services
	800,000	Noah Holdings - ADR (b)		7,360
		Wealth Management Product Distributor in China
	8,479,200	Wasion Group		2,449
		Electronic Power Meter Total Solution Provider
	265,146	Zuoan Fashion (b)(c)		729
		Men's Apparel Provider in China
				223,966
		> India 2.7%
	11,163,303	Jain Irrigation Systems		34,573
		Agricultural Micro-Irrigation Systems & Food Processing
	8,052,053	Mundra Port & Special Economic Zone		26,906
		Indian West Coast Shipping Port
	341,652	Asian Paints		21,990
		India's Largest Paint Company
	32,642,905	REI Agro		16,480
		Basmati Rice Processing
	14,381,649	Manappuram Finance		15,262
		Short-term Lending Collateralized by Household Gold
	767,100	Shriram Transport Finance		9,529
		Used Truck Finance
	1,203,445	United Breweries (c)		9,150
		India's Largest Brewer
	10,249,300	S. Kumars Nationwide		8,711
		Textiles, Clothing & Retail
	3,807,700	Infrastructure Development Finance		8,552
		Infrastructure Finance in India
				151,153
		> South Korea 1.5%
	1,242,590	Woongjin Coway		40,009
		South Korean Household Appliance Rental Service Provider
	160,150	NHN (c)		30,511
		Korean Online Search Services
	129,332	MegaStudy		12,973
		Education Service Provider
				83,493

Columbia Acorn International

Statement of Investments (Unaudited), continued

Number of Shares			Value (000)
		> Philipines 0.6%
	63,272,200	SM Prime Holdings	$	17,578
		Shopping Mall Operator
	7,931,700	Int'l Container Terminal		8,415
		Container Handling Terminals & Port Management
	14,299,600	Manila Water Company		6,190
		Water Utility Company in the Philippines
				32,183
		> Thailand 0.6%
	104,039,000	Home Product Center		31,099
		Home Improvement Retailer
				31,099
		> Indonesia 0.1%
	8,306,300	Ace Indonesia		3,105
		Home Improvement Retailer
				3,105
Asia: Total				2,297,905
Europe 35.3%
		> United Kingdom 7.7%
	1,853,000	Intertek Group		53,294
		Testing, Inspection, Certification Services
	5,700,000	Chemring		46,669
		Defense Manufacturer of Countermeasures and Energetics
	3,644,400	JLT Group (b)		35,688
		International Business Insurance Broker
	29,063,787	Archipelago Resources (a)(c)		31,066
		Gold Mining Projects in Indonesia, Vietnam, and the Philippines
	8,028,385	Workspace Group (a)		26,965
		United Kingdom Real Estate
	3,305,000	Serco		26,146
		Facilities Management
	2,109,700	Petropavlovsk		19,401
		Gold and Iron Ore Mining in Russia
	4,155,200	GlobeOp Financial Services		18,726
		Hedge Fund Administrator
	730,000	Rotork		17,570
		Valve Actuators for Oil & Water Pipelines
	446,300	Next		17,497
		Clothes and Home Retailer in the United Kingdom
	2,497,000	Domino's Pizza United Kingdom & Ireland		17,216
		Pizza Delivery in United Kingdom, Ireland and Germany
	2,950,000	Abcam (c)		16,676
		Online Sales of Antibodies
	1,761,742	Smith and Nephew		15,848
		Medical Equipment & Supplies
	5,804,000	Cobham		15,711
		Aerospace Components
	740,581	Tullow Oil		14,978
		Oil and Gas Producer
	2,636,932	Premier Oil (c)		14,176
		Oil and Gas Producer in Europe, Pakistan and Asia

Number of Shares			Value (000)
	1,691,711	Shaftesbury	$	12,221
		London Prime Retail REIT
	9,009,000	Kesa Electricals		11,704
		Europe's Leading Electricals Retailers
	4,163,948	PureCircle (c)		5,790
		Natural Sweeteners
	1,650,000	SKIL Ports and Logistics (c)		3,782
		Indian Container Port Project
	1,499,183	FlyBe (c)		2,665
		Largest European Regional Airline
	1,692,525	Sterling Resources (c)		1,599
	1,147,475	Sterling Resources (c)(d)		1,062
		Oil & Gas Exploration - Europe
				426,450
		> Netherlands 5.8%
	1,189,424	Vopak		56,848
		World's Largest Operator of Petroleum and Chemical Storage Terminals
	1,955,311	Imtech		55,001
		Electromechanical and ICT Installation and Maintenance
	844,967	Fugro		42,613
		Sub-sea Oilfield Services
	1,371,573	Koninklijke TenCate (a)		42,153
		Advanced Textiles and Industrial Fabrics
	1,591,702	Unit 4 Aggresso (a)		38,867
		Business Software Development
	2,479,123	Aalberts Industries		36,859
		Flow Control and Heat Treatment
	1,252,514	Arcadis		22,864
		Engineering Consultants
	228,095	Core Laboratories (b)		20,490
		Oil and Gas Reservoir Consulting
	454,772	USG People		3,766
		Temporary Staffing Services
				319,461
		> France 5.0%
	1,193,000	Gemalto		56,731
		Digital Security Solutions
	631,797	Neopost		46,327
		Postage Meter Machines
	554,800	Eurofins Scientific		41,935
		Food, Pharmaceuticals and Materials Screening and Testing
	971,800	Saft		26,097
		Niche Battery Manufacturer
	1,158,000	Teleperformance		24,600
		Call Center Operator
	556,874	Mersen		22,040
		Advanced Industrial Materials
	376,131	Rubis		18,947
		Tank Storage and LPG Distribution
	232,400	Norbert Dentressangle		17,861
		Leading European Logistics and Transport Group
	322,605	Pierre & Vacances		12,839
		Vacation Apartment Lets

Number of Shares			Value (000)
		> France—continued
	1,831,204	Hi-Media (b)(c)	$	5,935
		Online Advertiser in Europe
				273,312
		> Switzerland 3.8%
	265,000	Partners Group		43,634
		Private Markets Asset Management
	225,650	Geberit (c)		41,664
		Plumbing Supplies
	350,445	Kuehne & Nagel		39,331
		Freight Forwarding/Logistics
	19,251	Sika		34,085
		Chemicals for Construction & Industrial Applications
	286,300	Dufry Group (c)		25,029
		Operates Airport Duty Free and Duty Paid Shops
	773,707	Bank Sarasin & Cie		23,657
		Private Banking
				207,400
		> Germany 3.6%
	2,286,441	Wirecard		34,980
		Online Payment Processing & Risk Management
	148,295	Rational		33,290
		Commercial Ovens
	1,600,000	Rhoen-Klinikum		32,400
		Health Care Services
	679,600	Rheinmetall		31,877
		Defense & Automotive
	819,889	CTS Eventim		24,424
		Event Ticket Sales
	636,800	Dürr		20,520
		Automotive Plant Engineering & Associated Capital Equipment
	555,700	Elringklinger (b)		12,992
		Automobile Components
	338,886	Deutsche Beteiligungs		6,753
		Private Equity Investment Management
				197,236
		> Sweden 1.9%
	4,056,007	Hexagon		52,741
		Design, Measurement and Visualization Software and Equipment
	4,150,024	Sweco (a)		34,311
		Engineering Consultants
	658,700	Unibet (c)		12,388
		European Online Gaming Operator
	905,452	East Capital Explorer		6,920
		Sweden-Based RUS/CEE Investment Fund
	140,068	Orc Software (b)		941
		Software for Securities Trading, Analysis and Risk Management
				107,301
		> Italy 1.5%
	2,621,149	Ansaldo STS		26,050
		Railway Systems Integrator
	13,547,300	CIR		25,470
		Italian Holding Company

Number of Shares			Value (000)
	4,973,000	Geox	$	18,105
		Apparel and Shoe Maker
	155,200	Tod's		13,093
		Leather Shoes and Bags
				82,718
		> Denmark 1.3%
	329,760	Novozymes		46,885
		Industrial Enzymes
	168,042	SimCorp		24,107
		Software for Investment Managers
				70,992
		> Ireland 1.2%
	9,700,000	United Drug		29,701
		Irish Pharmaceutical Wholesaler & Outsourcer
	350,000	Paddy Power		18,020
		Irish Betting Services
	395,008	Aryzta		16,743
		Baked Goods
				64,464
		> Iceland 0.7%
	35,982,499	Marel (c)		35,777
		Largest Manufacturer of Poultry and Fish Processing Equipment
				35,777
		> Czech Republic 0.4%
	130,682	Komercni Banka		24,237
		Leading Czech Universal Bank
				24,237
		> Spain 0.4%
	494,320	Red Eléctrica de España		22,525
		Spanish Power Transmission
				22,525
		> Portugal 0.4%
	7,770,405	Redes Energéticas Nacionais		21,838
		Portuguese Power Transmission and Gas Transportation
				21,838
		> Finland 0.4%
	1,039,429	Stockmann (b)		17,483
		Department Store and Fashion Retailer in Scandinavia and Russia
	409,248	Poyry		3,206
		Engineering Consultants
				20,689
		> Norway 0.3%
	2,403,664	Atea		19,065
		Leading Nordic IT Hardware/Software Reseller and Installation Company
				19,065
		> Russia 0.3%
	629,642	Mail.ru - GDR (c)(f)		18,231
		Internet Social Networking and Games for Russian Speakers
				18,231

Columbia Acorn International

Statement of Investments (Unaudited), continued

Number of Shares			Value (000)
		> Belgium 0.3%
	332,977	EVS Broadcast Equipment	$	17,220
		Digital Live Mobile Production Software and Systems
				17,220
		> Kazakhstan 0.2%
	1,770,000	Halyk Savings Bank of Kazakhstan (c)		10,976
		Largest Retail Bank and Insurer in Kazakhstan
				10,976
		> Greece 0.1%
	6,954,400	Intralot		7,993
		Lottery and Gaming Systems and Services
				7,993
Europe: Total				1,947,885
Other Countries 15.5%
		> Canada 4.8%
	1,790,397	ShawCor		41,569
		Oil and Gas Pipeline Products
	1,403,772	CCL Industries		37,415
		Leading Global Label Manufacturer
	615,857	Baytex (b)(c)		25,747
		Oil and Gas Producer in Canada
	582,942	AG Growth		20,844
		Leading Manufacturer of Augers and Grain Handling Equipment
	653,200	Onex Capital		20,358
		Private Equity
	754,800	Alliance Grain Traders		16,063
		Global Leader in Pulse Processing and Distribution
	1,189,576	Black Diamond Group		15,382
		Provides Accommodations/Equipment for Oil Sands Development
	1,049,943	Ivanhoe Mines (c)		14,478
	914,678	Ivanhoe Mines (c)(g)		12,531
		Copper Mine Project in Mongolia
	963,600	Tahoe Resources (c)		13,885
		Silver Project in Guatemala
	505,000	Celtic Exploration (c)		10,877
		Canadian Oil and Gas Producer
	2,411,514	Horizon North Logistics		9,044
		Provides Diversified Oil Service Offering in Northern Canada
	2,919,000	DeeThree Exploration (a)(c)(d)		6,251
	1,142,377	DeeThree Exploration (a)(c)		2,497
		Canadian Oil and Gas Producer
	678,000	Crew Energy (c)		6,004
		Canadian Oil and Gas Producer
	6,217,500	Southern Arc Minerals (a)(c)(d)		5,350
		Gold and Copper Exploration in Indonesia
	1,607,306	Pan Orient (c)		3,574
		Pan Orient is Growth Oriented, Return Focused Asian Explorer
	12,500,000	Petromanas (c)		1,491
	6,250,000	Petromanas - Warrants (c)(d)		88
		Exploring for Oil in Albania

Number of Shares			Value (000)
	13,000,000	Eacom Timber (c)	$	1,241
		Canadian Lumber Producer
				264,689
		> United States 4.6%
	887,431	Alexion Pharmaceuticals (c)		56,849
		Biotech Focused on Orphan Diseases
	1,373,080	Atwood Oceanics (c)		47,179
		Offshore Drilling Contractor
	1,229,871	BioMarin Pharmaceutical (c)		39,196
		Biotech Focused on Orphan Diseases
	987,228	World Fuel Services		32,233
		Global Fuel Broker
	707,213	FMC Technologies (c)		26,591
		Oil and Gas Well Head Manufacturer
	421,732	Bristow		17,894
		Largest Provider of Helicopter Services to Offshore Oil and Gas Producers
	838,297	Textainer Group Holdings		17,001
		Top International Container Leasor
	270,000	Oil States International (c)		13,748
		Diversified North American Oil Service Provider
				250,691
		> South Africa 3.9%
	1,170,188	Naspers		50,535
		Media in Africa, China, Russia, and Other Emerging Markets
	4,992,200	Adcock Ingram Holdings		37,021
		Manufacturer of Pharmaceuticals and Medical Supplies
	3,722,083	Mr. Price		30,847
		South African Retailer of Apparel, Household and Sporting Goods
	19,098,300	Rand Merchant Insurance		29,575
		Directly Sold Property and Casualty Insurance; Holdings in Other Insurers
	6,463,160	Northam Platinum		26,207
		Platinum Mining in South Africa
	10,271,492	Coronation Fund Managers		25,354
		South African Fund Manager
	1,019,988	Massmart Holdings		17,460
		General Merchandise, Food, and Home Improvement Stores; Wal-Mart Subsidiary
				216,999
		> Australia 1.4%
	2,653,389	UGL		29,009
		Engineering and Facilities Management
	5,806,600	SAI Global		26,419
		Publishing, Certification, Compliance Services
	498,560	Cochlear		22,101
		Cochlear Implants
				77,529
		> Israel 0.6%
	3,085,527	Israel Chemicals		35,139
		Producer of Potash, Phosphates, Bromine, and Specialty Chemicals
				35,139

Number of Shares			Value (000)
		> Senegal 0.2%
	45,237	Sonatel	$	11,272
		Leading Telecoms Operator in Western Africa
				11,272
Other Countries: Total				856,319
Latin America 4.0%
		> Brazil 2.7%
	4,200,000	Localiza Rent A Car		55,419
		Car Rental
	3,184,900	Mills Estruturas e Servicos de Engenharia		29,829
		Civil Engineering & Construction
	6,344,043	Suzano - Preferred		28,578
		Brazilian Pulp and Paper Producer
	3,634,800	MRV Engenharia		18,520
		Brazilan Property Developer
	1,179,000	Multiplus		17,018
		Loyalty Program Operator in Brazil
				149,364
		> Mexico 0.5%
	624,168	Grupo Aeroportuario del Sureste - ADR		31,034
		Mexican Airport Operator
				31,034
		> Chile 0.3%
	362,996	Sociedad Quimica y Minera de Chile - ADR		17,355
		Producer of Specialty Fertilizers, Lithium and Iodine
				17,355
		> Argentina 0.3%
	1,136,364	Union Agriculture Group (c)(d)(e)		12,114
		Farmland Operator in Uruguay
	5,940,000	Madalena Ventures (c)(d)		2,666
		Oil and Gas Exploration in Argentina
				14,780
		> Colombia 0.2%
	8,893,869	Canacol Energy (c)		5,432
		Oil Producer in South America
	22,525,000	Gulf United (c)(d)		4,973
		Prospecting for Oil Alongside Large Producers in Colombia
				10,405
Latin America: Total				222,938
Total Equities: 96.4% (Cost: $4,746,140)				5,325,047

Number of Shares			Value (000)
		Securities Lending Collateral 0.9%
	47,260,372	Dreyfus Government Cash Management Fund (h) (7 day yield of 0.00%)	$	47,260
Total Securities Lending Collateral: (Cost: $47,260)				47,260
Total Investments: 97.3% (Cost: $4,793,400)(i)(j)				5,372,307
Obligation to Return Collateral for Securities Loaned: (0.9)%				(47,260	)
Cash and Other Assets Less Liabilities: 3.6%				198,718
Total Net Assets: 100.0%			$	5,523,765

ADR = American Depositary Receipts

GDR = Global Depositary Receipts

Columbia Acorn International

Statement of Investments (Unaudited), continued

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

Affiliates	Balance of Shares Held 12/31/10		Purchases/ Additions		Sales/ Reductions		Balance of Shares Held 9/30/11		Value		Dividend
Archipelago Resources		24,346,593		4,717,194		-		29,063,787	$	31,066	$	-
DeeThree Exploration		2,392,877		1,668,500		-		4,061,377		8,748		-
Gulf United*		-		22,525,000		-		22,525,000		4,973		-
Koninklijke TenCate		1,240,557		131,016		-		1,371,573		42,153		-
Southern Arc Minerals		-		6,217,500		-		6,217,500		5,350		-
Sweco		3,887,000		263,024		-		4,150,024		34,311		1,617
Unit 4 Aggresso		1,476,800		114,902		-		1,591,702		38,867		450
United Drug*		12,110,000		737,752		3,147,752		9,700,000		29,701		1,371
Wacom		20,900		4,480		-		25,380		29,747		721
Workspace Group+		60,304,000		640,600		52,916,215		8,028,385		26,965		522
Total of Affiliated Transactions		105,778,727		37,019,968		56,063,967		86,734,728	$	251,881	$	4,681

* At September 30, 2011, the Fund owned less than five percent of the company's outstanding voting shares.

+ Includes the effects of a corporate action.

(b) All or a portion of this security was on loan at September 30, 2011. The total market value of securities on loan at September 30, 2011 was $43,849,295.

Additional information on these securities is as follows:

Security	Acquisition Dates	Shares		Cost		Value
Union Agriculture Group	12/08/10		1,136,364	$	15,000	$	12,114
DeeThree Exploration	9/07/10-3/08/11		2,919,000		10,228		6,251
Southern Arc Minerals	2/16/11		6,217,500		10,087		5,350
Gulf United Energy	2/11/11		22,525,000		6,758		4,973
Madalena Ventures	10/21/10		5,940,000		3,764		2,666
Sterling Resources	12/02/10		1,147,475		3,425		1,062
Petromanas - Warrants	5/20/10		6,250,000		362		88
				$	49,624	$	32,504

(e) Illiquid security.

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

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

(j) On September 30, 2011, the Fund's total investments were denominated in currencies as follows:

Currency	Value		Percentage of Net Assets
Japanese Yen	$	1,029,699		18.6
Euro		1,006,966		18.2
U.S. Dollar		514,013		9.3
British Pound		423,789		7.7
Hong Kong Dollar		325,390		5.9
Other currencies less
than 5% of total net assets		2,072,450		40.3
	$	5,372,307		100.0

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

At September 30, 2011, the Fund had entered into the following forward foreign currency exchange contracts:

Forward Foreign Currency Exchange Contracts to Buy	Forward Foreign Currency Exchange Contracts to Sell	Principal Amount in Foreign Currency		Principal Amount in U.S. Dollar		Settlement Date	Unrealized Appreciation (Depreciation)
USD	EUR		56,462	$	79,721	10/14/11	$	4,082
USD	EUR		55,878		79,551	11/15/11		4,708
USD	EUR		58,431		80,000	12/15/11		1,742
AUD	USD		33,213		35,227	10/14/11		(3,130	)
AUD	USD		4,379		4,500	10/14/11		(268	)
AUD	USD		38,997		39,936	11/15/11		(2,405	)
AUD	USD		39,571		40,000	12/15/11		(2,045	)
CAD	USD		38,103		39,646	10/14/11		(3,294	)
CAD	USD		39,685		39,996	11/15/11		(2,164	)
CAD	USD		39,741		40,000	12/15/11		(2,136	)
				$	478,577		$	(4,910	)

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

AUD = Australian Dollar

CAD = Canadian Dollar

EUR = Euro

USD = United States Dollar

• 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)

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

The following table summarizes the inputs used, as of September 30, 2011, 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	$	114,258	$	2,183,647		$	-	$	2,297,905
Europe		22,089		1,925,796			-		1,947,885
Other Countries		503,692		352,627			-		856,319
Latin America		203,185		7,639			12,114		222,938
Total Equities		843,224		4,469,709			12,114		5,325,047
Total Securities Lending Collateral		47,260		-			-		47,260
Total Investments	$	890,484	$	4,469,709		$	12,114	$	5,372,307
Unrealized Appreciation on Forward Foreign Currency Contracts		-		10,532			-		10,532
Unrealized Depreciation on Forward Foreign Currency Contracts		-		(15,442	)		-		(15,442	)
Total	$	890,484	$	4,464,799		$	12,114	$	5,367,397

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 sales price on the foreign exchange or market on which they trade. The Fund may use a systematic fair valuation model 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

Columbia Acorn International

Statement of Investments (Unaudited), continued

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

same shares that are trading freely on the market. These discounts are determined by the adviser'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
$	214,727	$	22,667	$	22,667	$	214,727

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

Financial assets were transferred from Level 2 to Level 1 as resale restrictions expired.

Foreign exchange-traded financial assets were transferred from Level 1 to Level 2.

The following table reconciles asset balances for the nine months ending September 30, 2011, in which significant unobservable inputs (Level 3) were used in determining value:

Investments in Securities	Balance as of December 31, 2010		Realized Gain/(Loss)			Change in Unrealized Appreciation (Depreciation)			Purchases		Sales		Transfers into Level 3		Transfers out of Level 3		Balance as of September 30, 2011
Equities
Asia	$	79	$	(38,558	)	$	38,479		$	-	$	-	$	-	$	-	$	-
Latin America		15,000		-			(2,886	)		-		-		-		-		12,114
	$	15,079	$	(38,558	)	$	35,593		$	-	$	-	$	-	$	-	$	12,114

The change in unrealized depreciation attributed to securities owned at September 30, 2011, which were valued using significant unobservable inputs (Level 3) amounted to $2,886.

Columbia Acorn International

Portfolio Diversification (Unaudited)

At September 30, 2011, the Fund's portfolio investments as a percentage of net assets were diversified as follows:

	Value (000)		Percentage of Net Assets
> Industrial Goods & Services
Other Industrial Services	$	513,117		9.3
Industrial Materials & Specialty Chemicals		403,700		7.3
Machinery		391,682		7.1
Electrical Components		109,878		2.0
Construction		82,637		1.5
Conglomerates		80,992		1.5
Outsourcing Services		29,912		0.5
Industrial Distribution		17,312		0.3
		1,629,230		29.5
> Consumer Goods & Services
Retail		260,486		4.7
Food & Beverage		151,736		2.8
Casinos & Gaming		140,838		2.6
Nondurables		99,968		1.8
Other Consumer Services		96,444		1.7
Apparel		73,933		1.3
Travel		70,923		1.3
Other Entertainment		45,953		0.8
Educational Services		35,148		0.6
Restaurants		17,216		0.3
Consumer Goods Distribution		11,704		0.2
		1,004,349		18.1
> Information
Computer Hardware & Related Equipment		149,356		2.7
Internet Related		136,355		2.5
Business Software		132,935		2.4
Mobile Communications		67,734		1.2
Instrumentation		67,185		1.2
Financial Processors		52,573		1.0
Telephone and Data Services		35,872		0.6
Gaming Equipment & Services		34,736		0.6
CATV		28,110		0.5
Computer Services		20,006		0.4
Electronics Distribution		14,615		0.3
Advertising		5,935		0.1
		745,412		13.5

	Value (000)			Percentage of Net Assets
> Energy & Minerals
Mining	$	232,967			4.2
Oil Services		214,020			3.9
Oil & Gas Producers		101,415			1.8
Oil Refining, Marketing & Distribution		75,795			1.4
Agricultural Commodities		57,996			1.1
		682,193			12.4
> Other Industries
Real Estate		328,391			6.0
Transportation		135,149			2.4
Regulated Utilities		66,728			1.2
		530,268			9.6
> Finance
Brokerage & Money Management		125,044			2.3
Banks		117,024			2.1
Finance Companies		94,858			1.7
Insurance		65,263			1.2
		402,189			7.3
> Health Care
Medical Equipment & Devices		121,789			2.2
Pharmaceuticals		94,002			1.7
Medical Supplies		44,019			0.8
Biotechnology & Drug Delivery		39,196			0.7
Health Care Services		32,400			0.6
		331,406			6.0
Total Equities:		5,325,047			96.4
Securities Lending Collateral:		47,260			0.9
Total Investments:		5,372,307			97.3
Obligation to Return Collateral for Securities Loaned:		(47,260	)		(0.9	)
Cash and Other Assets Less Liabilities:		198,718			3.6
Net Assets:	$	5,523,765			100.0

Columbia Acorn USA

Major Portfolio Changes in the Third Quarter (Unaudited)

	Number of Shares
	06/30/11		09/30/11
Purchases
Information
AboveNet		168,800		192,800
Carbonite		0		62,597
ExlService Holdings		428,000		556,000
NetSuite		129,000		184,000
Polycom		386,000		460,000
Tangoe		0		57,400
Consumer Goods & Services
Cavco Industries		161,000		206,000
HomeAway		30,000		140,000
lululemon athletica		390,000		780,000
Pinnacle Entertainment		645,000		775,000
Shutterfly		254,000		289,000
Skullcandy		0		140,000
Teavana		0		161,500
Warnaco Group		192,000		222,000
Industrial Goods & Services
Acorn Energy		0		600,000
Albany International		135,000		187,000
Clean Harbors		0		65,000
GrafTech International		486,000		686,000
Kennametal		177,000		226,000
Toro		71,800		136,800
Finance
CAI International		230,000		330,000
City National		0		70,000
Financial Engines		0		173,000
Textainer Group Holdings		285,000		345,000
TrustCo Bank		245,300		595,300
Health Care
Akorn		725,000		796,500
Alimera Sciences		108,512		133,180
Gen-Probe		124,000		140,000
HealthSouth		0		205,000
Hill-Rom Holdings		0		84,007
Horizon Pharma		0		150,000
Sirona Dental Systems		184,000		224,000

	Number of Shares
	06/30/11		09/30/11
Sales
Information
Amphenol		196,000		159,000
Applied Micro Circuits		448,000		0
Blackbaud		333,000		300,000
Blackboard		247,000		0
Entegris		675,000		0
FLIR Systems		130,000		0
Global Payments		188,000		170,000
IMAX (Canada)		145,000		0
Informatica		985,000		910,000
Nice Systems - ADR (Israel)		280,000		252,000
PAETEC Holding		2,030,000		0
Plexus		261,000		236,000
SBA Communications		650,000		560,000
Spanish Broadcasting System		71,718		0
TheStreet.com		343,000		225,100
Consumer Goods & Services
Chico's FAS		481,000		0
Herman Miller		260,000		164,000
Penn National Gaming		270,000		69,000
Saks		875,000		790,000
Talbots		480,000		0
True Religion Apparel		241,530		181,000
Universal Technical Institute		165,000		0
Industrial Goods & Services
Albemarle		54,000		0
Kaydon		50,000		0
WABCO Holdings		100,000		0
Finance
Associated Banc-Corp		692,400		623,000
GATX		42,400		0
McGrath Rentcorp		335,418		210,000
Pacific Continental		527,700		513,755
TCF Financial		659,800		594,000
Valley National Bancorp		931,000		675,000
ViewPoint Financial		756,000		602,487
Health Care
Array Biopharma		450,000		0
Health Management Associates		1,038,900		738,900
Idexx Laboratories		53,000		0
Isis Pharmaceuticals		850,000		643,000
Kindred Healthcare		150,000		0
Nabi Biopharmaceuticals		455,000		0
Onyx Pharmaceuticals		232,000		178,000
United Therapeutics		102,000		18,675

	Number of Shares
	06/30/11		09/30/11
Sales (continued)
Energy & Minerals
Carrizo Oil & Gas		73,000		0
Core Laboratories (Netherlands)		100,000		85,000
Houston American Energy		386,000		368,200
Other Industries
Biomed Realty Trust		995,200		739,200
Corporate Office Properties		246,000		0
Heartland Express		310,000		0
Macerich Company		98,619		0
Summit Hotel Properties		208,000		0

Columbia Acorn USA

Statement of Investments (Unaudited), September 30, 2011

Number of Shares			Value (000)
			Equities: 99.0%
Information 31.1%
		> Business Software 9.6%
	910,000	Informatica (a)	$	37,265
		Enterprise Data Integration Software
	698,000	Micros Systems (a)		30,649
		Information Systems for Hotels, Restaurants and Retailers
	375,000	ANSYS (a)		18,390
		Simulation Software for Engineers and Designers
	408,000	Ariba (a)		11,306
		Cost Management Software
	243,000	Concur Technologies (a)		9,045
		Web Enabled Cost & Expense Management Software
	300,000	Blackbaud		6,681
		Software & Services for Non-Profits
	322,000	SPS Commerce (a)		5,245
		Supply Chain Management Software Delivered via the Web
	52,000	Quality Systems		5,044
		IT Systems for Medical Groups & Ambulatory Care Centers
	184,000	NetSuite (a)		4,970
		End to End IT Systems Solution Delivered Over the Web
	220,000	Advent Software (a)		4,587
		Asset Management & Trading Systems
	198,000	Constant Contact (a)		3,423
		E-mail & Other Marketing Campaign Mgmt Systems Delivered Over the Web
	57,400	Tangoe (a)		649
		Software Solution for Managing Communication Expense & Devices
				137,254
		> Instrumentation 4.2%
	678,000	IPG Photonics (a)		29,452
		Fiber Lasers
	180,000	Mettler Toledo (a)		25,193
		Laboratory Equipment
	168,000	Trimble Navigation (a)		5,637
		GPS-based Instruments
				60,282
		> Computer Hardware & Related Equipment 3.6%
	1,238,000	II-VI (a)		21,665
		Laser Optics and Specialty Materials
	324,000	Zebra Technologies (a)		10,025
		Bar Code Printers
	252,000	Nice Systems - ADR (Israel) (a)(g)		7,648
		Audio & Video Recording Solutions
	159,000	Amphenol		6,482
		Electronic Connectors
	196,000	Netgear (a)		5,075
		Networking Products for Small Business & Home
				50,895

Number of Shares			Value (000)
		> Semiconductors & Related Equipment 3.3%
	1,958,000	Atmel (a)	$	15,801
		Microcontrollers, RF, and Memory Semiconductors
	760,000	Microsemi (a)		12,145
		Analog/Mixed Signal Semiconductors
	1,061,750	ON Semiconductor (a)		7,613
		Mixed Signal & Power Management Semiconductors
	1,075,000	TriQuint Semiconductor (a)		5,397
		RF Semiconductors
	346,000	Monolithic Power Systems (a)		3,522
		High Performance Analog & Mixed Signal ICs
	430,000	Pericom Semiconductor (a)		3,186
		Interface ICs & Frequency Control Products
				47,664
		> Telephone and Data Services 2.6%
	1,617,000	tw telecom (a)		26,713
		Fiber Optic Telephone/Data Services
	192,800	AboveNet		10,334
		Metropolitan Fiber Communications Services
				37,047
		> Telecommunications Equipment 2.4%
	732,000	Finisar (a)		12,839
		Optical Subsystems and Components
	460,000	Polycom (a)		8,450
		Video Conferencing Equipment
	903,000	Ixia (a)		6,926
		Telecom Network Test Equipment
	752,000	Infinera (a)		5,806
		Optical Networking Equipment
				34,021
		> Gaming Equipment & Services 1.5%
	660,000	Bally Technologies (a)		17,807
		Slot Machines & Software
	235,000	WMS Industries (a)		4,133
		Slot Machine Provider
				21,940
		> Mobile Communications 1.4%
	560,000	SBA Communications (a)		19,309
		Communications Towers
				19,309
		> Computer Services 1.3%
	556,000	ExlService Holdings (a)		12,232
		Business Process Outsourcing
	1,005,500	Hackett Group (a)		3,750
		IT Integration & Best Practice Research
	710,000	RCM Technologies (a)(b)		3,188
		Technology & Engineering Services
				19,170
		> Financial Processors 0.5%
	170,000	Global Payments		6,866
		Credit Card Processor
				6,866

Number of Shares			Value (000)
		> Contract Manufacturing 0.4%
	236,000	Plexus (a)	$	5,338
		Electronic Manufacturing Services
				5,338
		> Radio 0.1%
	511,100	Salem Communications		1,170
		Radio Stations for Religious Programming
				1,170
		> TV Broadcasting 0.1%
	975,000	Entravision Communications (a)		994
		Spanish Language TV & Radio Stations
				994
		> Consumer Software 0.1%
	62,597	Carbonite (a)(c)		754
		Online File Storage
				754
		> Internet Related —%
	225,100	TheStreet.com		446
		Financial Information Websites
				446
Information: Total				443,150
Consumer Goods & Services 17.6%
		> Retail 6.8%
	780,000	lululemon athletica (a)		37,947
		Premium Active Apparel Retailer
	468,500	Abercrombie & Fitch		28,841
		Teen Apparel Retailer
	289,000	Shutterfly (a)		11,901
		Internet Photo-Centric Retailer
	805,000	Pier 1 Imports (a)		7,873
		Home Furnishing Retailer
	790,000	Saks (a)		6,913
		Luxury Department Store Retailer
	161,500	Teavana (a)(c)		3,285
		Specialty Tea Retailer
	9,000	The Fresh Market (a)		343
		Specialty Food Retailer
				97,103
		> Travel 2.9%
	849,700	Gaylord Entertainment (a)		16,433
		Convention Hotels
	1,175,950	Avis Budget Group (a)		11,371
		Second Largest Car Rental Company
	750,000	Hertz (a)		6,675
		Largest U.S. Rental Car Operator
	140,000	HomeAway (a)(c)		4,707
		Vacation Rental Online Marketplace
	71,000	Vail Resorts		2,683
		Ski Resort Operator & Developer
				41,869
		> Apparel 1.6%
	222,000	Warnaco Group (a)		10,232
		Global Branded Apparel Manufacturer

Number of Shares			Value (000)
	90,000	Deckers Outdoor (a)	$	8,393
		Fashion Footwear Wholesaler
	181,000	True Religion Apparel (a)		4,880
		Premium Denim
				23,505
		> Furniture & Textiles 1.5%
	880,000	Knoll		12,056
		Office Furniture
	540,000	Interface		6,404
		Modular & Broadloom Carpet
	164,000	Herman Miller		2,929
		Office Furniture
				21,389
		> Food & Beverage 1.1%
	197,000	Diamond Foods (c)		15,719
		Snack Foods and Culinary Ingredients
				15,719
		> Consumer Goods Distribution 0.9%
	472,000	Pool		12,357
		Distributor of Swimming Pool Supplies & Equipment
				12,357
		> Other Durable Goods 0.8%
	206,000	Cavco Industries (a)		7,095
		Manufactured Homes
	140,000	Jarden		3,956
		Branded Household Products
				11,051
		> Other Consumer Services 0.7%
	259,000	Lifetime Fitness (a)		9,544
		Sport & Fitness Club Operator
				9,544
		> Casinos & Gaming 0.7%
	775,000	Pinnacle Entertainment (a)		7,037
		Regional Casino Operator
	69,000	Penn National Gaming (a)		2,297
		Regional Casino Operator
				9,334
		> Leisure Products 0.4%
	162,000	Thor Industries		3,588
		RV & Bus Manufacturer
	140,000	Skullcandy (a)(c)		1,978
		Lifestyle Branded Headphones
				5,566
		> Educational Services 0.2%
	37,350	ITT Educational Services (a)(c)		2,151
		Postsecondary Degree Services
				2,151
		> Restaurants —%
	26,600	Bravo Brio Restaurant Group (a)		443
		Upscale Casual Italian Restaurants
				443
Consumer Goods & Services: Total				250,031

Columbia Acorn USA

Statement of Investments (Unaudited), continued

Number of Shares			Value (000)
Industrial Goods & Services 15.8%
		> Machinery 11.8%
	941,250	Ametek	$	31,033
		Aerospace/Industrial Instruments
	747,200	Nordson		29,694
		Dispensing Systems for Adhesives & Coatings
	445,000	Donaldson		24,386
		Industrial Air Filtration
	835,000	ESCO Technologies		21,292
		Automatic Electric Meter Readers
	585,000	Pentair		18,726
		Pumps & Water Treatment
	504,665	HEICO		16,987
		FAA Approved Aircraft Replacement Parts
	280,000	MOOG (a)		9,134
		Motion Control Products for Aerospace, Defense & Industrial Markets
	226,000	Kennametal		7,399
		Consumable Cutting Tools
	136,800	Toro		6,740
		Turf Maintenance Equipment
	162,000	Oshkosh Corporation (a)		2,550
		Specialty Truck Manufacturer
				167,941
		> Industrial Materials & Specialty Chemicals 1.0%
	496,000	Drew Industries		9,910
		RV & Manufactured Home Components
	187,000	Albany International		3,413
		Paper Machine Clothing and Advanced Textiles
				13,323
		> Electrical Components 0.7%
	280,000	Acuity Brands		10,091
		Commercial Lighting Fixtures
				10,091
		> Waste Management 0.7%
	195,000	Waste Connections		6,595
		Solid Waste Management
	65,000	Clean Harbors (a)		3,334
		Hazardous Waste Services & Disposal
				9,929
		> Other Industrial Services 0.6%
	600,000	Acorn Energy (a)		3,192
		Frac Well Exploration/Monitoring Device, Sonar Security,Electric Grid Monitoring
	265,000	TrueBlue (a)		3,003
		Temporary Manual Labor
	109,000	Forward Air		2,774
		Freight Transportation Between Airports
				8,969
		> Steel 0.6%
	686,000	GrafTech International (a)		8,712
		Industrial Graphite Materials Producer
				8,712
		> Industrial Distribution 0.3%
	350,000	Interline Brands (a)		4,505
		Industrial Distribution
				4,505

Number of Shares			Value (000)
		> Water 0.1%
	204,200	Mueller Water Products	$	506
		Fire Hydrants, Valves & Ductile Iron Pipes
				506
Industrial Goods & Services: Total				223,976
Finance 10.4%
		> Banks 5.1%
	431,597	Lakeland Financial		8,917
		Indiana Bank
	278,678	Hancock Holding		7,463
		Gulf Coast Bank
	675,000	Valley National Bancorp (c)		7,148
		New Jersey/New York Bank
	480,000	MB Financial		7,066
		Chicago Bank
	1,478,200	First Busey		6,430
		Illinois Bank
	170,000	SVB Financial Group (a)		6,290
		Bank to Venture Capitalists
	623,000	Associated Banc-Corp		5,794
		Midwest Bank
	594,000	TCF Financial		5,441
		Great Lakes Bank
	513,755	Pacific Continental		3,643
		Pacific N.W. Bank
	269,600	Eagle Bancorp (a)		3,173
		Metro D.C. Bank
	595,300	TrustCo Bank		2,655
		New York State Bank
	70,000	City National		2,643
		Bank & Asset Manager
	178,826	Sandy Spring Bancorp		2,616
		Baltimore, D.C. Bank
	210,000	CVB Financial		1,615
		Inland Empire Business Bank
	90,000	TriCo Bancshares		1,104
		California Central Valley Bank
	851,247	Guaranty Bancorp (a)		1,022
		Colorado Bank
				73,020
		> Finance Companies 3.4%
	345,000	World Acceptance (a)		19,303
		Personal Loans
	412,500	Aaron's		10,416
		Rent to Own
	345,000	Textainer Group Holdings		6,996
		Top International Container Leasor
	210,000	McGrath Rentcorp		4,996
		Temporary Space & IT Rentals
	330,000	CAI International (a)		3,868
		International Container Leasing
	201,000	H&E Equipment Services (a)		1,658
		Heavy Equipment Leasing
	99,200	Marlin Business Services (a)		1,051
		Small Equipment Leasing
				48,288

Number of Shares			Value (000)
		> Savings & Loans 0.9%
	602,487	ViewPoint Financial	$	6,899
		Texas Thrift
	215,000	Berkshire Hills Bancorp		3,971
		Northeast Thrift
	173,073	Kaiser Federal Financial Group		2,042
		Los Angeles Savings & Loan
				12,912
		> Brokerage & Money Management 0.7%
	209,500	Eaton Vance		4,665
		Specialty Mutual Funds
	173,000	Financial Engines (a)		3,133
		Asset Management for 401k Plans
	675,000	MF Global (a)		2,788
		Futures Broker
				10,586
		> Insurance 0.3%
	39,000	Enstar Group (a)		3,714
		Insurance/Reinsurance & Related Services
				3,714
Finance: Total				148,520
Health Care 10.0%
		> Biotechnology & Drug Delivery 4.2%
	520,000	BioMarin Pharmaceutical (a)		16,572
		Biotech Focused on Orphan Diseases
	495,000	Seattle Genetics (a)(c)		9,435
		Antibody-Based Therapies for Cancer
	375,000	Auxilium Pharmaceuticals (a)		5,621
		Biotech Focused on Niche Disease Areas
	840,000	NPS Pharmaceuticals (a)		5,468
		Orphan Drugs & Healthy Royalties
	178,000	Onyx Pharmaceuticals (a)		5,342
		Commercial-Stage Biotech Focused on Cancer
	643,000	Isis Pharmaceuticals (a)		4,360
		Biotech Pioneer in Antisense Drugs
	196,000	InterMune (a)		3,959
		Drugs for Pulmonary Fibrosis & Hepatitis C
	810,000	Micromet (a)		3,888
		Next-generation Antibody Technology
	790,000	Chelsea Therapeutics (a)		2,884
		Biotech Focused on Rare Diseases
	265,000	Anthera Pharmaceuticals (a)		1,264
		Biotech Focused on Cardiovascular, Cancer & Immunology
	243,000	Savient Pharmaceuticals (a)(c)		996
		Biotech Company Focused on Severe Gout
	18,675	United Therapeutics (a)		700
		Biotech Focused on Rare Diseases
	18,181	Metabolex, Series A-1 (a)(d)(e)		18
		Diabetes Drug Development
	738,060	Medicure - Warrants (a)(d)(e)		—
		Cardiovascular Biotech Company
	37,500	Locus Pharmaceuticals, Series A-1, Pfd. (a)(d)(e)		—
		High Throughput Rational Drug Design

Number of Shares			Value (000)
	19,329	Locus Pharmaceuticals, Series B-1, Pfd. (a)(d)(e)	$	—
		High Throughput Rational Drug Design
				60,507
		> Medical Equipment & Devices 3.1%
	370,000	Alexion Pharmaceuticals (a)		23,702
		Biotech Focused on Orphan Diseases
	224,000	Sirona Dental Systems (a)		9,500
		Manufacturer of Dental Equipment
	140,000	Gen-Probe (a)		8,015
		Molecular In-Vitro Diagnostics
	84,007	Hill-Rom Holdings		2,522
		Hospital Beds/Patient Handling
	155,000	Pacific Biosciences of California (a)(c)		498
		Genome Sequencing
				44,237
		> Medical Supplies 1.3%
	439,600	Cepheid (a)		17,070
		Molecular Diagnostics
	49,000	Neogen (a)		1,701
		Food and Animal Safety Products
				18,771
		> Health Care Services 0.8%
	738,900	Health Management Associates (a)		5,113
		Non-Urban Hospitals
	205,000	HealthSouth (a)		3,061
		Inpatient Rehabalitation Facilities
	151,000	Community Health Systems (a)		2,512
		Non-Urban Hospitals
				10,686
		> Pharmaceuticals 0.6%
	796,500	Akorn (a)		6,221
		Develops, Manufactures & Sells Specialty Generic Drugs
	133,180	Alimera Sciences (a)(c)		1,065
		Ophthalmology-Focused Pharmaceutical Company
	150,000	Horizon Pharma (a)(c)		1,049
		Specialty Pharma Company
				8,335
Health Care: Total				142,536
Energy & Minerals 8.2%
		> Oil Services 4.8%
	1,000,000	FMC Technologies (a)		37,600
		Oil and Gas Well Head Manufacturer
	803,000	Atwood Oceanics (a)		27,591
		Offshore Drilling Contractor
	86,000	Bristow		3,649
		Largest Provider of Helicopter Services to Offshore Oil and Gas Producers
				68,840
		> Oil & Gas Producers 2.5%
	1,135,000	Quicksilver Resources (a)(c)		8,603
		Natural Gas and Coal Seam Gas Producer
	133,000	SM Energy		8,067
		Oil and Gas Producer

Columbia Acorn USA

Statement of Investments (Unaudited), continued

Number of Shares			Value (000)
		> Oil & Gas Producers—continued
	368,200	Houston American Energy (c)	$	5,066
		Oil and Gas Exploration/Production in Colombia
	143,000	Rosetta Resources (a)		4,894
		Oil and Gas Producer Exploring in South Texas and Montana
	230,000	Northern Oil And Gas (a)(c)		4,460
		Small E&P Company in North Dakota Bakken
	168,000	Swift Energy (a)		4,089
		Oil and Gas Exploration and Production
	22,800	Oasis Petroleum (a)		509
		Oil Producer in North Dakota
				35,688
		> Mining 0.9%
	85,000	Core Laboratories (Netherlands) (g)		7,635
		Oil and Gas Reservoir Consulting
	600,000	Alexco Resource (a)		4,068
		Mining, Exploration & Environmental Services
	180,000	Augusta Resource (a)(c)		553
		U.S. Copper/Molybdenum Mine
				12,256
Energy & Minerals: Total				116,784
Other Industries 5.9%
		> Real Estate 4.8%
	915,000	Extra Space Storage		17,046
		Self Storage Facilities
	739,200	Biomed Realty Trust		12,249
		Life Science-focused Office Buildings
	600,000	Associated Estates Realty		9,276
		Multifamily Properties
	870,000	Education Realty Trust		7,473
		Student Housing
	177,000	Kilroy Realty		5,540
		West Coast Office and Industrial Properties
	1,380,000	Kite Realty Group		5,051
		Community Shopping Centers
	1,058,000	DCT Industrial Trust		4,645
		Industrial Properties
	191,000	Dupont Fabros Technology (c)		3,761
		Technology-focused Office Buildings
	100,000	Post Properties		3,474
		Multifamily Properties
				68,515
		> Transportation 1.1%
	256,000	World Fuel Services		8,358
		Global Fuel Broker
	410,091	Rush Enterprises, Class A (a)		5,807
	115,000	Rush Enterprises, Class B (a)		1,342
		Truck Sales and Service
				15,507
Other Industries: Total				84,022
Total Equities: 99.0% (Cost: $1,167,960)				1,409,019

Number of Shares			Value (000)
Securities Lending Collateral 3.2%
	45,915,875	Dreyfus Government Cash Management Fund (f) (7 day yield of 0.00%)	$	45,916
Total Securities Lending Collateral: (Cost: $45,916)				45,916
Total Investments: 102.2% (Cost: $1,213,876)(g)(h)				1,454,935
Obligation to Return Collateral for Securities Loaned: (3.2)%				(45,916	)
Cash and Other Assets Less Liabilities: 1.0%				14,590
Total Net Assets: 100.0%			$	1,423,609

ADR = American Depositary Receipts

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

(a) Non-income producing security.

Affiliates	Balance of Shares Held 12/31/10		Purchases/ Additions		Sales/ Reductions		Balance of Shares Held 9/30/11		Value		Dividend
RCM Technologies		710,000		-		-		710,000	$	3,188	$	-
Total of Affiliated Transactions		710,000		-		-		710,000	$	3,188	$	-

(c) All or a portion of this security was on loan at September 30, 2011. The total market value of securities on loan at September 30, 2011 was $43,598,480.

(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 September 30, 2011, the market value of these securities (in thousands) amounted to $18 which represented less than 0.01% of total net assets.

Security	Acquisition Dates	Shares		Cost		Value
Metabolex, Series A-1	2/11/00		18,181	$	2,000	$	18
Locus Pharmaceuticals, Series A-1 Pfd.	9/05/01		37,500		1,500		-
Locus Pharmaceuticals, Series B-1 Pfd.	2/08/07		19,329		56		-
Medicure - Warrants	12/22/06		738,060		-		-
				$	3,556	$	18

(e) Illiquid security.

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

(g) On September 30, 2011, the market value of foreign securities represents 1.08% of total net assets. The Fund's foreign portfolio was diversified as follows:

	Value		Percent
Israel	$	7,648		0.54
Netherlands		7,635		0.54
Total Foreign Portfolio	$	15,283		1.08

• 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)

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

Columbia Acorn USA

Statement of Investments (Unaudited), continued

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

The following table summarizes the inputs used, as of September 30, 2011, 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	$	443,150	$	-		$	-	$	443,150
Consumer Goods & Services		250,031		-			-		250,031
Industrial Goods & Services		223,976		-			-		223,976
Finance		148,520		-			-		148,520
Health Care		142,518		-	*		18		142,536
Energy & Minerals		116,784		-			-		116,784
Other Industries		84,022		-			-		84,022
Total Equities		1,409,001		-	*		18		1,409,019
Total Securities Lending Collateral		45,916		-			-		45,916
Total Investments	$	1,454,917	$	-	*	$	18	$	1,454,935

* Rounds to less than $500.

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

The following table reconciles asset balances for the nine months ending September 30, 2011, in which significant unobservable inputs (Level 3) were used in determining value:

Investments in Securities	Balance as of December 31, 2010		Realized Gain/(Loss)		Change in Unrealized Appreciation (Depreciation)			Purchases		Sales		Transfers into Level 3		Transfers out of Level 3		Balance as of September 30, 2011
Equities
Health Care	$	20	$	-	$	(2	)	$	-	$	-	$	-	$	-	$	18
	$	20	$	-	$	(2	)	$	-	$	-	$	-	$	-	$	18

The change in unrealized depreciation attributed to securities owned at September 30, 2011, which were valued using significant unobservable inputs (Level 3) amounted to $2.

Columbia Acorn International Select

Major Portfolio Changes in the Third Quarter (Unaudited)

	Number of Shares
	06/30/11		09/30/11
Purchases
Asia
> Japan
Asahi Diamond Industrial		480,000		528,000
Seven Bank		4,450		6,753
> Singapore
Mapletree Industrial Trust REIT		14,601,100		19,420,000
> China
Netease.com		0		84,000
Want Want		1,655,000		3,764,000
Zhaojin Mining Industry		2,649,400		6,276,000
> Taiwan
Far Eastone Telecom		0		11,208,400
Europe
> United Kingdom
Archipelago Resources		4,472,797		6,886,399
JLT Group		881,100		1,014,600
Shaftesbury		226,800		423,820
> Belgium
EVS Broadcast Equipment		33,800		74,000
Other Countries
> Israel
Israel Chemicals		310,000		460,000
> South Africa
Adcock Ingram Holdings		1,152,200		1,220,200
Rand Merchant Insurance		4,902,152		7,209,798

	Number of Shares
	06/30/11		09/30/11
Sales
Asia
> Japan
Gree		280,000		181,000
Kansai Paint		2,115,000		2,100,000
> China
Jiangsu Expressway		6,727,000		4,170,000
> South Korea
NHN		79,266		52,000
Woongjin Coway		151,000		111,000
Europe
> United Kingdom
Chemring		1,609,133		1,480,000
Intertek Group		400,000		312,000
Serco		985,000		850,000
Workspace Group		9,710,000		1,304,000
> Netherlands
Core Laboratories		45,000		38,000
Fugro		117,121		115,821
> Switzerland
Kuehne & Nagel		51,000		49,000
> Germany
Rhoen-Klinikum		297,000		270,000
Wirecard		672,000		630,000
> Ireland
United Drug		2,377,800		1,930,000
> France
Neopost		48,000		32,657
Other Countries
> South Africa
Naspers		122,700		88,700
> United States
SM Energy		67,000		52,000
> Australia
UGL		540,000		—

Columbia Acorn International Select

Statement of Investments (Unaudited), September 30, 2011

Number of Shares			Value (000)
			Equities: 95.3%
Asia 42.0%
		> Japan 16.5%
	2,100,000	Kansai Paint	$	20,124
		Paint Producer in Japan, India, China and Southeast Asia
	6,753	Seven Bank		13,180
		ATM Processing Services
	8,970	Jupiter Telecommunications		9,706
		Largest Cable Service Provider in Japan
	528,000	Asahi Diamond Industrial		7,344
		Consumable Diamond Tools
	181,000	Gree		5,520
		Mobile Social Networking Game Developer/Platform
	110,000	Ain Pharmaciez		4,847
		Dispensing Pharmacy/Drugstore Operator
				60,721
		> Singapore 11.8%
	13,130,000	Ascendas REIT		20,247
		Industrial Property Landlord
	19,420,000	Mapletree Industrial Trust REIT		15,978
		Industrial Property Landlord
	11,142,000	Mapletree Logistics Trust		7,217
		Industrial Property Landlord
				43,442
		> China 5.5%
	6,276,000	Zhaojin Mining Industry		10,440
		Gold Mining and Refining in China
	3,764,000	Want Want		3,409
		Chinese Branded Consumer Food Company
	84,000	Netease.com		3,205
		Chinese Online Gaming Services
	4,170,000	Jiangsu Expressway		3,150
		Chinese Toll Road Operator
				20,204
		> Taiwan 4.5%
	11,208,400	Far Eastone Telecom		16,572
		Taiwan's 3rd Largest Mobile Operator
				16,572
		> South Korea 3.7%
	52,000	NHN (a)		9,907
		Korean Online Search Services
	111,000	Woongjin Coway		3,574
		South Korean Household Appliance Rental Service Provider
				13,481
Asia: Total				154,420
Europe 38.3%
		> United Kingdom 14.8%
	1,480,000	Chemring		12,118
		Defense Manufacturer of Countermeasures and Energetics
	1,014,600	JLT Group (b)		9,936
		International Business Insurance Broker

Number of Shares			Value (000)
	312,000	Intertek Group	$	8,973
		Testing, Inspection, Certification Services
	6,886,399	Archipelago Resources (a)		7,361
		Gold Mining Projects in Indonesia, Vietnam, and the Philippines
	850,000	Serco		6,724
		Facilities Management
	1,304,000	Workspace Group		4,380
		United Kingdom Real Estate
	423,820	Shaftesbury		3,062
		London Prime Retail REIT
	616,000	Cobham		1,667
		Aerospace Components
				54,221
		> Netherlands 7.3%
	166,000	AkzoNobel		7,325
		Largest Global Supplier of Protective Paints and Coatings
	235,519	Imtech		6,625
		Electromechanical and ICT Installation and Maintenance
	115,821	Fugro		5,841
		Sub-sea Oilfield Services
	242,103	Aalberts Industries		3,599
		Flow Control and Heat Treatment
	38,000	Core Laboratories (b)		3,414
		Oil and Gas Reservoir Consulting
				26,804
		> Germany 5.6%
	630,000	Wirecard		9,638
		Online Payment Processing & Risk Management
	270,000	Rhoen-Klinikum		5,467
		Health Care Services
	115,500	Rheinmetall		5,418
		Defense & Automotive
				20,523
		> Switzerland 2.6%
	49,000	Kuehne & Nagel		5,499
		Freight Forwarding/Logistics
	24,000	Partners Group		3,952
		Private Markets Asset Management
				9,451
		> Sweden 2.3%
	658,666	Hexagon		8,565
		Design, Measurement and Visualization Software and Equipment
				8,565
		> Ireland 1.6%
	1,930,000	United Drug		5,909
		Irish Pharmaceutical Wholesaler & Outsourcer
				5,909
		> Iceland 1.3%
	4,800,000	Marel (a)		4,773
		Largest Manufacturer of Poultry and Fish Processing Equipment
				4,773

Number of Shares			Value (000)
		> Denmark 1.1%
	29,000	Novozymes	$	4,123
		Industrial Enzymes
				4,123
		> Belgium 1.0%
	74,000	EVS Broadcast Equipment		3,827
		Digital Live Mobile Production Software and Systems
				3,827
		> France 0.7%
	32,657	Neopost		2,395
		Postage Meter Machines
				2,395
Europe: Total				140,591
Other Countries 12.7%
		> South Africa 6.6%
	7,209,798	Rand Merchant Insurance		11,165
		Directly Sold Property and Casualty Insurance; Holdings in Other Insurers
	1,220,200	Adcock Ingram Holdings		9,049
		Manufacturer of Pharmaceuticals and Medical Supplies
	88,700	Naspers		3,830
		Media in Africa, China, Russia, and Other Emerging Markets
				24,044
		> Canada 2.8%
	210,400	CCL Industries		5,608
		Leading Global Label Manufacturer
	125,000	AG Growth		4,469
		Leading Manufacturer of Augers and Grain Handling Equipment
				10,077
		> United States 1.9%
	112,000	Atwood Oceanics (a)		3,848
		Offshore Drilling Contractor
	52,000	SM Energy		3,154
		Oil and Gas Producer
				7,002
		> Israel 1.4%
	460,000	Israel Chemicals		5,239
		Producer of Potash, Phosphates, Bromine, and Specialty Chemicals
				5,239
Other Countries: Total				46,362
Latin America 2.2%
		> Colombia 1.7%
	260,000	Pacific Rubiales Energy		5,508
		Oil Production & Exploration in Colombia
	18,800,000	Quetzal Energy (a)(c)		775
		Explores for Oil & Gas in Latin America
				6,283

Number of Shares			Value (000)
		> Argentina 0.5%
	166,667	Union Agriculture Group (a)(c)(f)	$	1,777
		Farmland Operator in Uruguay
				1,777
Latin America: Total				8,060
Total Equities: 95.2% (Cost: $321,163)				349,433
Securities Lending Collateral 1.1%
	3,965,250	Dreyfus Government Cash Management Fund (d) (7 day yield of 0.00%)		3,965
Total Securities Lending Collateral: (Cost: $3,965)				3,965
Total Investments: 96.3% (Cost: $325,128)(e)(g)				353,398
Obligation to Return Collateral for Securities Loaned: (1.1)%				(3,965	)
Cash and Other Assets Less Liabilities: 4.8%				17,494
Total Net Assets: 100.0%			$	366,927

Columbia Acorn International Select

Statement of Investments (Unaudited), continued

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

(a) Non-income producing security.

(b) All or a portion of this security was on loan at September 30, 2011. The total market value of securities on loan at September 30, 2011 was $3,742,527.

Additional information on these securities is as follows:

Security	Acquisition Dates	Shares		Cost		Value
Union Agriculture Group	12/8/10		166,667	$	2,200	$	1,777
Quetzal Energy	1/14/11		18,800,000		2,376		775
				$	4,576	$	2,552

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

(f) Illiquid security.

(g) On September 30, 2011, the Fund's total investments were denominated in currencies as follows:

Currency	Value		Percentage of Net Assets
Japanese Yen	$	60,721		16.5
Euro		56,045		15.3
Pound Sterling		54,221		14.8
Singapore Dollar		43,442		11.8
South African Rand		24,044		6.6
US Dollar		19,362		5.3
Other currencies less than 5% of total net assets		95,563		26.0
	$	353,398		96.3

• 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)

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

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

The following table summarizes the inputs used, as of September 30, 2011, 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	$	3,205	$	151,215	$	-	$	154,420
Europe		3,414		137,177		-		140,591
Other Countries		17,079		29,283		-		46,362
Latin America		5,508		775		1,777		8,060
Total Equities		29,206		318,450		1,777		349,433
Total Securities Lending Collateral		3,965		-		-		3,965
Total Investments	$	33,171	$	318,450	$	1,777	$	353,398

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

The following table reconciles asset balances for the nine months ending September 30, 2011, in which significant unobservable inputs (Level 3) were used in determining value:

Investments in Securities	Balance as of December 31, 2010		Realized Gain/(Loss)		Change in Unrealized Appreciation (Depreciation)			Purchases		Sales		Transfers into Level 3		Transfers out of Level 3		Balance as of September 30, 2011
Latin America
Argentina	$	2,200	$	-	$	(423	)	$	-	$	-	$	-	$	-	$	1,777
	$	2,200	$	-	$	(423	)	$	-	$	-	$	-	$	-	$	1,777

The change in unrealized depreciation attributed to securities owned at September 30, 2011, which were valued using significant unobservable inputs (Level 3) amounted to $423.

Columbia Acorn International Select

Portfolio Diversification (Unaudited)

At September 30, 2011, the Fund's portfolio investments as a percentage of net assets were diversified as follows:

	Value (000)		Percentage of Net Assets
> Industrial Goods & Services
Industrial Materials & Specialty Chemicals	$	36,811		10.0
Machinery		24,399		6.6
Other Industrial Services		21,098		5.8
Electrical Components		13,785		3.8
Outsourcing Services		6,724		1.8
Conglomerates		3,599		1.0
		106,416		29.0
> Information
Internet Related		16,943		4.6
Mobile Communications		16,572		4.5
Business Software		12,392		3.4
CATV		9,706		2.7
Financial Processors		9,638		2.6
Gaming Equipment & Services		5,520		1.5
		70,771		19.3
> Other Industries
Real Estate		50,883		13.9
Transportation		3,149		0.8
		54,032		14.7
> Energy & Minerals
Mining		21,214		5.8
Oil Services		9,689		2.6
Oil & Gas Producers		9,437		2.6
Agricultural Commodities		1,777		0.5
		42,117		11.5
> Finance
Insurance		21,101		5.7
Banks		13,180		3.6
Brokerage & Money Management		3,952		1.1
		38,233		10.4
> Health Care
Pharmaceuticals		14,958		4.1
Health Care Services		5,468		1.5
		20,426		5.6

	Value (000)			Percentage of Net Assets
> Consumer Goods & Services
Nondurables	$	5,608			1.4
Retail		4,847			1.3
Other Consumer Services		3,574			1.0
Food & Beverage		3,409			1.0
		17,438			4.7
Total Equities:		349,433			95.2
Securities Lending Collateral:		3,965			1.1
Total Investments:		353,398			96.3
Obligation to Return Collateral for Securities Loaned:		(3,965	)		(1.1	)
Cash and Other Assets Less Liabilities:		17,494			4.8
Net Assets:	$	366,927			100.0

Columbia Acorn Select

Major Portfolio Changes in the Third Quarter (Unaudited)

	Number of Shares
	06/30/11		09/30/11
Purchases
Consumer Goods & Services
Gaylord Entertainment		860,000		1,060,000
lululemon athletica		350,000		565,000
Skullcandy		0		266,300
GLG Life Tech (Canada)		1,000,000		1,850,000
IFM Investments (Century 21 China RE) - ADR (China)		2,300,000		2,946,537
Industrial Goods & Services
Quanta Services		1,400,000		1,500,000
Kennametal		885,000		1,085,000
Information
WNS - ADR (India)		4,227,186		4,276,336
Energy & Minerals
Petromanas (Canada)		5,000,000		18,125,000
Canacol Energy (Colombia)		30,530,000		33,500,000
Health Care
Horizon Pharma		0		195,000
NPS Pharmaceuticals		2,000,000		2,200,000
Akorn		2,250,000		2,500,000

	Number of Shares
	06/30/11		09/30/11
Sales
Consumer Goods & Services
Abercrombie & Fitch		1,100,000		950,000
Coach		1,025,000		875,000
Hertz		8,400,000		7,525,000
ITT Educational Services		325,000		315,000
RexLot Holdings (China)		335,000,000		315,000,000
Safeway		3,000,000		2,625,000
Tiffany & Co.		250,000		240,000
Industrial Goods & Services
Ametek		1,830,000		1,660,000
ChemSpec International - ADR (China)		1,500,000		0
Donaldson		785,000		735,000
Expeditors International of Washington		750,000		685,000
Oshkosh Corporation		650,000		325,000
Pall		840,000		790,000
Waste Management		1,200,000		650,000
WW Grainger		220,000		170,000
Information
Amphenol		750,000		700,000
Crown Castle International		1,510,000		1,360,000
Globalstar		15,000,000		12,000,000
Mettler Toledo		120,000		115,000
Navigant Consulting		813,073		0
Sanmina-SCI		6,950,000		6,275,000
SBA Communications		755,000		730,000
VisionChina Media - ADR (China)		3,573,400		2,573,400
Finance
CNO Financial Group		12,300,000		11,650,000
Discover Financial Services		5,050,000		3,800,000
MF Global		5,550,000		4,900,000
SEI Investments		1,100,000		1,050,000
Energy & Minerals
Canadian Solar (China)		3,300,000		2,700,000
Houston American Energy		1,450,000		1,309,500
Kirkland Lake Gold (Canada)		1,000,000		950,000
Pacific Rubiales Energy (Colombia)		2,500,000		2,255,000
Petromanas (Canada)		13,125,000		6,562,500
ShaMaran Petroleum (Iraq)		38,343,900		36,500,000
Synthesis Energy Systems (China)		3,850,372		3,050,372
Other Industries
Biomed Realty Trust		1,900,000		1,800,000
JB Hunt Transport Services		1,275,000		1,140,000
Wisconsin Energy		500,000		475,000

Columbia Acorn Select

Statement of Investments (Unaudited), September 30, 2011

Number of Shares			Value (000)
			Equities: 98.5%
Consumer Goods & Services 24.4%
		> Retail 10.7%
	950,000	Abercrombie & Fitch	$	58,482
		Teen Apparel Retailer
	2,625,000	Safeway		43,654
		Supermarkets
	565,000	lululemon athletica (a)		27,487
		Premium Active Apparel Retailer
	240,000	Tiffany & Co.		14,597
		Luxury Good Retailer
				144,220
		> Travel 6.5%
	7,525,000	Hertz (a)		66,973
		Largest U.S. Rental Car Operator
	1,060,000	Gaylord Entertainment (a)(b)		20,500
		Convention Hotels
				87,473
		> Apparel 3.4%
	875,000	Coach		45,351
		Designer & Retailer of Branded Leather Accessories
				45,351
		> Casinos & Gaming 1.4%
	315,000,000	RexLot Holdings (China)		18,724
		Lottery Equipment Supplier in China
				18,724
		> Educational Services 1.3%
	315,000	ITT Educational Services (a)(b)		18,138
		Post-secondary Degree Services
				18,138
		> Food & Beverage 0.5%
	1,850,000	GLG Life Tech (Canada) (a)(b)(c)		6,512
		Produce an All-Natural Sweetener Extracted from the Stevia Plant
				6,512
		> Leisure Products 0.3%
	266,300	Skullcandy (a)(b)		3,763
		Lifestyle Branded Headphones
				3,763
		> Other Consumer Services 0.3%
	2,946,537	IFM Investments (Century 21 China RE) - ADR (China) (a)(c)		3,388
		Provide Real Estate Services in China
				3,388
Consumer Goods & Services: Total				327,569
Industrial Goods & Services 20.2%
		> Machinery 12.6%
	1,660,000	Ametek		54,730
		Aerospace/Industrial Instruments
	735,000	Donaldson		40,278
		Industrial Air Filtration
	1,085,000	Kennametal		35,523
		Consumable Cutting Tools

Number of Shares			Value (000)
	790,000	Pall	$	33,496
		Filtration & Fluids Clarification
	325,000	Oshkosh Corporation (a)		5,115
		Specialty Truck Manufacturer
				169,142
		> Outsourcing Services 2.1%
	1,500,000	Quanta Services (a)		28,185
		Electrical & Telecom Construction Services
				28,185
		> Other Industrial Services 2.0%
	685,000	Expeditors International of Washington		27,777
		International Freight Forwarder
				27,777
		> Industrial Distribution 1.9%
	170,000	WW Grainger		25,422
		Industrial Distribution
				25,422
		> Waste Management 1.6%
	650,000	Waste Management		21,164
		U.S. Garbage Collection & Disposal
				21,164
Industrial Goods & Services: Total				271,690
Information 17.9%
		> Mobile Communications 6.4%
	1,360,000	Crown Castle International (a)		55,311
		Communications Towers
	730,000	SBA Communications (a)		25,171
		Communications Towers
	12,000,000	Globalstar (a)(b)		4,908
		Satellite Mobile Voice & Data Carrier
				85,390
		> Computer Services 3.8%
	4,276,336	WNS - ADR (India) (a)(c)		51,102
		Offshore BPO (Business Process Outsourcing) Services
				51,102
		> Contract Manufacturing 3.1%
	6,275,000	Sanmina-SCI (a)(c)		41,917
		Electronic Manufacturing Services
				41,917
		> Computer Hardware & Related Equipment 2.1%
	700,000	Amphenol		28,539
		Electronic Connectors
				28,539
		> Instrumentation 1.2%
	115,000	Mettler Toledo (a)		16,096
		Laboratory Equipment
				16,096
		> Business Software 0.5%
	182,000	Concur Technologies (a)		6,774
		Web Enabled Cost & Expense Management Software
				6,774

Number of Shares			Value (000)
		> Telecommunications Equipment 0.4%
	324,000	Finisar (a)	$	5,683
		Optical Subsystems and Components
				5,683
		> Advertising 0.4%
	2,573,400	VisionChina Media - ADR (China) (a)(b)		4,709
		Advertising on Digital Screens in China's Mass Transit System
				4,709
Information: Total				240,210
Finance 13.9%
		> Credit Cards 6.5%
	3,800,000	Discover Financial Services		87,172
		Credit Card Company
				87,172
		> Insurance 4.7%
	11,650,000	CNO Financial Group (a)		63,026
		Life, Long-term Care & Medical Supplement Insurance
				63,026
		> Brokerage & Money Management 2.7%
	4,900,000	MF Global (a)		20,237
		Futures Broker
	1,050,000	SEI Investments		16,149
		Mutual Fund Administration & Investment Management
				36,386
Finance: Total				186,584
Energy & Minerals 13.1%
		> Oil & Gas Producers 8.7%
	2,255,000	Pacific Rubiales Energy (Colombia)		47,773
		Oil Production & Exploration in Colombia
	33,500,000	Canacol Energy (Colombia) (a)(c)		20,460
		Oil Producer in South America
	1,309,500	Houston American Energy (b)		18,019
		Oil and Gas Exploration/Production in Colombia
	36,500,000	ShaMaran Petroleum (Iraq) (a)(c)		14,455
		Oil Exploration in Kurdistan
	24,000,000	Canadian Overseas Petroleum (United Kingdom) (a)(c)(d)		7,070
	12,000,000	Canadian Overseas Petroleum - Warrants (United Kingdom) (a)(d)(e)		662
		Oil & Gas Exploration/Production in the North Sea
	34,856,000	Petrodorado (Colombia) (a)(c)		5,655
	17,144,000	Petrodorado - Warrants (Colombia) (a)(d)(e)		356
		Oil & Gas Exploration/Production in Columbia, Peru & Paraguay
	18,125,000	Petromanas (Canada) (a)		2,162
	6,562,500	Petromanas - Warrants (Canada) (a)(d)		92
		Exploring for Oil in Albania
				116,704

Number of Shares			Value (000)
		> Agricultural Commodities 1.5%
	1,515,152	Union Agriculture Group (Argentina) (a)(d)(e)	$	16,152
		Farmland Operator in Uruguay
	38,000,000	Eacom Timber (Canada) (a)(c)		3,626
		Canadian Lumber Producer
				19,778
		> Alternative Energy 1.4%
	2,700,000	Canadian Solar (China) (a)(b)(c)		9,936
		Solar Cell & Module Manufacturer
	3,050,372	Synthesis Energy Systems (China) (a)(b)(c)		5,277
		Owner/Operator of Gasification Plants
	1,600,000	Real Goods Solar (a)(c)		2,912
		Residential Solar Energy Installer
				18,125
		> Mining 1.1%
	950,000	Kirkland Lake Gold (Canada) (a)		15,402
		Gold Mining
				15,402
		> Oil Services 0.4%
	10,885,700	Tuscany International Drilling (Colombia) (a)		6,025
	760,000	Tuscany International Drilling - Warrants (Colombia) (a)		4
		South America Based Drilling Rig Contractor
				6,029
Energy & Minerals: Total				176,038
Other Industries 6.4%
		> Transportation 3.1%
	1,140,000	JB Hunt Transport Services		41,177
		Truck & Intermodal Carrier
				41,177
		> Real Estate 2.2%
	1,800,000	Biomed Realty Trust		29,826
		Life Science-focused Office Buildings
				29,826
		> Regulated Utilities 1.1%
	475,000	Wisconsin Energy		14,863
		Wisconsin Utility
				14,863
Other Industries: Total				85,866
Health Care 2.6%
		> Pharmaceuticals 1.5%
	2,500,000	Akorn (a)		19,525
		Develops, Manufactures & Sells Specialty Generic Drugs
	195,000	Horizon Pharma (a)(b)		1,363
		Specialty Pharma Company
				20,888

Columbia Acorn Select

Statement of Investments (Unaudited), continued

Number of Shares			Value (000)
		> Biotechnology & Drug Delivery 1.1%
	2,200,000	NPS Pharmaceuticals (a)	$	14,322
		Orphan Drugs & Healthy Royalties
				14,322
Health Care: Total				35,210
Total Equities: 98.5% (Cost: $1,276,242)				1,323,167
Securities Lending Collateral 2.4%
	32,441,695	Dreyfus Government Cash Management Fund (f) (7 day yield of 0.00%)		32,442
Total Securities Lending Collateral: (Cost: $32,442)				32,442
Total Investments: 100.9% (Cost: $1,308,684)(g)(h)				1,355,609
Obligation to Return Collateral for Securities Loaned: (2.4)%				(32,442	)
Cash and Other Assets Less Liabilities: 1.5%				20,166
Total Net Assets: 100.0%			$	1,343,333

ADR = American Depositary Receipts

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

(a) Non-income producing security.

(b) All or a portion of this security was on loan at September 30, 2011. The total market value of securities on loan at September 30, 2011 was $29,941,439.

Affiliates	Balance of Shares Held 12/31/10		Purchases/ Additions		Sales/ Reductions		Balance of Shares Held 9/30/11		Value		Dividend
Canacol Energy		36,240,000		-		2,740,000		33,500,000	$	20,460	$	-
Canadian Overseas Petroleum*		16,800,000		7,200,000		-		24,000,000		7,070		-
Canadian Solar		3,200,000		100,000		600,000		2,700,000		9,936		-
Eacom Timber		38,000,000		-		-		38,000,000		3,626		-
GLG Life Tech		1,000,000		850,000		-		1,850,000		6,512		-
Globalstar*		15,000,000		-		3,000,000		12,000,000		4,908		-
IFM Investments (Century 21 China RE) - ADR		2,300,000		646,537		-		2,946,537		3,388		-
Petrodorado		28,400,000		6,456,000		-		34,856,000		5,655		-
Real Goods Solar		1,500,000		100,000		-		1,600,000		2,912		-
Sanmina-SCI		7,100,000		-		825,000		6,275,000		41,917		-
ShaMaran Petroleum		35,950,000		550,000		-		36,500,000		14,455		-
Synthesis Energy Systems		4,500,000		-		1,449,628		3,050,372		5,277		-
Tuscany International Drilling*	11,324,000				-		438,300		10,885,700		6,025
VisionChina Media - ADR*		3,675,000		-		1,101,600		2,573,400		4,709		-
WNS - ADR		4,200,000		76,336		-		4,276,336		51,102		-
Total of Affiliated Transactions		209,189,000		15,978,873		10,154,528		215,013,345	$	187,952	$	-

* At September 30, 2011, the Fund owned less than five percent of the company's outstanding voting shares.

Security	Acquisition Dates	Shares		Cost		Value
Union Agriculture Group	12/08/10		1,515,152	$	20,000	$	16,152
Canadian Overseas Petroleum	11/24/10		24,000,000		10,260		7,070
Canadian Overseas Petroleum - Warrants	11/24/10		12,000,000		1,502		662
Petrodorado - Warrants	11/20/09		17,144,000		2,118		357
Petromanas - Warrants	5/20/10		6,562,500		380		92
				$	34,260	$	24,333

(e) Illiquid security.

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

(g) On September 30, 2011, the market value of foreign securities represents 17.83% of total net assets. The Fund's foreign portfolio was diversified as follows:

	Value		Percent
Colombia	$	80,273		5.98
India		51,102		3.80
China		42,034		3.13
Canada		27,794		2.07
Argentina		16,152		1.20
Iraq		14,455		1.07
United Kingdom		7,732		0.58
Total Foreign Portfolio	$	239,542		17.83

Columbia Acorn Select

Statement of Investments (Unaudited), continued

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

• 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)

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

The following table summarizes the inputs used, as of September 30, 2011, 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
Consumer Goods & Services	$	308,845	$	18,724	$	-	$	327,569
Industrial Goods & Services		271,690		-		-		271,690
Information		240,210		-		-		240,210
Finance		186,584		-		-		186,584
Energy & Minerals		151,706		8,180		16,152		176,038
Other Industries		85,866		-		-		85,866
Health Care		35,210		-		-		35,210
Total Equities		1,280,111		26,904		16,152		1,323,167
Total Securities Lending Collateral		32,442		-		-		32,442
Total Investments	$	1,312,553	$	26,904	$	16,152	$	1,355,609

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
$	50,762	$	-	$	-	$	50,762

Financial assets were transferred from Level 2 to Level 1 as resale restrictions expired.

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

The following table reconciles asset balances for the nine months ending September 30, 2011, in which significant unobservable inputs (Level 3) were used in determining value:

Investments in Securities	Balance as of December 31, 2010		Realized Gain/(Loss)		Change in Unrealized Appreciation (Depreciation)			Purchases		Sales		Transfers into Level 3		Transfers out of Level 3		Balance as of September 30, 2011
Equities
Energy & Minerals	$	20,000	$	-	$	(3,848	)	$	-	$	-	$	-	$	-	$	16,152
	$	20,000	$	-	$	(3,848	)	$	-	$	-	$	-	$	-	$	16,152

The change in unrealized depreciation attributed to securities owned at September 30, 2011, which were valued using significant unobservable inputs (Level 3) amounted to $3,848.

Columbia Thermostat Fund

Statement of Investments (Unaudited), September 30, 2011

Number of Shares			Value (000)
		> Affiliated Stock Funds: 63.7%
	1,437,902	Columbia Dividend Income Fund, Class I	$	17,514
	512,910	Columbia Acorn International Fund, Class I		17,264
	501,194	Columbia Acorn Fund, Class I		12,871
	682,892	Columbia Marsico Growth Fund, Class I		12,572
	769,451	Columbia Large Cap Enhanced Core Fund, Class I		8,625
	677,414	Columbia Contrarian Core Fund, Class I		8,610
	395,830	Columbia Acorn Select Fund, Class I		8,562
Total Stock Funds: (Cost: $79,231)				86,018

Number of Shares			Value (000)
		> Affiliated Bond Funds: 35.8%
	2,623,446	Columbia Intermediate Bond Fund, Class I	$	24,215
	1,233,832	Columbia U.S. Treasury Index Fund, Class I		14,633
	1,040,371	Columbia Income Opportunities Fund, Class I		9,457
Total Bond Funds: (Cost: $47,009)				48,305
Total Investments: 99.5% (Cost: $126,240)(a)				134,323
Cash and Other Assets Less Liabilities: 0.5%				725
Total Net Assets: 100.0%			$	135,048

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

• 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)

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

The following table summarizes the inputs used, as of September 30, 2011, in valuing the Fund's assets:

Investment Type	Quoted Prices (Level 1)		Other Significant Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)		Total
Total Stock Funds	$	86,018	$	-	$	-	$	86,018
Total Bond Funds		48,305		-		-		48,305
Total Investments	$	134,323	$	-	$	-	$	134,323

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

Columbia Acorn Emerging Markets Fund

Statement of Investments (Unaudited), September 30, 2011

Number of Shares			Value (000)
			Equities: 87.4%
Asia 43.5%
		> Taiwan 12.9%
	26,990	Chroma Ate	$	55
		Automatic Test Systems, Testing & Measurement Instruments
	4,000	St. Shine Optical		49
		World's Leading Disposable Contact Lens OEM
	7,730	Simplo Technology		47
		Battery Packs for Notebook & Tablet PCs
	25,902	Far Eastone Telecom		38
		Taiwan's 3rd Largest Mobile Operator
	2,449	Formosa International Hotels		33
		Hotel, Food & Beverage Operation & Hospitality Management Services
	5,000	President Chain Store		28
		Taiwan's Number One Convenience Chain Store Operator
	9,277	Radiant Opto-Electronics		26
		LCD Back Light Modules
	11,085	Taiwan Hon Chuan		24
		Beverage Packaging (bottles, caps, labels) Manufacturer
	13,900	CTCI Corp		17
		International Engineering Firm
	4,800	Advantech		13
		Industrial PC & Components
	1,200	Lung Yen		3
		Funeral Services and Columbaria
				333
		> China 10.5%
	83,166	AMVIG Holdings		47
		Chinese Tobacco Packaging Material Supplier
	33,251	Digital China		43
		IT Distribution & Systems Integration Services
	1,000	Netease.com		38
		Chinese Online Gaming Services
	37,812	Jiangsu Expressway		29
		Chinese Toll Road Operator
	3,000	Noah Holdings - ADR		28
		Wealth Management Product Distributor in China
	451,892	RexLot Holdings		27
		Lottery Equipment Supplier in China
	7,538	ENN Energy		24
		China's Largest Private Gas Operator
	579	51job - ADR		23
		Integrated Human Resource Services
	10,727	China Yurun Food		11
		Meat Processor in China
				270
		> Hong Kong 8.9%
	219,935	Nagacorp		47
		Casino/Entertainment Complex in Cambodia
	48,909	Mongolian Mining (a)		43
		Coking Coal Mining in Mongolia
	16,865	Lifestyle International		43
		Mid to High-End Department Store Operator in Hong Kong & China

Number of Shares			Value (000)
	65,652	Sasa International	$	39
		Cosmetics Retailer
	4,137	Melco Crown Entertainment - ADR		34
		Macau Casino Operator
	33,000	Melco International		22
		Macau Casino Operator
				228
		> Philipines 4.6%
	189,156	SM Prime Holdings		53
		Shopping Mall Operator
	88,382	Manila Water Company		38
		Water Utility Company in the Philippines
	25,567	Int'l Container Terminal		27
		Container Handling Terminals & Port Management
				118
		> Indonesia 2.6%
	178,989	Ace Indonesia		67
		Home Improvement Retailer
				67
		> Japan 1.4%
	3,860	Kansai Paint		37
		Paint Producer in Japan, India, China and Southeast Asia
				37
		> Thailand 1.4%
	117,555	Home Product Center		35
		Home Improvement Retailer
				35
		> Singapore 1.2%
	27,403	Goodpack Limited		32
		International Bulk Container Leasing
				32
Asia: Total				1,120
Other Countries 17.8%
		> South Africa 12.3%
	9,580	Adcock Ingram Holdings		71
		Manufacturer of Pharmaceuticals and Medical Supplies
	24,626	Coronation Fund Managers		61
		South African Fund Manager
	39,175	Rand Merchant Insurance		61
		Directly Sold Property and Casualty Insurance; Holdings in Other Insurers
	11,354	Northam Platinum		46
		Platinum Mining in South Africa
	5,370	Mr. Price		44
		South African Retailer of Apparel, Household and Sporting Goods
	1,945	Massmart Holdings		33
		General Merchandise, Food, and Home Improvement Stores; Wal-Mart Subsidiary
				316
		> United States 3.0%
	645	Bristow		28
		Largest Provider of Helicopter Services to Offshore Oil and Gas Producers

Columbia Acorn Emerging Markets Fund

Statement of Investments (Unaudited), continued

Number of Shares			Value (000)
		> United States—continued
	752	Atwood Oceanics	$	26
		Offshore Drilling Contractor
	1,200	Textainer Group Holdings		24
		Top International Container Leasor
				78
		> Canada 2.5%
	3,100	Alliance Grain Traders		66
		Global Leader in Pulse Processing and Distribution
				66
Other Countries: Total				460
Europe 14.3%
		> Sweden 3.3%
	3,498	Hexagon		46
		Design, Measurement and Visualization Software and Equipment
	4,972	East Capital Explorer		38
		Sweden-Based RUS/CEE Investment Fund
				84
		> United Kingdom 2.6%
	62,959	Archipelago Resources (a)		67
		Gold Mining Projects in Indonesia, Vietnam, and the Philippines
				67
		> Czech Republic 2.5%
	352	Komercni Banka		65
		Leading Czech Universal Bank
				65
		> Switzerland 2.3%
	675	Dufry Group (a)		59
		Operates Airport Duty Free and Duty Paid Shops
				59
		> France 1.5%
	780	Rubis		39
		Tank Storage and LPG Distribution
				39
		> Kazakhstan 1.1%
	4,332	Halyk Savings Bank of Kazakhstan (a)		27
		Largest Retail Bank and Insurer in Kazakhstan
				27
		> Germany 1.0%
	824	Dürr		27
		Automotive Plant Engineering & Associated Capital Equipment
				27
Europe: Total				368
Latin America 11.8%
		> Brazil 8.5%
	4,436	Localiza Rent A Car		59
		Car Rental
	11,121	MRV Engenharia		57
		Brazilan Property Developer

Number of Shares			Value (000)
	4,617	Mills Estruturas e Servicos de Engenharia	$	43
		Civil Engineering & Construction
	7,431	Suzano - Preferred		33
		Brazilian Pulp and Paper Producer
	1,884	Multiplus		27
		Loyalty Program Operator in Brazil
				219
		> Mexico 2.3%
	1,203	Grupo Aeroportuario del Sureste - ADR		59
		Mexican Airport Operator
				59
		> Argentina 1.0%
	56,433	Madalena Ventures (a)		26
		Oil and Gas Exploration in Argentina
				26
Latin America: Total				304
Total Equities: 87.4% (Cost: $2,555)				2,252
			Exchange Traded Funds: 5.2%
India 5.2%
	3,065	EGShares India Small Cap ETF		45
	2,444	Wisdomtree India Earnings Index ETF		45
	3,649	Market Vectors India Small Cap Index ETF		43
India: Total				133
Total Exchange Traded Funds: 5.2% (Cost: $144)				133
Total Investments: 92.6% (Cost: $2,699)(b)(c)				2,385
Cash and Other Assets Less Liabilities: 7.4%				192
Total Net Assets: 100.0%			$	2,577

ADR = American Depositary Receipts

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

(a) Non-income producing security.

Currency	Value		Percentage of Net Assets
U.S. Dollar	$	420		16.3
Hong Kong Dollar		375		14.6
Taiwan Dollar		333		12.9
South African Rand		316		12.3
Brazilian Real		219		8.5
Other currencies less than 5% of total net assets		722		28.0
	$	2,385		92.6

• 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)

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

The following table summarizes the inputs used, as of September 30, 2011, 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	$	123	$	997	$	-	$	1,120
Other Countries		144		316		-		460
Europe		-		368		-		368
Latin America		304		-		-		304
Total Equities		571		1,681		-		2,252
Exchange Traded Funds
Asia		133		-		-		133
Total Exchange Traded Funds		133		-		-		133
Total Investments	$	704	$	1,681	$	-	$	2,385

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

Columbia Acorn Emerging Markets

Portfolio Diversification (Unaudited)

At September 30, 2011, the Fund's portfolio investments as a percentage of net assets were diversified as follows:

	Value (000)		Percentage of Net Assets
> Consumer Goods & Services
Retail	$	306		11.9
Casinos & Gaming		130		5.0
Other Consumer Services		69		2.6
Travel		59		2.3
Food & Beverage		38		1.5
Other Entertainment		33		1.3
		635		24.6
> Energy & Minerals
Mining		157		6.1
Agricultural Commodities		99		3.8
Oil Services		53		2.1
Oil Refining, Marketing & Distribution		39		1.5
Oil & Gas Producers		26		1.0
		374		14.5
> Information
Computer Hardware & Related Equipment		86		3.3
Instrumentation		56		2.1
Business Software		45		1.8
Electronics Distribution		44		1.7
Mobile Communications		38		1.5
Internet Related		38		1.5
		307		11.9
> Finance
Brokerage & Money Management		99		3.8
Banks		92		3.6
Insurance		60		2.4
Finance Companies		52		2.0
		303		11.8

	Value (000)		Percentage of Net Assets
> Other Industries
Real Estate	$	109		4.2
Transportation		88		3.4
Regulated Utilities		63		2.5
		260		10.1
> Industrial Goods & Services
Industrial Materials & Specialty Chemicals		107		4.2
Construction		60		2.3
Industrial Distribution		32		1.2
Other Industrial Services		27		1.1
Machinery		27		1.0
		253		9.8
> Health Care
Pharmaceuticals		71		2.8
Medical Supplies		49		1.9
		120		4.7
Total Equities:		2,252		87.4
Exchange Traded Funds:		133		5.2
Total Investments:		2,385		92.6
Cash and Other Assets Less Liabilities:		192		7.4
Net Assets:	$	2,577		100.0

Columbia Acorn European Fund

Statement of Investments (Unaudited), September 30, 2011

Number of Shares			Value (000)
			Equities: 92.7%
Europe 92.7%
		> France 22.2%
	1,580	1000mercis	$	78
		Interactive Advertising and Marketing
	1,100	Gemalto		52
		Digital Security Solutions
	600	Eurofins Scientific		46
		Food, Pharmaceuticals and Materials Screening and Testing
	590	Neopost		43
		Postage Meter Machines
	360	Norbert Dentressangle		28
		Leading European Logistics and Transport Group
	1,050	Teleperformance		22
		Call Center Operator
	420	Rubis		21
		Tank Storage and LPG Distribution
	720	Saft		20
		Niche Battery Manufacturer
	460	Mersen		18
		Advanced Industrial Materials
	4,670	Hi-Media (a)		15
		Online Advertiser in Europe
	220	Pierre & Vacances		9
		Vacation Apartment Lets
				352
		> United Kingdom 18.7%
	5,800	Chemring		47
		Defense Manufacturer of Countermeasures and Energetics
	1,400	Intertek Group		40
		Testing, Inspection, Certification Services
	17,220	Charles Taylor		37
		Insurance Services
	3,450	JLT Group		34
		International Business Insurance Broker
	5,430	GlobeOp Financial Services		24
		Hedge Fund Administrator
	3,000	Domino's Pizza United Kingdom & Ireland		21
		Pizza Delivery In UK, Ireland and Germany
	2,140	Serco		17
		Facilities Management
	5,020	Workspace Group		17
		UK Real Estate
	2,790	Abcam (a)		16
		Online Sales of Antibodies
	620	Rotork		15
		Valve Actuators for Oil & Water Pipelines
	2,540	Premier Oil (a)		14
		Oil and Gas Producer in Europe, Pakistan and Asia
	4,850	Cobham		13
		Aerospace Components
	160	Shaftesbury		1
		London Prime Retail REIT
				296

Number of Shares			Value (000)
		> Netherlands 16.8%
	1,340	Imtech	$	38
		Electromechanical and ICT Installation and Maintenance
	1,530	Unit 4 Aggresso		37
		Business Software Development
	770	Vopak		37
		World's Largest Operator of Petroleum and Chemical Storage Terminals
	2,420	Aalberts Industries		36
		Flow Control and Heat Treatment
	390	Core Laboratories		35
		Oil and Gas Reservoir Consulting
	1,910	Arcadis		35
		Engineering Consultants
	1,020	Koninklijke TenCate		31
		Advanced Textiles and Industrial Fabrics
	340	Fugro		17
		Sub-sea Oilfield Services
				266
		> Germany 10.6%
	2,880	Wirecard		44
		Online Payment Processing & Risk Management
	140	Rational		32
		Commercial Ovens
	560	Rheinmetall		26
		Defense & Automotive
	720	Elringklinger		17
		Automobile Components
	520	Dürr		17
		Automotive Plant Engineering & Associated Capital Equipment
	550	CTS Eventim		16
		Event Ticket Sales
	800	Rhoen-Klinikum		16
		Health Care Services
				168
		> Switzerland 7.7%
	290	Geberit (a)		53
		Plumbing Supplies
	15	Sika		27
		Chemicals for Construction & Industrial Applications
	160	Partners Group		26
		Private Markets Asset Management
	170	Dufry Group (a)		15
		Operates Airport Duty Free and Duty Paid Shops
				121
		> Sweden 4.8%
	5,250	Sweco		43
		Engineering Consultants
	2,460	Hexagon		32
		Design, Measurement and Visualization Software and Equipment
				75
		> Italy 2.8%
	10,650	CIR		20
		Italian Holding Company
	3,640	Geox		13
		Apparel and Shoe Maker
	130	Tod's		11
		Leather Shoes and Bags
				44

Columbia Acorn European Fund

Statement of Investments (Unaudited), continued

Number of Shares			Value (000)
		> Ireland 2.7%
	8,700	United Drug	$	27
		Irish Pharmaceutical Wholesaler & Outsourcer
	300	Paddy Power		15
		Irish Betting Services
				42
		> Portugal 2.0%
	11,230	Redes Energéticas Nacionais		32
		Portuguese Power Transmission and Gas Transportation
				32
		> Russia 1.6%
	860	Mail.ru - GDR (a)(b)		25
		Internet Social Networking and Games for Russian Speakers
				25
		> Belgium 1.0%
	300	EVS Broadcast Equipment		16
		Digital Live Mobile Production Software and Systems
				16
		> Norway 0.9%
	1,900	Atea		15
		Leading Nordic IT Hardware/Software Reseller and Installation Company
				15

Number of Shares			Value (000)
		> Greece 0.9%
	12,800	Intralot	$	15
		Lottery and Gaming Systems and Services
				15
		> Iceland —%
	400	Marel (a)		—
		Largest Manufacturer of Poultry and Fish Processing Equipment
				—
Europe: Total				1,467
Total Equities: 92.7% (Cost: $1,566)				1,467
Total Investments: 92.7% (Cost: $1,566)(c)(d)				1,467
Cash and Other Assets Less Liabilities: 7.3%				115
Total Net Assets: 100.0%			$	1,582

GDR = Global Depositary Receipts

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

(a) Non-income producing security.

(d) On September 30, 2011, the Fund's total investments were denominated in currencies as follows:

Currency	Value		Percentage of Net Assets
Euro	$	899		56.8
Pound Sterling		296		18.7
Swiss Franc		121		7.7
Other currencies less than 5% of total net assets		151		9.5
	$	1,467		92.7

• 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)

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

The following table summarizes the inputs used, as of September 30, 2011, 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	$	35	$	1,432	$	-	$	1,467
Total Equities		35		1,432		-		1,467
Total Investments	$	35	$	1,432	$	-	$	1,467

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

Columbia Acorn European Fund

Portfolio Diversification (Unaudited)

At September 30, 2011, the Fund's portfolio investments as a percentage of net assets were diversified as follows:

	Value (000)		Percentage of Net Assets
> Industrial Goods & Services
Other Industrial Services	$	201		12.7
Machinery		133		8.4
Industrial Machinery & Specialty Chemicals		93		5.9
Electrical Components		80		5.1
Conglomerates		56		3.5
Construction		54		3.4
Outsourcing Services		17		1.1
		634		40.1
> Information
Business Software		85		5.4
Business Information & Marketing Services		78		4.9
Computer Hardware & Related Equipment		52		3.3
Financial Processors		44		2.8
Internet Related		25		1.6
Telephone & Data Services		22		1.4
Advertising		15		0.9
Computer Services		15		0.9
		336		21.2
> Energy & Minerals
Oil Refining, Marketing & Distribution		58		3.7
Mining		35		2.2
Oil Services		17		1.1
Oil & Gas Producers		14		0.8
		124		7.8
> Finance
Insurance		71		4.5
Brokerage & Money Management		51		3.2
		122		7.7

	Value (000)		Percentage of Net Assets
> Consumer Goods & Services
Casinos & Gaming	$	30		1.9
Restaurants		21		1.4
Other Entertainment		16		1.0
Retail		15		0.9
Apparel		13		0.8
Nondurables		11		0.7
Travel		9		0.6
		115		7.3
> Other Industries
Regulated Utilities		31		2.0
Transportation		28		1.8
Real Estate		18		1.1
		77		4.9
> Health Care
Pharmaceuticals		27		1.7
Health Care Services		16		1.0
Medical Supplies		16		1.0
		59		3.7
Total Equities:		1,467		92.7
Total Investments:		1,467		92.7
Cash and Other Assets Less Liabilities:		115		7.3
Net Assets:	$	1,582		100.0

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Columbia Acorn Family of Funds

Third Quarter Class A, B, C, I, R and R5 Expense Information (Unaudited)

Columbia Acorn Fund	Class A			Class B*			Class C			Class I
Management Fees		0.64	%		0.64	%		0.64	%		0.64	%
Distribution and Service (12b-1) Fees		0.25	%		0.75	%		1.00	%		0.00	%
Other Expenses		0.16	%		0.36	%		0.18	%		0.07	%
Net Expense Ratio		1.05	%		1.75	%		1.82	%		0.71	%
Columbia Acorn International	Class A			Class B*			Class C			Class I			Class R†			Class R5†
Management Fees		0.76	%		0.76	%		0.76	%		0.76	%		0.76	%		0.76	%
Distribution and Service (12b-1) Fees		0.25	%		0.75	%		1.00	%		0.00	%		0.50	%		0.00	%
Other Expenses		0.29	%		0.46	%		0.30	%		0.17	%		0.28	%		0.26	%
Net Expense Ratio		1.30	%		1.97	%		2.06	%		0.93	%		1.54	%		1.02	%
Columbia Acorn USA	Class A			Class B*			Class C			Class I
Management Fees		0.86	%		0.86	%		0.86	%		0.86	%
Distribution and Service (12b-1) Fees		0.25	%		0.75	%		1.00	%		0.00	%
Other Expenses		0.16	%		0.39	%		0.18	%		0.08	%
Net Expense Ratio		1.27	%		2.00	%		2.04	%		0.94	%
Columbia Acorn International Select	Class A			Class B*			Class C			Class I
Management Fees		0.94	%		0.94	%		0.94	%		0.94	%
Distribution and Service (12b-1) Fees		0.25	%		0.75	%		1.00	%		0.00	%
Other Expenses		0.33	%		0.48	%		0.37	%		0.09	%
Net Expense Ratio		1.52	%		2.17	%		2.31	%		1.03	%
Columbia Acorn Select	Class A			Class B*			Class C			Class I
Management Fees		0.81	%		0.81	%		0.81	%		0.81	%
Distribution and Service (12b-1) Fees		0.25	%		0.75	%		1.00	%		0.00	%
Other Expenses		0.21	%		0.35	%		0.24	%		0.11	%
Net Expense Ratio		1.27	%		1.91	%		2.05	%		0.92	%
Columbia Thermostat Fund	Class A			Class B*			Class C
Management Fees		0.10	%		0.10	%		0.10	%
Distribution and Service (12b-1) Fees		0.25	%		0.75	%		1.00	%
Other Expenses**		0.15	%		0.15	%		0.15	%
Net Expense Ratio		0.50	%		1.00	%		1.25	%
Columbia Acorn Emerging Markets Fund	Class A			Class C			Class I
Management Fees		1.25	%		1.25	%		1.25	%
Distribution and Service (12b-1) Fees		0.25	%		1.00	%		0.00	%
Other Expenses		0.35	%		0.35	%		0.16	%
Net Expense Ratio		1.85	%		2.60	%		1.41	%
Columbia Acorn European Fund	Class A			Class C			Class I
Management Fees		1.19	%		1.19	%		1.19	%
Distribution and Service (12b-1) Fees		0.25	%		1.00	%		0.00	%
Other Expenses		0.31	%		0.31	%		0.12	%
Net Expense Ratio		1.75	%		2.50	%		1.31	%

See the Funds' prospectuses for information on minimum initial investment amounts and other details of buying, selling and exchanging shares of the Funds.

Fund	Class A			Class B			Class C			Class I
Columbia Acorn International Select		1.70	%		2.20	%		2.45	%		1.30	%
Columbia Acorn Select		1.60	%		2.10	%		2.35	%		1.25	%

These arrangements may be modified or terminated by either the Funds or CWAM upon 30 days notice.

Columbia Thermostat Fund's fees and expenses include the effect of CWAM's contractual undertaking to waive fees and/or reimburse the Fund for any ordinary operating expenses (exclusive of distribution and service fees, interest and fees on borrowings and expenses associated with the Fund's investments in other investment companies, but including custodian charges relating to overdrafts, if any), after giving effect to any balance credits from the Fund's custodian, in excess of the annual rate of 0.25% of the average daily net assets. Columbia Thermostat Fund's waiver/reimbursement arrangement is contractual through April 30, 2012. There is no guarantee that this arrangement will continue thereafter. Columbia Acorn Emerging Markets Fund's fees and expenses include the effect of CWAM's contractual undertaking to waive fees and/or reimburse the Fund so that its ordinary operating expenses (excluding interest and fees on borrowings and expenses associated with the Fund's investment in other investment companies, if any) do not exceed the annual rates of 1.85%, 2.60% and 1.41% of the Fund's average daily net assets attributable to Class A, Class C and Class I shares, respectively, through April 30, 2013. There is no guarantee that this arrangement will continue thereafter. Columbia Acorn European Fund's fees and expenses include the effect of CWAM's contractual undertaking to waive fees and/or reimburse the Fund so that its ordinary operating expenses (excluding interest and fees on borrowings and expenses associated with the Fund's investment in other investment companies, if any) do not exceed the annual rates of 1.75%, 2.50% and 1.31% of the Fund's average daily net assets attributable to Class A, Class C and Class I shares, respectively, through April 30, 2013. There is no guarantee that this arrangement will continue thereafter.

Columbia Acorn International's fees and expenses include the effect of the contractual undertaking of the Funds' transfer agent, effective August 12, 2011, to waive a portion of total annual Fund operating expenses attributable to transfer agency fees incurred by Class A, Class B and Class C shares of Columbia Acorn International such that the Fund's total annual Fund operating expenses will be reduced by 0.04%, 0.03% and 0.02% for Class A, Class B and Class C shares of the Fund, respectively, through August 14, 2013. There is no guarantee that this arrangement will continue thereafter.

* The Funds no longer offer Class B shares to new or existing investors (other than through dividend reinvestment).

** Does not include estimated fees and expenses of 0.65% incurred by the Fund from the underlying portfolio funds in which it invests.

† Class R and Class R5 shares of Columbia Acorn International commenced operations on August 15, 2011, in connection with the completed merger of two series of RiverSource International Managers Series, Inc. into Columbia Acorn International.

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

Allan B. Muchin

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 Adviser

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.

Columbia Acorn Funds are distributed by Columbia Management Investment Distributors, Inc., member FINRA and managed by Columbia Wanger Asset Management, LLC.

Find out what's new – visit our web site at:

www.columbiamanagement.com

Our e-mail address is:

ServiceInquiries@ColumbiaManagement.com

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PERMIT NO. 20

Columbia Management^®

Columbia Acorn Family of Funds
Class A, B, C, I, R and R5 Shares

Third Quarter Report, September 30, 2011

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

Prospectuses and the Statement of Additional Information (SAI)

Information Provided by the SEC

The investment company registration number of Columbia Acorn Trust, of which each of these Funds is a series, is 811-01829.

225 Franklin Street, Boston, MA 02110

800.345.6611 www.columbiamanagement.com

C-1448 A (11/11) 128294

Columbia Management^®

Columbia Acorn Family of Funds
Class A, B, C, I, R and R5 Shares

Third Quarter Report, September 30, 2011

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

Prospectuses and the Statement of Additional Information (SAI)

Information Provided by the SEC

The investment company registration number of Columbia Acorn Trust, of which each of these Funds is a series, is 811-01829.

225 Franklin Street, Boston, MA 02110

800.345.6611 www.columbiamanagement.com

C-1448 A (11/11) 128294

Columbia Management^®

Columbia Acorn Family of Funds
Class A, B, C, I, R and R5 Shares

Third Quarter Report, September 30, 2011

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

Prospectuses and the Statement of Additional Information (SAI)

Information Provided by the SEC

The investment company registration number of Columbia Acorn Trust, of which each of these Funds is a series, is 811-01829.

C-1448 A (11/11) 128294