Q1 2012

Columbia Acorn Family of Funds

Class Z Shares

Managed by Columbia Wanger Asset Management, LLC

First Quarter Report

March 31, 2012

n  Columbia
Acorn® Fund

n  Columbia
Acorn International®

n  Columbia
Acorn USA®

n  Columbia
Acorn International Select^SM

n  Columbia
Acorn Select^SM

n  Columbia
Thermostat Fund^SM

n  Columbia
Acorn Emerging Markets Fund^SM

n  Columbia
Acorn European Fund^SM

Not FDIC insured • No bank guarantee • May lose value

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

Save the Date!

We will be hosting our annual shareholder information meeting on September 19, 2012, in Chicago. The meeting will feature presentations by Columbia Acorn Fund's lead portfolio manager Chuck McQuaid and other members of Columbia Wanger Asset Management's investment team.

Meeting Location*

Offices of Drinker Biddle & Reath LLP
191 North Wacker Drive, Suite 3700
Chicago, Illinois.

Meeting Date & Time

Wednesday, September 19, 2012
12:00 p.m. CST

A buffet lunch will be served beginning at 11:30 a.m.

If you plan to attend, please RSVP by September 14 by calling (800) 922-6769.

Webcast Replay Available in October

For our many shareholders who are not able to attend the meeting, we will again provide a webcast replay of the event that can be accessed from our website, www.columbiamanagement.com, throughout the month of October.

If you have any questions about this event or any of your investments in our Columbia Acorn Funds, please call (800) 922-6769 to speak to a Columbia Acorn Funds shareholder representative.

*Up-to-date information on the Wacker Drive construction project can be found at www.wackerdrive.org. The meeting location is easily accessed via its Wacker Drive entrance but road repairs have closed other blocks of Wacker Drive.

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

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

Columbia Acorn Family of Funds

Table of Contents

Performance At A Glance	2
Descriptions of Indexes	3
Squirrel Chatter II: Genetic Science	4
Columbia Acorn Fund
In a Nutshell	8
At a Glance	9
Major Portfolio Changes	24
Statement of Investments	26
Columbia Acorn International
In a Nutshell	10
At a Glance	11
Major Portfolio Changes	40
Statement of Investments	42
Portfolio Diversification	51
Columbia Acorn USA
In a Nutshell	12
At a Glance	13
Major Portfolio Changes	52
Statement of Investments	53
Columbia Acorn International Select
In a Nutshell	14
At a Glance	15
Major Portfolio Changes	60
Statement of Investments	61
Portfolio Diversification	66
Columbia Acorn Select
In a Nutshell	16
At a Glance	17
Major Portfolio Changes	67
Statement of Investments	68
Columbia Thermostat Fund
In a Nutshell	18
At a Glance	19
Statement of Investments	73
Columbia Acorn Emerging Markets Fund
In a Nutshell	20
At a Glance	21
Major Portfolio Changes	75
Statement of Investments	77
Portfolio Diversification	81
Columbia Acorn European Fund
In a Nutshell	22
At a Glance	23
Major Portfolio Changes	82
Statement of Investments	83
Portfolio Diversification	87
Columbia Acorn Family of Funds
Columbia Acorn Family of Funds Information	88

1

Columbia Acorn Family of Funds

Performance At A Glance Class Z Average Annual Total Returns through 3/31/12

	NAV on 3/31/12		1st quarter*			1 year			5 years			10 years			Life of Fund
Columbia Acorn Fund (ACRNX) (6/10/70)	$	31.83		15.49	%		4.26	%		4.18	%		9.28	%		14.80	%
Russell 2500 Index				12.99	%		1.33	%		3.03	%		7.49	%		NA
S&P 500 Index**				12.59	%		8.54	%		2.01	%		4.12	%		10.68	%
Lipper Mid-Cap Growth Funds Index				14.99	%		1.19	%		4.83	%		6.25	%		NA
Columbia Acorn International (ACINX) (9/23/92)	$	39.48		15.07	%		-2.38	%		1.96	%		11.56	%		11.28	%
S&P Global Ex-U.S. Between $500M and $5B Index				13.97	%		-7.10	%		0.71	%		11.92	%		8.52	%
S&P Global Ex-U.S. SmallCap Index				14.86	%		-7.91	%		-0.73	%		11.19	%		7.77	%
Lipper International Small/Mid Growth Funds Index				14.60	%		-2.84	%		-0.11	%		10.18	%		NA
Columbia Acorn USA (AUSAX) (9/4/96)	$	31.40		16.38	%		2.88	%		3.21	%		7.29	%		10.40	%
Russell 2000 Index				12.44	%		-0.18	%		2.13	%		6.45	%		7.44	%
Russell 2500 Index				12.99	%		1.33	%		3.03	%		7.49	%		9.06	%
Lipper Small-Cap Growth Funds Index				14.16	%		1.35	%		3.16	%		5.19	%		6.02	%
Columbia Acorn Int'l Select (ACFFX) (11/23/98)	$	27.24		11.37	%		-2.06	%		1.77	%		10.74	%		9.37	%
S&P Developed Ex-U.S. Between $2B and $10B Index				11.98	%		-6.61	%		-1.92	%		9.20	%		7.25	%
MSCI EAFE Index				10.86	%		-5.77	%		-3.51	%		5.70	%		3.38	%
Lipper International Small/Mid Growth Funds Index				14.60	%		-2.84	%		-0.11	%		10.18	%		10.09	%
Columbia Acorn Select (ACTWX) (11/23/98)	$	27.80		17.70	%		-2.52	%		0.84	%		7.87	%		9.92	%
S&P MidCap 400 Index				13.50	%		1.98	%		4.78	%		7.70	%		9.44	%
S&P 500 Index**				12.59	%		8.54	%		2.01	%		4.12	%		3.29	%
Lipper Mid-Cap Growth Funds Index				14.99	%		1.19	%		4.83	%		6.25	%		6.56	%
Columbia Thermostat Fund (COTZX) (9/25/02)†	$	13.72		8.29	%		10.09	%		5.40	%		—			8.21	%
S&P 500 Index				12.59	%		8.54	%		2.01	%		—			8.00	%
Barclays U.S. Aggregate Bond Index				0.30	%		7.71	%		6.25	%		—			5.22	%
Lipper Flexible Portfolio Funds Index				8.90	%		2.88	%		3.42	%		—			7.88	%
50/50 Blended Benchmark				6.33	%		8.51	%		4.59	%		—			6.94	%
Columbia Acorn Emerging Markets Fund (CEFZX) (8/19/11)	$	10.95		18.00	%		—			—			—			9.50	%*
S&P Emerging Markets Between $500M and $5B Index				18.46	%		—			—			—			2.52	%*
MSCI Emering Markets Small Cap Index				16.63	%		—			—			—			-2.79	%*
Lipper Emerging Markets Index				14.55	%		—			—			—			6.75	%*
Columbia Acorn European Fund (CAEZX) (8/19/11)	$	11.11		17.69	%		—			—			—			12.07	%*
S&P Europe Between $500M and $5B Index				17.80	%		—			—			—			9.35	%*
HSBC Smaller European Companies Index				17.44	%		—			—			—			6.24	%*
Lipper European Region Index				13.97	%		—			—			—			12.56	%*

*Not annualized.

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

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

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

Annual operating expense ratios are stated as of each Fund's prospectus dated May 1, 2011, 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 (underlying funds), 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. See Page 88 for more information about the Funds' fees and expenses.

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

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

2

Columbia Acorn Family of Funds

Descriptions of Indexes Included in this Report

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

3

Squirrel Chatter II: Genetic Science

Genetic theory began with Gregor Mendel, a friar who in the middle 19th century meticulously bred different types of peas and tracked traits of offspring. He discovered recessive genes, which are carried by one generation but expressed in the next if both parents have that gene. Human genetic studies began a few decades later. In 1872, Huntington's disease was the first genetic disease identified by scientific research.¹

Humans normally have 23 pairs of chromosomes, with half of each pair inherited from each parent. The chromosomes combined consist of over 20,000 genes. These genes ultimately consist of over 3 billion units of four different nitrogenous bases, labeled by their first letters: A, G, C and T.²

DNA, the double helix structure of bases assembled into genes, was discovered by James Watson and Francis Crick in 1953. Various genes were identified over the next several decades. The Human Genome Project, an effort to sequence and identify all genes and bases in human DNA, started in 1990. After $2.7 billion of expenditures over 13 years, a composite genome from three people was specified.³

Gene Sequencing

Kevin Davies' book, The $1,000 Genome, discusses the incredible progress made in gene sequencing technology. First generation sequencing used bacteria to purify and grow DNA fragments utilizing equipment made by Applied Biosystems, which dominated the market for 15 years.⁴ Hundreds of machines labored for years to complete the Human Genome Project sequencing, at a direct cost of tens of millions of dollars.⁵

A company called 454 Life Sciences, later acquired by Roche, developed a second generation sequencer. Utilizing a semiconductor chip with thousands of wells, DNA fragments were sequenced in parallel via real-time image processing. First shipped in 2005, the $500,000 machines then sold as fast as they could be built. James Watson's genome was sequenced in 2007 at a cost of $1 million.⁶

In 2006, Solexa shipped a sequencing machine that also sequenced in parallel, but had throughput and cost advantages. Illumina bought Solexa later that year. By 2007, the equipment could sequence a human's DNA at a cost of $100,000.⁷ Illumina subsequently created faster and more accurate machines. In early 2010, it pushed the cost of human genome sequencing down to $10,000.⁸ Service company Knome currently offers full genome sequencing via Illumina equipment, plus interpretation of results, for $4,998.⁹ Roche recently attempted to acquire Illumina.¹⁰

Third generation machines, often utilizing nanotechnology as well as parallel sequencing and faster data processing chips, should cut the cost of sequencing a human genome to well below $1,000, Davies notes.¹¹ Pacific Biosciences of California claimed a potential 30,000-fold speed increase via sequencing in real time as DNA is replicated.¹² Another company, Oxford Nanopore, was working on sequencing via measurement of electric current passing through bases.¹³ Ion Torrent Systems measures the pH of bases streaming through pores.¹⁴

Davies calculated that the cost of DNA sequencing fell 50% a year through 2005, and then by an amazing 90% a year due to a series of disruptive technologies.¹⁵ He does not predict when a hand-held "Star Trek Medical Tricorder," capable of reading the DNA of a patient and his disease and then prescribing personalized medicine, will be available, but the world seems headed in that direction.

Personal Genomic Services

It doesn't take a full genome sequence to determine genetic characteristics such as ancestry and possible risks of disease. In November 2007, deCODEme and 23andMe launched competing $1,000 services. Processing cheek swab or saliva DNA on equipment utilizing specialized chips, they sampled up to 600,000 bases, 0.02% of the total, and looked for differences in bases between people, called single nucleotide polymorphisms (SNPs).¹⁶ By correlating SNPs with known ancestry and disease databases, the companies provided statistical probabilities to clients based on their DNA samples.

Since 2007, deCODEme has had financial problems; it currently offers the service for $1,100, including updates.¹⁷

4

23andMe currently charges $207 for an initial sampling and a one-year subscription for updates. According to its website, 23andMe provides probabilities for 118 diseases, shows likely responses to 20 drugs, and determines whether clients' children could be at risk for any of 44 inherited diseases.¹⁸ Navigenics has also entered the market and provides genetic counseling as well as data.

The personal genomic services companies update disease probabilities as additional data is analyzed. Probabilities can and do change, sometimes drastically, as new correlations and additional SNPs are incorporated into a person's profile. It's somewhat disconcerting that, according to Davies, Navigenics and 23andMe disagree qualitatively on one-third of diseases.¹⁹

As more of the population gets increasingly more genes sequenced, more data becomes available and the relationships between genes, health and responses to drugs become better known. Full genome sequencing will likely show an average of three million SNPs per person,²⁰ creating an enormous data management problem as well as new understandings of relationships between genes and diseases.

Limits to Predicting Diseases

Recent research published in Science Translational Medicine titled, "The Predictive Capacity of Personal Genome Sequencing,"²¹ ingeniously addressed the theoretical potential for genes to predict common diseases. The underlying question was, of course, what are the odds of someone with a specific genome getting a specific disease? According to the study, the answer can be determined by studying pairs of people with nearly identical genomes: identical twins. By comparing histories of 24 common diseases among identical twins versus fraternal twins, genetic determination of diseases were inferred.

The study concluded that for 19 of the 24 diseases a negative test score (below average risk) will hardly be reassuring because the odds of getting the disease will still be substantial, at 50% to 80% of the general population's odds. Over half of the ultimate victims of 12 diseases would have tested at below average risk, receiving a false sense of security. However, there was one disease category tested in the study, Alzheimer's disease, in which a negative test result might indicate as little as a 12% relative risk of disease compared to the general population.

Those testing positive for Alzheimer's, type 1 diabetes, male coronary heart disease and thyroid autoimmunity could account for over 75% of the patients developing the diseases. The study suggested that the utility of genetic tests will depend on the results of the individual tested, and cautions against complacency and unwise lifestyle choices for those testing negative.

I agree that some subscribers to personal genetics services could obtain valuable results. If, for example, someone learned that his probability of developing glaucoma was much higher than the 4% probability for the average person, the subscriber would more likely get regular glaucoma testing. This is of some value, assuming the stated odds are indeed properly calibrated, which may take years to confirm.

Inherited Diseases

Some inherited diseases, including cystic fibrosis, Tay-Sachs disease and sickle cell anemia, occur only when single defective genes are inherited from each parent. Other single gene diseases, such as Huntington's, are inherited with 50% odds of getting the gene and disease if just one parent is afflicted.

Dozens of rare genetic diseases affect newborns, many of which can be addressed by diet or vitamins.²² Quick diagnosis is often crucial as permanent damage can occur otherwise. As of March 2010, newborns were tested for 29 genetic diseases in most states.²³

Sometimes only a tendency to contract a disease is inherited. One version of a specific gene mutation implies a 65% to 85% lifetime probability of a woman developing breast cancer, while another version implies a 45% to 85% probability.²⁴ However, only 5% to 10% of breast cancer patients have those genes.²⁵ Others get the disease with no apparent genetic correlation. Having those genes is a cause for concern, but not having them should not provide a lot of comfort.

Personalized Medicine

In 2003, Allen Roses, vice-president of genetics for GlaxoSmithKline, shocked consumers by stating that more than 90% of drugs work in just 30% to 50% of people.²⁶

5

Roses was pushing the drug industry to pursue genetic testing rather than trial and error to determine which drugs work for a specific individual. Matt Ridley, in the 2006 version of his book, Genome, stated, "genetic diagnosis followed by conventional cure is probably the genome's greatest boon to medicine."²⁷

Indeed, the lung cancer drug Iressa was approved in 2003 and creates a "miraculous response" in the 10% of patients with a specific genetic mutation of the disease. Herceptin was approved in 2006 to target the 25% of breast cancer patients who are afflicted with a specific genetic version of that disease. Likewise, targeted cancer drugs such as Avastin, Tarceva and Erbitux, are prescribed after genetic testing.²⁸

On January 31, 2012, Kalydeco was approved to treat 1,200 cystic fibrosis patients, 4% of the total, who have a specific gene defect. It is the first drug to treat the defect rather than the symptoms of the disease, and has been termed "transformational" for those who can use it.²⁹ The Cystic Fibrosis Foundation spurred development of the drug by helping to fund the development effort, and aided the process by creating a registry that includes the genetic characteristics of the disease for 90% of American patients.

Some drugs appear to work for most people, but have widely varying optimal dosages. Variations in genes largely determine how quickly people metabolize drugs.³⁰ "Unanticipated drug responses are estimated to result in two million hospitalizations and 100,000 deaths in the United States each year," writes Nicholas Gillham in his book, Genes, Chromosomes, and Disease.³¹

In the case of blood thinner warfarin (brand name Coumadin), patients exhibit a tenfold range in ability to metabolize the drug.³² Too little of it can result in a stroke, but too much can cause bleeding and hemorrhaging.³³ The FDA now provides dosage information on the drug's label based on variants of two genes.³⁴ About 10% of labels for FDA-approved drugs now have pharmacogenomics information.³⁵

Investment Implications

Genetic science is rapidly advancing and will likely revolutionize many aspects of medical care. It is starting to be helpful in predicting susceptibility to common diseases, but will likely be more valuable in identifying risks of inherited diseases and in determining appropriate drug usage and dosage. Given the complexity of the subject, there will likely be increasing demands for genetic counselors.

There exists uncertainty regarding how the FDA and others will regulate genetic tests, as well as the extent to which genetic discoveries will be patentable. On the investment front, we have looked for and invested in opportunities created by genetic science. We've focused on a number of biotechnology and drug companies addressing personalized medicine and niche orphan diseases and we will continue to look for additional opportunities.

Charles P. McQuaid

President and Chief Investment Officer
Columbia Wanger Asset Management, LLC

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

¹  Gillham, Nicholas Wright, Genes, Chromosomes, and Disease, (Upper Saddle River, New Jersey, FT Press Science 2011) p. 5.

²  Davies, Kevin, The $1,000 Genome, (New York, New York, Free Press 2010) p. 1, 23.

³  Ibid., p. 9-11.

⁴  Ibid., p. 79.

⁵  Ibid., p. 90.

⁶  Ibid., p. 94.

⁷  Ibid., p. 111.

⁸  Gillham, Nicholas Wright, op. cit., p. 244.

⁹  Davies, Kevin, op. cit., p. 209. www.knome.com.

¹⁰  Falconi, Marta, "Roche To Return Tendered Illumina Shares to Shareholders," Dow Jones News Service, April 23, 2012.

¹¹  Davies, Kevin, op. cit., p. 231.

¹²  As of March 31, 2012, Pacific Biosciences of California was held in two Columbia Acorn Funds: Columbia Acorn Fund (less than 0.1% of assets) and Columbia Acorn USA (0.1% of assets). The company's shares are also held in other funds and accounts managed by CWAM.

¹³  Davies, Kevin, op. cit., p. 239.

¹⁴  Ibid., p. 245-246.

¹⁵  Ibid., p. 133. Disruptive technologies refers to making much more than incremental advances by utilizing a whole new or additional approach. In this context, the parallel sequencing and use of other detection mechanisms such as pH or electric conductivity have caused the cost of sequencing to plunge far faster than a regular learning curve might suggest.

6

¹⁶  Ibid., p. 31-32.

¹⁷  Ibid., p. 55,63. www.decodeme.com.

¹⁸  www.23andme.com.

¹⁹  Davies, Kevin, op. cit., p. 149.

²⁰  Ibid., p. 23.

²¹  Roberts, Nicholas J., and Vogelstein, Joshua T., et al, "The Predictive Capacity of Personal Genome Sequencing," Science Translational Medicine, Rapid Publication, April 2, 2012, stm.sciencemag.org.

²²  Gillham, Nicholas Wright, op. cit., p. 204.

²³  Ibid., p. 201.

²⁴  Ibid., p. 184.

²⁵  Ibid., p. 116.

²⁶  Connor, Steve, "Glaxo Chief: Our Drugs Do Not Work On Most Patients," The Independent, December 8, 2003.

²⁷  Ridley, Matt, Genome, (New York, New York, First Harper Perennial, 2006) p. 257.

²⁸  Davies, Kevin, op. cit., p. 255-256.

²⁹  Usdin, Steve, "Product Discovery & Development: Kalydescopic Vision," BioCentury, March 5, 2012, Volume 20, Number 10, p. A2.

³⁰  Davies, Kevin, op. cit., p. 257.

³¹  Gillham, Nicholas Wright, op. cit., p. 237.

³²  Davies, Kevin, op. cit., p. 257.

³³  Gillham, Nicholas Wright, op. cit., p. 238.

³⁴  Davies, Kevin, op. cit., p. 257.

³⁵  Hamburg, M.D., Margaret A., and Collins, M.D., Ph.D., Francis S., "The Path to Personalized Medicine," New England Journal of Medicine, July 22, 2010, Volume 363, p. 301-304, www.nejm.org.

7

Columbia Acorn Fund

In a Nutshell

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

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

Fund Positions
in Mentioned Holdings

As a percentage of net assets, as of 3/31/12

lululemon athletica	2.0	%
Informatica	1.4	%
Alexion Pharmaceuticals	1.2	%
Amphenol	1.1	%
Coach	0.9	%
PVH	0.8	%
Pentair	0.8	%
IPG Photonics	0.8	%
Pacific Rubiales Energy	0.7	%
Equinix	0.5	%
World Acceptance	0.5	%
Deckers Outdoor	0.4	%
MGM China Holdings	0.1	%

Columbia Acorn Fund jumped 15.49% in the first quarter of 2012, outperforming its primary benchmark, the Russell 2500 Index, which was up 12.99%. The Fund beat the Lipper Mid-Cap Growth Funds Index by a lesser amount, as that index grew 14.99%. See Page 2 for additional performance data.

Two important factors that had caused the Fund to underperform its benchmark modestly in 2011 reversed in the first quarter of 2012. Columbia Acorn Fund's international stocks, which substantially underperformed domestic stocks in 2011, outperformed somewhat in the first quarter. The Fund had little invested in utility stocks during both periods; relative performance was hurt in 2011 when utility stocks outperformed, but was helped in the first quarter as utility stocks underperformed. We thought foreign stocks were attractive and utility stocks were expensive during both periods, kept our convictions, and shareholders were rewarded in the quarter.

Our stock picking was also good, especially in technology. Enterprise data integration software provider Informatica jumped 43% in the quarter on a 23% earnings gain and what appeared to be fine prospects for selling more software to existing customers. Data center company Equinix rose steadily and ended the quarter up 55% as demand and pricing remained strong. Electronic connector maker Amphenol plugged into better-than-expected earnings and increasing expectations for profit margins, rising 32%. Fiber optic laser equipment producer IPG Photonics had a 54% gain due to improving Chinese orders and a better-than-expected outlook.

Consumer durables stocks also helped performance, due to both stock picking and the Fund's modest overweighting versus its benchmark. lululemon athletica, a premium active wear retailer, soundly refuted naysayers (who had been concerned about increasing inventories) when it announced same-store sales up 26% during its fiscal quarter; the stock surged 60% during the calendar quarter and was by far the Fund's largest dollar winner. Other successful consumer durable stocks were Coach, a branded leather accessories retailer, and PVH, an apparel wholesaler and retailer, both up 27% on fine earnings.

Several individual stocks were standouts. Biotech company Alexion Pharmaceuticals rose 30% as the company reported earnings more than doubling, revenues growing 46% (both versus the prior year December quarter), and positive drug studies. Pentair, a manufacturer of pumps and water treatment equipment, appreciated 43% in the quarter, during which it agreed to merge with Tyco's flow control division.

The Fund's worst dollar loser during the quarter was World Acceptance, a finance company offering personal loans, which fell 17%, despite a 15% earnings gain, as same-store growth decelerated and investors became concerned about the possibility of new regulations. Footware company Deckers Outdoor, also down 17%, fell on concerns about costs.

As previously mentioned, international stocks generally recovered during the quarter. Oil production and exploration company Pacific Rubiales Energy, which had lagged in 2011, gained 59% on increased production and higher reserves. Macau casino operator MGM China Holdings booked a 49% win on fine growth. Columbia Acorn Fund's international stocks had a 17.24% gain in the quarter and accounted for 9.4% of Fund assets at the end of the quarter.

Most of the Fund's portfolio companies continue to report favorable business conditions. During the quarter we recycled some dollars from large successful holdings to smaller, and what we believe to be cheaper, stocks that could enhance long-term returns.

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

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

8

Columbia Acorn Fund (ACRNX)

At a Glance

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

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

through March 31, 2012

Inception 6/10/70	Year to date*			1 year			5 years			10 years
Returns before taxes		15.49	%		4.26	%		4.18	%		9.28	%
Returns after taxes on distributions		15.49			3.59			3.62			8.69
Returns after taxes on distributions and sale of fund shares		10.07			3.53			3.50			8.14
Russell 2500 Index (pretax)**		12.99			1.33			3.03			7.49

All results shown assume reinvestment of distributions.

*Year to date data is not annualized.

**The Fund's primary benchmark.

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

The Fund's Class Z annual operating expense ratio, as stated in the May 1, 2011, prospectus, is 0.76%.

Columbia Acorn Fund Portfolio Diversification

as a percentage of net assets, as of 3/31/12

Columbia Acorn Fund Top 10 Holdings

as a percentage of net assets, as of 3/31/12

1.	lululemon athletica Premium Active Apparel Retailer	2.0	%
2.	Ametek Aerospace/Industrial Instruments	1.8	%
3.	Donaldson Industrial Air Filtration	1.6	%
4.	Mettler Toledo Laboratory Equipment	1.6	%
5.	FMC Technologies Oil & Gas Wellhead Manufacturer	1.5	%
6.	Informatica Enterprise Data Integration Software	1.4	%
7.	Crown Castle International Communications Towers	1.3	%
8.	Alexion Pharmaceuticals Biotech Focused on Orphan Diseases	1.2	%
9.	tw telecom Fiber Optic Telephone/Data Services	1.1	%
10.	Amphenol Electronic Connectors	1.1	%

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

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

June 10, 1970 through March 31, 2012

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

Total Net Assets of the Fund: $18.4 billion

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

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

9

Columbia Acorn International

In a Nutshell

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

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

Fund's Positions
in Mentioned Holdings

As a percentage of net assets, as of 3/31/12

Melco Crown Entertainment	1.5	%
Gemalto	1.1	%
Localiza Rent A Car	1.1	%
Eurofins Scientific	0.7	%
Start Today	0.5	%
Celtic Exploration	0.2	%
Gree	0.1	%
Manappuram Finance	0.0	%*

*Rounds to less than 0.1%.

Columbia Acorn International regained some of the ground lost in 2011, finishing the first quarter of 2012 up 15.07%. The Fund's primary benchmark, the S&P Global Ex-U.S. Between $500M and $5B Index, gained 13.97% in the quarter. Returns were driven foremost by a reversal of fortune for European and emerging market stocks, which stood out as poor performers in 2011. Investor anxiety regarding the future of the common European currency abated as the European Central Bank's long-term refinancing operations bought policymakers more time to craft fiscal solutions to the sovereign debt crisis. In key emerging markets, where high food inflation in recent years underpinned monetary tightening, the policy bias now appears to be distinctly in the direction of easing, which lowers costs of capital and equity discount rates, and is therefore generally good for equities.

Strong performers in the first quarter included Melco Crown Entertainment, a Macau-based casino that rose over 40% as mainland and Hong Kong gamblers continued to visit the baccarat tables despite fears of an economic slowdown. Brazilian auto rental company, Localiza Rent A Car, appreciated nearly 35% in U.S. dollar terms on the back of strong volume demand and improving financing costs. In Europe, Gemalto, a French provider of digital security solutions, rose 35% as its smart card solutions appeared increasingly well positioned to play an important role in evolving payment technologies. Another French company, Eurofins Scientific, jumped nearly 50% on steadily improving profitability in its core food and pharmaceutical testing business, which led management to revise expectations upwards.

On the downside, Japanese companies Start Today and Gree both fell over 20% on profit-taking after stellar returns in 2011. In India, Manappuram Finance declined 28% in the Fund on the announcement of new Indian regulations designed to constrain the growth of the gold loan industry. We believe there is probably more regulatory bad news in the pipeline and have exited the position. A number of small energy exploration companies declined sharply, including Celtic Exploration in Canada. Celtic Exploration suffered from weak North American natural gas prices and negative sentiment on energy stocks, as relatively high oil prices raised the specter that oil demand could slow.

Our strategy is to generally buy businesses with better-than-average economics and exposure to dislocations in their respective industries that confer an opportunity for growth over a three-year period, or longer. Additionally, we prefer balance sheets that allow businesses fitting this profile to execute a business plan regardless of capital market gyrations. We believe this strategy is well-suited to the present environment, characterized by high macroeconomic uncertainty, but also reasonable valuations.

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

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

10

Columbia Acorn International (ACINX)

At a Glance

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

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

through March 31, 2012

Inception 9/23/92	Year to date*			1 year			5 years			10 years
Returns before taxes		15.07	%		-2.38	%		1.96	%		11.56	%
Returns after taxes on distributions		15.07			-3.02			1.42			11.00
Returns after taxes on distributions and sale of fund shares		9.79			-1.34			1.63			10.32
S&P Global Ex-U.S. Between $500M and $5B Index**		13.97			-7.10			0.71			11.92

All results shown assume reinvestment of distributions.

*Year to date data is not annualized.

**The Fund's primary benchmark.

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

The Fund's Class Z shares annual operating expense ratio, as stated in the May 1, 2011, prospectus, is 0.98%.

Columbia Acorn International Portfolio Diversification

as a percentage of net assets, as of 3/31/12

Columbia Acorn International Top 10 Holdings

as a percentage of net assets, as of 3/31/12

1.	Melco Crown Entertainment - ADR (Hong Kong) Macau Casino Operator	1.5	%
2.	Hexagon (Sweden) Measurement Equipment	1.2	%
3.	Far EasTone Telecom (Taiwan) Taiwan's Third Largest Mobile Operator	1.2	%
4.	Gemalto (France) Digital Security Solutions	1.1	%
5.	Localiza Rent A Car (Brazil) Car Rental	1.1	%
6.	Naspers (South Africa) Media in Africa & other Emerging Markets	1.0	%
7.	Intertek Group (United Kingdom) Testing, Inspection & Certification Services	0.9	%
8.	Alexion Pharmaceuticals (United States) Biotech Focused on Orphan Diseases	0.9	%
9.	Kansai Paint (Japan) Paint Producer in Japan, India, China & Southeast Asia	0.9	%
10.	Imtech (Netherlands) Electromechanical & ICT Installation & Maintenance	0.9	%

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

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

September 23, 1992 through March 31, 2012

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

Total Net Assets of the Fund: $6.3 billion

11

Columbia Acorn USA

In a Nutshell

Robert A. Mohn

Lead Portfolio Manager

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

Fund's Positions
in Mentioned Holdings

As a percentage of net assets, as of 3/31/12

lululemon athletica	3.1	%
Informatica	2.7	%
Nordson	2.3	%
Mettler Toledo	1.9	%
II-VI	1.7	%
Pentair	1.6	%
IPG Photonics	1.5	%
World Acceptance	1.2	%
Quicksilver Resources	0.2	%
Chelsea Therapeutics International	0.1	%
True Religion Apparel	0.1	%
Houston American Energy	0.1	%

Columbia Acorn USA ended the first quarter of 2012 up 16.38%, outperforming the 12.44% gain of its primary benchmark, the Russell 2000 Index. Several Fund stocks that fell in the fourth quarter of 2011 on general economic fears snapped back in the first quarter of 2012, boosting the Fund's relative return.

Three of the four top contributors to Fund performance in the first quarter were stocks that had missed out on the generally bullish market trend in the fourth quarter: lululemon athletica, Informatica and IPG Photonics. lululemon athletica announced fourth quarter same-store sales growth up 26% over the prior year, as the company continued to benefit from growing awareness of its premium active apparel brand. Its stock was up 60% in the first quarter. Enterprise data integration software provider Informatica fell in the fourth quarter, as a weak sales report from a major competitor brought down the entire sector. But Informatica won back investor confidence in the first quarter after announcing a 23% earnings gain, which sent its stock up 43%. Up 54% in the first quarter, IPG Photonics experienced accelerating sales of its fiber lasers to U.S. automotive manufacturers, driving revenues up 22% over the prior year.

Concerns about the global economy eased in the first quarter, benefitting several Fund industrial stocks, especially those with a significant presence in non-U.S. markets. Nordson manufactures dispensing systems for adhesives and coatings and saw its stock gain 33% in the first quarter. Mettler Toledo, a maker of laboratory equipment, rose 25% in the quarter. II-VI, a manufacturer of laser optics, had a 29% gain in the quarter. Each of these stocks announced better-than-expected earnings for the quarter.

Rounding out the list of first-quarter winners was Pentair, a manufacturer of pumps and water treatment equipment. Its stock rose more than 40% on the announcement of plans to merge with Tyco's flow control business. Generally, the Fund enjoys a boost from merger activity when one of its holdings gets acquired by a larger suitor. In this case, however, Pentair was the suitor and was able to structure a highly accretive deal.

Laggards in the first quarter included personal lender World Acceptance, down 17% on moderating same-store revenue growth and concerns about possible new regulations that could be imposed by the Consumer Financial Protection Bureau. Off 51%, Chelsea Therapeutics International, a biotech company focused on rare diseases, collapsed when its main drug, Northera, was rejected by the FDA. Premium denim retailer True Religion Apparel announced earnings down 10% from the prior year, sending its stock down 20% in the first quarter.

Two of the Fund's oil and gas producers were among the laggards in the first quarter, but for different reasons. Houston American Energy fell 57% after announcing poor results at an important test well in Colombia. Quicksilver Resources, a natural gas and coal seam gas producer, fell 25%, dragged down by the ever-plunging price of natural gas.

Small-cap stocks appear to be reasonably valued, the economic outlook looks favorable, and investor sentiment seems to be fairly sedate. While the past is not a predictor of the future, historically, this combination of factors has, at times, ushered in reasonably good gains for small-cap stocks.

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

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

12

Columbia Acorn USA (AUSAX)

At a Glance

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

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

through March 31, 2012

Inception 9/4/96	Year to date*			1 year			5 years			10 years
Returns before taxes		16.38	%		2.88	%		3.21	%		7.29	%
Returns after taxes on distributions		16.38			2.78			2.90			7.01
Returns after taxes on distributions and sale of fund shares		10.65			1.97			2.71			6.40
Russell 2000 Index (pretax)**		12.44			-0.18			2.13			6.45

All results shown assume reinvestment of distributions.

*Year to date data is not annualized.

**The Fund's primary benchmark.

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

The Fund's Class Z shares annual operating expense ratio, as stated in the May 1, 2011, prospectus, is 1.01%.

Columbia Acorn USA Portfolio Diversification

as a percentage of net assets, as of 3/31/12

Columbia Acorn USA Top 10 Holdings

as a percentage of net assets, as of 3/31/12

1.	lululemon athletica Premium Active Apparel Retailer	3.1	%
2.	Informatica Enterprise Data Integration Software	2.7	%
3.	Ametek Aerospace/Industrial Instruments	2.4	%
4.	Nordson Dispensing Systems for Adhesives & Coatings	2.3	%
5.	Micros Systems Information Systems for Restaurants & Hotels	2.2	%
6.	Mettler Toledo Laboratory Equipment	1.9	%
7.	Atwood Oceanics Offshore Drilling Contractor	1.8	%
8.	tw telecom Fiber Optic Telephone/Data Services	1.8	%
9.	Donaldson Industrial Air Filtration	1.8	%
10.	II-VI Laser Optics & Specialty Materials	1.7	%

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 USA (Class Z)

September 4, 1996 through March 31, 2012

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

Total Net Assets of the Fund: $1.8 billion

13

Columbia Acorn International Select

In a Nutshell

Christopher J. Olson

Lead Portfolio Manager

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

Fund's Positions
in Mentioned Holdings

As a percentage of net assets, as of 3/31/12

Ascendas REIT	6.1	%
Kansai Paint	5.6	%
Mapletree Industrial Trust	5.2	%
Rand Merchant Insurance	5.0	%
Seven Bank	4.3	%
Hexagon	3.4	%
Archipelago Resources	2.8	%
Mapletree Logistics Trust	2.4	%
Imtech	2.2	%
Intertek Group	2.1	%
Rheinmetall	1.9	%
Novozymes	1.2	%
Taiwan Mobile	1.0	%
Gree	0.4	%

Columbia Acorn International Select ended the first quarter of 2012 up 11.37%, slightly behind the 11.98% gain of its primary benchmark, the S&P Developed Ex-U.S. Between $2B and $10B Index. Last year's fears of a global recession and a European currency crisis eased in the first quarter as central banks around the world took additional steps to provide liquidity to the global markets, which eased deflationary concerns. Yet the underlying global economic outlook remains questionable and, as a result, the Fund's portfolio remains focused on more defensive, secular growth companies with good dividend yields and strong balance sheets. Also, as much of the global debt problem is centered in developed markets, the Fund is underweight in areas such as Europe, the United Kingdom and Japan, with overweights in Asia ex-Japan and emerging markets.

Fund industrial stocks performed well in the quarter on the back of greater confidence in global economic growth. Based in the Netherlands, Imtech, a provider of electromechanical, information and communication technology services, was up 23% for the quarter on a more optimistic European outlook. UK testing, inspection and certification services provider Intertek Group gained 27% in the first quarter as new regulations and product quality requirements continued to benefit its business and recent acquisitions began to make a significant impact. Finally, Germany's Rheinmetall, a provider of defense and automotive supplies, bounced back after a dismal 2011. Its stock rose 34% in the quarter.

Financial stocks also helped the Fund despite its lack of exposure to commercial banks, which were a primary beneficiary of central bank intervention. Rand Merchant Insurance, a South African insurance company, led gains with a 38% return for the first quarter. The market is just getting to know the company's world-class car and home insurance business after spinning out of Rand Merchant Bank last year. Singapore's Ascendas REIT, Mapletree Industrial Trust and Mapletree Logistics Trust had gains ranging from 8% to 18%. These industrial property landlords benefited from an improved Singaporean economic outlook and investor interest in their roughly 7% dividend yields. Rounding out the list of financial winners, Japan's Seven Bank, a provider of ATM processing services, rose 14% as it continued to expand its ATM network throughout Japan.

Other standouts in the quarter included Hexagon, a Swedish company that manufactures design, measurement and visualization software and equipment. Its stock rose 29% on a very strong earnings report and better-than-expected cash generation. Japanese paint producer Kansai Paint gained 14% in the first quarter as the market began to recognize the quality of the business franchise outside Japan with the recent integration of a newly acquired South African business. Currently, 45% of its business is in emerging markets.

On the downside, Japanese mobile social networking game developer Gree fell 25% in the first quarter. If you recall, this stock was up 173% in 2011, so a retreat after its strong run was not unexpected. Other losses in the quarter were fairly insignificant. Indonesian gold miner Archipelago Resources fell 3%, despite massive increases to its gold reserves, as the markets took a cautious view on gold stocks worldwide. Denmark's Novozymes, a maker of industrial enzymes, fell 5% on expectations of a slowdown in the North American bioethanol market. Taiwanese mobile operator Taiwan Mobile fell 2%, despite an improving earnings outlook, as investors switched into more cyclical stocks in Taiwan.

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

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

14

Columbia Acorn International Select (ACFFX)

At a Glance

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

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

through March 31, 2012

Inception 11/23/98	Year to date*			1 year			5 years			10 years
Returns before taxes		11.37	%		-2.06	%		1.77	%		10.74	%
Returns after taxes on distributions		11.37			-2.58			1.36			10.53
Returns after taxes on distributions and sale of fund shares		7.39			-0.42			1.56			9.69
S&P Developed Ex-U.S. Between $2B and $10B Index (pretax)**		11.98			-6.61			-1.92			9.20

All results shown assume reinvestment of distributions.

*Year to date data is not annualized.

**The Fund's primary benchmark.

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

The Fund's Class Z shares annual operating expense ratio, as stated in the May 1, 2011, prospectus, is 1.16%.

Columbia Acorn International Select Portfolio Diversification

as a percentage of net assets, as of 3/31/12

Columbia Acorn International Select
Top 10 Holdings

as a percentage of net assets, as of 3/31/12

1.	Far EasTone Telecom (Taiwan) Taiwan's Third Largest Mobile Operator	6.6	%
2.	Ascendas REIT (Singapore) Industrial Property Landlord	6.1	%
3.	Kansai Paint (Japan) Paint Producer in Japan, India, China & Southeast Asia	5.6	%
4.	Mapletree Industrial Trust (Singapore) Industrial Property Landlord	5.2	%
5.	Rand Merchant Insurance (South Africa) Directly Sold Property & Casualty Insurance; Holdings in Other Insurers	5.0	%
6.	Seven Bank (Japan) ATM Processing Services	4.3	%
7.	Wirecard (Germany) Online Payment Processing & Risk Management	3.5	%
8.	Hexagon (Sweden) Measurement Equipment	3.4	%
9.	NHN (South Korea) Korean Online Search Services	3.3	%
10.	Adcock Ingram Holdings (South Africa) Manufacturer of Pharmaceuticals & Medical Supplies	2.9	%

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

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

November 23, 1998 through March 31, 2012

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

Total Net Assets of the Fund: $343.8 million

15

Columbia Acorn Select

In a Nutshell

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

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

Fund's Positions
in Mentioned Holdings

As a percentage of net assets, as of 3/31/12

Hertz	5.8	%
Discover Financial Services	5.2	%
CNO Financial Group	4.7	%
Sanmina-SCI	3.7	%
WNS	3.5	%
Pacific Rubiales Energy	3.2	%
FMC Corporation	1.2	%
Henry Schein	1.1	%
Associated Banc-Corp	1.1	%
Dupont Fabros Technology	0.9	%
Nordson	0.6	%
Seattle Genetics	0.6	%

Columbia Acorn Select gained 17.70% in the first quarter of 2012, outperforming the S&P MidCap 400 Index, the Fund's primary benchmark, which was up 13.50% for the same period. The large-cap S&P 500 Index gained 12.59% in the quarter.

As we noted in previous reports, during the second half of last year many of the Fund's opportunistic holdings lagged the market averages, despite having strong earnings growth. While a cause of Fund underperformance last year, we believed these names would continue to have earnings growth in 2012 and so we opted to continue to hold them in anticipation of the market recognizing their solid earnings performance and increasing their valuations accordingly. Our patience started to pay off in the first quarter. Looking at the Fund's top performers, rental car operator Hertz, Colombian oil company Pacific Rubiales Energy, credit card company Discover Financial Services, insurance company CNO Financial Group, Indian business outsourcing company WNS and electronics manufacturer Sanmina-SCI each added between 1% and 2% to the Fund's performance in the quarter. Only seven of the 55 stocks in the Fund's portfolio were down in the quarter, which, when added together, amounted to a little more than 1% of performance loss.

In the second half of last year, we stated that we were working on reducing the Fund's opportunistic holdings within the portfolio but felt they were too cheap to sell at then-current prices. Unfortunately, we watched prices just get cheaper as investors worried about the possibility of a global recession late last year. As noted above, in the first quarter we saw many of these holdings rebound strongly and were able to increase our efforts to transition toward more core holdings. In the first quarter we trimmed the Fund's exposure to Sanmina-SCI, WNS, CNO Financial, Discover and Pacific Rubiales.

During the first quarter, we added six new companies to the portfolio, while exiting from five companies. Our new positions include U.S. bank Associated Banc-Corp, real estate company Dupont Fabros Technology, oil and gas wellhead manufacturer FMC Corporation, healthcare product distributor Henry Schein, dispensing systems manufacturer Nordson and cancer therapies manufacturer Seattle Genetics, all of which are CWAM analysts' best ideas. WW Grainger, JB Hunt, Continental Resources, Oshkosh and Waste Management were sold based on what we believe will be slower future earnings growth at these companies.

We were happy to see some strengthening in the U.S. economic indicators during the first quarter, and it looks like this may continue for a while. But we are still quite concerned with the amount of artificial stimulus in our economy, from interest rates to large budget deficits. Against this backdrop, we expect a continuation of above-average volatility in the stock market.

Risks include stock market fluctuations due to economic and business developments. The Fund also has potentially greater price volatility due to the Fund's concentration in a limited number of stocks of mid-size companies. International investing involves special risks, including foreign taxation, currency risks, risks associated with possible differences in financial standards, operational and settlement risks and other risks associated with future political and economic developments.

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

16

Columbia Acorn Select (ACTWX)

At a Glance

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

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

through March 31, 2012

Inception 11/23/98	Year to date*			1 year			5 years			10 years
Returns before taxes		17.70	%		-2.52	%		0.84	%		7.87	%
Returns after taxes on distributions		17.70			-3.10			0.57			7.59
Returns after taxes on distributions and sale of fund shares		11.50			-1.65			0.64			6.90
S&P MidCap 400 Index (pretax)**		13.50			1.98			4.78			7.70

All results shown assume reinvestment of distributions.

*Year to date data is not annualized.

**The Fund's primary benchmark.

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

The Fund's Class Z shares annual operating expense ratio, as stated in the May 1, 2011, prospectus, is 0.97%.

Columbia Acorn Select Portfolio Diversification

as a percentage of net assets, as of 3/31/12

Columbia Acorn Select Top 10 Holdings

as a percentage of net assets, as of 3/31/12

1.	Hertz Largest U.S. Rental Car Operator	5.8	%
2.	Ametek Aerospace/Industrial Instruments	5.3	%
3.	Discover Financial Services Credit Card Company	5.2	%
4.	CNO Financial Group Life, Long-term Care & Medical Supplement Insurance	4.8	%
5.	SBA Communications Communications Towers	3.8	%
6.	Sanmina-SCI Electronic Manufacturing Services	3.7	%
7.	Coach Designer & Retailer of Branded Leather Accessories	3.5	%
8.	WNS - ADR (India) Offshore Business Process Outsourcing Services	3.5	%
9.	Donaldson Industrial Air Filtration	3.3	%
10.	Kennametal Consumable Cutting Tools	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 March 31, 2012

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

Total Net Assets of the Fund: $1.4 billion

17

Columbia Thermostat Fund

In a Nutshell

Charles P. McQuaid

Lead Portfolio Manager

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

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

Columbia Thermostat Fund ended the first quarter of 2012 up 8.29%. The Fund's primary equity benchmark, the S&P 500 Index, gained 12.59% for the same period and its primary fixed income benchmark, the Barclays U.S. Aggregate Bond Index, was up just 0.30%.

The Fund hit three reallocation triggers in the first quarter, reducing stock exposure each time on the strength of the equity market. At quarter end, the Fund had a 45% weighting in stock funds and a 55% weighting in its bond funds.

The equity portion of the portfolio provided a 14.33% weighted average return for the first quarter with Columbia Select Large Cap Growth Fund providing top gains of 19.98% for the three months. As we noted in our last report, Columbia Select Large Cap Growth Fund was added to the portfolio late last year. We're now pleased to see its immediate strong contribution.

The bond portion of the Fund provided a 1.86% weighted average gain, with Columbia Income Opportunities Fund leading the performance, up 4.23%. Columbia Income Opportunities Fund, which provides exposure to high-yield securities, had its weighting increased from 20% to 30% late last year, another move that proved beneficial this quarter.

Columbia Thermostat Fund enjoyed a substantial inflow of new assets in the first quarter. At quarter end, the Fund's total net assets were $325 million. We thank you for your investment in the Fund.

Results of the Funds Owned in Columbia Thermostat Fund as of March 31, 2012

Stock Funds Fund	Weightings in category			1st quarter
Columbia Acorn International, Class I		20	%		15.12	%
Columbia Dividend Income Fund, Class I		20	%		8.28	%
Columbia Acorn Fund, Class I		15	%		15.52	%
Columbia Select Large Cap Growth Fund, Class I		10	%		19.98	%
Columbia Acorn Select, Class I		10	%		17.76	%
Columbia Contrarian Core Fund, Class I		15	%		14.68	%
Columbia Large Cap Enhanced Core Fund, Class I		10	%		13.43	%
Weighted Average Equity Gain		100	%		14.33	%
Bond Funds Fund	Weightings in category			1st quarter
Columbia Intermediate Bond Fund, Class I		50	%		1.72	%
Columbia U.S. Treasury Index Fund, Class I		20	%		-1.31	%
Columbia Income Opportunities Fund, Class I		30	%		4.23	%
Weighted Average Income Gain		100	%		1.86	%

Columbia Thermostat Fund
Rebalancing in the First Quarter

January 19, 2012	55% stocks, 45% bonds
February 10, 2012	50% stocks, 50% bonds
March 16, 2012	45% stocks, 55% 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, operational and settlement risks and other risks associated with future political and economic developments. Changes in interest rates and changes in the financial strength of issuers of lower-rated bonds may also affect underlying fund performance. The Fund is also subject to the risk that the investment advisor's decisions regarding asset classes and underlying portfolio funds will not anticipate market trends successfully, resulting in a failure to preserve capital or lower total return. In addition, the Fund may buy and sell shares of the portfolio funds frequently. This may result in higher transaction costs and additional tax liability. This is not an offer of the shares of any other mutual fund mentioned herein.

18

Columbia Thermostat Fund (COTZX)

At a Glance

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

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

through March 31, 2012

Inception 9/25/02	Year to date*			1 year			5 years			Life of fund
Returns before taxes		8.29	%		10.09	%		5.40	%		8.21	%
Returns after taxes on distributions		8.29			8.98			4.30			6.99
Returns after taxes on distributions and sale of fund shares		5.39			6.50			4.05			6.59
S&P 500 Index (pretax)**		12.59			8.54			2.01			8.00
Barclays U.S. Aggregate Bond Index (pretax)**		0.30			7.71			6.25			5.22
Lipper Flexible Portfolio Funds Index (pretax)		8.90			2.88			3.42			7.88

All results shown assume reinvestment of distributions.

*Year to date data is not annualized.

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

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

The Fund's Class Z annual operating expense ratio, as stated in the May 1, 2011, prospectus, is 1.04%. Columbia Thermostat Fund has 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 (underlying funds), 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 3/31/12

Columbia Thermostat Fund Portfolio Weightings

as a percentage of assets in each investment category, as of 3/31/12

Stock Mutual Funds

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

Bond Mutual Funds

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

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

September 25, 2002 through March 31, 2012

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

Total Net Assets of the Fund: $325.0 million

19

Columbia Acorn Emerging Markets Fund

In a Nutshell

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

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

Fund's Positions
in Mentioned Holdings

As a percentage of net assets, as of 3/31/12

Alliance Grain Traders	2.9	%
Nagacorp	2.7	%
Dufry Group	2.5	%
Pirelli	1.4	%
Dürr	1.4	%
Radiant Opto-Electronics	1.2	%
Crew Energy	0.7	%
Madalena Ventures	0.6	%

Columbia Acorn Emerging Markets Fund returned 18.00% in the first quarter of 2012, slightly behind the 18.46% return of the Fund's primary benchmark, the S&P Emerging Markets Between $500M and $5B Index. We mentioned in our first shareholder report that we have sought to structure the Fund so that it will fall less in downturns but, as a result, it may lag the index in strong up markets. We are encouraged that since the Fund's launch on August 19, 2011, a period that included both a significant market decline followed by a strong emerging markets rally, the Fund has gained 9.50%, outperforming the benchmark gain of 2.52%.

In the first quarter, the Fund benefitted from good stock selection in its consumer discretionary picks. Nagacorp, a casino/entertainment complex operator based in Cambodia, continues to be a strong performer, up 81% on continued robust earnings growth in the Cambodian gaming market. Dufry Group, a Switzerland-based operator of duty free shops, which generates the majority of its earnings in Latin America, gained over 43% as it achieved record margins.

Other key contributors were Radiant Opto-Electronics, which specializes in ultra-thin backlight units for use in tablet computers. Up 54%, the company has benefitted from the growth in tablet computing and its key relationships with market leaders Apple and Samsung. Dürr, a German manufacturer of advanced automatic paint finishing plants, has followed the global auto giants to Latin America and Asia, while winning market share with new Chinese automakers. The stock gained 46% during the quarter. Another auto-related name, premium tire maker Pirelli, was up nearly 43% on robust revenue growth in Latin America. Eighty percent of the company's tires are now made in emerging market countries.

The largest performance detractor for the quarter was Alliance Grain Traders, a Canada-based processor of lentils and peas, down roughly 25%. The company's customers are largely in the Middle East, India and Northern Africa. Political turmoil, currency depreciations and tighter trade finance in those markets caused buying of these pulse crops to shrink. Two energy names listed in Canada, Crew Energy and Madalena Ventures, were each down about 14% for the quarter. Madalena's resources are in Argentina and have traded down as the government has pressured an industry peer, depressing sentiment. Indian gold lender Manappuram Finance fell 9% in the Fund after the government introduced new restrictions on the industry. We believe additional detrimental regulations are coming, and have sold out of the position.

The Fund seeks to benefit by leveraging the global expertise of the CWAM investment team. Three of the Fund's best performers in the quarter, European-listed stocks Dürr, Dufry and Pirelli, were selected by CWAM's Europe analysts. Columbia Acorn Emerging Markets Fund expects to take advantage of CWAM's strength in this area. We hope that CWAM's deep experience may help to identify the best ideas in a wide universe of emerging markets investments.

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

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

20

Columbia Acorn Emerging
Markets Fund(CEFZX)

At a Glance

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

Pretax and After-tax Total Returns (Class Z)

through March 31, 2012

Inception 8/19/11	Year to date*			Life of fund**
Returns before taxes		18.00	%		9.50	%
Returns after taxes on distributions		18.00			9.51
Returns after taxes on distributions and sale of fund shares		11.70			6.18
S&P Emerging Markets Between $500M and $5B Index (pretax)***		18.46			2.52

All results shown assume reinvestment of distributions.

*Year to date data is not annualized.

**Reflects performance from Fund inception on 8/19/11 through 3/31/12.

***The Fund's primary benchmark.

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

The Fund's Class Z annual operating expense ratio, as stated in the August 19, 2011, prospectus, is 1.58%. Columbia Acorn Emerging Markets Fund has a contractual fee waiver and expense reimbursement agreement with CWAM that generally limits the Fund's ordinary expenses to 1.60% of the Fund's average daily net assets, and which expires April 30, 2013; expense ratios without and with the contractual waiver/reimbursement are 1.58%.

Columbia Acorn Emerging Markets Fund Portfolio Diversification

as a percentage of net assets, as of 3/31/12

Columbia Acorn Emerging Markets Fund Top 10 Holdings

as a percentage of net assets, as of 3/31/12

1.	Ace Indonesia (Indonesia) Home Improvement Retailer	3.1	%
2.	Tower Bersama Infrastructure (Indonesia) Communications Towers	3.0	%
3.	Rand Merchant Insurance (South Africa) Directly Sold Property & Casualty Insurance; Holdings in Other Insurers	2.8	%
4.	Nagacorp (Cambodia) Casino/Entertainment Complex in Cambodia	2.7	%
5.	Coronation Fund Managers (South Africa) South African Fund Manager	2.6	%
6.	Dufry Group (Switzerland) Operator of Airport Duty Free & Duty Paid Shops	2.5	%
7.	Archipelago Resources (Indonesia) Gold Mining Projects in Indonesia, Vietnam & the Philippines	2.5	%
8.	Alliance Grain Traders (Canada) Global Leader in Pulse Processing & Distribution	2.1	%
9.	Far EasTone Telecom (Taiwan) Taiwan's Third Largest Mobile Operator	2.1	%
10.	Home Product Center (Thailand) Home Improvement Retailer	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 Emerging Markets Fund (Class Z)

August 19, 2011 through March 31, 2012

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

Total Net Assets of the Fund:
$5.8 million

21

Columbia Acorn European Fund

In a Nutshell

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

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

Fund's Positions
in Mentioned Holdings

As a percentage of net assets, as of 3/31/12

Gemalto	3.2	%
Eurofins Scientific	3.2	%
1000 mercis	2.8	%
Alliance Grain Traders	1.3	%

Columbia Acorn European Fund returned 17.69% in the first quarter of 2012, in line with, but slightly less than, its primary benchmark, the S&P Europe Between $500M and $5B Index, which was up 17.80% in the period. Generally, our stock picks in mainland Europe contributed to performance, while stocks listed in the United Kingdom and Ireland were detractors.

The strongest returns came from GlobeOp Financial Services, up almost 60% in the quarter. GlobeOp, an independent financial administrator specializing in middle- and back-office services, became the object of a takeover battle in March, only weeks after listing on the London Stock Exchange. We sold the Fund's shares of the stock.

Eurofins Scientific, a company with its origins in France, headquarters in Brussels and company registration in Luxembourg, was also strong in the quarter. The company provides screening and testing services for foodstuffs, pharmaceuticals, soils and materials and operates worldwide. Having spent the last five years investing heavily in consolidating a very fragmented industry, the company has started to reap the fruit of its labor, reporting much improved operating margins on the back of better capacity utilization. The improved 2011 figures and management's bullish outlook for 2012 and beyond sent the stock up 50% in the first quarter.

Another star performer was Gemalto, a company headquartered in Paris, France, and registered in the Netherlands. The company is a maker of chip cards and digital security solutions with strong market shares in mobile telephone SIM cards, smart credit cards and identification and access control solutions. Gemalto saw demand increase sharply as hardware makers, telecom operators and financial institutions the world over looked at the potential of new payment methods based on mobile telephone and intelligent chip cards. The stock was up more than 35% in the quarter.

On the downside, Alliance Grain Traders, a Canada-listed trader of lentils and peas with large operations in Turkey, suffered from the liquidity squeeze that many of its Middle Eastern clients experienced following political instabilities and currency devaluations. The company had to take write downs on accounts receivables, while suffering foreign currency-related losses in the fourth quarter of 2011. Since then, the situation has slightly improved, with currencies recovering and orders up. Nevertheless, the stock slid almost 25% in the quarter.

Another detractor was 1000 mercis, a specialist marketer and online advertiser. The company reported lower fourth quarter sales than expected, with some sales postponed to the first quarter of 2012 and some cancelled altogether, which scared off investors. After sliding 23% on the news, the stock recovered somewhat and finished the quarter down 18%.

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

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

22

Columbia Acorn
European Fund(CAEZX)

At a Glance

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

Pretax and After-tax Total Returns (Class Z)

through March 31, 2012

Inception 8/19/11	Year to date*			Life of fund**
Returns before taxes		17.69	%		12.07	%
Returns after taxes on distributions		17.69			11.81
Returns after taxes on distributions and sale of fund shares		11.50			7.90
S&P Europe Between $500M and $5B Index (pretax)***		17.80			9.35

All results shown assume reinvestment of distributions.

*Year to date data is not annualized.

**Reflects performance from Fund inception on 8/19/11 through 3/31/12.

***The Fund's primary benchmark.

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

The Fund's Class Z annual operating expense ratio, as stated in the August 19, 2011, 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. Absent the waiver or reimbursement, performance results would have been lower.

Columbia Acorn European Fund Portfolio Diversification

as a percentage of net assets, as of 3/31/12

Columbia Acorn European Fund Top 10 Holdings

as a percentage of net assets, as of 3/31/12

1.	Gemalto (France) Smart Card Products & Solutions	3.2	%
2.	Eurofins Scientific (France) Food, Pharmaceuticals & Materials Screening & Testing	3.2	%
3.	Wirecard (Germany) Online Payment Processing & Risk Management	2.9	%
4.	1000 mercis (France) Interactive Advertising & Marketing	2.8	%
5.	Geberit (Switzerland) Plumbing Supplies	2.6	%
6.	Hexagon (Sweden) Design, Measurement & Visualization Software & Equipment	2.6	%
7.	Marel (Iceland) Largest Manufacturer of Poultry & Fish Processing Equipment	2.5	%
8.	Aalberts Industries (Netherlands) Flow Control & Heat Treatment	2.5	%
9.	UNIT4 (Netherlands) Business Software Development	2.2	%
10.	Intertek Group (United Kingdom) Testing, Inspection & Certification Services	2.2	%

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

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

August 19, 2011 through March 31, 2012

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

Total Net Assets of the Fund:
$2.0 million

23

Columbia Acorn Fund

Major Portfolio Changes in the First Quarter (Unaudited)

	Number of Shares
	12/31/11		03/31/12
Purchases
Information
Active Network		0		900,000
Boingo Wireless		1,500,000		1,650,000
Cree		0		380,000
ExlService Holdings		1,145,000		1,435,200
Informatica		4,850,000		5,000,000
ON Semiconductor		6,842,000		7,932,000
Quality Systems		2,333,500		2,350,000
TIBCO		2,139,800		2,150,000
Ultratech		415,000		615,000
WNS - ADR (India)		1,076,353		1,091,353
Industrial Goods & Services
Drew Industries		1,500,000		1,880,000
Fortune Brands Home & Security		1,300,000		1,350,000
Heico		2,250,000		2,450,000
Middleby		123,344		166,419
Nordson		3,000,000		3,125,000
Polypore International		0		900,000
Valmont Industries		100,000		435,000
Consumer Goods & Services
American Eagle Outfitters		0		300,000
Annie's		0		45,500
Caesarstone (Israel)		0		215,000
Deckers Outdoor		1,045,000		1,140,000
Fossil		115,000		392,500
GNC Holdings		0		1,528,500
HomeAway		1,400,000		1,600,000
Shutterfly		3,070,000		3,370,000
Skullcandy		975,000		1,290,000
United Stationers		493,771		625,000
Finance
Alliance Data Systems		400,000		550,000
Allied World Holdings		500,000		833,000
Assured Guaranty		300,000		500,000
Enstar Group		216,766		250,000
First Commonwealth		0		1,000,000
Kemper		762,252		925,000
MB Financial		2,360,000		2,860,000
Oriental Financial Group		0		500,000
Regional Management		0		422,500
Tower Group		1,675,000		2,764,000
TrustCo Bank		1,940,318		2,136,500
Wintrust Financial		0		700,000
Wright Express		180,000		275,000
Health Care
Allscripts Healthcare Solutions		700,000		1,200,000
Anthera Pharmaceuticals		1,740,000		2,990,000
Cepheid		3,200,000		3,900,000

	Number of Shares
	12/31/11		03/31/12
Chelsea Therapeutics International		4,550,000		5,750,000
DENTSPLY International		0		1,136,500
Henry Schein		650,000		950,000
Pacific Biosciences of California		0		2,525,000
PerkinElmer Inc.		0		950,000
Raptor Pharmaceutical		3,455,000		4,200,000
Synageva Biopharma		0		180,167
Techne		0		375,000
Energy & Minerals
Approach Resource		0		200,000
Petroleum Development Corporation		0		340,000
Rowan		0		585,000
Other Industries
Dupont Fabros Technology		3,350,000		3,700,000
Genesee & Wyoming		300,000		400,000
Jones Lang LaSalle		0		325,000
St. Joe		1,000,000		1,300,000
Summit Hotel Properties		1,500,000		2,000,031

24

	Number of Shares
	12/31/11		03/31/12
Sales
Information
Akamai		700,500		250,000
Blackbaud		1,680,198		1,650,000
Crown Castle International		4,600,000		4,465,000
Discovery Series C		2,050,000		1,595,000
Finisar		1,905,000		1,695,000
FTI Consulting		900,000		868,516
Gemalto (France)		230,000		207,000
Global Payments		2,429,000		2,299,000
IMAX (Canada)		1,250,000		1,100,000
Intralinks		550,000		0
Jack Henry & Associates		920,000		750,000
Mail.ru - GDR (Russia)		423,040		400,000
MetroPCS Communications		600,000		0
NetEase.com - ADR (China)		365,000		304,000
Netgear		1,200,000		900,000
Polycom		1,165,000		0
Red Hat		850,000		750,000
Salem Communications		1,527,700		0
Supertex		535,000		0
Industrial Goods & Services
Arcadis (Netherlands)		100,000		0
Expeditors International of Washington		3,200,000		3,050,000
GrafTech International		4,000,000		3,750,000
Imtech (Netherlands)		1,767,165		1,601,465
Interline Brands		2,600,000		2,399,751
Kaydon		1,300,000		501,000
LKQ		1,635,000		1,350,000
Mersen (France)		420,000		260,000
Mine Safety Appliances		566,497		0
Pentair		3,535,000		3,100,000
WABCO Holdings		1,150,000		950,000
WW Grainger		270,000		0
Consumer Goods & Services
Crocs		580,000		0
Diamond Foods		1,050,000		0
Guess?		530,000		0
Hanesbrands		1,000,000		0
Jarden		1,650,000		1,500,000
lululemon athletica		5,740,000		4,922,800
Thor Industries		1,100,000		0
True Religion Apparel		1,507,000		393,452
Vail Resorts		1,680,000		1,430,000
Finance
Aaron's		1,834,695		0
BOK Financial		2,738,000		2,691,414
City National		1,275,000		1,175,000

	Number of Shares
	12/31/11		03/31/12
CVB Financial		4,300,000		3,400,000
Delphi Financial Group		1,200,000		0
Valley National Bancorp		5,450,000		5,070,000
World Acceptance		1,505,202		1,459,555
Health Care
Akorn		4,432,716		4,000,000
Alexion Pharmaceuticals		3,208,000		2,290,000
Community Health Systems		625,000		0
HealthSouth		2,075,000		825,000
Hill-Rom Holdings		1,975,000		1,873,800
HMS Holdings		850,000		0
Micromet		6,702,347		0
Onyx Pharmaceuticals		1,170,000		1,000,000
Sirona Dental Systems		2,075,000		675,000
Energy & Minerals
Core Laboratories (Netherlands)		545,000		442,000
FMC Technologies		6,036,100		5,298,000
GT Solar International		2,800,000		2,000,000
Houston American Energy		900,000		393,600
Kodiak Oil and Gas		2,200,000		1,100,000
Northern Oil & Gas		638,000		0
Oasis Petroleum		840,000		0
Pacific Rubiales Energy (Colombia)		4,300,000		4,250,000
Southwestern Energy Co.		75,071		0
Tullow Oil (United Kingdom)		2,400,000		1,697,000
Other Industries
Biomed Realty Trust		3,000,000		2,450,000
Kilroy Realty		1,120,000		770,000
Macerich		530,000		0
Wisconsin Energy		1,800,000		1,660,000

25

Columbia Acorn Fund

Statement of Investments (Unaudited), March 31, 2012

Number of Shares			Value (000)
			Equities: 97.4%
Information 29.0%
		> Business Software 8.3%
	5,000,000	Informatica (a)	$	264,500
		Enterprise Data Integration Software
	2,550,000	Ansys (a)		165,801
		Simulation Software for Engineers & Designers
	2,700,000	Micros Systems (a)		149,283
		Information Systems for Hotels, Restaurants & Retailers
	1,830,000	Concur Technologies (a)		105,005
		Web Enabled Cost & Expense Management Software
	2,350,000	Quality Systems		102,765
		IT Systems for Medical Groups & Ambulatory Care Centers
	5,164,999	Hexagon (Sweden)		100,243
		Design, Measurement & Visualization Software & Equipment
	2,850,000	Ariba (a)		93,223
		Cost Management Software
	2,350,000	Constant Contact (a)(b)		70,006
		Email & Other Marketing Campaign Management Systems Delivered Over the Web
	2,150,000	TIBCO (a)		65,575
		Datacenter Software
	1,700,000	Tyler Technologies (a)(b)		65,297
		Financial, Tax, Court & Document Management Systems for Local Governments
	1,150,000	NetSuite (a)		57,834
		End to End IT Systems Solution Delivered Over the Web
	1,650,000	Blackbaud		54,830
		Software & Services for Non-profits
	1,700,000	Kenexa (a)(b)		53,108
		Recruiting & Workforce Management Solutions
	750,000	Red Hat (a)		44,918
		Maintenance & Support for Opensource OS & Middleware
	2,500,000	Velti (a)		33,875
		Mobile Marketing Software Platform
	750,000	Jack Henry & Associates		25,590
		Systems Financial Institutions
	900,000	SPS Commerce (a)(b)		24,192
		Supply Chain Management Software Delivered via the Web
	690,000	Advent Software (a)		17,664
		Asset Management & Trading Systems
	900,000	Active Network (a)		15,147
		Web Delivered Software Solutions for Managing Events & Activities
	1,000,000	InContact (a)		5,580
		Call Center Systems Delivered via the Web & Telco Services
	55,000	Solera Holdings		2,524
		Software for Automotive Insurance Claims Processing
				1,516,960

Number of Shares			Value (000)
		> Instrumentation 3.0%
	1,600,000	Mettler Toledo (a)(b)	$	295,600
		Laboratory Equipment
	2,780,000	IPG Photonics (a)(b)		144,699
		Fiber Lasers
	2,035,000	Trimble Navigation (a)		110,745
		GPS-based Instruments
				551,044
		> Computer Hardware & Related Equipment 2.6%
	3,495,000	Amphenol		208,896
		Electronic Connectors
	4,550,000	II-VI (a)(b)		107,607
		Laser Optics & Specialty Materials
	1,605,000	Zebra Technologies (a)		66,094
		Bar Code Printers
	900,000	Netgear (a)		34,380
		Networking Products for Small Business & Home
	800,000	Nice Systems - ADR (Israel) (a)		31,440
		Audio & Video Recording Solutions
	605,000	Stratasys (a)		22,095
		Rapid Prototyping Systems
	207,000	Gemalto (France)		13,663
		Digital Security Solutions
				484,175
		> Semiconductors & Related Equipment 2.4%
	12,300,000	Atmel (a)		121,278
		Microcontrollers, RF & Memory Semiconductors
	7,932,000	ON Semiconductor (a)		71,467
		Mixed Signal & Power Management Semiconductors
	5,000,000	Entegris (a)		46,700
		Semiconductor Materials Management Products
	2,160,000	Microsemi (a)		46,310
		Analog/Mixed Signal Semiconductors
	500,000	Littelfuse		31,350
		Little Fuses
	1,900,000	IXYS (a)(b)		25,080
		Power Semiconductors
	1,165,000	Monolithic Power Systems (a)		22,916
		High Performance Analog & Mixed Signal ICs
	400,000	Hittite Microwave (a)		21,724
		Radio Frequency, Microwave & Millimeterwave Semiconductors
	615,000	Ultratech (a)		17,823
		Semiconductor Equipment
	2,290,000	TriQuint Semiconductor (a)		15,790
		RF Semiconductors
	1,765,000	Pericom Semiconductor (a)(b)		14,279
		Interface ICs & Frequency Control Products
	380,000	Cree (a)		12,019
		LED Lighting, Components & Chips
				446,736

26

Number of Shares			Value (000)
		> Mobile Communications 2.3%
	4,465,000	Crown Castle International (a)	$	238,163
		Communications Towers
	3,700,000	SBA Communications (a)		187,997
		Communications Towers
	1,500,000	Globalstar (a)		1,050
		Satellite Mobile Voice & Data Carrier
				427,210
		> Telephone & Data Services 2.2%
	9,500,000	tw telecom (a)(b)		210,520
		Fiber Optic Telephone/Data Services
	1,400,000	AboveNet (a)(b)		115,920
		Metropolitan Fiber Communications Services
	2,200,000	Cogent Communications (a)		41,976
		Internet Data Pipelines
	1,650,000	Boingo Wireless (a)		19,965
		Wholesale & Retail Wi-Fi Networks
	2,000,000	General Communications (a)(b)		17,440
		Commercial Communication & Consumer CATV, Web & Phone in Alaska
				405,821
		> Computer Services 1.3%
	3,400,000	iGATE (a)(b)		56,984
		IT & Business Process Outsourcing Services
	1,435,200	ExlService Holdings (a)		39,382
		Business Process Outsourcing
	680,000	Syntel		38,080
		Offshore IT Services
	2,125,000	Virtusa (a)(b)		36,699
		Offshore IT Outsourcing
	1,575,000	Genpact (a)		25,672
		Business Process Outsourcing
	3,849,207	Hackett Group (a)(b)		22,980
		IT Integration & Best Practice Research
	1,091,353	WNS - ADR (India) (a)		13,151
		Offshore BPO (Business Process Outsourcing) Services
				232,948
		> Gaming Equipment & Services 1.2%
	3,725,000	Bally Technologies (a)(b)		174,144
		Slot Machines & Software
	1,530,000	WMS Industries (a)		36,307
		Slot Machine Provider
				210,451
		> Internet Related 1.0%
	585,000	Equinix (a)		92,108
		Network Neutral Data Centers
	1,450,000	TripAdvisor (a)		51,722
		Online Travel Research
	304,000	NetEase.com - ADR (China) (a)		17,662
		Chinese Online Gaming Services
	400,000	Mail.ru - GDR (Russia) (a)(c)		15,780
		Internet Social Networking & Games for Russian Speakers
	250,000	Akamai (a)		9,175
		Content Delivery Network (CDN) for Better Delivery of Online Content
				186,447

Number of Shares			Value (000)
		> Telecommunications Equipment 0.9%
	685,000	F5 Networks (a)	$	92,448
		Internet Traffic Management Equipment
	1,695,000	Finisar (a)		34,154
		Optical Subsystems & Components
	2,330,000	Ixia (a)		29,102
		Telecom Network Test Equipment
	1,925,000	Infinera (a)		15,631
		Optical Networking Equipment
				171,335
		> Business Information & Marketing Services 0.9%
	1,900,000	Verisk Analytics (a)		89,243
		Risk & Decision Analytics
	2,800,000	Navigant Consulting (a)(b)		38,948
		Financial Consulting Firm
	868,516	FTI Consulting (a)		32,586
		Financial Consulting Firm
	505,000	RPX (a)		8,565
		Patent Aggregation & Defensive Patent Consulting
				169,342
		> CATV 0.8%
	1,595,000	Discovery Series C (a)		74,773
		CATV Programming
	1,250,000	Liberty Global Series A (a)		62,600
		Cable TV Franchises Outside the USA
	15,770	Jupiter Telecommunications (Japan)		15,795
		Largest Cable Service Provider in Japan
				153,168
		> Financial Processors 0.7%
	2,299,000	Global Payments		108,053
		Credit Card Processor
	5,000,000	Singapore Exchange (Singapore)		27,656
		Singapore Equity & Derivatives Market Operator
				135,709
		> Electronics Distribution 0.6%
	3,125,000	Avnet (a)		113,719
		Electronic Components Distribution
				113,719
		> Contract Manufacturing 0.5%
	3,800,000	Sanmina-SCI (a)		43,510
		Electronic Manufacturing Services
	1,100,000	Plexus (a)		38,489
		Electronic Manufacturing Services
				81,999
		> Entertainment Programming 0.2%
	1,100,000	IMAX (Canada) (a)		26,884
		IMAX Movies, Theatre Equipment & Theatre Joint Ventures
				26,884
		> TV Broadcasting 0.1%
	2,500,000	Entravision Communications		4,275
		Spanish Language TV & Radio Stations
	1,750,000	Gray Television (a)		3,307
		Mid Market Affiliated TV Stations
				7,582

27

Columbia Acorn Fund

Statement of Investments (Unaudited), continued

Number of Shares			Value (000)
		> Radio —%
	164,991	Saga Communications (a)	$	5,907
		Radio Stations in Small & Mid-sized Cities
				5,907
		> Consumer Software —%
	273,500	Carbonite (a)(d)		3,011
		Online File Storage
				3,011
		> Advertising —%
	1,500,000	VisionChina Media - ADR (China) (a)		2,370
		Advertising on Digital Screens in China's Mass Transit System
				2,370
Information: Total				5,332,818
Industrial Goods & Services 18.7%
		> Machinery 11.1%
	6,750,000	Ametek		327,442
		Aerospace/Industrial Instruments
	8,400,000	Donaldson (b)		300,132
		Industrial Air Filtration
	3,125,000	Nordson		170,344
		Dispensing Systems for Adhesives & Coatings
	3,725,000	Kennametal		165,874
		Consumable Cutting Tools
	3,100,000	Pentair		147,591
		Pumps & Water Treatment
	2,775,000	Moog (a)(b)		119,020
		Motion Control Products for Aerospace, Defense & Industrial Markets
	2,325,000	Clarcor		114,134
		Mobile & Industrial Filters
	1,800,000	Pall		107,334
		Filtration & Fluids Clarification
	2,450,000	Heico (b)		98,368
		FAA Approved Aircraft Replacement Parts
	2,200,000	ESCO Technologies (b)		80,894
		Automatic Electric Meter Readers
	2,675,000	Oshkosh Corporation (a)		61,980
		Specialty Truck Manufacturer
	950,000	WABCO Holdings (a)		57,456
		Truck & Bus Component Supplier
	805,000	Toro		57,244
		Turf Maintenance Equipment
	435,000	Valmont Industries		51,073
		Center Pivot Irrigation Systems & Utility Poles
	600,000	Wabtec		45,222
		Freight & Transit Component Supplier
	1,776,000	Generac (a)		43,601
		Standby Power Generators
	900,000	Polypore International (a)(d)		31,644
		Battery Separators & Filtration Media
	166,419	Middleby (a)		16,838
		Manufacturer of Cooking Equipment
	210,000	Neopost (France)		13,505
		Postage Meter Machines
	501,000	Kaydon		12,781
		Specialized Friction & Motion Control Products

Number of Shares			Value (000)
	10,000,000	Marel (Iceland)	$	11,735
		Largest Manufacturer of Poultry & Fish Processing Equipment
	3,450,000	Jain Irrigation Systems (India)		6,656
	172,500	Jain Irrigation Systems - DVR (India) (a)		162
		Agricultural Micro-irrigation Systems & Food Processing
	1,000,000	Spartan Motors		5,290
		Specialty Truck & Chassis Manufacturer
				2,046,320
		> Industrial Materials & Specialty Chemicals 2.1%
	1,750,000	Albemarle		111,860
		Refinery Catalysts & Other Specialty Chemicals
	760,000	FMC Corporation		80,454
		Niche Specialty Chemicals
	1,880,000	Drew Industries (a)(b)		51,343
		RV & Manufactured Home Components
	1,525,000	Novozymes (Denmark)		44,415
		Industrial Enzymes
	673,000	Sociedad Quimica y Minera de Chile - ADR (Chile)		39,485
		Producer of Specialty Fertilizers, Lithium & Iodine
	2,218,700	Kansai Paint (Japan)		22,493
		Paint Producer in Japan, India, China & Southeast Asia
	900,000	Albany International		20,655
		Paper Machine Clothing & Advanced Textiles
	260,000	Mersen (France)		9,215
		Advanced Industrial Materials
	200,000	Silgan Holdings		8,840
		Metal & Plastic Packaging
				388,760
		> Other Industrial Services 1.9%
	3,050,000	Expeditors International of Washington		141,855
		International Freight Forwarder
	1,601,465	Imtech (Netherlands)		51,197
		Electromechanical & ICT Installation & Maintenance
	1,300,000	Forward Air		47,671
		Freight Transportation Between Airports
	1,350,000	LKQ (a)		42,079
		Alternative Auto Parts Distribution
	1,600,000	Mobile Mini (a)		33,792
		Portable Storage Units Leasing
	1,500,000	Acorn Energy (b)		16,305
		Frac Well Exploration/Monitoring Device, Sonar Security, Electric Grid Monitoring
	750,000	UTI Worldwide		12,923
		Freight Forwarding & Logistics
				345,822
		> Construction 0.9%
	1,725,000	Chicago Bridge & Iron		74,503
		Engineering & Construction for LNG & Petrochemicals

28

Number of Shares			Value (000)
		> Construction—continued
	66,000	NVR (a)	$	47,938
		DC Homebuilder
	1,350,000	Fortune Brands Home & Security (a)		29,794
		Home Building Supplies & Small Locks
	1,800,000	Mills Estruturas e Servicos de Engenharia (Brazil)		22,877
		Civil Engineering & Construction
				175,112
		> Electrical Components 0.7%
	1,440,000	Acuity Brands		90,475
		Commercial Lighting Fixtures
	1,500,000	Ushio (Japan)		21,249
		Industrial Light Sources
	351,000	Saft Batteries (France)		11,375
		Niche Battery Manufacturer
				123,099
		> Waste Management 0.6%
	2,400,000	Waste Connections		78,072
		Solid Waste Management
	560,000	Clean Harbors (a)		37,705
		Hazardous Waste Services & Disposal
				115,777
		> Outsourcing Services 0.6%
	2,800,000	Quanta Services (a)		58,520
		Electrical & Telecom Construction Services
	1,210,000	Insperity		37,074
		Professional Employer Organization
	600,000	GP Strategies (a)		10,500
		Training Programs
				106,094
		> Industrial Distribution 0.3%
	2,399,751	Interline Brands (a)(b)		51,859
		Industrial Distribution
				51,859
		> Conglomerates 0.3%
	2,263,654	Aalberts Industries (Netherlands)		46,795
		Flow Control & Heat Treatment
				46,795
		> Steel 0.2%
	3,750,000	GrafTech International (a)		44,775
		Industrial Graphite Materials Producer
				44,775
Industrial Goods & Services: Total				3,444,413
Consumer Goods & Services 16.4%
		> Retail 5.0%
	4,922,800	lululemon athletica (a)		367,635
		Premium Active Apparel Retailer
	3,460,000	Abercrombie & Fitch		171,651
		Teen Apparel Retailer
	3,370,000	Shutterfly (a)(b)		105,582
		Internet Photo-centric Retailer
	5,600,000	Pier 1 Imports (a)(b)		101,808
		Home Furnishing Retailer

Number of Shares			Value (000)
	5,225,000	Saks (a)	$	60,662
		Luxury Department Store Retailer
	392,500	Fossil (a)		51,802
		Watch Designer & Retailer
	525,000	DSW		28,754
		Branded Footwear Retailer
	971,500	Teavana (a)(d)		19,158
		Specialty Tea Retailer
	1,371,366	Gaiam (a)(b)		5,458
		Healthy Living Catalogs & E-Commerce
	300,000	American Eagle Outfitters		5,157
		Teen Apparel Retailer
	66,000	The Fresh Market (a)		3,165
		Specialty Food Retailer
				920,832
		> Apparel 3.0%
	2,100,000	Coach		162,288
		Designer & Retailer of Branded Leather Accessories
	1,660,000	PVH		148,288
		Apparel Wholesaler & Retailer
	2,190,000	Warnaco Group (a)(b)		127,896
		Global Branded Apparel Manufacturer
	1,140,000	Deckers Outdoor (a)		71,877
		Fashion Footwear Wholesaler
	600,000	Steven Madden (a)		25,650
		Wholesaler/Retailer of Fashion Footwear
	393,452	True Religion Apparel (a)		10,780
		Premium Denim
				546,779
		> Travel 2.5%
	3,850,000	Gaylord Entertainment (a)(b)		118,580
		Convention Hotels
	1,430,000	Vail Resorts		61,847
		Ski Resort Operator & Developer
	3,750,000	Hertz (a)		56,400
		Largest U.S. Rental Car Operator
	3,800,000	Avis Budget Group (a)		53,770
		Second Largest Car Rental Company
	1,450,000	Expedia (d)		48,488
		Online Travel Services Company
	1,600,000	HomeAway (a)		40,592
		Vacation Rental Online Marketplace
	2,000,000	Localiza Rent A Car (Brazil)		36,813
		Car Rental
	970,000	Choice Hotels		36,220
		Franchisor of Budget Hotel Brands
				452,710
		> Food & Beverage 1.2%
	2,340,000	Monster Beverage (a)		145,290
		Alternative Beverages
	32,000,000	Olam International (Singapore)		60,136
		Agriculture Supply Chain Manager
	240,000	Snyder's-Lance		6,204
		Snack Foods
	45,500	Annie's (a)		1,585
		Developer & Marketer of Natural & Organic Food

29

Columbia Acorn Fund

Statement of Investments (Unaudited), continued

Number of Shares			Value (000)
		> Food & Beverage—continued
	1,678,125	GLG Life Tech (Canada) (a)(b)(d)	$	1,326
		Produce an All-natural Sweetener Extracted from the Stevia Plant
				214,541
		> Other Consumer Services 0.8%
	2,190,000	Lifetime Fitness (a)(b)		110,748
		Sport & Fitness Club Operator
	13,500,000	Lifestyle International (Hong Kong)		34,392
		Mid to High-end Department Store Operator in Hong Kong & China
	1,062,500	Move (a)		10,317
		Real Estate Internet Websites
	1,325,000	IFM Investments (Century 21 China RE) - ADR (China) (a)		954
		Provide Real Estate Services in China
				156,411
		> Furniture & Textiles 0.8%
	4,200,000	Knoll (b)		69,888
		Office Furniture
	2,250,000	Herman Miller		51,660
		Office Furniture
	1,750,000	Interface		24,413
		Modular & Broadloom Carpet
	215,000	Caesarstone (Israel) (a)		2,511
		Quartz Countertops
				148,472
		> Consumer Goods Distribution 0.8%
	2,015,000	Pool		75,401
		Distributor of Swimming Pool Supplies & Equipment
	1,528,500	GNC Holdings		53,329
		Specialty Retailer of Health + Wellness Products
	625,000	United Stationers		19,394
		Wholesale Distributor of Business Products
				148,124
		> Casinos & Gaming 0.8%
	3,950,000	Pinnacle Entertainment (a)(b)		45,464
		Regional Casino Operator
	3,000,000	Melco Crown Entertainment - ADR (Hong Kong) (a)		40,830
		Macau Casino Operator
	850,000	Penn National Gaming (a)		36,533
		Regional Casino Operator
	12,000,000	MGM China Holdings (Hong Kong) (d)		21,906
		Macau Casino Operator
				144,733
		> Other Durable Goods 0.5%
	1,500,000	Jarden		60,345
		Branded Household Products
	460,000	Cavco Industries (a)(b)		21,427
		Manufactured Homes
	400,000	Tesla Motors (a)		14,896
		Design, Manufacture and Sell High-performance Electric Vehicles
				96,668

Number of Shares			Value (000)
		> Restaurants 0.3%
	2,000,000	AFC Enterprises (a)(b)	$	33,920
		Popeye's Restaurants
	675,000	Bravo Brio Restaurant Group (a)		13,473
		Upscale Casual Italian Restaurants
	450,000	Cheesecake Factory (a)		13,226
		Casual Dining Restaurants
				60,619
		> Nondurables 0.3%
	1,600,000	Helen of Troy (a)(b)		54,416
		Personal Care, Housewares, Healthcare & Home Environment Products
				54,416
		> Educational Services 0.3%
	800,000	New Oriental Education & Technology - ADR (China) (a)		21,968
		Education Service Provider
	300,000	ITT Educational Services (a)(d)		19,842
		Postsecondary Degree Services
	612,205	Universal Technical Institute		8,075
		Vocational Training
	2,000,000	Voyager Learning, Contingent Value Rights (a)(e)(f)		220
		Education Services for the K-12 Market
				50,105
		> Leisure Products 0.1%
	1,290,000	Skullcandy (a)(d)		20,421
		Lifestyle Branded Headphones
				20,421
		> Other Entertainment —%
	265,000	CTS Eventim (Germany)		9,154
		Event Ticket Sales
				9,154
Consumer Goods & Services: Total				3,023,985
Finance 10.2%
		> Banks 4.2%
	2,691,414	BOK Financial		151,473
		Tulsa-based S.W. Bank
	6,287,800	Associated Banc-Corp		87,778
		Midwest Bank
	2,337,313	Hancock Holding		82,998
		Gulf Coast Bank
	5,070,000	Valley National Bancorp		65,657
		New Jersey/New York Bank
	1,175,000	City National		61,652
		Bank & Asset Manager
	2,860,000	MB Financial (b)		60,031
		Chicago Bank
	810,000	SVB Financial Group (a)		52,115
		Bank to Venture Capitalists
	3,400,000	CVB Financial		39,916
		Inland Empire Business Bank
	2,200,000	TCF Financial		26,158
		Great Lakes Bank
	700,000	Wintrust Financial		25,053
		Chicago & Milwaukee Full Service Bank

30

Number of Shares			Value (000)
		> Banks—continued
	1,350,000	TriCo Bancshares (b)	$	23,517
		California Central Valley Bank
	4,299,507	First Busey		21,240
		Illinois Bank
	1,121,188	Sandy Spring Bancorp		20,372
		Baltimore, D.C. Bank
	811,295	Hudson Valley		13,086
		Metro New York City Bank
	2,136,500	TrustCo Bank		12,199
		New York State Bank
	706,559	Eagle Bancorp (a)		11,828
		Metro D.C. Bank
	1,000,000	First Commonwealth		6,120
		Western Pennsylvania Bank
	500,000	Oriental Financial Group		6,050
		Puerto Rican Bank
	246,505	Pacific Continental Bank		2,322
		Pacific N.W. Bank
	152,569	Green Bankshares (a)		258
		Tennessee Bank
				769,823
		> Insurance 2.6%
	2,820,000	Leucadia National		73,602
		Insurance Holding Company
	8,900,000	CNO Financial Group (a)		69,242
		Life, Long Term Care & Medical Supplement Insurance
	2,764,000	Tower Group (b)		61,997
		Commercial & Personal Lines Insurance
	833,000	Allied World Holdings		57,202
		Commercial Lines Insurance/Reinsurance
	1,120,000	The Hanover Insurance Group		46,054
		Personal & Commercial Lines Insurance
	2,050,000	Selective Insurance Group		36,100
		Commercial & Personal Lines Insurance
	1,100,000	HCC Insurance Holdings		34,287
		Specialty Insurance
	832,000	Willis Group (Ireland)		29,103
		Insurance Broker
	925,000	Kemper		28,009
		Multi-line Insurance
	250,000	Enstar Group (a)		24,748
		Insurance/Reinsurance & Related Services
	900,000	Brown & Brown		21,402
		Insurance Broker
	500,000	Assured Guaranty		8,260
		Global Muni Bond Insurance
				490,006
		> Finance Companies 1.4%
	1,459,555	World Acceptance (a)(b)		89,398
		Personal Loans
	2,150,000	McGrath Rentcorp (b)		69,037
		Temporary Space & IT Rentals
	3,400,000	H & E Equipment Services (a)(b)		64,328
		Heavy Equipment Leasing
	1,123,400	CAI International (a)(b)		20,423
		International Container Leasing

Number of Shares			Value (000)
	1,091,000	Marlin Business Services (b)	$	16,430
		Small Equipment Leasing
	422,500	Regional Management (a)		7,098
		Consumer Loans
	78,500	Textainer Group Holdings		2,661
		Top International Container Leaser
				269,375
		> Brokerage & Money Management 1.3%
	6,198,000	SEI Investments		128,237
		Mutual Fund Administration & Investment Management
	3,700,000	Eaton Vance		105,746
		Specialty Mutual Funds
	1,000,000	Artio Global Investors (d)		4,770
		International Asset Manager
				238,753
		> Credit Cards 0.5%
	550,000	Alliance Data Systems (a)		69,278
		Diversified Credit Card Provider
	275,000	Wright Express (a)		17,801
		Pay Card Processor
				87,079
		> Savings & Loans 0.2%
	400,000	Financial Engines (a)		8,944
		Asset Management for 401k Plans
	1,010,000	Provident New York Bancorp		8,545
		New York State Thrift
	470,000	ViewPoint Financial		7,229
		Texas Thrift
	452,146	Kaiser Federal		6,325
		Los Angeles Savings & Loan
	65,991	Berkshire Hills Bancorp		1,512
		Northeast Thrift
				32,555
Finance: Total				1,887,591
Health Care 8.7%
		> Biotechnology & Drug Delivery 4.1%
	2,290,000	Alexion Pharmaceuticals (a)		212,649
		Biotech Focused on Orphan Diseases
	4,315,000	BioMarin Pharmaceutical (a)		147,789
		Biotech Focused on Orphan Diseases
	6,153,000	Seattle Genetics (a)(b)(d)		125,398
		Antibody-based Therapies for Cancer
	3,250,000	Auxilium Pharmaceuticals (a)(b)		60,352
		Biotech Focused on Niche Disease Areas
	2,950,000	InterMune (a)		43,277
		Drugs for Pulmonary Fibrosis & Hepatitis C
	6,000,000	NPS Pharmaceuticals (a)(b)		41,040
		Orphan Drugs & Healthy Royalties
	1,000,000	Onyx Pharmaceuticals (a)		37,680
		Commercial-stage Biotech Focused on Cancer
	3,430,000	Isis Pharmaceuticals (a)		30,081
		Biotech Pioneer in Antisense Drugs
	4,200,000	Raptor Pharmaceutical (a)(b)(d)		28,392
		Orphan Drug Company

31

Columbia Acorn Fund

Statement of Investments (Unaudited), continued

Number of Shares			Value (000)
		> Biotechnology & Drug Delivery—continued
	5,750,000	Chelsea Therapeutics International (a)(b)	$	14,720
		Biotech Focused on Rare Diseases
	2,990,000	Anthera Pharmaceuticals (a)(b)		6,608
		Biotech Focused on Cardiovascular, Cancer & Immunology
	180,167	Synageva Biopharma (a)		6,463
		Biotech Focused on Orphan Diseases
	359,944	MicroDose Therapeutx (a)(e)(f)		270
		Drug Inhaler Development
				754,719
		> Medical Supplies 2.1%
	3,900,000	Cepheid (a)(b)		163,137
		Molecular Diagnostics
	950,000	Henry Schein (a)		71,896
		Largest Distributor of Healthcare Products
	2,126,000	Patterson Companies		71,008
		Dental/Vet/Med Distributor
	1,136,500	DENTSPLY International		45,608
		Leading Dental Supplies Manufacturer
	375,000	Techne		26,287
		Cytokines, Antibodies & Other Reagents for Life Science
				377,936
		> Medical Equipment & Devices 1.3%
	1,873,800	Hill-Rom Holdings		62,604
		Hospital Beds/Patient Handling
	760,000	Gen-Probe (a)		50,472
		Molecular In-vitro Diagnostics
	550,000	Haemonetics (a)		38,324
		Blood & Plasma Collection Equipment
	675,000	Sirona Dental Systems (a)		34,789
		Manufacturer of Dental Equipment
	950,000	PerkinElmer Inc.		26,277
		Analytical Instruments for Life Sciences
	570,000	Orthofix International (a)		21,421
		Bone Fixation & Stimulation Devices
	2,525,000	Pacific Biosciences of California (a)		8,635
		Genome Sequencing
				242,522
		> Health Care Services 0.7%
	665,000	Mednax (a)		49,456
		Physician Management for Pediatric & Anesthesia Practices
	4,900,000	eResearch Technology (a)(b)		38,318
		Clinical Research Services
	1,200,000	Allscripts Healthcare Solutions (a)		19,920
		IT for Physician Offices & Hospitals
	825,000	HealthSouth (a)		16,896
		Inpatient Rehabilitation Facilities
	1,875,000	Health Management Associates (a)		12,600
		Non-urban Hospitals
				137,190
		> Pharmaceuticals 0.5%
	4,000,000	Akorn (a)		46,800
		Develops, Manufactures & Sells Specialty Generic Drugs

Number of Shares			Value (000)
	3,388,000	Adcock Ingram Holdings (South Africa)	$	25,926
		Manufacturer of Pharmaceuticals & Medical Supplies
	2,040,000	Alimera Sciences (a)(b)		6,895
		Ophthalmology-focused Pharmaceutical Company
	1,095,000	Horizon Pharma (a)		4,533
		Specialty Pharmaceutical Company
				84,154
Health Care: Total				1,596,521
Energy & Minerals 8.6%
		> Oil Services 3.9%
	5,298,000	FMC Technologies (a)		267,125
		Oil & Gas Well Head Manufacturer
	1,988,054	Fugro (Netherlands)		141,641
		Sub-sea Oilfield Services
	2,114,000	Atwood Oceanics (a)		94,898
		Offshore Drilling Contractor
	743,000	Oil States International (a)		57,999
		Diversified North American Oil Service Provider
	1,670,000	ShawCor (Canada)		52,572
		Oil & Gas Pipeline Products
	1,000,000	Hornbeck Offshore (a)		42,030
		Supply Vessel Operator in U.S. Gulf of Mexico
	1,056,600	Black Diamond Group (Canada)		21,059
		Provides Accommodations/Equipment for Oil Sands Development
	585,000	Rowan (a)		19,264
		Contract Offshore Driller
	2,890,900	Horizon North Logistics (Canada)		18,114
		Provides Diversified Oil Service Offering in Northern Canada
	4,435,000	Tuscany International Drilling (Colombia) (a)		3,335
		South America-based Drilling Rig Contractor
				718,037
		> Oil & Gas Producers 3.1%
	4,250,000	Pacific Rubiales Energy (Colombia)		124,162
		Oil Production & Exploration in Colombia
	900,000	SM Energy		63,693
		Oil & Gas Producer
	2,700,000	Denbury Resources (a)		49,221
		Oil Producer Using Co2 Injection
	974,000	Rosetta Resources (a)		47,492
		Oil & Gas Producer Exploring in South Texas & Montana
	1,697,000	Tullow Oil (United Kingdom)		41,448
		Oil & Gas Producer
	695,000	Range Resources		40,407
		Oil & Gas Producer
	650,000	Baytex (Canada)		33,749
		Oil & Gas Producer in Canada
	2,160,000	Athabasca Oil Sands (Canada) (a)		24,016
		Oil Sands SAGD & Alberta Deep Basin Development
	1,140,000	Celtic Exploration (Canada) (a)		16,618
		Canadian Oil & Gas Producer

32

Number of Shares			Value (000)
		> Oil & Gas Producers—continued
	550,000	Swift Energy (a)	$	15,966
		Oil & Gas Exploration & Production
	500,000	Cabot Oil and Gas		15,585
		Large Natural Gas Producer in Appalachia & Gulf Coast
	1,547,000	Crew Energy (Canada) (a)		14,765
		Canadian Oil & Gas Producer
	340,000	Petroleum Development Corporation (a)		12,611
		Oil & Gas Producer in U.S.
	7,582,928	PetroMagdalena Energy (Colombia) (a)(b)(d)		12,164
		Oil & Gas Exploration/Production in Colombia
	1,100,000	Kodiak Oil and Gas (a)		10,956
		Bakken Oil & Gas Producer
	37,500,000	Petromanas (Canada) (a)(b)		8,647
	18,750,000	Petromanas - Warrants (Canada) (a)(e)		92
		Exploring for Oil in Albania
	200,000	Approach Resource (a)		7,390
		Oil & Gas Producer in West Texas Permian
	27,000,000	Shamaran Petroleum (Iraq) (a)		6,903
		Oil Exploration in Kurdistan
	26,000,000	Petrodorado (Colombia) (a)(b)		5,995
	24,000,000	Petrodorado - Warrants (Colombia) (a)(e)(f)		941
		Oil & Gas Exploration & Production in Colombia, Peru & Paraguay
	1,198,100	Pan Orient (Canada) (a)		4,889
		Growth-oriented, Return-focused Asian Explorer
	5,917,100	Canacol (Colombia) (a)		4,686
		Oil Producer in South America
	25,000,000	Petroamerica (Colombia) (a)		4,010
		Oil Exploration & Production in Colombia
	41,100,000	Quetzal Energy (Colombia) (a)(b)(e)		2,176
	8,900,000	Quetzal Energy (Colombia) (a)(b)		491
		Explores for Oil & Gas in Latin America
	393,600	Houston American Energy (a)		2,054
		Oil & Gas Exploration/Production in Colombia
	8,400,000	Canadian Overseas Petroleum (United Kingdom) (a)(e)		1,779
	4,200,000	Canadian Overseas Petroleum - Warrants (United Kingdom) (a)(e)(f)		106
		Oil & Gas Exploration/Production in the North Sea
				573,012
		> Mining 1.3%
	442,000	Core Laboratories (Netherlands)		58,154
		Oil & Gas Reservoir Consulting
	1,600,000	Silver Wheaton (Canada)		53,120
		Silver Mining Royalty Company
	15,000,000	Zhaojin Mining Industry (China)		25,231
		Gold Mining & Refining in China
	4,432,000	Northam Platinum (South Africa)		19,713
		Platinum Mining in South Africa
	2,800,000	Alexco Resource (a)		19,544
		Mining, Exploration & Environmental Services

Number of Shares			Value (000)
	1,150,000	Ivanhoe Mines (Mongolia) (a)	$	18,090
		Copper Mine Project in Mongolia
	7,500,000	Duluth Metals (Canada) (a)(b)(d)		17,068
		Copper & Nickel Miner
	920,000	Kirkland Lake Gold (Canada) (a)		13,300
		Gold Mining
	12,000,000	Mongolian Mining (Mongolia) (a)		11,421
		Coking Coal Mining in Mongolia
	800,000	Augusta Resource (a)		2,184
		US Copper/Moly Mine
	4,000,000	Wolverine Minerals (Canada) (a)(b)(e)		674
	2,000,000	Wolverine Minerals - Warrants (Canada) (a)(e)(f)		30
		Gold Miner
	500,000	Duluth Exploration - Special Warrants (Canada) (a)(e)(f)		45
		Copper & Nickel Miner
				238,574
		> Alternative Energy 0.1%
	2,000,000	GT Solar International (a)		16,540
		Largest Manufacturer of Furnaces & Reactors to Produce & Cast Polysilicon
	1,210,300	Synthesis Energy Systems (China) (a)		1,779
		Owner/Operator of Gasification Plants
				18,319
		> Oil Refining, Marketing & Distribution 0.1%
	300,000	Vopak (Netherlands)		17,283
		World's Largest Operator of Petroleum & Chemical Storage Terminals
				17,283
		> Agricultural Commodities 0.1%
	1,250,000	Union Agriculture Group (Argentina) (a)(e)(f)		13,275
		Farmland Operator in Uruguay
				13,275
Energy & Minerals: Total				1,578,500
Other Industries 5.8%
		> Real Estate 3.6%
	3,700,000	Dupont Fabros Technology (b)		90,465
		Technology-focused Office Buildings
	750,000	Federal Realty Investment Trust		72,592
		Shopping Centers
	3,700,000	Associated Estates Realty (b)		60,458
		Multifamily Properties
	1,850,000	Extra Space Storage		53,262
		Self Storage Facilities
	720,000	Digital Realty Trust		53,258
		Technology-focused Office Buildings
	2,450,000	Biomed Realty Trust		46,501
		Life Science-focused Office Buildings
	975,000	Post Properties		45,689
		Multifamily Properties
	770,000	Kilroy Realty		35,890
		West Coast Office & Industrial Properties
	3,000,000	Education Realty Trust		32,520
		Student Housing

33

Columbia Acorn Fund

Statement of Investments (Unaudited), continued

Number of Shares			Value (000)
		> Real Estate—continued
	43,000,000	Mapletree Logistics Trust (Singapore)	$	32,348
		Industrial Property Landlord
	325,000	Jones Lang LaSalle		27,076
		Real Estate Services
	1,300,000	St. Joe (a)(d)		24,713
		Florida Panhandle Landowner
	15,000,000	Ascendas REIT (Singapore)		24,130
		Industrial Property Landlord
	3,750,000	DCT Industrial Trust		22,125
		Industrial Properties
	3,500,000	Kite Realty Group (b)		18,445
		Community Shopping Centers
	2,000,031	Summit Hotel Properties (b)		15,160
		Owner of Select Service Hotels
	2,800	Orix JREIT (Japan)		13,084
		Diversified REIT
				667,716
		> Transportation 1.3%
	1,155,000	JB Hunt Transport Services		62,797
		Truck & Intermodal Carrier
	2,800,000	Rush Enterprises, Class A (a)(b)		59,416
	550,000	Rush Enterprises, Class B (a)(b)		9,565
		Truck Sales & Service
	1,260,000	World Fuel Services		51,660
		Global Fuel Broker
	2,400,000	Heartland Express		34,704
		Regional Trucker
	400,000	Genesee & Wyoming (a)		21,832
		Short-line Operator
				239,974
		> Regulated Utilities 0.9%
	2,000,000	Northeast Utilities		74,240
		Regulated Electric Utility
	1,660,000	Wisconsin Energy		58,399
		Wisconsin Utility
	500,000	Allete		20,745
		Regulated Electric Utility in Minnesota
	200,000	Red Eléctrica de España (Spain)		9,786
		Spanish Power Transmission
				163,170
Other Industries: Total				1,070,860
Total Equities: 97.4% (Cost: $10,807,922)				17,934,688

Number of Shares			Value (000)
Securities Lending Collateral 0.9%
	169,250,625	Dreyfus Government Cash Management Fund (7 day yield of 0.01%) (g)	$	169,251
Total Securities Lending Collateral: (Cost: $169,251)				169,251
Total Investments: 98.3% (Cost: $10,977,173)(h)(i)				18,103,939	(j)
Obligation to Return Collateral for Securities Loaned: (0.9)%				(169,251	)
Cash and Other Assets Less Liabilities: 2.6%				480,744
Total Net Assets: 100.0%			$	18,415,432

ADR - American Depositary Receipts

DVR - Differential Voting Right Equity Shares

GDR - Global Depositary Receipts

34

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

(a)  Non-income producing security.

(b)  An affiliated person of the Fund may include any company in which the Fund owns five percent or more of its outstanding voting shares. Holdings and transactions in these affiliated companies during the three months ended March 31, 2012, are as follows:

Affiliates	Balance of Shares Held at 12/31/11		Purchases/ Additions		Sales/ Reductions		Balance of Shares Held at 3/31/12		Value		Dividend
AboveNet		1,400,000		-		-		1,400,000	$	115,920	$	-
Acorn Energy		1,500,000		-		-		1,500,000		16,305		128
AFC Enterprises		2,000,000		-		-		2,000,000		33,920		-
Alimera Sciences		2,040,000		-		-		2,040,000		6,895		-
Anthera Pharmaceuticals		1,740,000		1,250,000		-		2,990,000		6,608		-
Associated Estates Realty		3,700,000		-		-		3,700,000		60,458		629
Auxilium Pharmaceuticals		3,033,715		216,285		-		3,250,000		60,352		-
Bally Technologies		3,725,000		-		-		3,725,000		174,144		-
CAI International		1,123,400		-		-		1,123,400		20,423		-
Cavco Industries		460,000		-		-		460,000		21,427		-
Cepheid		3,200,000		700,000		-		3,900,000		163,137		-
Chelsea Therapeutics International		4,550,000		1,200,000		-		5,750,000		14,720		-
Cogent Communications*		2,520,000		-		320,000		2,200,000		41,976		-
Constant Contact		2,350,000		-		-		2,350,000		70,006		-
Donaldson**		4,200,000		4,200,000		-		8,400,000		300,132		672
Drew Industries		1,500,000		380,000		-		1,880,000		51,343		-
Duluth Metals		7,500,000		-		-		7,500,000		17,068		-
Dupont Fabros Technology		3,350,000		350,000		-		3,700,000		90,465		378
eResearch Technology		4,900,000		-		-		4,900,000		38,318		-
ESCO Technologies		2,200,000		-		-		2,200,000		80,894		176
Gaiam		1,371,366		-		-		1,371,366		5,458		-
Gaylord Entertainment		3,850,000		-		-		3,850,000		118,580		-
General Communications		2,000,000		-		-		2,000,000		17,440		-
GLG Life Tech		1,750,000		-		71,875		1,678,125		1,326		-
H & E Equipment Services		3,400,000		-		-		3,400,000		64,328		-
Hackett Group+		4,500,000		-		650,793		3,849,207		22,980		-
Heico		2,250,000		200,000		-		2,450,000		98,368		135
Helen of Troy		1,600,000		-		-		1,600,000		54,416		-
Horizon Pharma*		1,095,000		-		-		1,095,000		4,533		-
iGATE		3,400,000		-		-		3,400,000		56,984		-
II-VI		4,550,000		-		-		4,550,000		107,607		-
Interline Brands		2,600,000		-		200,249		2,399,751		51,859		-
IPG Photonics		2,780,000		-		-		2,780,000		144,699		-
IXYS		1,900,000		-		-		1,900,000		25,080		-
Kenexa		1,700,000		-		-		1,700,000		53,108		-
Kite Realty Group		3,500,000		-		-		3,500,000		18,445		210
Knoll		4,200,000		-		-		4,200,000		69,888		420
Lifetime Fitness		2,190,000		-		-		2,190,000		110,748		-
lululemon athletica*		5,740,000		-		817,200		4,922,800		367,635		-
Marlin Business Services		1,091,000		-		-		1,091,000		16,430		65
MB Financial		2,360,000		500,000		-		2,860,000		60,031		26
McGrath Rentcorp		2,150,000		-		-		2,150,000		69,037		495
Mettler Toledo		1,600,000		-		-		1,600,000		295,600		-
Micromet*		6,702,347		64,547		6,766,894		-		-		-
Moog		2,775,000		-		-		2,775,000		119,020		-
Navigant Consulting		2,800,000		-		-		2,800,000		38,948		-
NPS Pharmaceuticals		6,000,000		-		-		6,000,000		41,040		-
Pericom Semiconductor		1,765,000		-		-		1,765,000		14,279		-
Petroamerica*		30,275,000		-		5,275,000		25,000,000		4,010		-
Petrodorado		26,000,000		-		-		26,000,000		5,995		-
PetroMagdalena Energy		7,582,928		-		-		7,582,928		12,164		-
Petromanas		37,500,000		-		-		37,500,000		8,647		-
Pier 1 Imports		5,600,000		-		-		5,600,000		101,808		-
Pinnacle Entertainment		3,950,000		-		-		3,950,000		45,464		-
Quetzal Energy		50,000,000		-		-		50,000,000		2,667		-
Raptor Pharmaceutical		3,455,000		745,000		-		4,200,000		28,392		-
Rush Enterprises		3,350,000		-		-		3,350,000		68,981		-
Salem Communications*		1,527,700		-		1,527,700		-		-		-

35

Columbia Acorn Fund

Statement of Investments (Unaudited), continued

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

Affiliates	Balance of Shares Held at 12/31/11		Purchases/ Additions		Sales/ Reductions		Balance of Shares Held at 3/31/12		Value		Dividend
Seattle Genetics		6,153,000		-		-		6,153,000	$	125,398	$	-
Shutterfly		3,070,000		300,000		-		3,370,000		105,582		-
SPS Commerce		900,000		-		-		900,000		24,192		-
Summit Hotel Properties		1,500,000		500,031		-		2,000,031		15,160		188
Tower Group		1,675,000		1,089,000		-		2,764,000		61,997		518
TriCo Bancshares		1,350,000		-		-		1,350,000		23,517		122
True Religion Apparel*		1,507,000		-		1,113,548		393,452		10,780		-
tw telecom		9,500,000		-		-		9,500,000		210,520		-
Tyler Technologies		1,700,000		-		-		1,700,000		65,297		-
Virtusa		2,125,000		-		-		2,125,000		36,699		-
Warnaco Group		2,190,000		-		-		2,190,000		127,896		-
Wolverine Minerals		4,000,000		-		-		4,000,000		674		-
World Acceptance		1,505,202		-		45,647		1,459,555		89,398		-
Total of Affiliated Transactions		345,027,658		11,694,863		16,788,906		339,933,615	$	4,607,616	$	4,162

*  At March 31, 2012, the Fund owned less than five percent of the company's outstanding voting shares.

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

+  Includes the effects of a corporate action.

  The aggregate cost and value of these companies at March 31, 2012, were $2,743,348 and $4,178,682, respectively. Investments in affiliated companies represented 22.69% of the Fund's total net assets at March 31, 2012.

(c)  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 March 31, 2012, this security had an aggregate value of $15,780, which represented 0.09% of total net assets.

(d)  All or a portion of this security was on loan at March 31, 2012. The total market value of securities on loan at March 31, 2012 was $166,411.

(e)  Denotes a restricted security, which is subject to restrictions on resale under federal securities laws. These securities are valued at fair value determined in good faith under consistently applied procedures established by the Board of Trustees. At March 31, 2012, the market value of these securities amounted to $19,608, which represented 0.11% of total net assets.

  Additional information on these securities is as follows:

Security	Acquisition Dates	Shares		Cost		Value
Union Agriculture Group	12/8/10-12/16/11		1,250,000	$	15,000	$	13,275
Quetzal Energy	1/14/11		41,100,000		5,193		2,176
Canadian Overseas Petroleum	11/24/10		8,400,000		3,591		1,779
Petrodorado - Warrants	11/20/09		24,000,000		2,965		941
Wolverine Minerals	6/3/11		4,000,000		2,005		674
MicroDose Therapeutx	11/24/00		359,944		2,005		270
Voyager Learning, Contingent Value Rights	12/24/09		2,000,000		-		220
Canadian Overseas Petroleum - Warrants	11/24/10		4,200,000		526		106
Petromanas - Warrants	5/20/10		18,750,000		1,086		92
Duluth Exploration - Special Warrants	8/19/11		500,000		-		45
Wolverine Minerals - Warrants	6/3/11		2,000,000		243		30
				$	32,614	$	19,608

(f)  Illiquid security.

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

(h)  At March 31, 2012, for federal income tax purposes, the cost of investments was $10,977,173 and net unrealized appreciation was $7,126,766 consisting of gross unrealized appreciation of $7,687,302 and gross unrealized depreciation of $(560,536).

36

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

(i)  On March 31, 2012, the market value of foreign securities represented 9.36% of total net assets. The Fund's foreign portfolio was diversified as follows:

	Value		Percentage of Net Assets
Netherlands	$	315,070		1.71
Canada		306,968		1.67
Colombia		157,960		0.86
Singapore		144,270		0.78
Sweden		100,243		0.54
Hong Kong		97,128		0.53
Japan		72,621		0.39
China		69,964		0.38
Brazil		59,690		0.32
France		47,758		0.26
South Africa		45,639		0.25
Denmark		44,415		0.24
United Kingdom		43,333		0.24
	Value		Percentage of Net Assets
Chile	$	39,485		0.21
Israel		33,951		0.18
Mongolia		29,511		0.16
Ireland		29,103		0.16
India		19,969		0.12
Russia		15,780		0.09
Argentina		13,275		0.07
Iceland		11,735		0.06
Spain		9,786		0.05
Germany		9,154		0.05
Iraq		6,903		0.04
Total Foreign Portfolio	$	1,723,711		9.36

(j)  Securities are valued using policies described in the Notes to Financial Statements in the most recent shareholder report.

  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.

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

  The Committee meets at least quarterly to review and approve valuation matters, which may include a description of fair value actions, data regarding pricing information received from approved pricing vendors and brokers and the results of Board-approved valuation control policies and procedures (the Policies). The Policies address, among other things, instances when market quotations are readily available, including recommendation of third party pricing vendors and determining appropriate pricing methodologies; events that require fair valuation and assessment of fair value techniques; securities with a potential for stale pricing, including those that are illiquid, restricted, or in default; and the effectiveness of third-party pricing vendors. The Committee meets more frequently, as needed, to discuss additional valuation matters, which may include the need to review back-testing results, review time-sensitive information or approve related valuation actions.

  For investments categorized as Level 3, the Committee monitors information similar to that described above, which may include: (i) data specific to the issuer or comparable issuers, (ii) general market or specific sector news and (iii) quoted prices and specific or similar security transactions. The Committee considers this data and any changes from prior periods in order to assess the reasonableness of observable and unobservable inputs, any assumptions or internal models used to value those securities and changes in fair value. This data is also used to corroborate, when available, information received from approved pricing vendors. Various factors impact the frequency of monitoring (which may occur as often as daily), however the Committee may determine that changes to inputs, assumptions and models are not required with the same frequency.

37

Columbia Acorn Fund

Statement of Investments (Unaudited), continued

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

  The following table summarizes the inputs used, as of March 31, 2012, in valuing the Fund's assets:

Investment Type	Quoted Prices (Level 1)		Other Significant Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)		Total
Equities
Information	$	5,051,628	$	281,190	$	-	$	5,332,818
Industrial Goods & Services		3,205,616		238,797		-		3,444,413
Consumer Goods & Services		2,898,177		125,588		220		3,023,985
Finance		1,887,591		-		-		1,887,591
Health Care		1,570,325		25,926		270		1,596,521
Energy & Minerals		1,302,645		262,535		13,320		1,578,500
Other Industries		991,512		79,348		-		1,070,860
Total Equities		16,907,494		1,013,384		13,810		17,934,688
Total Securities Lending Collateral		169,251		-		-		169,251
Total Investments	$	17,076,745	$	1,013,384	$	13,810	$	18,103,939

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

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

Transfers In				Tranfers Out
Level 1		Level 2		Level 1		Level 2
$	-	$	115,086	$	115,086	$	-

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

  The following table reconciles asset balances for the period ending March 31, 2012, in which significant unobservable inputs (Level 3) were used in determining value:

Investments in Securities	Balance as of December 31, 2011		Realized Gain/(Loss)		Change in Unrealized Appreciation (Depreciation)		Purchases		Sales		Transfers into Level 3		Transfers out of Level 3		Balance as of March 31, 2012
Equities
Consumer Goods & Services	$	180	$	-	$	40	$	-	$	-	$	-	$	-	$	220
Health Care		270		-		-		-		-		-		-		270
Energy & Minerals		12,507		-		813		-		-		-		-		13,320
	$	12,957	$	-	$	853	$	-	$	-	$	-	$	-	$	13,810

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

  The change in unrealized appreciation attributed to securities owned at March 31, 2012, which were valued using significant unobservable inputs (Level 3) amounted to $853.

38

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

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

  Certain common stock classified as Level 3 are valued using a market approach. To determine fair value for these securities, management considered various factors which may have included, but were not limited to, trades of similar securities, estimated earnings of the respective company, market multiples derived from a set of comparable companies, and the position of the security within the respective company's capital structure. Significant increases (decreases) to any of these inputs would result in a significantly lower (higher) fair value measurement. Generally, a change in estimated earnings of the respective company may result in a change to the comparable companies and market multiples utilized.

39

Columbia Acorn International Fund

Major Portfolio Changes in the First Quarter (Unaudited)

	Number of Shares
	12/31/11		03/31/12
Purchases
Asia
> Japan
Daiseki		1,277,429		1,427,129
Disco		306,000		480,000
Doshisha		24,000		750,600
FP Corporation		254,000		339,000
Glory		1,055,562		1,694,562
Horiba		0		257,800
Nihon Parkerizing		0		145,700
Park24		2,263,000		3,029,900
Sanrio		0		500,000
Start Today		527,001		1,718,724
> Taiwan
Chroma Ate		9,857,400		10,277,000
CTCI Corp		13,957,000		18,571,200
MStar Semiconductor		0		2,930,000
St. Shine Optical		2,450,000		2,492,300
Taiwan Hon Chuan		10,357,000		11,200,000
Taiwan Mobile		6,647,000		10,329,000
Tripod Technologies		10,147,270		12,218,270
> Hong Kong
Lifestyle International		17,000,000		18,000,000
Melco International		7,419,000		8,000,000
Sasa International		37,703,800		38,000,000
> Singapore
CDL Hospitality Trust		18,000,000		20,000,000
Mapletree Commercial Trust		32,300,000		35,000,000
> China
Digital China		12,446,800		13,570,200
Want Want		19,410,400		26,565,000
> India
Redington India		0		1,477,269
United Breweries		1,500,251		2,262,300
> Korea
Grand Korea Leisure		0		1,134,000
Hana Tour Service		0		182,000
Handsome		61,600		471,971
Hyundai Home Shopping		0		10,090
iMarketKorea		0		570,990
> Mongolia
Mongolian Mining		35,923,500		42,636,400
> Indonesia
Tower Bersama Infrastructure		13,942,000		48,560,000
> Cambodia
Nagacorp		42,522,600		50,000,000

	Number of Shares
	12/31/11		03/31/12
Europe
> United Kingdom
BBA Aviation		0		3,167,139
Greggs		467,193		1,060,885
Rightmove		0		548,000
> Netherlands
TKH Group		0		403,800
> Switzerland
Dufry Group		324,000		360,000
Geberit		225,650		255,000
Partners Group		265,000		280,000
Zehnder		0		236,217
> Italy
Geox		5,300,000		5,800,000
Pirelli		1,756,000		2,661,000
> Denmark
Solar A/S		0		130,651
> Spain
Red Eléctrica de España		494,320		618,320
> Portugal
Redes Energéticas Nacionais		7,770,405		8,531,175
> Kazakhstan
Halyk Savings Bank of Kazakhstan - GDR		1,770,000		3,319,000
Other Countries
> South Africa
Coronation Fund Managers		10,271,492		11,763,907
Northam Platinum		6,943,940		8,679,940
> Canada
Alliance Grain Traders		868,000		984,500
Americas Petrogas		0		1,611,000
> Australia
Challenger Financial		0		4,546,885
Commonwealth Property Office Fund		0		17,451,906
> Israel
Caesarstone		0		125,000
Israel Chemicals		3,085,527		4,706,527
Latin America
> Argentina
Madalena Ventures		0		2,475,000
> Chile
Viña Concha y Toro		0		4,016,878

40

	Number of Shares
	12/31/11		03/31/12
Sales
Asia
> Japan
Gree		1,139,000		246,300
Hamamatsu Photonics		479,854		0
Hoshizaki Electric		1,697,200		1,582,200
Kansai Paint		7,044,100		5,582,600
Miura		636,250		511,450
Pigeon		469,500		0
Shinsei Bank		25,769,649		18,673,649
> Taiwan
Formosa International Hotels		468,917		0
President Chain Store		7,000,000		3,181,000
> Singapore
Ascendas REIT		21,600,000		20,000,000
Mapletree Industrial Trust		39,000,000		28,000,000
Mapletree Logistics Trust		50,000,000		35,000,000
Olam International		33,000,000		27,000,000
> China
China Yurun Food		12,047,000		0
ENN Energy		5,000,000		0
Noah Holdings - ADR		493,398		0
Zhaojin Mining Industry		34,745,554		18,920,554
> India
Manappuram Finance		16,621,332		1,668,793
> Korea
MegaStudy		63,916		0
Woongjin Coway		1,242,590		623,410
> Thailand
Home Product Center		120,000,000		118,000,000
> Philippines
SM Prime Holdings		69,967,000		58,577,000
Europe
> United Kingdom
Chemring		5,700,000		5,654,735
GlobeOp Financial Services		4,150,000		0
Intertek Group		1,480,000		1,460,000
Kesa Electricals		2,533,060		0
Next		446,300		262,300
> Netherlands
Core Laboratories		228,095		177,395
Imtech		1,955,311		1,763,611
Koninklijke TenCate		1,371,573		1,181,073
> Switzerland
Bank Sarasin & Cie		696,331		580,000

	Number of Shares
	12/31/11		03/31/12
> Germany
CTS Eventim		819,889		625,000
Dürr		636,800		500,000
> France
Eurofins Scientific		532,368		418,000
Gemalto		1,193,000		1,073,700
Neopost		555,324		430,000
> Italy
CIR		13,547,300		12,503,754
> Ireland
United Drug		9,074,112		6,750,000
Other Countries
> South Africa
Mr. Price		3,722,083		3,175,083
> United States
FMC Technologies		606,253		461,213
Latin America
> Brazil
Localiza Rent A Car		4,000,000		3,700,000
Mills Estruturas e Servicos de Engenharia		2,303,200		1,880,200
Suzano		6,344,043		0
> Mexico
Grupo Aeroportuario del Sureste - ADR		624,168		600,000
> Chile
Sociedad Quimica y Minera de Chile - ADR		362,996		0

41

Columbia Acorn International

Statement of Investments (Unaudited), March 31, 2012

Number of Shares			Value (000)
			Equities: 95.7%
Asia 42.3%
		> Japan 17.3%
	5,582,600	Kansai Paint	$	56,596
		Paint Producer in Japan, India, China & Southeast Asia
	22,694,000	Seven Bank		49,767
		ATM Processing Services
	22,300	Wacom (a)		46,834
		Computer Graphic Illustration Devices
	2,981,100	Kuraray		42,398
		Special Resin, Fine Chemical, Fibers & Textures
	3,029,900	Park24		40,971
		Parking Lot Operator
	1,860,438	Aeon Delight		39,233
		Facility Maintenance & Management
	1,582,200	Hoshizaki Electric		37,531
		Commercial Kitchen Equipment
	1,694,562	Glory		37,164
		Currency Handling Systems & Related Equipment
	7,780	Orix JREIT		36,356
		Diversified REIT
	2,400,000	NGK Insulators		34,575
		Ceramic Products for Auto, Power & Electronics
	937,651	Kintetsu World Express		32,758
		Airfreight Logistics
	589,792	Ain Pharmaciez		31,834
		Dispensing Pharmacy/Drugstore Operator
	1,718,724	Start Today		31,742
		Online Japanese Apparel Retailer
	295,762	Nakanishi		31,399
		Dental Tools & Machinery
	16,005	Advance Residence Investment		30,405
		Residential REIT
	2,137,272	Japan Airport Terminal		28,174
		Airport Terminal Operator at Haneda
	480,000	Disco		26,729
		Semiconductor Dicing & Grinding Equipment
	1,427,129	Daiseki		26,533
		Waste Disposal & Recycling
	25,979	Jupiter Telecommunications		26,020
		Largest Cable Service Provider in Japan
	855,604	Tsumura		24,732
		Traditional Chinese/Japanese Herbal Rx Drugs (Kampo)
	18,673,649	Shinsei Bank		24,582
		Commercial Bank
	2,600,000	Shimadzu		23,663
		Analytical Instrument, Medical & Industrial Equipment
	6,140	Kenedix Realty Investment		22,592
		Tokyo Mid-size Office REIT
	1,885,600	Asahi Diamond Industrial		22,292
		Consumable Diamond Tools
	857,144	Ibiden		22,164
		Electronic Parts & Ceramics

Number of Shares			Value (000)
	5,540	Mori Hills REIT Investment	$	22,162
		Tokyo-centric Diversified REIT
	1,940,200	Sintokogio		21,723
		Automated Casting Machines, Surface Treatment System & Consumables
	750,600	Doshisha		21,581
		Wholesaler
	339,000	FP Corporation		21,373
		Disposable Food Trays & Containers
	880,474	Aeon Mall		20,567
		Suburban Shopping Mall Developer, Owner & Operator
	1,405,739	Ushio		19,914
		Industrial Light Sources
	500,000	Sanrio (b)		19,528
		Character Goods & Licensing
	772,000	Misumi Group		18,870
		Industrial Components Distributor
	1,346,963	Torishima Pump Manufacturing		18,472
		Industrial Pump for Power Generation & Water Supply Systems
	732,108	Icom		17,800
		Two Way Radio Communication Equipment
	2,417	Fukuoka REIT		17,371
		Diversified REIT in Fukuoka
	1,603	Japan Real Estate Investment		14,134
		Office REIT in Tokyo
	511,450	Miura		13,302
		Industrial Boiler
	257,800	Horiba		8,898
		Measuring Instruments & Analyzers
	246,300	Gree (b)		6,206
		Mobile Social Networking Game Developer/Platform
	145,700	Nihon Parkerizing		2,166
		Metal Surface Treatment Agents & Processing
				1,091,111
		> Taiwan 6.5%
	36,606,000	Far EasTone Telecom		75,238
		Taiwan's Third Largest Mobile Operator
	5,614,530	Simplo Technology		42,547
		Battery Packs for Notebook & Tablet PCs
	12,218,270	Tripod Technologies		41,172
		Printed Circuit Boards (PCB)
	2,492,300	St. Shine Optical		32,412
		World's Leading Disposable Contact Lens OEM
	10,329,000	Taiwan Mobile		31,491
		Taiwan's Second-largest Mobile Operator
	18,571,200	CTCI Corp		30,790
		International Engineering Firm
	5,910,000	Radiant Opto-Electronics		26,393
		LCD Back Light Units & Modules
	10,277,000	Chroma Ate		26,310
		Automatic Test Systems, Testing & Measurement Instruments
	11,200,000	Taiwan Hon Chuan		25,449
		Beverage Packaging (Bottles, Caps, Labels) Manufacturer

42

Number of Shares			Value (000)
		> Taiwan—continued
	6,603,000	Advantech	$	22,973
		Industrial PC & Components
	2,930,000	MStar Semiconductor		17,953
		ICs for TV, Digital Set-top-box & Handset
	3,181,000	President Chain Store		17,745
		Taiwan's Number One Convenience Chain Store Operator
	2,595,000	PC Home		14,671
		Taiwanese Internet Retail Company
	2,468,300	Lung Yen		7,895
		Funeral Services & Columbaria
				413,039
		> Hong Kong 4.0%
	7,000,000	Melco Crown Entertainment - ADR (c)		95,270
		Macau Casino Operator
	18,000,000	Lifestyle International		45,856
		Mid to High-end Department Store Operator in Hong Kong & China
	15,625,000	L'Occitane International		37,052
		Skin Care & Cosmetics Producer
	8,475,000	AAC Technologies		23,083
		Miniature Acoustic Components
	12,500,000	MGM China Holdings		22,819
		Macau Casino Operator
	38,000,000	Sasa International		22,050
		Cosmetics Retailer
	8,000,000	Melco International (c)		7,642
		Macau Casino Operator
				253,772
		> Singapore 3.6%
	27,000,000	Olam International		50,740
		Agriculture Supply Chain Manager
	20,000,000	Ascendas REIT		32,174
		Industrial Property Landlord
	20,000,000	CDL Hospitality Trust		27,648
		Hotel Owner/Operator
	35,000,000	Mapletree Logistics Trust		26,329
		Industrial Property Landlord
	28,000,000	Mapletree Industrial Trust		24,477
		Industrial Property Landlord
	35,000,000	Mapletree Commercial Trust		24,406
		Retail & Office Property Landlord
	15,000,000	Goodpack Limited		21,186
		International Bulk Container Leasing
	3,500,000	Singapore Exchange		19,359
		Singapore Equity & Derivatives Market Operator
				226,319
		> China 3.3%
	644,000	NetEase.com - ADR (c)		37,416
		Chinese Online Gaming Services
	18,920,554	Zhaojin Mining Industry		31,826
		Gold Mining & Refining in China
	1,100,000	New Oriental Education & Technology - ADR (c)		30,206
		Education Service Provider
	26,565,000	Want Want		29,725
		Chinese Branded Consumer Food Company

Number of Shares			Value (000)
	13,570,200	Digital China	$	26,998
		IT Distribution & Systems Integration Services
	220,000,000	RexLot Holdings (b)		19,557
		Lottery Equipment Supplier in China
	28,763,700	AMVIG Holdings		15,604
		Chinese Tobacco Packaging Material Supplier
	263,700	51job - ADR (b)(c)		14,994
		Integrated Human Resource Services
				206,326
		> India 2.1%
	2,262,300	United Breweries		23,890
		India's Largest Brewer
	341,652	Asian Paints		21,739
		India's Largest Paint Company
	11,163,303	Jain Irrigation Systems		21,537
	558,165	Jain Irrigation Systems - DVR (c)		525
		Agricultural Micro-irrigation Systems & Food Processing
	8,052,053	Adani Ports & Special Economic Zone		20,442
		Indian West Coast Shipping Port
	1,550,000	Shriram Transport Finance		18,232
		Used Truck Finance
	32,642,905	REI Agro		7,849
		Basmati Rice Processing
	10,249,300	S. Kumars Nationwide		6,646
		Textiles, Clothing & Retail
	791,352	Titan Industries		3,549
		Jewelry, Watches, Eyeglasses
	1,650,000	SKIL Ports and Logistics (c)		3,220
		Indian Container Port Project
	1,477,269	Redington India		2,555
		Supply Chain Solutions for IT & Mobile Handsets in Emerging Markets
	1,668,793	Manappuram Finance		997
		Short-term Lending Collateralized by Household Gold
				131,181
		> Korea 1.6%
	101,150	NHN		23,216
		Korean Online Search Services
	1,134,000	Grand Korea Leisure		21,907
		Largest 'Foreigner Only' Casino Group in Korea
	623,410	Woongjin Coway		20,729
		Korean Household Appliance Rental Service Provider
	471,971	Handsome		13,873
		Korea's Leading High-end Apparel Company
	570,990	iMarketKorea		9,865
		Procurement, Distribution of MRO (Maintenance, Repair, Operations) Goods
	182,000	Hana Tour Service		7,244
		Korea's Largest Wholesale Tour Provider
	10,090	Hyundai Home Shopping		1,198
		TV Home Shopping Company
				98,032

43

Columbia Acorn International

Statement of Investments (Unaudited), continued

Number of Shares			Value (000)
		> Mongolia 1.1%
	42,636,400	Mongolian Mining (c)	$	40,577
		Coking Coal Mining in Mongolia
	1,049,943	Ivanhoe Mines (c)		16,516
		Copper Mine Project in Mongolia
	914,678	Ivanhoe Mines (c)(d)		14,397
		Copper Mine Project in Mongolia
				71,490
		> Indonesia 0.9%
	29,063,787	Archipelago Resources (a)(c)		30,217
		Gold Mining Projects in Indonesia, Vietnam & the Philippines
	48,560,000	Tower Bersama Infrastructure		15,696
		Communications Towers
	10,000,000	Ace Indonesia		4,872
		Home Improvement Retailer
	6,937,300	Jasa Marga		3,914
		Largest Toll Road Operator in Indonesia
	6,217,500	Southern Arc Minerals (a)(c)(e)		2,663
		Gold & Copper Exploration in Indonesia
				57,362
		> Thailand 0.8%
	118,000,000	Home Product Center		53,181
		Home Improvement Retailer
				53,181
		> Philippines 0.7%
	58,577,000	SM Prime Holdings		23,053
		Shopping Mall Operator
	7,931,700	Int'l Container Terminal		12,116
		Container Handling Terminals & Port Management
	19,454,700	Manila Water Company		10,535
		Water Utility Company in the Philippines
				45,704
		> Cambodia 0.4%
	50,000,000	Nagacorp		22,733
		Casino/Entertainment Complex in Cambodia
				22,733
Asia: Total				2,670,250
Europe 33.0%
		> United Kingdom 5.8%
	1,460,000	Intertek Group		58,639
		Testing, Inspection, Certification Services
	5,654,735	Chemring		36,857
		Defense Manufacturer of Countermeasures & Energetics
	3,000,000	JLT Group		33,518
		International Business Insurance Broker
	3,305,000	Serco		28,678
		Facilities Management
	7,500,000	Workspace Group (a)		28,221
		UK Real Estate
	730,000	Rotork		23,925
		Valve Actuators for Oil & Water Pipelines

Number of Shares			Value (000)
	740,581	Tullow Oil	$	18,088
		Oil & Gas Producer
	1,761,742	Smith and Nephew		17,851
		Medical Equipment & Supplies
	2,497,000	Domino's Pizza United Kingdom & Ireland		17,238
		Pizza Delivery in the United Kingdom, Ireland & Germany
	2,636,932	Premier Oil (c)		16,546
		Oil & Gas Producer in Europe, Pakistan & Asia
	2,950,000	Abcam		16,468
		Online Sales of Antibodies
	1,773,408	Shaftesbury		13,970
		London Prime Retail REIT
	548,000	Rightmove		12,727
		Internet Real Estate Listings
	262,300	Next		12,515
		Clothes & Home Retailer in the UK
	3,167,139	BBA Aviation		10,841
		Aviation Support Services
	1,060,885	Greggs		8,832
		Bakery
	4,163,948	PureCircle (b)(c)		7,127
		Natural Sweeteners
	2,840,000	Sterling Resources (c)		4,556
		Oil & Gas Exploration in Europe
				366,597
		> Netherlands 5.1%
	1,763,611	Imtech		56,380
		Electromechanical & ICT Installation & Maintenance
	2,479,123	Aalberts Industries		51,249
		Flow Control & Heat Treatment
	687,967	Fugro		49,015
		Sub-sea Oilfield Services
	1,591,702	UNIT4 (a)		46,172
		Business Software Development
	1,181,073	Koninklijke TenCate (a)		41,034
		Advanced Textiles & Industrial Fabrics
	1,252,514	Arcadis		26,176
		Engineering Consultants
	177,395	Core Laboratories		23,340
		Oil & Gas Reservoir Consulting
	317,424	Vopak		18,287
		World's Largest Operator of Petroleum & Chemical Storage Terminals
	403,800	TKH Group		10,968
		Dutch Industrial Conglomerate
				322,621
		> Switzerland 4.1%
	280,000	Partners Group		54,623
		Private Markets Asset Management
	255,000	Geberit (c)		53,362
		Plumbing Supplies
	360,000	Dufry Group (c)		47,059
		Operates Airport Duty Free & Duty Paid Shops
	15,500	Sika		33,551
		Chemicals for Construction & Industrial Applications

44

Number of Shares			Value (000)
		> Switzerland—continued
	245,000	Kuehne & Nagel	$	33,139
		Freight Forwarding/Logistics
	580,000	Bank Sarasin & Cie		18,183
		Private Banking
	236,217	Zehnder		17,506
		Radiators & Ventilation Systems
				257,423
		> Germany 3.9%
	2,500,000	Wirecard		47,596
		Online Payment Processing & Risk Management
	679,600	Rheinmetall		40,239
		Defense & Automotive
	148,295	Rational		34,681
		Commercial Ovens
	1,600,000	Rhoen-Klinikum		32,126
		Health Care Services
	500,000	Dürr		31,829
		Automotive Plant Engineering & Associated Capital Equipment
	625,000	CTS Eventim		21,589
		Event Ticket Sales
	555,700	Elringklinger		15,912
		Automobile Components
	165,400	Bertrandt		12,464
		Outsourced Engineering
	338,886	Deutsche Beteiligungs (b)		7,690
		Private Equity Investment Management
				244,126
		> France 3.8%
	1,073,700	Gemalto		70,869
		Digital Security Solutions
	418,000	Eurofins Scientific		45,602
		Food, Pharmaceuticals & Materials Screening & Testing
	971,800	Saft Batteries		31,495
		Niche Battery Manufacturer
	430,000	Neopost		27,654
		Postage Meter Machines
	353,648	Rubis		20,680
		Tank Storage & LPG Distribution
	232,400	Norbert Dentressangle		20,643
		Leading European Logistics & Transport Group
	460,000	Mersen		16,304
		Advanced Industrial Materials
	1,831,204	Hi-Media (b)(c)		6,399
		Online Advertiser in Europe
				239,646
		> Sweden 2.4%
	4,056,007	Hexagon		78,720
		Design, Measurement & Visualization Software & Equipment
	4,150,024	Sweco (a)		45,008
		Engineering Consultants

Number of Shares			Value (000)
	658,700	Unibet	$	18,469
		European Online Gaming Operator
	905,452	East Capital Explorer		7,630
		Sweden-based RUS/CEE Investment Fund
				149,827
		> Italy 1.8%
	2,661,000	Pirelli		31,657
		Global Tire Supplier
	2,621,149	Ansaldo STS		26,009
		Railway Systems Integrator
	5,800,000	Geox		18,952
		Apparel & Shoe Maker
	166,200	Tod's (b)		18,697
		Leather Shoes & Bags
	12,503,754	CIR		17,693
		Italian Holding Company
				113,008
		> Denmark 1.3%
	1,648,800	Novozymes		48,020
		Industrial Enzymes
	168,042	SimCorp		29,365
		Software for Investment Managers
	130,651	Solar A/S		7,189
		Technical Wholesaler of Electrical, Plumbing & HVAC Equipment
				84,574
		> Russia 0.7%
	629,642	Mail.ru - GDR (c)(f)		24,839
		Internet Social Networking & Games for Russian Speakers
	2,109,700	Petropavlovsk		18,796
		Gold & Iron Ore Mining in Russia
				43,635
		> Iceland 0.6%
	35,982,499	Marel		41,095
		Largest Manufacturer of Poultry & Fish Processing Equipment
				41,095
		> Ireland 0.6%
	6,750,000	United Drug		19,085
		Irish Pharmaceutical Wholesaler & Outsourcer
	289,400	Paddy Power		18,226
		Irish Betting Services
				37,311
		> Spain 0.5%
	618,320	Red Eléctrica de España		30,257
		Spanish Power Transmission
				30,257
		> Norway 0.5%
	2,403,664	Atea		29,018
		Leading Nordic IT Hardware/Software Reseller & Installation Company
				29,018

45

Columbia Acorn International

Statement of Investments (Unaudited), continued

Number of Shares			Value (000)
		> Czech Republic 0.4%
	130,682	Komercni Banka	$	26,023
		Leading Czech Universal Bank
				26,023
		> Portugal 0.4%
	8,531,175	Redes Energéticas Nacionais		25,828
		Portuguese Power Transmission & Gas Transportation
				25,828
		> Belgium 0.4%
	438,880	EVS Broadcast Equipment		22,758
		Digital Live Mobile Production Software & Systems
				22,758
		> Finland 0.3%
	1,039,429	Stockmann		22,402
		Department Store & Fashion Retailer in Scandinavia & Russia
				22,402
		> Kazakhstan 0.3%
	3,319,000	Halyk Savings Bank of Kazakhstan - GDR (c)		21,574
		Largest Retail Bank & Insurer in Kazakhstan
				21,574
		> Greece 0.1%
	6,954,400	Intralot		6,623
		Lottery & Gaming Systems & Services
				6,623
Europe: Total				2,084,346
Other Countries 16.2%
		> South Africa 4.6%
	1,170,188	Naspers		65,748
		Media in Africa, China, Russia & Other Emerging Markets
	11,763,907	Coronation Fund Managers		43,707
		South African Fund Manager
	19,098,300	Rand Merchant Insurance		42,847
		Directly Sold Property & Casualty Insurance; Holdings in Other Insurers
	3,175,083	Mr. Price		39,048
		South African Retailer of Apparel, Household & Sporting Goods
	8,679,940	Northam Platinum		38,608
		Platinum Mining in South Africa
	4,992,200	Adcock Ingram Holdings		38,201
		Manufacturer of Pharmaceuticals & Medical Supplies
	1,025,504	Massmart Holdings		21,649
		General Merchandise, Food & Home Improvement Stores; Wal-Mart Subsidiary
				289,808
		> United States 4.5%
	627,431	Alexion Pharmaceuticals (c)		58,263
		Biotech Focused on Orphan Diseases
	952,080	Atwood Oceanics (c)		42,739
		Offshore Drilling Contractor

Number of Shares			Value (000)
	1,229,871	BioMarin Pharmaceutical (c)	$	42,123
		Biotech Focused on Orphan Diseases
	987,228	World Fuel Services		40,476
		Global Fuel Broker
	965,297	Textainer Group Holdings		32,724
		Top International Container Leaser
	555,500	Hornbeck Offshore (c)		23,348
		Supply Vessel Operator in U.S. Gulf of Mexico
	461,213	FMC Technologies (c)		23,254
		Oil & Gas Well Head Manufacturer
	270,000	Oil States International (c)		21,076
		Diversified North American Oil Service Provider
				284,003
		> Canada 4.4%
	1,403,772	CCL Industries		51,369
		Leading Global Label Manufacturer
	1,212,597	ShawCor		38,173
		Oil & Gas Pipeline Products
	615,857	Baytex		31,977
		Oil & Gas Producer in Canada
	582,942	AG Growth (b)		24,377
		Leading Manufacturer of Augers & Grain Handling Equipment
	653,200	Onex Capital		24,040
		Private Equity
	1,049,576	Black Diamond Group		20,919
		Provides Accommodations/Equipment for Oil Sands Development
	984,500	Alliance Grain Traders		15,121
		Global Leader in Pulse Processing & Distribution
	2,411,514	Horizon North Logistics		15,110
		Provides Diversified Oil Service Offering in Northern Canada
	2,919,000	DeeThree Exploration (a)(c)(e)		12,734
	1,142,377	DeeThree Exploration (a)(c)		5,085
		Canadian Oil & Gas Producer
	721,000	Celtic Exploration (c)		10,510
		Canadian Oil & Gas Producer
	1,043,000	Crew Energy (c)		9,955
		Canadian Oil & Gas Producer
	731,000	Athabasca Oil Sands (c)		8,127
		Oil Sands SAGD & Alberta Deep Basin Development
	1,607,306	Pan Orient (c)		6,558
		Growth-oriented, Return-focused Asian Explorer
	1,611,000	Americas Petrogas (c)		5,750
		Oil & Gas Exploration in Argentina, Potash in Peru
	6,250,000	Petromanas - Warrants (c)(e)		31
		Exploring for Oil in Albania
				279,836
		> Australia 1.6%
	2,653,389	UGL		36,352
		Engineering & Facilities Management
	498,560	Cochlear		31,939
		Cochlear Implants

46

Number of Shares			Value (000)
		> Australia—continued
	4,546,885	Challenger Financial	$	17,908
		Largest Annuity Provider
	17,451,906	Commonwealth Property Office Fund		17,814
		Australia Prime Office REIT
				104,013
		> Israel 0.9%
	4,706,527	Israel Chemicals		54,374
		Producer of Potash, Phosphates, Bromine & Specialty Chemicals
	125,000	Caesarstone (c)		1,460
		Quartz Countertops
				55,834
		> Senegal 0.2%
	45,237	Sonatel		11,681
		Leading Telecoms Operator in Western Africa
				11,681
Other Countries: Total				1,025,175
Latin America 4.2%
		> Brazil 2.6%
	3,700,000	Localiza Rent A Car		68,104
		Car Rental
	1,500,000	Odontoprev		25,226
		Dental Insurance
	1,200,000	Multiplus		24,849
		Loyalty Program Operator in Brazil
	1,880,200	Mills Estruturas e Servicos de Engenharia		23,896
		Civil Engineering & Construction
	2,917,000	MRV Engenharia		20,661
		Brazilian Property Developer
				162,736
		> Mexico 0.7%
	600,000	Grupo Aeroportuario del Sureste - ADR		41,112
		Mexican Airport Operator
				41,112
		> Argentina 0.3%
	1,250,000	Union Agriculture Group (c)(e)(g)		13,275
		Farmland Operator in Uruguay
	4,950,000	Madalena Ventures (c)(e)		4,474
	2,475,000	Madalena Ventures (c)		2,283
		Oil & Gas Exploration in Argentina
				20,032
		> Guatemala 0.3%
	932,600	Tahoe Resources (c)		19,653
		Silver Project in Guatemala
				19,653
		> Colombia 0.2%
	8,353,169	Canacol (c)		6,616
		Oil Producer in South America
	22,525,000	Gulf United (c)(e)		2,595
		Prospecting for Oil Alongside Large Producers in Colombia
				9,211

Number of Shares			Value (000)
		> Chile 0.1%
	4,016,878	Viña Concha y Toro	$	9,208
		Global Branded Wine Manufacturer
				9,208
Latin America: Total				261,952
Total Equities: 95.7% (Cost: $4,641,672)				6,041,723
Securities Lending Collateral 0.5%
	32,332,947	Dreyfus Government Cash Management Fund (7 day yield of 0.01%) (h)		32,333
Total Securities Lending Collateral: (Cost: $32,333)				32,333
Total Investments: 96.2% (Cost: $4,674,005)(i)(j)				6,074,056	(k)
Obligation to Return Collateral for Securities Loaned: (0.5)%				(32,333	)
Cash and Other Assets Less Liabilities: 4.3%				272,701
Total Net Assets: 100.0%			$	6,314,424

ADR - American Depositary Receipts

DVR - Differential Voting Right Equity Shares

GDR - Global Depositary Receipts

47

Columbia Acorn International Fund

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 three months ended March 31, 2012, are as follows:

Affiliates	Balance of Shares Held 12/31/11		Purchases/ Additions		Sales/ Reductions		Balance of Shares Held 3/31/12		Value		Dividend
Archipelago Resources		29,063,787		-		-		29,063,787	$	30,217	$	-
DeeThree Exploration		4,061,377		-		-		4,061,377		17,819		-
Koninklijke TenCate*		1,371,573		-		190,500		1,181,073		41,034		-
Southern Arc Minerals		6,217,500		-		-		6,217,500		2,663		-
Sweco		4,150,024		-		-		4,150,024		45,008		-
UNIT4		1,591,702		-		-		1,591,702		46,172		-
Wacom		23,790		-		1,490		22,300		46,834		-
Workspace Group		8,000,000		-		500,000		7,500,000		28,221		372,696
Total of Affiliated Transactions		54,479,753		-		691,990		53,787,763	$	257,968	$	372,696

*  At March 31, 2012, the Fund owned less than five percent of the company's outstanding voting shares.

  The aggregate cost and value of these companies at March 31, 2012, were $149,124 and $216,934, respectively. Investments in affiliated companies represented 3.44% of the Fund's total net assets at March 31, 2012.

(b)  All or a portion of this security was on loan at March 31, 2012. The total market value of securities on loan at March 31, 2012 was $30,746.

(c)  Non-income producing security.

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

(e)  Denotes a restricted security, which is subject to restrictions on resale under federal securities laws. These securities are valued at fair value determined in good faith under consistently applied procedures established by the Board of Trustees. At March 31, 2012, the market value of these securities amounted to $35,772, which represented 0.57% of total net assets.

  Additional information on these securities is as follows:

Security	Acquisition Dates	Shares		Cost		Value
Union Agriculture Group	12/8/10-12/16/11		1,250,000	$	15,000	$	13,275
DeeThree Exploration	9/7/10-3/8/11		2,919,000		10,228		12,734
Madalena Ventures	10/21/10		4,950,000		3,136		4,474
Southern Arc Minerals	2/16/11		6,217,500		10,087		2,663
Gulf United	2/11/11		22,525,000		6,758		2,595
Petromanas - Warrants	5/20/10		6,250,000		362		31
				$	45,571	$	35,772

(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 March 31, 2012, this security had an aggregate value of $24,839, which represented 0.39% of total net assets.

(g)  Illiquid security.

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

(i)  At March 31, 2012, for federal income tax purposes, the cost of investments was $4,674,005 and net unrealized appreciation was $1,400,051 consisting of gross unrealized appreciation of $1,708,166 and gross unrealized depreciation of $(308,115).

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

Currency	Value		Percentage of Net Assets
Japanese Yen	$	1,091,111		17.3
Euro		1,041,240		16.5
U.S. Dollar		604,481		9.6
British Pound		414,274		6.6
Taiwan Dollar		413,039		6.5
Hong Kong Dollar		345,522		5.5
Canadian Dollar		336,597		5.3
Other currencies less than 5% of total net assets		1,795,459		28.4
	$	6,041,723		95.7

(k)  Securities are valued using policies described in the Notes to Financial Statements in the most recent shareholder report.

48

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

  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.

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

  The Committee meets at least quarterly to review and approve valuation matters, which may include a description of fair value actions, data regarding pricing information received from approved pricing vendors and brokers and the results of Board-approved valuation control policies and procedures (the Policies). The Policies address, among other things, instances when market quotations are readily available, including recommendation of third party pricing vendors and determining appropriate pricing methodologies; events that require fair valuation and assessment of fair value techniques; securities with a potential for stale pricing, including those that are illiquid, restricted, or in default; and the effectiveness of third-party pricing vendors. The Committee meets more frequently, as needed, to discuss additional valuation matters, which may include the need to review back-testing results, review time-sensitive information or approve related valuation actions.

  For investments categorized as Level 3, the Committee monitors information similar to that described above, which may include: (i) data specific to the issuer or comparable issuers, (ii) general market or specific sector news and (iii) quoted prices and specific or similar security transactions. The Committee considers this data and any changes from prior periods in order to assess the reasonableness of observable and unobservable inputs, any assumptions or internal models used to value those securities and changes in fair value. This data is also used to corroborate, when available, information received from approved pricing vendors. Various factors impact the frequency of monitoring (which may occur as often as daily), however the Committee may determine that changes to inputs, assumptions and models are not required with the same frequency.

The following table summarizes the inputs used, as of March 31, 2012, in valuing the Fund's assets:

Investment Type	Quoted Prices (Level 1)		Other Significant Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)		Total
Equities
Asia	$	208,799	$	2,461,451	$	-	$	2,670,250
Europe		27,896		2,056,450		-		2,084,346
Other Countries		552,534		472,641		-		1,025,175
Latin America		241,608		7,069		13,275		261,952
Total Equities		1,030,837		4,997,611		13,275		6,041,723
Total Securities Lending Collateral		32,333		-		-		32,333
Total Investments	$	1,063,170	$	4,997,611	$	13,275	$	6,074,056

  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, in accordance with the policy adopted by the Board of Trustees, provided by an independent third party to value securities principally traded in foreign markets in order to adjust for possible stale pricing that may occur between the close of the foreign exchanges and the time for valuation. These models take into account available market data including intraday index, ADR, and ETF movements. Securities acquired via private placement that have a holding period or an extended settlement period are valued at a discount to the same shares that are trading freely on the market. These discounts are determined by the investment manager's experience with similar securities or situations. Factors may include, but are not limited to, trade volume, shares outstanding and stock price.

49

Columbia Acorn International Fund

Statement of Investments (Unaudited), continued

> 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				Transfers Out
Level 1		Level 2		Level 1		Level 2
$	1,843	$	-	$	-	$	1,843

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

  The following table reconciles asset balances for the three months ending March 31, 2012, in which significant unobservable inputs (Level 3) were used in determining value:

Investments in Securities	Balance as of December 31, 2011		Realized Gain/(Loss)		Change in Unrealized Appreciation (Depreciation)		Purchases		Sales		Transfers into Level 3		Transfers out of Level 3		Balance as of March 31, 2012
Equities
Latin America	$	12,462	$	-	$	813	$	-	$	-	$	-	$	-	$	13,275
	$	12,462	$	-	$	813	$	-	$	-	$	-	$	-	$	13,275

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

  The change in unrealized appreciation attributed to securities owned at March 31, 2012, which were valued using significant unobservable inputs (Level 3) amounted to $813.

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

  Certain common stock classified as Level 3 are valued using a market approach. To determine fair value for these securities, management considered various factors which may have included, but were not limited to, trades of similar securities, estimated earnings of the respective company, market multiples derived from a set of comparable companies, and the position of the security within the respective company's capital structure. Significant increases (decreases) to any of these inputs would result in a significantly lower (higher) fair value measurement. Generally, a change in estimated earnings of the respective company may result in a change to the comparable companies and market multiples utilized.

50

Columbia Acorn International

Portfolio Diversification (Unaudited)

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

	Value (000)		Percentage of Net Assets
> Industrial Goods & Services
Other Industrial Services	$	521,450		8.3
Machinery		396,343		6.3
Industrial Materials & Specialty Chemicals		394,522		6.3
Electrical Components		122,840		1.9
Construction		108,048		1.7
Conglomerates		102,075		1.6
Outsourcing Services		51,983		0.8
Industrial Distribution		38,240		0.6
		1,735,501		27.5
> Consumer Goods & Services
Retail		341,207		5.4
Casinos & Gaming		233,246		3.7
Food & Beverage		162,219		2.6
Nondurables		107,117		1.7
Other Consumer Services		89,473		1.4
Travel		75,348		1.2
Apparel		61,874		1.0
Other Durable Goods		49,163		0.8
Educational Services		30,206		0.4
Consumer Goods Distribution		24,136		0.4
Other Entertainment		21,589		0.3
Restaurants		17,238		0.3
Furniture & Textiles		1,460		0.0	*
		1,214,276		19.2
> Information
Computer Hardware & Related Equipment		296,628		4.7
Internet Related		163,947		2.6
Business Software		154,256		2.5
Mobile Communications		140,225		2.2
Financial Processors		66,955		1.1
Instrumentation		58,871		0.9
Semiconductors & Related Equipment		44,681		0.7
Computer Services		29,018		0.5
Electronics Distribution		26,998		0.4
CATV		26,020		0.4
Telephone & Data Services		11,681		0.2
Advertising		6,399		0.1
Gaming Equipment & Services		6,206		0.1
		1,031,885		16.4

	Value (000)			Percentage of Net Assets
> Energy & Minerals
Mining	$	236,593			3.7
Oil Services		233,634			3.7
Oil & Gas Producers		145,885			2.3
Oil Refining Marketing & Distribution		38,967			0.6
Agricultural Commodities		28,396			0.5
		683,475			10.8
> Other Industries
Real Estate		381,775			6.0
Transportation		134,319			2.1
Regulated Utilities		66,619			1.1
		582,713			9.2
> Finance
Brokerage & Money Management		131,833			2.1
Banks		121,946			1.9
Insurance		119,499			1.9
Finance Companies		75,993			1.2
		449,271			7.1
> Health Care
Biotechnology & Drug Delivery		100,387			1.6
Pharmaceuticals		82,019			1.3
Medical Equipment & Devices		81,190			1.3
Medical Supplies		48,880			0.8
Health Care Services		32,126			0.5
		344,602			5.5
Total Equities:		6,041,723			95.7
Securities Lending Collateral:		32,333			0.5
Total Investments:		6,074,056			96.2
Obligation to Return Collateral for Securities Loaned:		(32,333	)		(0.5	)
Cash and Other Assets Less Liabilities:		272,701			4.3
Net Assets:	$	6,314,424			100.0

*  Rounds to less than 0.1%.

51

Columbia Acorn USA Fund

Major Portfolio Changes in the First Quarter (Unaudited)

	Number of Shares
	12/31/11		03/31/12
Purchases
Information
Ultratech		0		262,000
WNS - ADR (India)		0		359,000
Industrial Goods & Services
Polypore International		0		100,000
Consumer Goods & Services
Avis Budget Group		1,175,950		1,300,950
Helen of Troy		0		106,000
Shutterfly		289,000		356,000
Skullcandy		140,000		230,000
Finance
Associated Banc-Corp		923,000		1,053,000
City National		144,000		211,000
First Commonwealth		0		556,000
Hudson Valley		26,935		105,700
MB Financial		480,000		833,000
McGrath Rentcorp		210,000		346,000
Health Care
Cepheid		439,600		488,600
Chelsea Therapeutics International		790,000		948,000
Pacific Biosciences of California		0		385,000
Raptor Pharmaceutical		0		374,000
Synageva Biopharma		0		29,671
Techne		0		53,000
Other Industries
Dupont Fabros Technology		191,000		519,000
St. Joe		0		200,000
Energy & Minerals
Approach Resource		0		100,000
Hornbeck Offshore		0		83,000
Petroleum Development Corporation		57,184		117,000

	Number of Shares
	12/31/11		03/31/12
Sales
Information
Amphenol		159,000		0
Constant Contact		198,000		0
Netgear		196,000		107,000
Nice Systems - ADR (Israel)		252,000		177,000
Polycom		330,000		165,000
Salem Communications		460,100		0
Industrial Goods & Services
Ametek		941,250		876,300
Consumer Goods & Services
Diamond Foods		72,000		0
True Religion Apparel		163,000		82,300
Finance
Aaron's		231,320		0
Health Care
Alexion Pharmaceuticals		275,000		251,000
Community Health Systems		151,000		0
Gen-Probe		126,000		72,000
HealthSouth		205,000		0
Micromet		843,689		0
Other Industries
Biomed Realty Trust		739,200		561,200
Kilroy Realty		159,000		77,000
Energy & Minerals
FMC Technologies		844,600		167,000
Houston American Energy		300,000		262,200
Northern Oil & Gas		115,000		0
Oasis Petroleum		107,800		0
Quicksilver Resources		773,400		567,000

52

Columbia Acorn USA

Statement of Investments (Unaudited), March 31, 2012

Number of Shares			Value (000)
			Equities: 99.5%
Information 32.5%
		> Business Software 10.2%
	910,000	Informatica (a)	$	48,139
		Enterprise Data Integration Software
	698,000	Micros Systems (a)		38,592
		Information Systems for Hotels, Restaurants & Retailers
	375,000	Ansys (a)		24,383
		Simulation Software for Engineers & Designers
	281,000	NetSuite (a)		14,131
		End to End IT Systems Solution Delivered Over the Web
	243,000	Concur Technologies (a)		13,943
		Web Enabled Cost & Expense Management Software
	408,000	Ariba (a)		13,346
		Cost Management Software
	300,000	Blackbaud		9,969
		Software & Services for Non-profits
	322,000	SPS Commerce (a)		8,655
		Supply Chain Management Software Delivered via the Web
	400,000	Velti (a)		5,420
		Mobile Marketing Software Platform
	198,000	Advent Software (a)		5,069
		Asset Management & Trading Systems
				181,647
		> Semiconductors & Related Equipment 4.1%
	1,958,000	Atmel (a)		19,306
		Microcontrollers, RF & Memory Semiconductors
	690,000	Microsemi (a)		14,794
		Analog/Mixed Signal Semiconductors
	1,061,750	ON Semiconductor (a)		9,566
		Mixed Signal & Power Management Semiconductors
	426,000	Monolithic Power Systems (a)		8,379
		High Performance Analog & Mixed Signal ICs
	262,000	Ultratech (a)		7,593
		Semiconductor Equipment
	1,075,000	TriQuint Semiconductor (a)		7,412
		RF Semiconductors
	390,000	Pericom Semiconductor (a)		3,155
		Interface ICs & Frequency Control Products
	50,000	Hittite Microwave (a)		2,716
		Radio Frequency, Microwave & Millimeterwave Semiconductors
				72,921
		> Instrumentation 3.9%
	180,000	Mettler Toledo (a)		33,255
		Laboratory Equipment
	525,000	IPG Photonics (a)		27,326
		Fiber Lasers
	168,000	Trimble Navigation (a)		9,143
		GPS-based Instruments
				69,724

Number of Shares			Value (000)
		> Computer Hardware & Related Equipment 3.0%
	1,317,000	II-VI (a)	$	31,147
		Laser Optics & Specialty Materials
	292,000	Zebra Technologies (a)		12,025
		Bar Code Printers
	177,000	Nice Systems - ADR (Israel) (a)		6,956
		Audio & Video Recording Solutions
	107,000	Netgear (a)		4,087
		Networking Products for Small Business & Home
				54,215
		> Telephone & Data Services 2.8%
	1,457,000	tw telecom (a)		32,287
		Fiber Optic Telephone/Data Services
	148,000	AboveNet (a)		12,254
		Metropolitan Fiber Communications Services
	400,000	Boingo Wireless (a)		4,840
		Wholesale & Retail Wi-Fi Networks
				49,381
		> Gaming Equipment & Services 2.0%
	660,000	Bally Technologies (a)		30,855
		Slot Machines & Software
	235,000	WMS Industries (a)		5,576
		Slot Machine Provider
				36,431
		> Telecommunications Equipment 2.0%
	732,000	Finisar (a)		14,750
		Optical Subsystems & Components
	903,000	Ixia (a)		11,278
		Telecom Network Test Equipment
	752,000	Infinera (a)(b)		6,106
		Optical Networking Equipment
	165,000	Polycom (a)		3,147
		Video Conferencing Equipment
				35,281
		> Computer Services 1.9%
	556,000	ExlService Holdings (a)		15,257
		Business Process Outsourcing
	97,000	Syntel		5,432
		Offshore IT Services
	776,766	Hackett Group (a)		4,637
		IT Integration & Best Practice Research
	359,000	WNS - ADR (India) (a)		4,326
		Offshore BPO (Business Process Outsourcing) Services
	640,000	RCM Technologies (a)(c)		3,565
		Technology & Engineering Services
				33,217
		> Mobile Communications 1.6%
	560,000	SBA Communications (a)		28,454
		Communications Towers
				28,454
		> Contract Manufacturing 0.5%
	236,000	Plexus (a)		8,258
		Electronic Manufacturing Services
				8,258

53

Columbia Acorn USA

Statement of Investments (Unaudited), continued

Number of Shares			Value (000)
		> Financial Processors 0.4%
	170,000	Global Payments	$	7,990
		Credit Card Processor
				7,990
		> TV Broadcasting 0.1%
	875,000	Entravision Communications		1,496
		Spanish Language TV & Radio Stations
				1,496
Information: Total				579,015
Industrial Goods & Services 17.8%
		> Machinery 13.5%
	876,300	Ametek		42,509
		Aerospace/Industrial Instruments
	747,200	Nordson		40,730
		Dispensing Systems for Adhesives & Coatings
	890,000	Donaldson		31,800
		Industrial Air Filtration
	835,000	ESCO Technologies		30,703
		Automatic Electric Meter Readers
	585,000	Pentair		27,852
		Pumps & Water Treatment
	504,665	Heico		20,262
		FAA Approved Aircraft Replacement Parts
	355,000	Moog (a)		15,226
		Motion Control Products for Aerospace, Defense & Industrial Markets
	166,219	Toro		11,820
		Turf Maintenance Equipment
	226,000	Kennametal		10,064
		Consumable Cutting Tools
	100,000	Polypore International (a)(b)		3,516
		Battery Separators & Filtration Media
	146,000	Oshkosh Corporation (a)		3,383
		Specialty Truck Manufacturer
	25,327	Middleby (a)		2,562
		Manufacturer of Cooking Equipment
				240,427
		> Electrical Components 1.0%
	280,000	Acuity Brands		17,592
		Commercial Lighting Fixtures
				17,592
		> Industrial Materials & Specialty Chemicals 1.0%
	496,000	Drew Industries (a)		13,546
		RV & Manufactured Home Components
	170,000	Albany International		3,901
		Paper Machine Clothing & Advanced Textiles
				17,447
		> Other Industrial Services 0.8%
	600,000	Acorn Energy (b)		6,522
		Frac Well Exploration/Monitoring Device, Sonar Security, Electric Grid Monitoring
	240,000	TrueBlue (a)		4,291
		Temporary Manual Labor
	109,000	Forward Air		3,997
		Freight Transportation Between Airports
				14,810

Number of Shares			Value (000)
		> Waste Management 0.6%
	176,000	Waste Connections	$	5,725
		Solid Waste Management
	65,000	Clean Harbors (a)		4,377
		Hazardous Waste Services & Disposal
				10,102
		> Steel 0.4%
	686,000	GrafTech International (a)		8,191
		Industrial Graphite Materials Producer
				8,191
		> Industrial Distribution 0.3%
	233,400	Interline Brands (a)		5,044
		Industrial Distribution
				5,044
		> Construction 0.2%
	200,000	Fortune Brands Home & Security (a)		4,414
		Home Building Supplies & Small Locks
				4,414
Industrial Goods & Services: Total				318,027
Consumer Goods & Services 16.2%
		> Retail 6.5%
	730,000	lululemon athletica (a)		54,516
		Premium Active Apparel Retailer
	468,500	Abercrombie & Fitch		23,242
		Teen Apparel Retailer
	805,000	Pier 1 Imports (a)		14,635
		Home Furnishing Retailer
	356,000	Shutterfly (a)		11,153
		Internet Photo-centric Retailer
	790,000	Saks (a)		9,172
		Luxury Department Store Retailer
	161,500	Teavana (a)(b)		3,185
		Specialty Tea Retailer
	9,000	The Fresh Market (a)		432
		Specialty Food Retailer
				116,335
		> Travel 3.5%
	849,700	Gaylord Entertainment (a)		26,171
		Convention Hotels
	1,300,950	Avis Budget Group (a)		18,408
		Second Largest Car Rental Company
	750,000	Hertz (a)		11,280
		Largest U.S. Rental Car Operator
	140,000	HomeAway (a)		3,552
		Vacation Rental Online Marketplace
	64,000	Vail Resorts		2,768
		Ski Resort Operator & Developer
				62,179
		> Furniture & Textiles 1.5%
	880,000	Knoll		14,643
		Office Furniture
	540,000	Interface		7,533
		Modular & Broadloom Carpet
	148,000	Herman Miller		3,398
		Office Furniture
	20,000	Caesarstone (Israel) (a)		234
		Quartz Countertops
				25,808

54

Number of Shares			Value (000)
		> Apparel 1.2%
	222,000	Warnaco Group (a)	$	12,965
		Global Branded Apparel Manufacturer
	81,000	Deckers Outdoor (a)		5,107
		Fashion Footwear Wholesaler
	82,300	True Religion Apparel (a)		2,255
		Premium Denim
				20,327
		> Consumer Goods Distribution 1.0%
	472,000	Pool		17,662
		Distributor of Swimming Pool Supplies & Equipment
				17,662
		> Other Durable Goods 0.8%
	206,000	Cavco Industries (a)		9,596
		Manufactured Homes
	126,000	Jarden		5,069
		Branded Household Products
				14,665
		> Other Consumer Services 0.7%
	259,000	Lifetime Fitness (a)		13,098
		Sport & Fitness Club Operator
				13,098
		> Casinos & Gaming 0.5%
	775,000	Pinnacle Entertainment (a)		8,920
		Regional Casino Operator
				8,920
		> Leisure Products 0.2%
	230,000	Skullcandy (a)(b)		3,641
		Lifestyle Branded Headphones
				3,641
		> Nondurables 0.2%
	106,000	Helen of Troy (a)		3,605
		Personal Care, Housewares, Healthcare & Home Environment Products
				3,605
		> Educational Services 0.1%
	37,350	ITT Educational Services (a)(b)		2,470
		Postsecondary Degree Services
				2,470
		> Food & Beverage —%
	4,900	Annie's (a)		171
		Developer & Marketer of Natural & Organic Food
				171
Consumer Goods & Services: Total				288,881
Finance 12.3%
		> Banks 7.1%
	833,000	MB Financial		17,485
		Chicago Bank
	1,053,000	Associated Banc-Corp		14,700
		Midwest Bank
	431,597	Lakeland Financial		11,234
		Indiana Bank

Number of Shares			Value (000)
	211,000	City National	$	11,071
		Bank & Asset Manager
	170,000	SVB Financial Group (a)		10,938
		Bank to Venture Capitalists
	278,678	Hancock Holding		9,896
		Gulf Coast Bank
	675,000	Valley National Bancorp		8,741
		New Jersey/New York Bank
	1,478,200	First Busey		7,302
		Illinois Bank
	594,000	TCF Financial		7,063
		Great Lakes Bank
	513,755	Pacific Continental Bank		4,840
		Pacific N.W. Bank
	844,000	TrustCo Bank		4,819
		New York State Bank
	269,600	Eagle Bancorp (a)		4,513
		Metro D.C. Bank
	556,000	First Commonwealth		3,403
		Western Pennsylvania Bank
	178,826	Sandy Spring Bancorp		3,249
		Baltimore, D.C. Bank
	210,000	CVB Financial		2,465
		Inland Empire Business Bank
	105,700	Hudson Valley		1,705
		Metro New York City Bank
	851,247	Guaranty Bancorp (a)		1,694
		Colorado Bank
	90,000	TriCo Bancshares		1,568
		California Central Valley Bank
				126,686
		> Finance Companies 3.4%
	345,000	World Acceptance (a)		21,131
		Personal Loans
	345,000	Textainer Group Holdings		11,696
		Top International Container Leaser
	346,000	McGrath Rentcorp		11,110
		Temporary Space & IT Rentals
	397,172	H & E Equipment Services (a)		7,515
		Heavy Equipment Leasing
	330,000	CAI International (a)		5,999
		International Container Leasing
	100,000	Marlin Business Services		1,506
		Small Equipment Leasing
	45,500	Regional Management (a)		764
		Consumer Loans
				59,721
		> Savings & Loans 0.9%
	602,487	ViewPoint Financial		9,266
		Texas Thrift
	194,000	Berkshire Hills Bancorp		4,447
		Northeast Thrift
	173,073	Kaiser Federal		2,421
		Los Angeles Savings & Loan
				16,134

55

Columbia Acorn USA

Statement of Investments (Unaudited), continued

Number of Shares			Value (000)
		> Brokerage & Money Management 0.5%
	340,500	Eaton Vance	$	9,732
		Specialty Mutual Funds
				9,732
		> Insurance 0.4%
	39,000	Enstar Group (a)		3,860
		Insurance/Reinsurance & Related Services
	55,000	Allied World Holdings		3,777
		Commercial Lines Insurance/Reinsurance
				7,637
Finance: Total				219,910
Health Care 8.9%
		> Biotechnology & Drug Delivery 5.2%
	251,000	Alexion Pharmaceuticals (a)		23,308
		Biotech Focused on Orphan Diseases
	520,000	BioMarin Pharmaceutical (a)		17,810
		Biotech Focused on Orphan Diseases
	682,000	Seattle Genetics (a)(b)		13,899
		Antibody-based Therapies for Cancer
	421,000	Auxilium Pharmaceuticals (a)		7,818
		Biotech Focused on Niche Disease Areas
	1,055,000	NPS Pharmaceuticals (a)		7,216
		Orphan Drugs & Healthy Royalties
	160,000	Onyx Pharmaceuticals (a)		6,029
		Commercial-stage Biotech Focused on Cancer
	643,000	Isis Pharmaceuticals (a)		5,639
		Biotech Pioneer in Antisense Drugs
	313,000	InterMune (a)		4,592
		Drugs for Pulmonary Fibrosis & Hepatitis C
	374,000	Raptor Pharmaceutical (a)(b)		2,528
		Orphan Drug Company
	948,000	Chelsea Therapeutics International (a)		2,427
		Biotech Focused on Rare Diseases
	530,000	Anthera Pharmaceuticals (a)		1,172
		Biotech Focused on Cardiovascular, Cancer & Immunology
	29,671	Synageva Biopharma (a)		1,064
		Biotech Focused on Orphan Diseases
	18,181	Metabolex, Series A-1 (a)(d)(e)		11
		Diabetes Drug Development
				93,513
		> Medical Equipment & Devices 1.5%
	224,000	Sirona Dental Systems (a)		11,545
		Manufacturer of Dental Equipment
	268,000	Hill-Rom Holdings		8,954
		Hospital Beds/Patient Handling
	72,000	Gen-Probe (a)		4,781
		Molecular In-vitro Diagnostics
	385,000	Pacific Biosciences of California (a)		1,317
		Genome Sequencing
				26,597
		> Medical Supplies 1.4%
	488,600	Cepheid (a)		20,438
		Molecular Diagnostics
	53,000	Techne		3,716
		Cytokines, Antibodies & Other Reagents for Life Science
				24,154

Number of Shares			Value (000)
		> Pharmaceuticals 0.5%
	733,000	Akorn (a)	$	8,576
		Develops, Manufactures & Sells Specialty Generic Drugs
	150,000	Horizon Pharma (a)		621
		Specialty Pharmaceutical Company
	133,180	Alimera Sciences (a)		450
		Ophthalmology-focused Pharmaceutical Company
				9,647
		> Health Care Services 0.3%
	738,900	Health Management Associates (a)		4,965
		Non-urban Hospitals
				4,965
Health Care: Total				158,876
Other Industries 6.5%
		> Real Estate 5.3%
	915,000	Extra Space Storage		26,343
		Self Storage Facilities
	519,000	Dupont Fabros Technology		12,689
		Technology-focused Office Buildings
	561,200	Biomed Realty Trust		10,651
		Life Science-focused Office Buildings
	600,000	Associated Estates Realty		9,804
		Multifamily Properties
	870,000	Education Realty Trust		9,431
		Student Housing
	1,380,000	Kite Realty Group		7,273
		Community Shopping Centers
	958,000	DCT Industrial Trust		5,652
		Industrial Properties
	100,000	Post Properties		4,686
		Multifamily Properties
	200,000	St. Joe (a)(b)		3,802
		Florida Panhandle Landowner
	77,000	Kilroy Realty		3,589
		West Coast Office & Industrial Properties
				93,920
		> Transportation 1.2%
	256,000	World Fuel Services		10,496
		Global Fuel Broker
	410,091	Rush Enterprises, Class A (a)		8,702
	115,000	Rush Enterprises, Class B (a)		2,000
		Truck Sales & Service
				21,198
Other Industries: Total				115,118
Energy & Minerals 5.3%
		> Oil Services 2.5%
	725,000	Atwood Oceanics (a)		32,545
		Offshore Drilling Contractor
	167,000	FMC Technologies (a)		8,420
		Oil & Gas Well Head Manufacturer
	83,000	Hornbeck Offshore (a)		3,489
		Supply Vessel Operator in U.S. Gulf of Mexico
				44,454

56

Number of Shares			Value (000)
		> Oil & Gas Producers 1.9%
	133,000	SM Energy	$	9,412
		Oil & Gas Producer
	143,000	Rosetta Resources (a)		6,973
		Oil & Gas Producer Exploring in South Texas & Montana
	168,000	Swift Energy (a)		4,877
		Oil & Gas Exploration & Production
	117,000	Petroleum Development Corporation (a)		4,339
		Oil & Gas Producer in U.S.
	100,000	Approach Resource (a)		3,695
		Oil & Gas Producer in West Texas Permian
	567,000	Quicksilver Resources (a)(b)		2,858
		Natural Gas & Coal Seam Gas Producer
	262,200	Houston American Energy (a)		1,369
		Oil & Gas Exploration/Production in Colombia
				33,523
		> Mining 0.9%
	85,000	Core Laboratories (Netherlands)		11,184
		Oil & Gas Reservoir Consulting
	600,000	Alexco Resource (a)		4,188
		Mining, Exploration & Environmental Services
	180,000	Augusta Resource (a)		491
		US Copper/Moly Mine
				15,863
Energy & Minerals: Total				93,840
Total Equities: 99.5% (Cost: $1,166,642)				1,773,667

Number of Shares			Value (000)
Securities Lending Collateral 1.3%
	22,953,025	Dreyfus Government Cash Management Fund (7 day yield of 0.01%) (f)	$	22,953
Total Securities Lending Collateral: (Cost: $22,953)				22,953
Total Investments: 100.8% (Cost: $1,189,595)(g)(h)				1,796,620	(i)
Obligation to Return Collateral for Securities Loaned: (1.3)%				(22,953	)
Cash and Other Assets Less Liabilities: 0.5%				8,134
Total Net Assets: 100.0%			$	1,781,801

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 March 31, 2012. The total market value of securities on loan at March 31, 2012 was $22,452.

(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 three months ended March 31, 2012, are as follows:

Affiliates	Balance of Shares Held at 12/31/11		Purchases/ Additions		Sales/ Reductions		Balance of Shares Held at 3/31/12		Value		Dividend
RCM Technologies		640,000		-		-		640,000	$	3,565	$	-
Total of Affiliated Transactions		640,000		-		-		640,000	$	3,565	$	-

  The aggregate cost and value of this company at March 31, 2012, were $3,624 and $3,565, respectively. Investments in affiliated companies represented 0.20% of the Fund's total net assets at March 31, 2012.

(d)  Denotes a restricted security, which is subject to restrictions on resale under federal securities laws. These securities are valued at fair value determined in good faith under consistently applied procedures established by the Board of Trustees. At March 31, 2012, the market value of this security amounted to $11, 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	$	11
				$	2,000	$	11

(e)  Illiquid security.

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

57

Columbia Acorn USA

Statement of Investments (Unaudited), continued

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

(g)  At March 31, 2012, for federal income tax purposes, the cost of investments was $1,189,595 and net unrealized appreciation (depreciation) was $607,025 consisting of gross unrealized appreciation of $685,305 and gross unrealized depreciation of $(78,280).

(h)  On March 31, 2012, the market value of foreign securities represented 1.27% of total net assets. The Fund's foreign portfolio was diversified as follows:

	Value		Percentage of Net Assets
Netherlands	$	11,183		0.63
Israel		7,190		0.40
India		4,326		0.24
Total Foreign Portfolio	$	22,699		1.27

(i)  Securities are valued using polices described in the Notes to Financial Statements in the most recent shareholder report.

Fair Value Measurements

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

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

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

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

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

  Examples of the types of securities in which the Fund would typically invest and how they are classified within this hierarchy are as follows. Typical Level 1 securities include exchange traded domestic equities, mutual funds whose NAVs are published each day and exchange traded foreign equities that are not statistically fair valued. Typical Level 2 securities include exchange traded foreign equities that are statistically fair valued, forward foreign currency exchange contracts and short-term investments valued at amortized cost. Additionally, securities fair valued by the Valuation Committee 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.

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

  The Committee meets at least quarterly to review and approve valuation matters, which may include a description of fair value actions, data regarding pricing information received from approved pricing vendors and brokers and the results of Board-approved valuation control policies and procedures (the Policies). The Policies address, among other things, instances when market quotations are readily available, including recommendation of third party pricing vendors and determining appropriate pricing methodologies; events that require fair valuation and assessment of fair value techniques; securities with a potential for stale pricing, including those that are illiquid, restricted, or in default; and the effectiveness of third-party pricing vendors. The Committee meets more frequently, as needed, to discuss additional valuation matters, which may include the need to review back-testing results, review time-sensitive information or approve related valuation actions.

  For investments categorized as Level 3, the Committee monitors information similar to that described above, which may include: (i) data specific to the issuer or comparable issuers, (ii) general market or specific sector news and (iii) quoted prices and specific or similar security transactions. The Committee considers this data and any changes from prior periods in order to assess the reasonableness of observable and unobservable inputs, any assumptions or internal models used to value those securities and changes in fair value. This data is also used to corroborate, when available, information received from approved pricing vendors. Various factors impact the frequency of monitoring (which may occur as often as daily), however the Committee may determine that changes to inputs, assumptions and models are not required with the same frequency.

The following table summarizes the inputs used, as of March 31, 2012, in valuing the Fund's assets:

Investment Type	Quoted Prices (Level 1)		Other Significant Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)		Total
Equities
Information	$	571,025	$	7,990	$	-	$	579,015
Industrial Goods & Services		318,027		-		-		318,027
Consumer Goods & Services		288,881		-		-		288,881
Finance		219,910		-		-		219,910
Health Care		158,865		-		11		158,876
Other Industries		115,118		-		-		115,118
Energy & Minerals		93,840		-		-		93,840
Total Equities		1,765,666		7,990		11		1,773,667
Total Securities Lending Collateral		22,953		-		-		22,953
Total Investments	$	1,788,619	$	7,990	$	11	$	1,796,620

58

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

  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. Securities which have halted or temporarily stopped trading are valued at the last sale and adjusted by a premium or a discount to account for the anticipated re-opening price. These adjustments are determined by the investment manager's experience with similar securities or situations.

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

Transfers In				Transfers Out
Level 1		Level 2		Level 1		Level 2
$	-	$	8,055	$	8,055	$	-

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

  The following table reconciles asset balances for the three months ending March 31, 2012, in which significant unobservable inputs (Level 3) were used in determining value:

Investments in Securities	Balance as of December 31, 2011		Realized Gain/(Loss)		Change in Unrealized Appreciation (Depreciation)			Purchases		Sales		Transfers into Level 3		Transfers out of Level 3		Balance as of March 31, 2012
Equities
Health Care	$	27	$	-	$	(16	)	$	-	$	-	$	-	$	-	$	11
	$	27	$	-	$	(16	)	$	-	$	-	$	-	$	-	$	11

  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 March 31, 2012, which were valued using significant unobservable inputs (Level 3) amounted to $(16).

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

  Certain common stock classified as Level 3 are valued using a market approach. To determine fair value for these securities, management considered various factors which may have included, but were not limited to, trades of similar securities, estimated earnings of the respective company, market multiples derived from a set of comparable companies, and the position of the security within the respective company's capital structure. Significant increases (decreases) to any of these inputs would result in a significantly lower (higher) fair value measurement. Generally, a change in estimated earnings of the respective company may result in a change to the comparable companies and market multiples utilized.

59

Columbia Acorn International Select Fund

Major Portfolio Changes in the First Quarter (Unaudited)

	Number of Shares
	12/31/11		03/31/12
Purchases
Other Countries
> South Africa
Adcock Ingram Holdings		1,220,200		1,317,200
Naspers		80,700		112,700
Northam Platinum		0		1,146,000
Rand Merchant Insurance		7,415,000		7,601,015
> Australia
Challenger Financial		0		826,355
Commonwealth Property Office Fund		0		3,170,358

	Number of Shares
	12/31/11		03/31/12
Sales
Other Countries
> Japan
Ain Pharmaciez		105,000		74,000
Gree		181,000		59,400
Kansai Paint		2,100,000		1,911,000
> Korea
Woongjin Coway		111,000		0
Europe
> United Kingdom
Intertek Group		210,000		178,000
JLT Group		665,000		314,000
Shaftesbury		432,000		0
Workspace Group		897,000		0
> Sweden
Hexagon		658,666		595,666
> Netherlands
Imtech		277,519		239,919
> Ireland
United Drug		1,329,400		0
Other Countries
> Canada
AG Growth		125,000		89,000
CCL Industries		210,400		106,400

60

Columbia Acorn International Select

Statement of Investments (Unaudited), March 31, 2012

Number of Shares			Value (000)
			Equities: 95.1%
Asia 49.3%
		> Japan 16.0%
	1,911,000	Kansai Paint	$	19,374
		Paint Producer in Japan, India, China & Southeast Asia
	6,753,000	Seven Bank		14,809
		ATM Processing Services
	8,970	Jupiter Telecommunications		8,984
		Largest Cable Service Provider in Japan
	528,000	Asahi Diamond Industrial		6,242
		Consumable Diamond Tools
	74,000	Ain Pharmaciez		3,994
		Dispensing Pharmacy/Drugstore Operator
	59,400	Gree (a)		1,496
		Mobile Social Networking Game Developer/Platform
				54,899
		> Singapore 13.8%
	13,130,000	Ascendas REIT		21,122
		Industrial Property Landlord
	20,395,000	Mapletree Industrial Trust		17,829
		Industrial Property Landlord
	11,142,000	Mapletree Logistics Trust		8,382
		Industrial Property Landlord
				47,333
		> Taiwan 9.0%
	11,103,000	Far EasTone Telecom		22,821
		Taiwan's Third Largest Mobile Operator
	2,789,400	CTCI Corp		4,625
		International Engineering Firm
	1,179,000	Taiwan Mobile		3,594
		Taiwan's Second-largest Mobile Operator
				31,040
		> China 4.4%
	4,146,000	Zhaojin Mining Industry		6,974
		Gold Mining & Refining in China
	84,000	NetEase.com - ADR (b)		4,880
		Chinese Online Gaming Services
	3,044,000	Want Want		3,406
		Chinese Branded Consumer Food Company
				15,260
		> Korea 3.3%
	49,830	NHN		11,437
		Korean Online Search Services
				11,437
		> Indonesia 2.8%
	9,272,000	Archipelago Resources (b)		9,640
		Gold Mining Projects in Indonesia, Vietnam & the Philippines
				9,640
Asia: Total				169,609

Number of Shares			Value (000)
Europe 25.7%
		> Germany 6.4%
	630,000	Wirecard	$	11,994
		Online Payment Processing & Risk Management
	109,500	Rheinmetall		6,484
		Defense & Automotive
	175,000	Rhoen-Klinikum		3,514
		Health Care Services
				21,992
		> United Kingdom 6.2%
	178,000	Intertek Group		7,149
		Testing, Inspection, Certification Services
	659,000	Serco		5,719
		Facilities Management
	772,800	Chemring		5,037
		Defense Manufacturer of Countermeasures & Energetics
	314,000	JLT Group		3,508
		International Business Insurance Broker
				21,413
		> Sweden 3.4%
	595,666	Hexagon		11,561
		Design, Measurement & Visualization Software & Equipment
				11,561
		> Netherlands 3.3%
	239,919	Imtech		7,670
		Electromechanical & ICT Installation & Maintenance
	28,100	Core Laboratories		3,697
		Oil & Gas Reservoir Consulting
				11,367
		> Switzerland 2.5%
	24,000	Partners Group		4,682
		Private Markets Asset Management
	28,000	Kuehne & Nagel		3,787
		Freight Forwarding/Logistics
				8,469
		> Iceland 1.6%
	4,800,000	Marel		5,633
		Largest Manufacturer of Poultry & Fish Processing Equipment
				5,633
		> Denmark 1.2%
	145,000	Novozymes		4,223
		Industrial Enzymes
				4,223
		> Belgium 1.1%
	74,000	EVS Broadcast Equipment		3,837
		Digital Live Mobile Production Software & Systems
				3,837
Europe: Total				88,495

61

Columbia Acorn International Select

Statement of Investments (Unaudited), continued

Number of Shares			Value (000)
Other Countries 19.2%
		> South Africa 11.2%
	7,601,015	Rand Merchant Insurance	$	17,053
		Directly Sold Property & Casualty Insurance; Holdings in Other Insurers
	1,317,200	Adcock Ingram Holdings		10,080
		Manufacturer of Pharmaceuticals & Medical Supplies
	112,700	Naspers		6,332
		Media in Africa, China, Russia & Other Emerging Markets
	1,146,000	Northam Platinum		5,097
		Platinum Mining in South Africa
				38,562
		> United States 2.3%
	94,000	Atwood Oceanics (b)		4,220
		Offshore Drilling Contractor
	52,000	SM Energy		3,680
		Oil & Gas Producer
				7,900
		> Canada 2.2%
	106,400	CCL Industries		3,893
		Leading Global Label Manufacturer
	89,000	AG Growth		3,722
		Leading Manufacturer of Augers & Grain Handling Equipment
				7,615
		> Australia 1.9%
	826,355	Challenger Financial		3,255
		Largest Annuity Provider
	3,170,358	Commonwealth Property Office Fund		3,236
		Australia Prime Office REIT
				6,491
		> Israel 1.6%
	460,000	Israel Chemicals		5,314
		Producer of Potash, Phosphates, Bromine & Specialty Chemicals
	10,000	Caesarstone (b)		117
		Quartz Countertops
				5,431
Other Countries: Total				65,999
Latin America 0.9%
		> Argentina 0.6%
	183,333	Union Agriculture Group (b)(c)(d)		1,947
		Farmland Operator in Uruguay
				1,947
		> Colombia 0.3%
	18,800,000	Quetzal Energy (b)(c)		995
		Explores for Oil & Gas in Latin America
				995
Latin America: Total				2,942
Total Equities: 95.1% (Cost: $265,888)				327,045

Number of Shares			Value (000)
Securities Lending Collateral 0.8%
	2,658,332	Dreyfus Government Cash Management Fund (7 day yield of 0.01%) (e)	$	2,658
Total Securities Lending Collateral: (Cost: $2,658)				2,658
Total Investments: 95.9% (Cost: $268,546)(f)(g)				329,703	(h)
Obligation to Return Collateral for Securities Loaned: (0.8)%				(2,658	)
Cash and Other Assets Less Liabilities: 4.9%				16,804
Total Net Assets: 100.0%			$	343,849

ADR - American Depositary Receipts

62

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

(a)  All or a portion of this security was on loan at March 31, 2012. The total market value of securities on loan at March 31, 2012 was $2,531.

(b)  Non-income producing security.

(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 March 31, 2012, the market value of these securities amounted to $2,942 which represented 0.86% of total net assets.

  Additional information on these securities is as follows:

Security	Acquisition Dates	Shares		Cost		Value
Union Agriculture Group	12/8/10-12/16/11		183,333	$	2,200	$	1,947
Quetzal Energy	1/14/11		18,800,000		2,376		995
				$	4,576	$	2,942

(d)  Illiquid security.

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

(f)  At March 31, 2012, for federal income tax purposes, the cost of investments was $268,546 and net unrealized appreciation was $61,157 consisting of gross unrealized appreciation of $74,081 and gross unrealized depreciation of $(12,924).

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

Currency	Value		Percentage of Net Assets
Japanese Yen	$	54,900		16.0
Singapore Dollar		47,333		13.8
South African Rand		38,562		11.2
Euro		33,499		9.7
Pound Sterling		31,052		9.0
Taiwan Dollar		31,040		9.0
U.S. Dollar		18,541		5.4
Other currencies less than 5% of total net assets		72,118		21.0
	$	327,045		95.1

(h)  Securities are valued using policies described in the Notes to Financial Statements in the most recent shareholder report.

  At March 31, 2012, the Fund had entered into the following forward foreign currency exchange contracts:

Forward Foreign Currency Exchange Contracts to Buy	Forward Foreign Currency Exchange Contracts to Sell	Principal Amount in Foreign Currency		Principal Amount in U.S. Dollar		Settlement Date	Unrealized Depreciation
USD	ZAR		200,400	$	26,000	04/13/12	$	(86	)

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

USD = United States Dollar

ZAR = South African Rand

Fair Value Measurements

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

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

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

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

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

  Examples of the types of securities in which the Fund would typically invest and how they are classified within this hierarchy are as follows. Typical Level 1 securities include exchange traded domestic equities, mutual funds whose NAVs are published each day and exchange traded foreign equities that are not statistically fair valued. Typical Level 2 securities include exchange traded foreign equities that are statistically fair valued, forward foreign currency exchange contracts and short-term investments valued at amortized cost. Additionally, securities fair valued by the Valuation Committee 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.

63

Columbia Acorn International Select

Statement of Investments (Unaudited), continued

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

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

  The Committee meets at least quarterly to review and approve valuation matters, which may include a description of fair value actions, data regarding pricing information received from approved pricing vendors and brokers and the results of Board-approved valuation control policies and procedures (the Policies). The Policies address, among other things, instances when market quotations are readily available, including recommendation of third party pricing vendors and determining appropriate pricing methodologies; events that require fair valuation and assessment of fair value techniques; securities with a potential for stale pricing, including those that are illiquid, restricted, or in default; and the effectiveness of third-party pricing vendors. The Committee meets more frequently, as needed, to discuss additional valuation matters, which may include the need to review back-testing results, review time-sensitive information or approve related valuation actions.

The following table summarizes the inputs used, as of March 31, 2012, in valuing the Fund's assets:

Investment Type	Quoted Prices (Level 1)		Other Significant Observable Inputs (Level 2)			Significant Unobservable Inputs (Level 3)		Total
Equities
Asia	$	4,880	$	164,729		$	-	$	169,609
Europe		3,697		84,798			-		88,495
Other Countries		15,632		50,367			-		65,999
Latin America		-		995			1,947		2,942
Total Equities		24,209		300,889			1,947		327,045
Total Securities Lending Collateral		2,658		-			-		2,658
Total Investments	$	26,867	$	300,889		$	1,947	$	329,703
Unrealized Depreciation of Forward Foreign Currency Exchange Contracts		-		(86	)		-		(86	)
Total	$	26,867	$	300,803		$	1,947	$	329,617

  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, in accordance with the policy adopted by the Board of Trustees, provided by an independent third party to value securities principally traded in foreign markets in order to adjust for possible stale pricing that may occur between the close of the foreign exchanges and the time for valuation. These models take into account available market data including intraday index, ADR, and ETF movements. Forward foreign currency exchange contracts are valued at the prevailing forward exchange rate of the underlying currencies. Securities acquired via private placement that have a holding period or an extended settlement period are valued at a discount to the same shares that are trading freely on the market. These discounts are determined by the investment manager's experience with similar securities or situations. Factors may include, but are not limited to, trade volume, shares outstanding and stock price.

  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, the investment manager will utilize the valuation technique that it deems 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.

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

The following table reconciles asset balances for the three months ending March 31, 2012, in which significant unobservable inputs (Level 3) were used in determining value:

Investment Type	Balance as of December 31, 2011		Realized Gain/(Loss)		Change in Unrealized Appreciation (Depreciation)		Purchases		Sales		Transfers Into Level 3		Transfers out of Level 3		Balance as of March 31, 2012
Latin America
Argentina	$	1,828	$	-	$	119	$	-	$	-	$	-	$	-	$	1,947
	$	1,828	$	-	$	119	$	-	$	-	$	-	$	-	$	1,947

64

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

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

  The change in unrealized appreciation attributed to securities owned at March 31, 2012, which were valued using significant unobservable inputs (Level 3) amounted to $119.

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

  Certain common stock classified as Level 3 are valued using a market approach. To determine fair value for these securities, management considered various factors which may have included, but were not limited to, trades of similar securities, estimated earnings of the respective company, market multiples derived from a set of comparable companies, and the position of the security within the respective company's capital structure. Significant increases (decreases) to any of these inputs would result in a significantly lower (higher) fair value measurement. Generally, a change in estimated earnings of the respective company may result in a change to the comparable companies and market multiples utilized.

65

Columbia Acorn International Select

Portfolio Diversification (Unaudited)

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

	Value (000)		Percentage of Net Assets
> Information
Mobile Communications	$	26,415		7.7
Internet Related		22,649		6.6
Financial Processors		11,994		3.5
Business Software		11,561		3.4
CATV		8,984		2.6
Computer Hardware & Related Equipment		3,837		1.1
Gaming Equipment & Services		1,497		0.4
		86,937		25.3
> Industrial Goods & Services
Industrial Materials & Specialty Chemicals		28,911		8.4
Machinery		22,080		6.4
Other Industrial Services		18,607		5.4
Outsourcing Services		5,718		1.7
Electrical Components		5,037		1.5
Construction		4,625		1.3
		84,978		24.7
> Other Industries
Real Estate		50,569		14.7
> Finance
Insurance		23,816		6.9
Banks		14,809		4.3
Brokerage & Money Management		4,682		1.4
		43,307		12.6
> Energy & Minerals
Mining		25,408		7.4
Oil & Gas Producers		4,675		1.4
Oil Services		4,220		1.2
Agricultural Commodities		1,947		0.5
		36,250		10.5
> Health Care
Pharmaceuticals		10,079		3.0
Health Care Services		3,514		1.0
		13,593		4.0

	Value (000)			Percentage of Net Assets
> Consumer Goods & Services
Retail	$	3,994			1.2
Nondurables		3,894			1.1
Food & Beverage		3,406			1.0
Furniture & Textiles		117			0.0	*
		11,411			3.3
Total Equities:		327,045			95.1
Securities Lending Collateral:		2,658			0.8
Total Investments:		329,703			95.9
Obligation to Return Collateral for Securities Loaned:		(2,658	)		(0.8	)
Cash and Other Assets Less Liabilities:		16,804			4.9
Net Assets:	$	343,849			100.0

*  Rounds to less than 0.1%.

66

Columbia Acorn Select Fund

Major Portfolio Changes in the First Quarter (Unaudited)

	Number of Shares
	12/31/11		03/31/12
Purchases
Information
Atmel		825,000		1,175,000
Globalstar		13,184,322		15,000,000
Industrial Goods & Services
FMC Corporation		0		150,000
Nordson		0		160,000
Finance
Associated Banc-Corp		0		1,075,000
Regional Management		0		84,500
Energy & Minerals
Tuscany International Drilling (Colombia)		10,600,000		12,700,000
Other Industries
Dupont Fabros Technology		0		475,000
Health Care
Henry Schein		0		190,000
Seattle Genetics		0		395,000

	Number of Shares
	12/31/11		03/31/12
Sales
Consumer Goods & Services
Abercrombie & Fitch		830,000		555,000
Coach		650,000		615,000
Gaylord Entertainment		1,060,000		1,020,000
lululemon athletica		417,900		390,000
RexLot Holdings (China)		300,000,000		260,000,000
Safeway		2,000,000		1,100,000
Information
Amphenol		670,000		645,000
Crown Castle International		825,000		770,000
Sanmina-SCI		6,100,000		4,375,000
SBA Communications		1,100,000		1,010,000
WNS - ADR (India)		4,254,230		3,940,000
Industrial Goods & Services
Ametek		1,550,000		1,490,000
Expeditors International of Washington		620,000		600,000
Kennametal		1,035,000		975,000
Oshkosh Corporation		250,000		0
Pall		740,000		690,000
Quanta Services		1,470,000		1,420,000
Waste Management		500,000		0
WW Grainger		135,000		0
Finance
CNO Financial Group		9,100,000		8,325,000
Discover Financial Services		3,225,000		2,115,000
SEI Investments		1,000,000		965,000
Energy & Minerals
Continental Resources		65,000		0
Eacom Timber (Canada)		36,000,000		33,572,000
Houston American Energy		1,060,000		826,400
Kirkland Lake Gold (Canada)		900,000		870,000
Pacific Rubiales Energy (Colombia)		2,150,000		1,480,000
Other Industries
JB Hunt Transport Services		115,000		0
Health Care
Akorn		1,802,464		1,400,000

67

Columbia Acorn Select

Statement of Investments (Unaudited), March 31, 2012

Number of Shares			Value (000)
			Equities: 98.8%
Consumer Goods & Services 21.7%
		> Travel 8.1%
	5,225,000	Hertz (a)	$	78,584
		Largest U.S. Rental Car Operator
	1,020,000	Gaylord Entertainment (a)		31,416
		Convention Hotels
				110,000
		> Retail 6.8%
	390,000	lululemon athletica (a)		29,125
		Premium Active Apparel Retailer
	555,000	Abercrombie & Fitch		27,534
		Teen Apparel Retailer
	1,100,000	Safeway (b)		22,231
		Supermarkets
	200,000	Tiffany & Co.		13,826
		Luxury Good Retailer
				92,716
		> Apparel 3.5%
	615,000	Coach		47,527
		Designer & Retailer of Branded Leather Accessories
				47,527
		> Casinos & Gaming 1.7%
	260,000,000	RexLot Holdings (China) (b)		23,113
		Lottery Equipment Supplier in China
				23,113
		> Educational Services 1.3%
	270,000	ITT Educational Services (a)(b)		17,858
		Postsecondary Degree Services
				17,858
		> Other Consumer Services 0.2%
	3,430,000	IFM Investments (Century 21 China RE) - ADR (China) (a)(b)(c)		2,469
		Provide Real Estate Services in China
				2,469
		> Food & Beverage 0.1%
	1,500,000	GLG Life Tech (Canada) (a)(b)		1,185
		Produce an All-natural Sweetener Extracted from the Stevia Plant
	9,100	Annie's (a)		317
		Developer & Marketer of Natural & Organic Food
				1,502
Consumer Goods & Services: Total				295,185
Information 21.4%
		> Mobile Communications 7.5%
	1,010,000	SBA Communications (a)		51,318
		Communications Towers
	770,000	Crown Castle International (a)		41,072
		Communications Towers
	15,000,000	Globalstar (a)(c)		10,500
		Satellite Mobile Voice & Data Carrier
				102,890

Number of Shares			Value (000)
		> Contract Manufacturing 3.7%
	4,375,000	Sanmina-SCI (a)(c)	$	50,094
		Electronic Manufacturing Services
				50,094
		> Computer Services 3.5%
	3,940,000	WNS - ADR (India) (a)(c)		47,477
		Offshore BPO (Business Process Outsourcing) Services
				47,477
		> Computer Hardware & Related Equipment 2.8%
	645,000	Amphenol		38,552
		Electronic Connectors
				38,552
		> Instrumentation 1.5%
	110,000	Mettler Toledo (a)		20,322
		Laboratory Equipment
				20,322
		> Semiconductors & Related Equipment 0.8%
	1,175,000	Atmel (a)		11,586
		Microcontrollers, RF & Memory Semiconductors
				11,586
		> Business Software 0.8%
	182,000	Concur Technologies (a)		10,443
		Web Enabled Cost & Expense Management Software
				10,443
		> Advertising 0.7%
	6,108,437	VisionChina Media - ADR (China) (a)(c)		9,651
		Advertising on Digital Screens in China's Mass Transit System
				9,651
Information: Total				291,015
Industrial Goods & Services 20.8%
		> Machinery 15.4%
	1,490,000	Ametek		72,280
		Aerospace/Industrial Instruments
	1,260,000	Donaldson		45,020
		Industrial Air Filtration
	975,000	Kennametal		43,417
		Consumable Cutting Tools
	690,000	Pall		41,145
		Filtration & Fluids Clarification
	160,000	Nordson		8,721
		Dispensing Systems for Adhesives & Coatings
				210,583
		> Outsourcing Services 2.2%
	1,420,000	Quanta Services (a)		29,678
		Electrical & Telecom Construction Services
				29,678

68

Number of Shares			Value (000)
		> Other Industrial Services 2.0%
	600,000	Expeditors International of Washington	$	27,906
		International Freight Forwarder
				27,906
		> Industrial Materials & Specialty Chemicals 1.2%
	150,000	FMC Corporation		15,879
		Niche Specialty Chemicals
				15,879
Industrial Goods & Services: Total				284,046
Finance 15.0%
		> Credit Cards 5.2%
	2,115,000	Discover Financial Services		70,514
		Credit Card Company
				70,514
		> Insurance 4.7%
	8,325,000	CNO Financial Group (a)		64,768
		Life, Long Term Care & Medical Supplement Insurance
				64,768
		> Banks 3.5%
	630,000	City National		33,056
		Bank & Asset Manager
	1,075,000	Associated Banc-Corp		15,007
		Midwest Bank
				48,063
		> Brokerage & Money Management 1.5%
	965,000	SEI Investments		19,966
		Mutual Fund Administration & Investment Management
				19,966
		> Finance Companies 0.1%
	84,500	Regional Management (a)		1,420
		Consumer Loans
				1,420
Finance: Total				204,731
Energy & Minerals 11.5%
		> Oil & Gas Producers 7.3%
	1,480,000	Pacific Rubiales Energy (Colombia)		43,238
		Oil Production & Exploration in Colombia
	30,872,300	Canacol (Colombia) (a)		24,452
		Oil Producer in South America
	36,500,000	Shamaran Petroleum (Iraq) (a)		9,331
		Oil Exploration in Kurdistan
	34,700,000	Petrodorado (Colombia) (a)(c)		8,001
	17,144,000	Petrodorado - Warrants (Colombia) (a)(d)(e)		672
		Oil & Gas Exploration & Production in Colombia, Peru & Paraguay

Number of Shares			Value (000)
	24,000,000	Canadian Overseas Petroleum (United Kingdom) (a)(c)(d)	$	5,082
	12,000,000	Canadian Overseas Petroleum - Warrants (United Kingdom) (a)(d)(e)		302
		Oil & Gas Exploration/Production in the North Sea
	826,400	Houston American Energy (a)		4,314
		Oil & Gas Exploration/Production in Colombia
	18,125,000	Petromanas (Canada) (a)		4,179
	6,562,500	Petromanas - Warrants (Canada) (a)(d)		32
		Exploring for Oil in Albania
				99,603
		> Agricultural Commodities 1.6%
	1,666,667	Union Agriculture Group (Argentina) (a)(d)(e)		17,700
		Farmland Operator in Uruguay
	33,572,000	Eacom Timber (Canada) (a)(c)		3,702
		Canadian Lumber Producer
				21,402
		> Alternative Energy 1.0%
	2,700,000	Canadian Solar (China) (a)(b)(c)		8,586
		Solar Cell & Module Manufacturer
	2,500,000	Synthesis Energy Systems (China) (a)		3,675
		Owner/Operator of Gasification Plants
	1,200,000	Real Goods Solar (a)		1,740
		Residential Solar Energy Installer
				14,001
		> Mining 0.9%
	870,000	Kirkland Lake Gold (Canada) (a)		12,578
		Gold Mining
				12,578
		> Oil Services 0.7%
	12,700,000	Tuscany International Drilling (Colombia) (a)		9,549
		South America-based Drilling Rig Contractor
				9,549
Energy & Minerals: Total				157,133
Other Industries 4.3%
		> Real Estate 3.2%
	1,660,000	Biomed Realty Trust		31,507
		Life Science-focused Office Buildings
	475,000	Dupont Fabros Technology		11,614
		Technology-focused Office Buildings
				43,121
		> Regulated Utilities 1.1%
	435,000	Wisconsin Energy		15,303
		Wisconsin Utility
				15,303
Other Industries: Total				58,424

69

Columbia Acorn Select

Statement of Investments (Unaudited), continued

Number of Shares			Value (000)
Health Care 4.1%
		> Biotechnology & Drug Delivery 1.8%
	2,510,000	NPS Pharmaceuticals (a)	$	17,169
		Orphan Drugs & Healthy Royalties
	395,000	Seattle Genetics (a)(b)		8,050
		Antibody-based Therapies for Cancer
				25,219
		> Pharmaceuticals 1.2%
	1,400,000	Akorn (a)		16,380
		Develops, Manufactures & Sells Specialty Generic Drugs
				16,380
		> Medical Supplies 1.1%
	190,000	Henry Schein (a)		14,379
		Largest Distributor of Healthcare Products
				14,379
Health Care: Total				55,978
Total Equities: 98.8% (Cost: $979,694)				1,346,512

Number of Shares			Value (000)
Securities Lending Collateral 3.5%
	47,277,255	Dreyfus Government Cash Management Fund (7 day yield of 0.01%) (f)	$	47,277
Total Securities Lending Collateral: (Cost: $47,277)				47,277
Total Investments: 102.3% (Cost: $1,026,971)(g)(h)				1,393,789	(i)
Obligation to Return Collateral for Securities Loaned: (3.5)%				(47,277	)
Cash and Other Assets Less Liabilities: 1.2%				16,749
Total Net Assets: 100.0%			$	1,363,261

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 March 31, 2012. The total market value of securities on loan at March 31, 2012 was $45,804.

(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 three months ended March 31, 2012, are as follows:

Affiliates	Balance of Shares Held 12/30/11		Purchases/ Additions		Sales/ Reductions		Balance of Shares Held 3/30/12		Value		Dividend
Canacol*		31,372,300		-		500,000		30,872,300	$	24,452	$	-
Canadian Overseas Petroleum		24,000,000		-		-		24,000,000		5,082		-
Canadian Solar		2,700,000		-		-		2,700,000		8,586		-
Eacom Timber		36,000,000		-		2,428,000		33,572,000		3,702		-
GLG Life Tech*		1,850,000		-		350,000		1,500,000		1,185		-
Globalstar		13,184,322		1,815,678		-		15,000,000		10,500		-
IFM Investments (Century 21 China RE) - ADR		3,430,000		-		-		3,430,000		2,469		-
Petrodorado		34,700,000		-		-		34,700,000		8,001		-
Real Goods Solar*		1,500,000		-		300,000		1,200,000		1,740		-
Sanmina-SCI		6,100,000		-		1,725,000		4,375,000		50,094		-
Synthesis Energy Systems*		2,950,372		-		450,372		2,500,000		3,675		-
VisionChina Media - ADR		7,000,000		-		891,563		6,108,437		9,651		-
WNS - ADR		4,254,230		-		314,230		3,940,000		47,477		-
Total of Affiliated Transactions		169,041,224		1,815,678		6,959,165		163,897,737	$	176,614	$	-

*  At March 31, 2012, the Fund owned less than five percent of the company's outstanding voting shares.

  The aggregate cost and value of these companies at March 31, 2012, were $219,738 and $145,562, respectively. Investments in affiliated companies represented 10.68% of the Fund's total net assets at March 31, 2012.

(d)  Denotes a restricted security, which is subject to restrictions on resale under federal securities laws. These securities are valued at a fair value determined in good faith under consistenly applied procedures established by the Board of Trustees. At March 31, 2012, the market value of these securities amounted to $23,788 which represented 1.74% of total net assets.

70

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

Security	Acquisition Dates	Shares		Cost		Value
Union Agriculture Group	12/8/10-12/16/11		1,666,667	$	20,000	$	17,700
Canadian Overseas Petroleum	11/24/10		24,000,000		10,260		5,082
Petrodorado - Warrants	11/20/09		17,144,000		2,118		672
Canadian Overseas Petroleum - Warrants	11/24/10		12,000,000		1,502		302
Petromanas - Warrants	5/20/10		6,562,500		380		32
				$	34,260	$	23,788

(e)  Illiquid security.

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

(g)  At March 31, 2012, for federal income tax purposes, the cost of investments was $1,026,971 and net unrealized appreciation was $366,818 consisting of gross unrealized appreciation of $495,701 and gross unrealized depreciation of $(128,883).

(h)  On March 31, 2012, the market value of foreign securities represented 17.24% of total net assets. The Fund's foreign portfolio was diversified as follows:

	Value		Percentage of Net Assets
Colombia	$	85,912		6.30
China		47,494		3.49
India		47,477		3.48
Canada		21,676		1.59
Argentina		17,700		1.30
Iraq		9,331		0.68
United Kingdom		5,384		0.40
Total Foreign Portfolio	$	234,974		17.24

(i)  Securities are valued using policies described in the Notes to Financial Statements in the most recent shareholder report.

  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.

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

  The Committee meets at least quarterly to review and approve valuation matters, which may include a description of fair value actions, data regarding pricing information received from approved pricing vendors and brokers and the results of Board-approved valuation control policies and procedures (the Policies). The Policies address, among other things, instances when market quotations are readily available, including recommendation of third party pricing vendors and determining appropriate pricing methodologies; events that require fair valuation and assessment of fair value techniques; securities with a potential for stale pricing, including those that are illiquid, restricted, or in default; and the effectiveness of third-party pricing vendors. The Committee meets more frequently, as needed, to discuss additional valuation matters, which may include the need to review back-testing results, review time-sensitive information or approve related valuation actions.

  For investments categorized as Level 3, the Committee monitors information similar to that described above, which may include: (i) data specific to the issuer or comparable issuers, (ii) general market or specific sector news and (iii) quoted prices and specific or similar security transactions. The Committee considers this data and any changes from prior periods in order to assess the reasonableness of observable and unobservable inputs, any assumptions or internal models used to value those securities and changes in fair value. This data is also used to corroborate, when available, information received from approved pricing vendors. Various factors impact the frequency of monitoring (which may occur as often as daily), however the Committee may determine that changes to inputs, assumptions and models are not required with the same frequency.

71

Columbia Acorn Select

Statement of Investments (Unaudited), continued

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

The following table summarizes the inputs used, as of March 31, 2012, in valuing the Fund's assets:

Investment Type	Quoted Prices (Level 1)		Other Significant Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)		Total
Equities
Consumer Goods & Services	$	272,072	$	23,113	$	-	$	295,185
Information		291,015		-		-		291,015
Industrial Goods & Services		284,046		-		-		284,046
Finance		204,731		-		-		204,731
Energy & Minerals		133,345		6,088		17,700		157,133
Other Industries		58,424		-		-		58,424
Health Care		55,978		-		-		55,978
Total Equities		1,299,611		29,201		17,700		1,346,512
Total Securities Lending Collateral		47,277		-		-		47,277
Total Investments	$	1,346,888	$	29,201	$	17,700	$	1,393,789

  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, in accordance with the policy adopted by the Board of Trustees, provided by an independent third party to value securities principally traded in foreign markets in order to adjust for possible stale pricing that may occur between the close of the foreign exchanges and the time for valuation. These models take into account available market data including intraday index, ADR, and ETF movements. Securities acquired via private placement that have a holding period or an extended settlement period are valued at a discount to the same shares that are trading freely on the market. These discounts are determined by the investment manager's experience with similar securities or situations. Factors may include, but are not limited to, trade volume, shares outstanding and stock price. Warrants which do not trade are valued as a percentage of the actively trading common stock using a model, based on Black Scholes.

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

  The following table reconciles asset balances for the six months ending March 31, 2012, in which significant unobservable inputs (Level 3) were used in determining value:

Investments in Securities	Balance as of December 31, 2011		Realized Gain/(Loss)		Change in Unrealized Appreciation (Depreciation)		Purchases		Sales		Transfers into Level 3		Transfers out of Level 3		Balance as of March 31, 2012
Equities
Energy & Minerals	$	16,617	$	-	$	1,083	$	-	$	-	$	-	$	-	$	17,700
	$	16,617	$	-	$	1,083	$	-	$	-	$	-	$	-	$	17,700

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

  The change in unrealized appreciation attributed to securities owned at March 31, 2012, which were valued using significant unobservable inputs (Level 3) amounted to $1,083.

  Quantitative information pertaining to Level 3 unobservable fair value measurements

	Fair Value at 03/31/12		Valuation Technique(s)	Unobservable Input (s)	Range (Weighted Average)
Equities		17,700	Market comparable companies	Discount for lack of marketability	-6% - +16% (-9%)

  Certain common stock classified as Level 3 are valued using a market approach. To determine fair value for these securities, management considered various factors which may have included, but were not limited to, trades of similar securities, estimated earnings of the respective company, market multiples derived from a set of comparable companies, and the position of the security within the respective company's capital structure. Significant increases (decreases) to any of these inputs would result in a significantly lower (higher) fair value measurement. Generally, a change in estimated earnings of the respective company may result in a change to the comparable companies and market multiples utilized.

72

Columbia Thermostat Fund

Statement of Investments (Unaudited), March 31, 2012

Number of Shares			Value (000)
		> Affiliated Bond Funds: 53.4%
	9,295,325	Columbia Intermediate Bond Fund, Class I	$	86,725
	5,457,987	Columbia Income Opportunities Fund, Class I		52,233
	2,987,862	Columbia U.S. Treasury Income Fund, Class I		34,629
Total Bond Funds (Cost: $171,419)				173,587
		> Affiliated Stock Funds: 43.8%
	725,247	Columbia Acorn International Fund, Class I		28,662
	1,946,023	Columbia Dividend Income Fund, Class I		28,529
	1,353,681	Columbia Contrarian Core Fund, Class I		21,361
	668,359	Columbia Acorn Fund, Class I		21,287

Number of Shares			Value (000)
	1,014,784	Columbia Large Cap Enhanced Core Fund, Class I	$	14,227
	981,120	Columbia Select Large Cap Growth Fund, Class I (a)		14,197
	509,047	Columbia Acorn Select Fund, Class I		14,177
Total Stock Funds (Cost: $114,924)				142,440
Total Investments: 97.2% (Cost: $286,343)(b)				316,027	(c)
Cash and Other Assets Less Liabilities: 2.8%				8,998
Total Net Assets: 100.0%			$	325,025

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

(a)  Non-income producing security.

(b)  At March 31, 2012, for federal income tax purposes, the cost of investments was $286,343 and net unrealized appreciation was $29,684 consisting of gross unrealized appreciation of $29,684 and gross unrealized depreciation of $(—).

(c)  Securities are valued using policies described in the Notes to Financial Statements in the most recent shareholder report.

Fair Value Measurements

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

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

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

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

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

  Examples of the types of securities in which the Fund would typically invest and how they are classified within this hierarchy are as follows. Typical Level 1 securities include exchange traded domestic equities, mutual funds whose NAVs are published each day and exchange traded foreign equities that are not statistically fair valued. Typical Level 2 securities include exchange traded foreign equities that are statistically fair valued, forward foreign currency exchange contracts and short-term investments valued at amortized cost. Additionally, securities fair valued by the Valuation Committee 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.

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

  The Committee meets at least quarterly to review and approve valuation matters, which may include a description of fair value actions, data regarding pricing information received from approved pricing vendors and brokers and the results of Board-approved valuation control policies and procedures (the Policies). The Policies address, among other things, instances when market quotations are readily available, including recommendation of third party pricing vendors and determining appropriate pricing methodologies; events that require fair valuation and assessment of fair value techniques; securities with a potential for stale pricing, including those that are illiquid, restricted, or in default; and the effectiveness of third-party pricing vendors. The Committee meets more frequently, as needed, to discuss additional valuation matters, which may include the need to review back-testing results, review time-sensitive information or approve related valuation actions.

  For investments categorized as Level 3, the Committee monitors information similar to that described above, which may include: (i) data specific to the issuer or comparable issuers, (ii) general market or specific sector news and (iii) quoted prices and specific or similar security transactions. The Committee considers this data and any changes from prior periods in order to assess the reasonableness of observable and unobservable inputs, any assumptions or internal models used to value those securities and changes in fair value. This data is also used to corroborate, when available, information received from approved pricing vendors. Various factors impact the frequency of monitoring (which may occur as often as daily), however the Committee may determine that changes to inputs, assumptions and models are not required with the same frequency.

73

Columbia Thermostat Fund

Statement of Investments (Unaudited), continued

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

The following table summarizes the inputs used, as of March 31, 2012, in valuing the Fund's assets:

Investment Type	Quoted Prices (Level 1)		Other Significant Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)		Total
Total Bond Funds	$	173,587	$	-	$	-	$	173,587
Total Stock Funds		142,440		-		-		142,440
Total Investments	$	316,027	$	-	$	-	$	316,027

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

74

Columbia Acorn Emerging Markets Fund

Major Portfolio Changes in the First Quarter (Unaudited)

	Number of Shares
	12/31/11		03/31/12
Purchases
Asia
> Taiwan
Advantech		12,000		19,169
Chroma Ate		26,990		38,990
CTCI Corp		33,200		64,762
Far EasTone Telecom		43,700		58,126
Lung Yen		11,000		16,500
MStar Semiconductor		0		9,800
PC Home		3,900		13,700
Radiant Opto-Electronics		11,277		15,277
Simplo Technology		7,730		10,342
St. Shine Optical		5,800		7,200
Taiwan Hon Chuan		15,385		21,689
Tripod Technologies		0		30,000
> Indonesia
Ace Indonesia		178,989		369,019
Archipelago Resources		76,959		137,500
Jasa Marga		67,000		109,911
Surya Citra Media		44,000		93,264
Tower Bersama Infrastructure		241,000		535,709
> Hong Kong
AAC Technologies		13,000		18,027
Lifestyle International		16,865		28,089
Melco Crown Entertainment - ADR		4,137		5,150
Melco International		33,000		118,462
Sasa International		65,652		89,999
> China
51job - ADR		741		1,154
Digital China		34,651		45,651
NetEase.com - ADR		1,000		1,277
RexLot Holdings		451,892		823,246
> India
Adani Ports & Special Economic Zone		12,250		22,500
Jain Irrigation Systems		20,800		30,249
Redington India		0		7,562
Titan Industries		2,200		13,040
United Breweries		4,180		7,835
> Philippines
Int'l Container Terminal		25,567		40,787
Manila Water Company		88,382		100,465
> Cambodia
Nagacorp		229,035		340,000
> Thailand
Home Product Center		134,348		249,018
> Mongolia
Mongolian Mining		48,909		98,500

	Number of Shares
	12/31/11		03/31/12
> Japan
Kansai Paint		3,860		7,060
Other Countries
> South Africa
Adcock Ingram Holdings		9,580		15,850
Coronation Fund Managers		24,626		42,926
Massmart Holdings		1,945		3,197
Mr. Price		5,370		6,597
Northam Platinum		11,354		15,354
Rand Merchant Insurance		39,175		71,200
> Canada
Alliance Grain Traders		3,565		10,801
Americas Petrogas		0		17,500
> United States
Atwood Oceanics		752		952
Hornbeck Offshore		1,000		1,509
Textainer Group Holdings		1,200		2,204
Europe
> Sweden
East Capital Explorer		6,072		8,806
Hexagon		3,498		7,231
> Switzerland
Dufry Group		675		1,116
> Kazakhstan
Halyk Savings Bank of Kazakhstan - GDR		4,332		17,800
> Italy
Pirelli		3,000		7,000
> Germany
Dürr		824		1,229
> France
Rubis		780		965
Latin America
> Brazil
Localiza Rent A Car		4,436		5,490
MRV Engenharia		11,121		11,325
Multiplus		1,884		3,144
> Mexico
Grupo Aeroportuario del Sureste - ADR		1,203		1,647
> Chile
Viña Concha y Toro		0		16,500

75

Columbia Acorn Emerging Markets Fund

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

	Number of Shares
	12/31/11		03/31/12
Sales
Asia
> Taiwan
Formosa International Hotels		949		0
President Chain Store		5,000		0
> China
ENN Energy		7,538		0
> India
Manappuram Finance		35,100		0
> Singapore
Goodpack Limited		27,403		0
Latin America
> Brazil
Suzano		7,431		0
> Argentina
Madalena Ventures		56,433		40,200

76

Columbia Acorn Emerging Markets Fund

Statement of Investments (Unaudited), March 31, 2012

Number of Shares			Value (000)
			Equities: 96.1%
Asia 55.2%
		> Taiwan 16.8%
	58,126	Far EasTone Telecom	$	120
		Taiwan's Third Largest Mobile Operator
	64,762	CTCI Corp		107
		International Engineering Firm
	30,000	Tripod Technologies		101
		Printed Circuit Boards (PCB)
	38,990	Chroma Ate		100
		Automatic Test Systems, Testing & Measurement Instruments
	7,200	St. Shine Optical		94
		World's Leading Disposable Contact Lens OEM
	10,342	Simplo Technology		78
		Battery Packs for Notebook & Tablet PCs
	13,700	PC Home		77
		Taiwanese Internet Retail Company
	15,277	Radiant Opto-Electronics		68
		LCD Back Light Units & Modules
	19,169	Advantech		67
		Industrial PC & Components
	9,800	MStar Semiconductor		60
		ICs for TV, Digital Set-top-box & Handset
	16,500	Lung Yen		53
		Funeral Services & Columbaria
	21,689	Taiwan Hon Chuan		49
		Beverage Packaging (Bottles, Caps, Labels) Manufacturer
				974
		> Indonesia 11.1%
	369,019	Ace Indonesia		180
		Home Improvement Retailer
	535,709	Tower Bersama Infrastructure		173
		Communications Towers
	137,500	Archipelago Resources (a)		143
		Gold Mining Projects in Indonesia, Vietnam & the Philippines
	93,264	Surya Citra Media		82
		Free to Air TV in Indonesia
	109,911	Jasa Marga		62
		Largest Toll Road Operator in Indonesia
				640
		> Hong Kong 6.2%
	118,462	Melco International (a)		113
		Macau Casino Operator
	28,089	Lifestyle International		72
		Mid to High-end Department Store Operator in Hong Kong & China
	5,150	Melco Crown Entertainment - ADR (a)		70
		Macau Casino Operator
	89,999	Sasa International		52
		Cosmetics Retailer
	18,027	AAC Technologies		49
		Miniature Acoustic Components
				356

Number of Shares			Value (000)
		> China 6.1%
	45,651	Digital China	$	91
		IT Distribution & Systems Integration Services
	1,277	NetEase.com - ADR (a)		74
		Chinese Online Gaming Services
	823,246	RexLot Holdings		73
		Lottery Equipment Supplier in China
	1,154	51job - ADR (a)(b)		66
		Integrated Human Resource Services
	89,275	AMVIG Holdings		48
		Chinese Tobacco Packaging Material Supplier
				352
		> India 4.7%
	7,835	United Breweries		83
		India's Largest Brewer
	13,040	Titan Industries		59
		Jewelry, Watches, Eyeglasses
	30,249	Jain Irrigation Systems		58
		Agricultural Micro-irrigation Systems & Food Processing
	22,500	Adani Ports & Special Economic Zone		57
		Indian West Coast Shipping Port
	7,562	Redington India		13
		Supply Chain Solutions for IT & Mobile Handsets in Emerging Markets
				270
		> Philippines 2.9%
	40,787	Int'l Container Terminal		62
		Container Handling Terminals & Port Management
	100,465	Manila Water Company		54
		Water Utility Company in the Philippines
	128,155	SM Prime Holdings		51
		Shopping Mall Operator
				167
		> Cambodia 2.7%
	340,000	Nagacorp		155
		Casino/Entertainment Complex in Cambodia
				155
		> Thailand 1.9%
	249,018	Home Product Center		112
		Home Improvement Retailer
				112
		> Mongolia 1.6%
	98,500	Mongolian Mining (a)		94
		Coking Coal Mining in Mongolia
				94
		> Japan 1.2%
	7,060	Kansai Paint		72
		Paint Producer in Japan, India, China & Southeast Asia
				72
Asia: Total				3,192

77

Columbia Acorn Emerging Markets Fund

Statement of Investments (Unaudited), continued

Number of Shares			Value (000)
Other Countries 19.1%
		> South Africa 11.4%
	71,200	Rand Merchant Insurance	$	160
		Directly Sold Property & Casualty Insurance; Holdings in Other Insurers
	42,926	Coronation Fund Managers		159
		South African Fund Manager
	15,850	Adcock Ingram Holdings		121
		Manufacturer of Pharmaceuticals & Medical Supplies
	6,597	Mr. Price		81
		South African Retailer of Apparel, Household & Sporting Goods
	15,354	Northam Platinum		68
		Platinum Mining in South Africa
	3,197	Massmart Holdings		68
		General Merchandise, Food & Home Improvement Stores; Wal-Mart Subsidiary
				657
		> Canada 4.6%
	10,801	Alliance Grain Traders		166
		Global Leader in Pulse Processing & Distribution
	17,500	Americas Petrogas (a)		62
		Oil & Gas Exploration in Argentina, Potash in Peru
	4,172	Crew Energy (a)		40
		Canadian Oil & Gas Producer
				268
		> United States 3.1%
	2,204	Textainer Group Holdings		75
		Top International Container Leaser
	1,509	Hornbeck Offshore (a)		63
		Supply Vessel Operator in U.S. Gulf of Mexico
	952	Atwood Oceanics (a)		43
		Offshore Drilling Contractor
				181
Other Countries: Total				1,106
Europe 13.5%
		> Sweden 3.7%
	7,231	Hexagon		141
		Design, Measurement & Visualization Software & Equipment
	8,806	East Capital Explorer		74
		Sweden-based RUS/CEE Investment Fund
				215
		> Switzerland 2.5%
	1,116	Dufry Group (a)		146
		Operates Airport Duty Free & Duty Paid Shops
				146
		> Kazakhstan 2.0%
	17,800	Halyk Savings Bank of Kazakhstan - GDR (a)		116
		Largest Retail Bank & Insurer in Kazakhstan
				116

Number of Shares			Value (000)
		> Czech Republic 1.5%
	434	Komercni Banka	$	86
		Leading Czech Universal Bank
				86
		> Italy 1.4%
	7,000	Pirelli		83
		Global Tire Supplier
				83
		> Germany 1.4%
	1,229	Dürr		78
		Automotive Plant Engineering & Associated Capital Equipment
				78
		> France 1.0%
	965	Rubis		57
		Tank Storage & LPG Distribution
				57
Europe: Total				781
Latin America 8.3%
		> Brazil 5.0%
	5,490	Localiza Rent A Car		101
		Car Rental
	11,325	MRV Engenharia		80
		Brazilian Property Developer
	3,144	Multiplus		65
		Loyalty Program Operator in Brazil
	3,361	Mills Estruturas e Servicos de Engenharia		43
		Civil Engineering & Construction
				289
		> Mexico 2.0%
	1,647	Grupo Aeroportuario del Sureste - ADR		113
		Mexican Airport Operator
				113
		> Chile 0.7%
	16,500	Viña Concha y Toro		38
		Global Branded Wine Manufacturer
				38
		> Argentina 0.6%
	40,200	Madalena Ventures (a)		37
		Oil & Gas Exploration in Argentina
				37
Latin America: Total				477
Total Equities: 96.1% (Cost: $5,066)				5,556

78

Number of Shares Value (000)

Securities Lending Collateral 0.6%
	35,100	Dreyfus Government Cash Management Fund (7 day yield of 0.01%) (c)	$	35
Total Securities Lending Collateral: (Cost: $35)				35
Total Investments: 96.7% (Cost: $5,101)(d)(e)				5,591	(f)
Obligation to Return Collateral for Securities Loaned: (0.6)%				(35	)
Cash and Other Assets Less Liabilities: 3.9%				226
Total Net Assets: 100.0%			$	5,782

ADR - American Depositary Receipts

GDR - Global Depositary Receipts

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

(a)  Non-income producing security.

(b)  All or a portion of this security was on loan at March 31, 2012. The total market value of securities on loan at March 31, 2012 was $34.

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

(d)  At March 31, 2012, for federal income tax purposes, the cost of investments was $5,101 and net unrealized appreciation was $490 consisting of gross unrealized appreciation of $630 and gross unrealized depreciation of $(140).

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

Currency	Value		Percentage of Net Assets
Taiwan Dollar	$	974		16.8
South African Rand		657		11.4
Indonesian Rupiah		640		11.1
Hong Kong Dollar		356		6.2
Brazilain Real		289		5.0
U.S. Dollar		181		3.1
Other currencies less than 5% of total net assets		2,459		42.5
	$	5,556		96.1

(f)  Securities are valued using policies described in the Notes to Financial Statements in the most recent shareholder report.

  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.

79

Columbia Acorn Emerging Markets Fund

Statement of Investments (Unaudited), continued

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

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

  The Committee meets at least quarterly to review and approve valuation matters, which may include a description of fair value actions, data regarding pricing information received from approved pricing vendors and brokers and the results of Board-approved valuation control policies and procedures (the Policies). The Policies address, among other things, instances when market quotations are readily available, including recommendation of third party pricing vendors and determining appropriate pricing methodologies; events that require fair valuation and assessment of fair value techniques; securities with a potential for stale pricing, including those that are illiquid, restricted, or in default; and the effectiveness of third-party pricing vendors. The Committee meets more frequently, as needed, to discuss additional valuation matters, which may include the need to review back-testing results, review time-sensitive information or approve related valuation actions.

  For investments categorized as Level 3, the Committee monitors information similar to that described above, which may include: (i) data specific to the issuer or comparable issuers, (ii) general market or specific sector news and (iii) quoted prices and specific or similar security transactions. The Committee considers this data and any changes from prior periods in order to assess the reasonableness of observable and unobservable inputs, any assumptions or internal models used to value those securities and changes in fair value. This data is also used to corroborate, when available, information received from approved pricing vendors. Various factors impact the frequency of monitoring (which may occur as often as daily), however the Committee may determine that changes to inputs, assumptions and models are not required with the same frequency.

The following table summarizes the inputs used, as of March 31, 2012, in valuing the Fund's assets:

Investment Type	Quoted Prices (Level 1)		Other Significant Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)		Total
Equities
Asia	$	210	$	2,982	$	-	$	3,192
Other Countries		449		657		-		1,106
Europe		-		781		-		781
Latin America		477		-		-		477
Total Equities		1,136		4,420		-		5,556
Total Securities Lending Collateral		35		-		-		35
Total Investments	$	1,171	$	4,420	$	-	$	5,591

  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, in accordance with the policy adopted by the Board of Trustees, provided by an independent third party to value securities principally traded in foreign markets in order to adjust for possible stale pricing that may occur between the close of the foreign exchanges and the time for valuation. These models take into account available market data including intraday index, ADR, and ETF movements.

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

80

Columbia Acorn Emerging Markets Fund

Portfolio Diversification (Unaudited)

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

	Value (000)		Percentage of Net Assets
>Consumer Goods & Services
Retail	$	775		13.5
Casinos & Gaming		411		7.1
Other Consumer Services		190		3.3
Food & Beverage		186		3.2
Travel		101		1.7
Other Durable Goods		83		1.4
Consumer Goods Distribution		13		0.2
		1,759		30.4
> Information
Computer Hardware & Related Equipment		363		6.3
Mobile Communications		293		5.1
Business Software		140		2.4
Instrumentation		100		1.7
Electronics Distribution		91		1.6
TV Broadcasting		82		1.4
Internet Related		74		1.3
Semiconductors & Related Equipment		60		1.0
		1,203		20.8
> Energy & Minerals
Mining		305		5.3
Agricultural Commodities		166		2.9
Oil & Gas Producers		139		2.4
Oil Services		106		1.8
Oil Refining, Marketing & Distribution		57		1.0
		773		13.4
> Finance
Brokerage & Money Management		234		4.0
Banks		202		3.5
Insurance		160		2.8
Finance Companies		75		1.3
		671		11.6
> Industrial Goods & Services
Industrial Materials & Specialty Chemicals		169		2.9
Construction		150		2.6
Machinery		137		2.4
Other Industrial Services		119		2.1
		575		10.0
> Other Industries
Transportation		175		3.0
Real Estate		131		2.3
Regulated Utilities		54		0.9
		360		6.2

	Value (000)			Percentage of Net Assets
> Health Care
Pharmaceuticals	$	121			2.1
Medical Supplies		94			1.6
		215			3.7
Total Equities:		5,556			96.1
Securities Lending Collateral:		35			0.6
Total Investments:		5,591			96.7
Obligation to Return Collateral for Securities Loaned:		(35	)		(0.6	)
Cash and Other Assets Less Liabilities:		226			3.9
Net Assets:	$	5,782			100.0

81

Columbia Acorn European Fund

Major Portfolio Changes in the First Quarter (Unaudited)

	Number of Shares
	12/31/11		03/31/12
Purchases
Europe
> United Kingdom
Rightmove		0		1,000
> France
1000 mercis		700		1,200
> Netherlands
TKH Group		0		400
> Switzerland
Zehnder		0		243
> Sweden
Hexagon		2,570		2,670
> Denmark
Solar A/S		0		300

	Number of Shares
	12/31/11		03/31/12
Sales
Europe
> United Kingdom
GlobeOp Financial Services		6,480		0
> France
Gemalto		1,100		1,000
> Germany
Elringklinger		810		0

82

Columbia Acorn European Fund

Statement of Investments (Unaudited), March 31, 2012

Number of Shares			Value (000)
			Equities: 94.0%
Europe 91.7%
		> United Kingdom 16.2%
	1,100	Intertek Group	$	44
		Testing, Inspection, Certification Services
	15,220	Charles Taylor		37
		Insurance Services
	2,927	JLT Group		33
		International Business Insurance Broker
	4,900	Chemring		32
		Defense Manufacturer of Countermeasures & Energetics
	3,180	Shaftesbury		25
		London Prime Retail REIT
	3,610	Domino's Pizza United Kingdom & Ireland		25
		Pizza Delivery in the United Kingdom, Ireland & Germany
	1,000	Rightmove		23
		Internet Real Estate Listings
	5,800	Workspace Group		22
		UK Real Estate
	660	Rotork		22
		Valve Actuators for Oil & Water Pipelines
	2,480	Serco		21
		Facilities Management
	2,870	Premier Oil (a)		18
		Oil & Gas Producer in Europe, Pakistan & Asia
	3,190	Abcam		18
		Online Sales of Antibodies
	999	Greggs		8
		Bakery
				328
		> France 16.1%
	1,000	Gemalto		66
		Digital Security Solutions
	600	Eurofins Scientific		65
		Food, Pharmaceuticals & Materials Screening & Testing
	1,200	1000 mercis		57
		Interactive Advertising & Marketing
	360	Norbert Dentressangle		32
		Leading European Logistics & Transport Group
	790	Saft Batteries		26
		Niche Battery Manufacturer
	352	Neopost		23
		Postage Meter Machines
	600	Mersen		21
		Advanced Industrial Materials
	310	Rubis		18
		Tank Storage & LPG Distribution
	5,030	Hi-Media (a)		18
		Online Advertiser in Europe
				326
		> Netherlands 14.0%
	2,420	Aalberts Industries		50
		Flow Control & Heat Treatment
	1,530	UNIT4		44
		Business Software Development

Number of Shares			Value (000)
	330	Core Laboratories	$	44
		Oil & Gas Reservoir Consulting
	1,160	Koninklijke TenCate		40
		Advanced Textiles & Industrial Fabrics
	1,260	Imtech		40
		Electromechanical & ICT Installation & Maintenance
	410	Fugro		29
		Sub-sea Oilfield Services
	1,280	Arcadis		27
		Engineering Consultants
	400	TKH Group		11
		Dutch Industrial Conglomerate
				285
		> Germany 11.1%
	3,080	Wirecard		59
		Online Payment Processing & Risk Management
	170	Rational		40
		Commercial Ovens
	560	Rheinmetall		33
		Defense & Automotive
	520	Dürr		33
		Automotive Plant Engineering & Associated Capital Equipment
	300	Bertrandt		23
		Outsourced Engineering
	590	CTS Eventim		20
		Event Ticket Sales
	450	Stratec Biomedical Systems		18
		Diagnostic Instrumentation
				226
		> Switzerland 7.7%
	250	Geberit (a)		52
		Plumbing Supplies
	15	Sika		33
		Chemicals for Construction & Industrial Applications
	160	Partners Group		31
		Private Markets Asset Management
	170	Dufry Group (a)		22
		Operates Airport Duty Free & Duty Paid Shops
	243	Zehnder		18
		Radiators & Ventilation Systems
				156
		> Sweden 6.1%
	2,670	Hexagon		52
		Design, Measurement & Visualization Software & Equipment
	4,070	Sweco		44
		Engineering Consultants
	1,000	Unibet		28
		European Online Gaming Operator
				124
		> Italy 4.4%
	2,000	Pirelli		24
		Global Tire Supplier
	7,000	Geox		23
		Apparel & Shoe Maker

83

Columbia Acorn European Fund

Statement of Investments (Unaudited), continued

Number of Shares			Value (000)
		> Italy—continued
	200	Tod's	$	22
		Leather Shoes & Bags
	13,860	CIR		20
		Italian Holding Company
				89
		> Iceland 2.5%
	43,750	Marel		51
		Largest Manufacturer of Poultry & Fish Processing Equipment
				51
		> Ireland 2.2%
	9,300	United Drug		26
		Irish Pharmaceutical Wholesaler & Outsourcer
	300	Paddy Power		19
		Irish Betting Services
				45
		> Portugal 2.0%
	13,480	Redes Energéticas Nacionais		41
		Portuguese Power Transmission & Gas Transportation
				41
		> Norway 2.0%
	3,310	Atea		40
		Leading Nordic IT Hardware/Software Reseller & Installation Company
				40
		> Russia 1.9%
	1,000	Mail.ru - GDR (a)(b)		39
		Internet Social Networking & Games for Russian Speakers
				39
		> Belgium 1.6%
	630	EVS Broadcast Equipment		33
		Digital Live Mobile Production Software & Systems
				33
		> Czech Republic 1.4%
	140	Komercni Banka		28
		Leading Czech Universal Bank
				28
		> Poland 1.1%
	4,000	FX Energy (a)		22
		Oil & Gas Producer in Poland
				22
		> Denmark 0.8%
	300	Solar A/S		17
		Technical Wholesaler of Electrical, Plumbing & HVAC Equipment
				17
		> Greece 0.6%
	12,800	Intralot		12
		Lottery & Gaming Systems & Services
				12
Europe: Total				1,862

Number of Shares			Value (000)
Other Countries 1.3%
		> Canada 1.3%
	1,670	Alliance Grain Traders	$	26
		Global Leader in Pulse Processing & Distribution
				26
Other Countries: Total				26
Asia 1.0%
		> Hong Kong 1.0%
	9,000	L'Occitane International		21
		Skin Care & Cosmetics Producer
				21
Asia: Total				21
Total Equities: 94.0% (Cost: $1,708)				1,909
Total Investments: 94.0% (Cost: $1,708)(c)(d)				1,909	(e)
Cash and Other Assets Less Liabilities: 6.0%				122
Total Net Assets: 100.0%			$	2,031

GDR - Global Depositary Receipts

84

> 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 March 31, 2012, this security had an aggregate value of $39, which represented 1.92% of total net assets.

(c)  At March 31, 2012, for federal income tax purposes, the cost of investments was $1,708 and net unrealized appreciation was $201 consisting of gross unrealized appreciation of $249 and gross unrealized depreciation of $(48).

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

Currency	Value		Percentage of Net Assets
Euro	$	1,014		49.9
British Pound		328		16.2
Swiss Franc		156		7.7
Swedish Krona		124		6.1
U.S. Dollar		105		5.1
Other currencies less than 5% of total net assets		182		9.0
	$	1,909		94.0

(e)  Securities are valued using policies described in the Notes to Financial Statements in the most recent shareholder report.

  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.

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

  The Committee meets at least quarterly to review and approve valuation matters, which may include a description of fair value actions, data regarding pricing information received from approved pricing vendors and brokers and the results of Board-approved valuation control policies and procedures (the Policies). The Policies address, among other things, instances when market quotations are readily available, including recommendation of third party pricing vendors and determining appropriate pricing methodologies; events that require fair valuation and assessment of fair value techniques; securities with a potential for stale pricing, including those that are illiquid, restricted, or in default; and the effectiveness of third-party pricing vendors. The Committee meets more frequently, as needed, to discuss additional valuation matters, which may include the need to review back-testing results, review time-sensitive information or approve related valuation actions.

  For investments categorized as Level 3, the Committee monitors information similar to that described above, which may include: (i) data specific to the issuer or comparable issuers, (ii) general market or specific sector news and (iii) quoted prices and specific or similar security transactions. The Committee considers this data and any changes from prior periods in order to assess the reasonableness of observable and unobservable inputs, any assumptions or internal models used to value those securities and changes in fair value. This data is also used to corroborate, when available, information received from approved pricing vendors. Various factors impact the frequency of monitoring (which may occur as often as daily), however the Committee may determine that changes to inputs, assumptions and models are not required with the same frequency.

85

Columbia Acorn European Fund

Statement of Investments (Unaudited), continued

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

The following table summarizes the inputs used, as of March 31, 2012, in valuing the Fund's assets:

Investment Type	Quoted Prices (Level 1)		Other Significant Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)		Total
Equities
Europe	$	65	$	1,797	$	-	$	1,862
Other Countries		26		-		-		26
Asia		-		21		-		21
Total Equities		91		1,818		-		1,909
Total Investments	$	91	$	1,818	$	-	$	1,909

  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, in accordance with the policy adopted by the Board of Trustees, provided by an independent third party to value securities principally traded in foreign markets in order to adjust for possible stale pricing that may occur between the close of the foreign exchanges and the time for valuation. These models take into account available market data including intraday index, ADR, and ETF movements.

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

86

Columbia Acorn European Fund

Portfolio Diversification (Unaudited)

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

	Value (000)		Percentage of Net Assets
>Industrial Goods & Services
Other Industrial Services	$	221		10.9
Machinery		202		9.9
Industrial Materials & Specialty Chemicals		94		4.6
Conglomerates		80		3.9
Electrical Components		58		2.9
Construction		52		2.6
Outsourcing Services		44		2.2
Industrial Distribution		16		0.8
		767		37.8
>Information
Internet Related		99		4.9
Instrumentation		96		4.7
Financial Processors		63		3.1
CATV		59		2.9
Gaming Equipment & Services		57		2.8
Business Software		40		2.0
Advertising		17		0.8
		431		21.2
>Consumer Goods & Services
Casinos & Gaming		59		2.9
Nondurables		44		2.2
Other Durable Goods		42		2.1
Restaurants		25		1.2
Apparel		23		1.1
Retail		22		1.1
Other Entertainment		20		1.0
Food & Beverage		8		0.4
		243		12.0
>Energy & Minerals
Mining		43		2.1
Oil & Gas Producers		40		2.0
Oil Services		29		1.4
Agricultural Commodities		26		1.3
Oil Refining, Marketing & Distribution		18		0.9
		156		7.7
>Finance
Insurance		70		3.4
Brokerage & Money Management		31		1.5
Banks		28		1.4
		129		6.3
>Other Industries
Real Estate		47		2.3
Regulated Utilities		41		2.0
Transportation		32		1.6
		120		5.9

	Value (000)		Percentage of Net Assets
>Health Care
Pharmaceuticals	$	26		1.3
Medical Equipment & Devices		19		0.9
Medical Supplies		18		0.9
		63		3.1
Total Equities:		1,909		94.0
Total Investments:		1,909		94.0
Cash and Other Assets Less Liabilities:		122		6.0
Net Assets:	$	2,031		100.0

87

Columbia Acorn Family of Funds

First Quarter Class Z Share Information (Unaudited)

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

Columbia Acorn Fund	ACRNX
Management Fee		0.64	%
12b-1 Fee		0.00	%
Other Expenses		0.12	%
Net Expense Ratio		0.76	%
Columbia Acorn International	ACINX
Management Fee		0.76	%
12b-1 Fee		0.00	%
Other Expenses		0.15	%
Net Expense Ratio		0.91	%
Columbia Acorn USA	AUSAX
Management Fee		0.86	%
12b-1 Fee		0.00	%
Other Expenses		0.13	%
Net Expense Ratio		0.99	%
Columbia Acorn International Select	ACFFX
Management Fee		0.94	%
12b-1 Fee		0.00	%
Other Expenses		0.23	%
Net Expense Ratio		1.17	%
Columbia Acorn Select	ACTWX
Management Fee		0.83	%
12b-1 Fee		0.00	%
Other Expenses		0.15	%
Net Expense Ratio		0.98	%
Columbia Thermostat Fund	COTZX
Management Fee		0.10	%
12b-1 Fee		0.00	%
Other Expenses		0.15	%*
Net Expense Ratio		0.25	%*
Columbia Acorn Emerging Markets Fund	CEFZX
Management Fee		1.25	%
12b-1 Fee		0.00	%
Other Expenses		0.19	%
Net Expense Ratio		1.44	%
Columbia Acorn European Fund	CAEZX
Management Fee		1.19	%
12b-1 Fee		0.00	%
Other Expenses		0.15	%
Net Expense Ratio		1.34	%

    Fees and expenses are for the three months ended March 31, 2012. The fees and expenses of Columbia Acorn Select and Columbia Acorn International Select include the effect of the voluntary undertaking by Columbia Wanger Asset Management, LLC (CWAM) to waive fees and/or reimburse the Funds for any ordinary operating expenses (exclusive of brokerage commissions, interest, taxes and extraordinary expenses, but inclusive of custodian charges relating to overdrafts, if any), after giving effect to any balance credits from the Funds' custodian, in excess of the following annual rates:

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

    These arrangements may be modified or terminated by either the Funds or CWAM upon 30 days notice.

    Columbia Thermostat Fund's fees and expenses include the effect of CWAM's contractual undertaking to waive fees and/or reimburse the Fund for any ordinary operating expenses (exclusive of distribution and service fees, interest and fees on borrowings and expenses associated with the Fund's investments in other investment companies, but including custodian charges relating to overdrafts, if any), after giving effect to any balance credits from the Fund's custodian, in excess of the annual rate of 0.25% of the average daily net assets. Columbia Thermostat Fund's waiver/reimbursement arrangement is contractual through April 30, 2012. There is no guarantee that this arrangement will continue thereafter.

    The fees and expenses of Columbia Acorn Emerging Markets Fund and Columbia Acorn European Fund also include the effect of fee waivers/reimbursements. CWAM has contractually undertaken to waive fees and/or reimburse Columbia Acorn Emerging Markets Fund so that the Fund's ordinary operating expenses (excluding interest and fees on borrowings and expenses associated with the Fund's investment in other investment companies, if any) do not exceed the annual rate of 1.60% of the Fund's average daily net assets attributable to Class Z shares, through April 30, 2013. There is no guarantee that this arrangement will continue thereafter. CWAM has contractually undertaken to waive fees and/or reimburse Columbia Acorn European Fund so that its ordinary operating expenses (excluding interest and fees on borrowings and expenses associated with the Fund's investment in other investment companies, if any) do not exceed the annual rate of 1.50% of the Fund's average daily net assets attributable to Class Z shares, through April 30, 2013. There is no guarantee that this arrangement will continue thereafter.

  *  Does not include estimated fees and expenses of 0.62% incurred by the Fund from the underlying portfolio funds in which it invests.

88

Columbia Acorn Family of Funds

Trustees

Laura M. Born

Chair of the Board

Steven N. Kaplan

Vice Chair of the Board

Michelle L. Collins

Maureen M. Culhane

Margaret M. Eisen

John C. Heaton

Charles P. McQuaid

David J. Rudis

David B. Small

Ralph Wanger (Trustee Emeritus)

Officers

Charles P. McQuaid

President

Ben Andrews

Vice President

Robert A. Chalupnik

Vice President

Michael G. Clarke

Assistant Treasurer

Joseph F. DiMaria

Assistant Treasurer

P. Zachary Egan

Vice President

Fritz Kaegi

Vice President

John M. Kunka

Assistant Treasurer

Stephen Kusmierczak

Vice President

Joseph C. LaPalm

Vice President

Bruce H. Lauer

Vice President, Secretary and Treasurer

Louis J. Mendes III

Vice President

Robert A. Mohn

Vice President

Christopher J. Olson

Vice President

Christopher O. Petersen

Assistant Secretary

Scott R. Plummer

Assistant Secretary

Andreas Waldburg-Wolfegg

Vice President

Linda K. Roth-Wiszowaty

Assistant Secretary

Robert P. Scales

Chief Compliance Officer, Chief Legal Officer,
Senior Vice President and General Counsel

Investment Manager

Columbia Wanger Asset Management, LLC
227 West Monroe Street, Suite 3000
Chicago, Illinois 60606

1-800-922-6769

Distributor

Columbia Management Investment Distributors, Inc.
225 Franklin Street
Boston, Massachusetts 02110

Transfer Agent, Dividend Disbursing Agent

Columbia Management Investment Services Corp.
P. O. Box 8081
Boston, Massachusetts 02266-8081

1-800-345-6611

Legal Counsel to the Funds

Perkins Coie LLP
Washington, DC

Legal Counsel to the Independent Trustees

Drinker Biddle & Reath LLP
Philadelphia, Pennsylvania

Independent Registered Public Accounting Firm

PricewaterhouseCoopers LLP
Chicago, Illinois

This report, including the schedules of investments, is submitted for the general information of the shareholders of Columbia Acorn Trust.

A description of the policies and procedures that the Funds use to determine how to vote proxies and a copy of the Funds' voting record are available (i) without charge, upon request, by calling 800-922-6769 and (ii) on the Securities and Exchange Commission's website at www.sec.gov. Information regarding how the Funds voted proxies relating to portfolio securities during the 12-month period ended June 30, is available from the SEC's website. Information regarding how the Funds voted proxies relating to portfolio securities is also available at www.columbiamanagement.com under "About Us." From there, click on "Disclosures."

The Funds file a complete schedule of portfolio holdings with the SEC for the first and third quarters of each fiscal year on Form N-Q. The Funds' Form N-Q is available on the SEC's website at www.sec.gov and may be reviewed and copied at the SEC's Public Reference Room in Washington, D.C. Information on the operation of the Public Reference Room may be obtained by calling 1-800-SEC-0330.

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.

This document contains Global Industry Classification Standard data. The Global Industry Classification Standard ("GICS") was developed by and is the exclusive property and a service mark of MSCI Inc. ("MSCI") and Standard & Poor's Financial Services LLC ("S&P") and is licensed for use by Columbia Wanger Asset Management, LLC. Neither MSCI, S&P, nor any other party involved in making or compiling the GICS or any GICS classifications makes any express or implied warranties or representations with respect to such standard or classification (or the results to be obtained by the use thereof), and all such parties hereby expressly disclaim all warranties of originality, accuracy, completeness, merchantability and fitness for a particular purpose with respect to any of such standard or classification. Without limiting any of the foregoing, in no event shall MSCI, S&P, any of their affiliates or any third party involved in making or compiling the GICS or any GICS classifications have any liability for any direct, indirect, special, punitive, consequential or any other damages (including lost profits) even if notified of the possibility of such damages.

Columbia Management^®

Columbia Acorn Family of Funds
Class Z Shares

First Quarter Report, March 31, 2012

For More Information

You'll find more information about the Columbia Acorn Family of Funds in the documents described below. Contact Columbia Funds as follows to obtain these documents free of charge:

By Mail:  Columbia Funds
c/o Columbia Management Investment Services Corp.
P. O. Box 8081 Boston, MA 02266-8081

By Telephone: 800.345.6611

Online: www.columbiamanagement.com

Shareholder Communications with the Board

The Funds' Board of Trustees has adopted procedures by which shareholders may communicate with the Board. Shareholders who wish to communicate with the Board should send their written communications to the Board by mail, c/o Columbia Wanger Asset Management, LLC, 227 West Monroe Street, Suite 3000, Chicago, Illinois 60606, Attention: Secretary. Shareholder communications must (i) be in writing, (ii) identify the Columbia Acorn Fund to which the communication relates and (iii) state the particular class of shares and number of shares held by the communicating shareholder.

Prospectuses and the Statement of Additional Information (SAI)

The prospectuses and the SAI provide more detailed information about the Funds and their policies. The SAI is legally part of each prospectus (it's incorporated by reference). A copy of each has been filed with the SEC.

Information Provided by the SEC

You can review and copy information about the Funds (including their prospectuses, the SAI and shareholder reports) at the SEC's Public Reference Room in Washington, DC. To find out more about the operation of the Public Reference Room, call the SEC at 202.551.8090. Reports and other information about the Fund are also available in the EDGAR Database on the SEC's website at http://www.sec.gov, or you can receive copies of this information, for a fee, by electronic request at the following e-mail address: publicinfo@sec.gov. You can also obtain copies of this information by writing the Public Reference Section, Securities and Exchange Commission, Washington, DC 20549-0102.

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

© 2012 Columbia Management Investment Advisers, LLC. All rights reserved.

225 Franklin Street, Boston, MA 02110

800.345.6611 www.columbiamanagement.com

C-1447 D (5/12) 137595

Q1 2012

Columbia Acorn Family of Funds

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

Managed by Columbia Wanger Asset Management, LLC

First Quarter Report

March 31, 2012

n  Columbia
Acorn® Fund

n  Columbia
Acorn International®

n  Columbia
Acorn USA®

n  Columbia
Acorn International Select^SM

n  Columbia
Acorn Select^SM

n  Columbia
Thermostat Fund^SM

n  Columbia
Acorn Emerging Markets Fund^SM

n  Columbia
Acorn European Fund^SM

Not FDIC insured • No bank guarantee • May lose value

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

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

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

Save the Date!

We will be hosting our annual shareholder information meeting on September 19, 2012, in Chicago. The meeting will feature presentations by Columbia Acorn Fund's lead portfolio manager Chuck McQuaid and other members of Columbia Wanger Asset Management's investment team.

Meeting Location*

Offices of Drinker Biddle & Reath LLP
191 North Wacker Drive, Suite 3700
Chicago, Illinois

Meeting Date & Time

Wednesday, September 19, 2012
12:00 p.m. CST

A buffet lunch will be served beginning at 11:30 a.m.

If you plan to attend, please RSVP by September 14 by calling (800) 922-6769.

Webcast Replay Available in October

For our many shareholders who are not able to attend the meeting, we will again provide a webcast replay of the event that can be accessed from our website, www.columbiamanagement.com, throughout the month of October.

If you have any questions about this event or any of your investments in our Columbia Acorn Funds, please call (800) 922-6769 to speak to a Columbia Acorn Funds shareholder representative.

*Up-to-date information on the Wacker Drive construction project can be found at www.wackerdrive.org. The meeting location is easily accessed via its Wacker Drive entrance but road repairs have closed other blocks of Wacker Drive.

Columbia Acorn Family of Funds

Table of Contents

Share Class Performance	2
Fund Performance vs. Benchmark	3
Descriptions of Indexes	4
Squirrel Chatter: Genetic Science	5
Columbia Acorn Fund
In a Nutshell	9
At a Glance	10
Major Portfolio Changes	25
Statement of Investments	27
Columbia Acorn International
In a Nutshell	11
At a Glance	12
Major Portfolio Changes	41
Statement of Investments	43
Portfolio Diversification	52
Columbia Acorn USA
In a Nutshell	13
At a Glance	14
Major Portfolio Changes	53
Statement of Investments	54
Columbia Acorn International Select
In a Nutshell	15
At a Glance	16
Major Portfolio Changes	61
Statement of Investments	62
Portfolio Diversification	67
Columbia Acorn Select
In a Nutshell	17
At a Glance	18
Major Portfolio Changes	68
Statement of Investments	69
Columbia Thermostat Fund
In a Nutshell	19
At a Glance	20
Statement of Investments	74
Columbia Acorn Emerging Markets Fund
In a Nutshell	21
At a Glance	22
Major Portfolio Changes	76
Statement of Investments	78
Portfolio Diversification	82
Columbia Acorn European Fund
In a Nutshell	23
At a Glance	24
Major Portfolio Changes	83
Statement of Investments	84
Portfolio Diversification	88
Columbia Acorn Family of Funds
Columbia Acorn Family of Funds Information	89

Net Asset Value Per Share as of 3/31/12

	Columbia Acorn Fund		Columbia Acorn International		Columbia Acorn USA		Columbia Acorn International Select		Columbia Acorn Select		Columbia Thermostat Fund		Columbia Acorn Emerging Markets Fund		Columbia Acorn European Fund
Class A	$	30.74	$	39.27	$	30.16	$	27.00	$	27.00	$	13.87	$	10.92	$	11.10
Class B	$	28.27	$	38.07	$	27.83	$	25.86	$	25.14	$	13.95		NA		NA
Class C	$	27.86	$	37.91	$	27.53	$	25.73	$	24.89	$	13.94	$	10.88	$	11.09
Class I	$	31.85	$	39.52	$	31.43	$	27.24	$	27.85		NA	$	10.96	$	11.11
Class R		NA	$	39.19		NA		NA		NA		NA		NA		NA
Class R5		NA	$	39.49		NA		NA		NA		NA		NA		NA

1

Columbia Acorn Family of Funds

Share Class Performance Average Annual Total Returns through 3/31/12

	Class A						Class B*						Class C						Class I			Class R†			Class R5†
	Without Sales Charge			With Sales Charge			Without Sales Charge			With Sales Charge			Without Sales Charge			With Sales Charge			Without Sales Charge			Without Sales Charge**			Without Sales Charge**
Columbia Acorn Fund (10/16/00)
3 months**		15.43	%		8.81	%		15.25	%		10.25	%		15.22	%		14.22	%		15.52	%		NA			NA
1 year		3.97	%		-2.00	%		3.53	%		-1.42	%		3.20	%		2.21	%		4.34	%		NA			NA
5 years		3.87	%		2.65	%		3.26	%		2.92	%		3.06	%		3.06	%		NA			NA			NA
10 years		8.89	%		8.25	%		8.20	%		8.20	%		8.07	%		8.07	%		NA			NA			NA
Life of Fund		9.35	%		8.79	%		8.66	%		8.66	%		8.54	%		8.54	%		17.69	%		NA			NA
Columbia Acorn International (10/16/00)
3 months**		14.99	%		8.39	%		14.77	%		9.77	%		14.77	%		13.77	%		15.12	%		14.89	%		15.10	%
1 year		-2.72	%		-8.31	%		-3.39	%		-8.10	%		-3.46	%		-4.40	%		-2.34	%		NA			NA
5 years		1.59	%		0.40	%		0.95	%		0.60	%		0.81	%		0.81	%		NA			NA			NA
10 years		11.14	%		10.49	%		10.42	%		10.42	%		10.31	%		10.31	%		NA			NA			NA
Life of Fund		7.10	%		6.54	%		6.40	%		6.40	%		6.31	%		6.31	%		5.49	%		-2.29	%		-1.86	%
Columbia Acorn USA (10/16/00)
3 months**		16.27	%		9.59	%		16.06	%		11.06	%		16.06	%		15.06	%		16.41	%		NA			NA
1 year		2.58	%		-3.33	%		2.09	%		-2.91	%		1.81	%		0.81	%		2.94	%		NA			NA
5 years		2.91	%		1.70	%		2.27	%		1.90	%		2.11	%		2.11	%		NA			NA			NA
10 years		6.92	%		6.29	%		6.22	%		6.22	%		6.11	%		6.11	%		NA			NA			NA
Life of Fund		8.84	%		8.28	%		8.14	%		8.14	%		8.05	%		8.05	%		19.30	%		NA			NA
Columbia Acorn International Select (10/16/00)
3 months**		11.29	%		4.90	%		11.13	%		6.13	%		11.05	%		10.05	%		11.41	%		NA			NA
1 year		-2.39	%		-8.00	%		-2.98	%		-7.71	%		-3.18	%		-4.13	%		-1.96	%		NA			NA
5 years		1.41	%		0.22	%		0.77	%		0.40	%		0.61	%		0.61	%		NA			NA			NA
10 years		10.35	%		9.70	%		9.64	%		9.64	%		9.52	%		9.52	%		NA			NA			NA
Life of Fund		5.17	%		4.63	%		4.48	%		4.48	%		4.38	%		4.38	%		6.01	%		NA			NA
Columbia Acorn Select (10/16/00)
3 months**		17.65	%		10.88	%		17.48	%		12.48	%		17.41	%		16.41	%		17.76	%		NA			NA
1 year		-2.81	%		-8.40	%		-3.33	%		-8.12	%		-3.55	%		-4.50	%		-2.33	%		NA			NA
5 years		0.54	%		-0.65	%		-0.09	%		-0.47	%		-0.27	%		-0.27	%		NA			NA			NA
10 years		7.51	%		6.88	%		6.81	%		6.81	%		6.70	%		6.70	%		NA			NA			NA
Life of Fund		7.71	%		7.16	%		7.01	%		7.01	%		6.90	%		6.90	%		9.44	%		NA			NA
Columbia Thermostat Fund (3/3/03) ††
3 months**		8.19	%		1.99	%		8.06	%		3.06	%		7.98	%		6.98	%		NA			NA			NA
1 year		9.87	%		3.56	%		9.38	%		4.38	%		9.13	%		8.13	%		NA			NA			NA
5 years		5.15	%		3.91	%		4.62	%		4.29	%		4.36	%		4.36	%		NA			NA			NA
Life of Fund		8.22	%		7.52	%		7.62	%		7.62	%		7.42	%		7.42	%		NA			NA			NA
Columbia Acorn Emerging Markets Fund (8/19/11)
3 months**		17.93	%		11.20	%		NA			NA			17.75	%		16.75	%		17.98	%		NA			NA
Life of Fund**		9.20	%		2.92	%		NA			NA			8.80	%		7.80	%		9.60	%		NA			NA
Columbia Acorn European Fund (8/19/11)
3 months**		17.71	%		10.89	%		NA			NA			17.48	%		16.48	%		17.82	%		NA			NA
Life of Fund**		11.86	%		5.43	%		NA			NA			11.44	%		10.44	%		12.15	%		NA			NA

*The Funds generally no longer accept investments by new or existing investors in Class B shares, except in connection with the reinvestment of any dividend and/or capital gain distributions in Class B shares of the Funds and exchanges by existing Class B shareholders of certain other funds within the Columbia Family of Funds.

**Not annualized.

†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 manager and/or any of its affiliates. Absent these fee waivers and/or expense reimbursement arrangements, performance results would have been lower. Current performance may be lower or higher than the performance data shown. Please visit columbiamanagement.com for daily and most recent month-end updates.

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

Please see Page 89 of this report for each Fund's operating expense ratio as of the end of the quarter. On this page, you will find information on fee waiver/expense reimbursement arrangements in place for Columbia Acorn International, Columbia Thermostat Fund, Columbia Acorn Emerging Markets Fund and Columbia Acorn European Fund.

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

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.

2

Columbia Acorn Family of Funds

Fund Performance vs. Benchmarks Average Annual Total Returns through 3/31/12

Class A Shares, without sales charge	1st quarter*			1 year			5 years			10 years			Life of Fund
Columbia Acorn Fund (LACAX) (10/16/00)		15.43	%		3.97	%		3.87	%		8.89	%		9.35	%
Russell 2500 Index		12.99	%		1.33	%		3.03	%		7.49	%		7.26	%
S&P 500 Index**		12.59	%		8.54	%		2.01	%		4.12	%		2.14	%
Lipper Mid-Cap Growth Funds Index		14.99	%		1.19	%		4.83	%		6.25	%		1.67	%
Columbia Acorn International (LAIAX) (10/16/00)		14.99	%		-2.72	%		1.59	%		11.14	%		7.10	%
S&P Global Ex-U.S. Between $500M and $5B Index		13.97	%		-7.10	%		0.71	%		11.92	%		9.55	%
S&P Global Ex-U.S. SmallCap Index		14.86	%		-7.91	%		-0.73	%		11.19	%		8.70	%
Lipper International Small/Mid Growth Funds Index		14.60	%		-2.84	%		-0.11	%		10.18	%		5.77	%
Columbia Acorn USA (LAUAX) (10/16/00)		16.27	%		2.58	%		2.91	%		6.92	%		8.84	%
Russell 2000 Index		12.44	%		-0.18	%		2.13	%		6.45	%		6.28	%
Russell 2500 Index		12.99	%		1.33	%		3.03	%		7.49	%		7.26	%
Lipper Small-Cap Growth Funds Index		14.16	%		1.35	%		3.16	%		5.19	%		2.38	%
Columbia Acorn Int'l Select (LAFAX) (10/16/00)		11.29	%		-2.39	%		1.41	%		10.35	%		5.17	%
S&P Developed Ex-U.S. Between $2B and $10B Index		11.98	%		-6.61	%		-1.92	%		9.20	%		7.09	%
MSCI EAFE Index		10.86	%		-5.77	%		-3.51	%		5.70	%		2.92	%
Lipper International Small/Mid Growth Funds Index		14.60	%		-2.84	%		-0.11	%		10.18	%		5.77	%
Columbia Acorn Select (LTFAX) (10/16/00)		17.65	%		-2.81	%		0.54	%		7.51	%		7.71	%
S&P MidCap 400 Index		13.50	%		1.98	%		4.78	%		7.70	%		7.54	%
S&P 500 Index**		12.59	%		8.54	%		2.01	%		4.12	%		2.14	%
Lipper Mid-Cap Growth Funds Index		14.99	%		1.19	%		4.83	%		6.25	%		1.67	%
Columbia Thermostat Fund (CTFAX) (3/3/03)†		8.19	%		9.87	%		5.15	%		—			8.22	%
S&P 500 Index		12.59	%		8.54	%		2.01	%		—			7.98	%
Barclays U.S. Aggregate Bond Index		0.30	%		7.71	%		6.25	%		—			5.11	%
Lipper Flexible Portfolio Funds Index		8.90	%		2.88	%		3.42	%		—			7.92	%
50/50 Blended Benchmark		6.33	%		8.51	%		4.59	%		—			6.86	%
Columbia Acorn Emerging Markets Fund (CAGAX) (8/19/11)		17.93	%		—			—			—			9.20	%*
S&P Emerging Markets Between $500M and $5B Index		18.46	%		—			—			—			2.52	%*
MSCI Emering Markets Small Cap Index		16.63	%		—			—			—			-2.79	%*
Lipper Emerging Markets Index		14.55	%		—			—			—			6.75	%*
Columbia Acorn European Fund (CAEAX) (8/19/11)		17.71	%		—			—			—			11.86	%*
S&P Europe Between $500M and $5B Index		17.80	%		—			—			—			9.35	%*
HSBC Smaller European Companies Index		17.44	%		—			—			—			6.24	%*
Lipper European Region Index		13.97	%		—			—			—			12.56	%*

*Not annualized.

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

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

Performance results reflect any fee waivers or reimbursements of Fund expenses by the investment manager and/or its affiliates. Please see Page 89 of this report for information on contractual fee waiver/expense reimbursement arrangements in place for Columbia Acorn International, Columbia Thermostat Fund, Columbia Acorn Emerging Markets Fund and Columbia Acorn European Fund. Absent these fee waivers/expense reimbursement arrangements, performance results would have been lower. Annual operating expense ratios are stated as of each Fund's current prospectus as of March 31, 2012, and differences in expense ratios disclosed elsewhere in this report may result from application of any fee waivers/expense reimbursements as well as different time periods used in calculating the ratios. Columbia Acorn Fund: Class A: 1.07%; 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%.

†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.

3

Columbia Acorn Family of Funds

Descriptions of Indexes Included in this Report

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

4

Squirrel Chatter II: Genetic Science

Genetic theory began with Gregor Mendel, a friar who in the middle 19th century meticulously bred different types of peas and tracked traits of offspring. He discovered recessive genes, which are carried by one generation but expressed in the next if both parents have that gene. Human genetic studies began a few decades later. In 1872, Huntington's disease was the first genetic disease identified by scientific research.¹

Humans normally have 23 pairs of chromosomes, with half of each pair inherited from each parent. The chromosomes combined consist of over 20,000 genes. These genes ultimately consist of over 3 billion units of four different nitrogenous bases, labeled by their first letters: A, G, C and T.²

DNA, the double helix structure of bases assembled into genes, was discovered by James Watson and Francis Crick in 1953. Various genes were identified over the next several decades. The Human Genome Project, an effort to sequence and identify all genes and bases in human DNA, started in 1990. After $2.7 billion of expenditures over 13 years, a composite genome from three people was specified.³

Gene Sequencing

Kevin Davies' book, The $1,000 Genome, discusses the incredible progress made in gene sequencing technology. First generation sequencing used bacteria to purify and grow DNA fragments utilizing equipment made by Applied Biosystems, which dominated the market for 15 years.⁴ Hundreds of machines labored for years to complete the Human Genome Project sequencing, at a direct cost of tens of millions of dollars.⁵

A company called 454 Life Sciences, later acquired by Roche, developed a second generation sequencer. Utilizing a semiconductor chip with thousands of wells, DNA fragments were sequenced in parallel via real-time image processing. First shipped in 2005, the $500,000 machines then sold as fast as they could be built. James Watson's genome was sequenced in 2007 at a cost of $1 million.⁶

In 2006, Solexa shipped a sequencing machine that also sequenced in parallel, but had throughput and cost advantages. Illumina bought Solexa later that year. By 2007, the equipment could sequence a human's DNA at a cost of $100,000.⁷ Illumina subsequently created faster and more accurate machines. In early 2010, it pushed the cost of human genome sequencing down to $10,000.⁸ Service company Knome currently offers full genome sequencing via Illumina equipment, plus interpretation of results, for $4,998.⁹ Roche recently attempted to acquire Illumina.¹⁰

Third generation machines, often utilizing nanotechnology as well as parallel sequencing and faster data processing chips, should cut the cost of sequencing a human genome to well below $1,000, Davies notes.¹¹ Pacific Biosciences of California claimed a potential 30,000-fold speed increase via sequencing in real time as DNA is replicated.¹² Another company, Oxford Nanopore, was working on sequencing via measurement of electric current passing through bases.¹³ Ion Torrent Systems measures the pH of bases streaming through pores.¹⁴

Davies calculated that the cost of DNA sequencing fell 50% a year through 2005, and then by an amazing 90% a year due to a series of disruptive technologies.¹⁵ He does not predict when a hand-held "Star Trek Medical Tricorder," capable of reading the DNA of a patient and his disease and then prescribing personalized medicine, will be available, but the world seems headed in that direction.

Personal Genomic Services

It doesn't take a full genome sequence to determine genetic characteristics such as ancestry and possible risks of disease. In November 2007, deCODEme and 23andMe launched competing $1,000 services. Processing cheek swab or saliva DNA on equipment utilizing specialized chips, they sampled up to 600,000 bases, 0.02% of the total, and looked for differences in bases between people, called single nucleotide polymorphisms (SNPs).¹⁶ By correlating SNPs with known ancestry and disease databases, the companies provided statistical probabilities to clients based on their DNA samples.

Since 2007, deCODEme has had financial problems; it currently offers the service for $1,100, including updates.¹⁷ 23andMe currently charges $207 for an initial sampling

5

and a one-year subscription for updates. According to its website, 23andMe provides probabilities for 118 diseases, shows likely responses to 20 drugs, and determines whether clients' children could be at risk for any of 44 inherited diseases.¹⁸ Navigenics has also entered the market and provides genetic counseling as well as data.

The personal genomic services companies update disease probabilities as additional data is analyzed. Probabilities can and do change, sometimes drastically, as new correlations and additional SNPs are incorporated into a person's profile. It's somewhat disconcerting that, according to Davies, Navigenics and 23andMe disagree qualitatively on one-third of diseases.¹⁹

As more of the population gets increasingly more genes sequenced, more data becomes available and the relationships between genes, health and responses to drugs become better known. Full genome sequencing will likely show an average of three million SNPs per person,²⁰ creating an enormous data management problem as well as new understandings of relationships between genes and diseases.

Limits to Predicting Diseases

Recent research published in Science Translational Medicine titled, "The Predictive Capacity of Personal Genome Sequencing,"²¹ ingeniously addressed the theoretical potential for genes to predict common diseases. The underlying question was, of course, what are the odds of someone with a specific genome getting a specific disease? According to the study, the answer can be determined by studying pairs of people with nearly identical genomes: identical twins. By comparing histories of 24 common diseases among identical twins versus fraternal twins, genetic determination of diseases were inferred.

The study concluded that for 19 of the 24 diseases a negative test score (below average risk) will hardly be reassuring because the odds of getting the disease will still be substantial, at 50% to 80% of the general population's odds. Over half of the ultimate victims of 12 diseases would have tested at below average risk, receiving a false sense of security. However, there was one disease category tested in the study, Alzheimer's disease, in which a negative test result might indicate as little as a 12% relative risk of disease compared to the general population.

Those testing positive for Alzheimer's, type 1 diabetes, male coronary heart disease and thyroid autoimmunity could account for over 75% of the patients developing the diseases. The study suggested that the utility of genetic tests will depend on the results of the individual tested, and cautions against complacency and unwise lifestyle choices for those testing negative.

I agree that some subscribers to personal genetics services could obtain valuable results. If, for example, someone learned that his probability of developing glaucoma was much higher than the 4% probability for the average person, the subscriber would more likely get regular glaucoma testing. This is of some value, assuming the stated odds are indeed properly calibrated, which may take years to confirm.

Inherited Diseases

Some inherited diseases, including cystic fibrosis, Tay-Sachs disease and sickle cell anemia, occur only when single defective genes are inherited from each parent. Other single gene diseases, such as Huntington's, are inherited with 50% odds of getting the gene and disease if just one parent is afflicted.

Dozens of rare genetic diseases affect newborns, many of which can be addressed by diet or vitamins.²² Quick diagnosis is often crucial as permanent damage can occur otherwise. As of March 2010, newborns were tested for 29 genetic diseases in most states.²³

Sometimes only a tendency to contract a disease is inherited. One version of a specific gene mutation implies a 65% to 85% lifetime probability of a woman developing breast cancer, while another version implies a 45% to 85% probability.²⁴ However, only 5% to 10% of breast cancer patients have those genes.²⁵ Others get the disease with no apparent genetic correlation. Having those genes is a cause for concern, but not having them should not provide a lot of comfort.

Personalized Medicine

In 2003, Allen Roses, vice-president of genetics for GlaxoSmithKline, shocked consumers by stating that more than 90% of drugs work in just 30% to 50% of people.²⁶ Roses was pushing the drug industry to pursue genetic testing rather than trial and error to determine which drugs

6

work for a specific individual. Matt Ridley, in the 2006 version of his book, Genome, stated, "genetic diagnosis followed by conventional cure is probably the genome's greatest boon to medicine."²⁷

Indeed, the lung cancer drug Iressa was approved in 2003 and creates a "miraculous response" in the 10% of patients with a specific genetic mutation of the disease. Herceptin was approved in 2006 to target the 25% of breast cancer patients who are afflicted with a specific genetic version of that disease. Likewise, targeted cancer drugs such as Avastin, Tarceva and Erbitux, are prescribed after genetic testing.²⁸

On January 31, 2012, Kalydeco was approved to treat 1,200 cystic fibrosis patients, 4% of the total, who have a specific gene defect. It is the first drug to treat the defect rather than the symptoms of the disease, and has been termed "transformational" for those who can use it.²⁹ The Cystic Fibrosis Foundation spurred development of the drug by helping to fund the development effort, and aided the process by creating a registry that includes the genetic characteristics of the disease for 90% of American patients.

Some drugs appear to work for most people, but have widely varying optimal dosages. Variations in genes largely determine how quickly people metabolize drugs.³⁰ "Unanticipated drug responses are estimated to result in two million hospitalizations and 100,000 deaths in the United States each year," writes Nicholas Gillham in his book, Genes, Chromosomes, and Disease.³¹

In the case of blood thinner warfarin (brand name Coumadin), patients exhibit a tenfold range in ability to metabolize the drug.³² Too little of it can result in a stroke, but too much can cause bleeding and hemorrhaging.³³ The FDA now provides dosage information on the drug's label based on variants of two genes.³⁴ About 10% of labels for FDA-approved drugs now have pharmacogenomics information.³⁵

Investment Implications

Genetic science is rapidly advancing and will likely revolutionize many aspects of medical care. It is starting to be helpful in predicting susceptibility to common diseases, but will likely be more valuable in identifying risks of inherited diseases and in determining appropriate drug usage and dosage. Given the complexity of the subject, there will likely be increasing demands for genetic counselors.

There exists uncertainty regarding how the FDA and others will regulate genetic tests, as well as the extent to which genetic discoveries will be patentable. On the investment front, we have looked for and invested in opportunities created by genetic science. We've focused on a number of biotechnology and drug companies addressing personalized medicine and niche orphan diseases and we will continue to look for additional opportunities.

Charles P. McQuaid

President and Chief Investment Officer
Columbia Wanger Asset Management, LLC

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

¹  Gillham, Nicholas Wright, Genes, Chromosomes, and Disease, (Upper Saddle River, New Jersey, FT Press Science 2011) p. 5.

²  Davies, Kevin, The $1,000 Genome, (New York, New York, Free Press 2010) p. 1, 23.

³  Ibid., p. 9-11.

⁴  Ibid., p. 79.

⁵  Ibid., p. 90.

⁶  Ibid., p. 94.

⁷  Ibid., p. 111.

⁸  Gillham, Nicholas Wright, op. cit., p. 244.

⁹  Davies, Kevin, op. cit., p. 209. www.knome.com.

¹⁰  Falconi, Marta, "Roche To Return Tendered Illumina Shares to Shareholders," Dow Jones News Service, April 23, 2012.

¹¹  Davies, Kevin, op. cit., p. 231.

¹²  As of March 31, 2012, Pacific Biosciences of California was held in two Columbia Acorn Funds: Columbia Acorn Fund (less than 0.1% of assets) and Columbia Acorn USA (0.1% of assets). The company's shares are also held in other funds and accounts managed by CWAM.

¹³  Davies, Kevin, op. cit., p. 239.

¹⁴  Ibid., p. 245-246.

¹⁵  Ibid., p. 133. Disruptive technologies refers to making much more than incremental advances by utilizing a whole new or additional approach. In this context, the parallel sequencing and use of other detection mechanisms such as pH or electric conductivity have caused the cost of sequencing to plunge far faster than a regular learning curve might suggest.

¹⁶  Ibid., p. 31-32.

¹⁷  Ibid., p. 55,63. www.decodeme.com.

7

¹⁸  www.23andme.com.

¹⁹  Davies, Kevin, op. cit., p. 149.

²⁰  Ibid., p. 23.

²¹  Roberts, Nicholas J., and Vogelstein, Joshua T., et al, "The Predictive Capacity of Personal Genome Sequencing," Science Translational Medicine, Rapid Publication, April 2, 2012, stm.sciencemag.org.

²²  Gillham, Nicholas Wright, op. cit., p. 204.

²³  Ibid., p. 201.

²⁴  Ibid., p. 184.

²⁵  Ibid., p. 116.

²⁶  Connor, Steve, "Glaxo Chief: Our Drugs Do Not Work On Most Patients," The Independent, December 8, 2003.

²⁷  Ridley, Matt, Genome, (New York, New York, First Harper Perennial, 2006) p. 257.

²⁸  Davies, Kevin, op. cit., p. 255-256.

²⁹  Usdin, Steve, "Product Discovery & Development: Kalydescopic Vision," BioCentury, March 5, 2012, Volume 20, Number 10, p. A2.

³⁰  Davies, Kevin, op. cit., p. 257.

³¹  Gillham, Nicholas Wright, op. cit., p. 237.

³²  Davies, Kevin, op. cit., p. 257.

³³  Gillham, Nicholas Wright, op. cit., p. 238.

³⁴  Davies, Kevin, op. cit., p. 257.

³⁵  Hamburg, M.D., Margaret A., and Collins, M.D., Ph.D., Francis S., "The Path to Personalized Medicine," New England Journal of Medicine, July 22, 2010, Volume 363, p. 301-304, www.nejm.org.

8

Columbia Acorn Fund

In a Nutshell

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

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

Fund Positions
in Mentioned Holdings

As a percentage of net assets, as of 3/31/12

lululemon athletica	2.0	%
Informatica	1.4	%
Alexion Pharmaceuticals	1.2	%
Amphenol	1.1	%
Coach	0.9	%
PVH	0.8	%
Pentair	0.8	%
IPG Photonics	0.8	%
Pacific Rubiales Energy	0.7	%
Equinix	0.5	%
World Acceptance	0.5	%
Deckers Outdoor	0.4	%
MGM China Holdings	0.1	%

Columbia Acorn Fund jumped 15.43% (Class A shares, without sales charge) in the first quarter of 2012, outperforming its primary benchmark, the Russell 2500 Index, which was up 12.99%. The Fund beat the Lipper Mid-Cap Growth Funds Index by a lesser amount, as that index grew 14.99%. See Page 3 for additional performance data.

Two important factors that had caused the Fund to underperform its benchmark modestly in 2011 reversed in the first quarter of 2012. Columbia Acorn Fund's international stocks, which substantially underperformed domestic stocks in 2011, outperformed somewhat in the first quarter. The Fund had little invested in utility stocks during both periods; relative performance was hurt in 2011 when utility stocks outperformed, but was helped in the first quarter as utility stocks underperformed. We thought foreign stocks were attractive and utility stocks were expensive during both periods, kept our convictions, and shareholders were rewarded in the quarter.

Our stock picking was also good, especially in technology. Enterprise data integration software provider Informatica jumped 43% in the quarter on a 23% earnings gain and what appeared to be fine prospects for selling more software to existing customers. Data center company Equinix rose steadily and ended the quarter up 55% as demand and pricing remained strong. Electronic connector maker Amphenol plugged into better-than-expected earnings and increasing expectations for profit margins, rising 32%. Fiber optic laser equipment producer IPG Photonics had a 54% gain due to improving Chinese orders and a better-than-expected outlook.

Consumer durables stocks also helped performance, due to both stock picking and the Fund's modest overweighting versus its benchmark. lululemon athletica, a premium active wear retailer, soundly refuted naysayers (who had been concerned about increasing inventories) when it announced same-store sales up 26% during its fiscal quarter; the stock surged 60% during the calendar quarter and was by far the Fund's largest dollar winner. Other successful consumer durable stocks were Coach, a branded leather accessories retailer, and PVH, an apparel wholesaler and retailer, both up 27% on fine earnings.

Several individual stocks were standouts. Biotech company Alexion Pharmaceuticals rose 30% as the company reported earnings more than doubling, revenues growing 46% (both versus the prior year December quarter), and positive drug studies. Pentair, a manufacturer of pumps and water treatment equipment, appreciated 43% in the quarter, during which it agreed to merge with Tyco's flow control division.

The Fund's worst dollar loser during the quarter was World Acceptance, a finance company offering personal loans, which fell 17%, despite a 15% earnings gain, as same-store growth decelerated and investors became concerned about the possibility of new regulations. Footware company Deckers Outdoor, also down 17%, fell on concerns about costs.

As previously mentioned, international stocks generally recovered during the quarter. Oil production and exploration company Pacific Rubiales Energy, which had lagged in 2011, gained 59% on increased production and higher reserves. Macau casino operator MGM China Holdings booked a 49% win on fine growth. Columbia Acorn Fund's international stocks had a 17.24% gain in the quarter and accounted for 9.4% of Fund assets at the end of the quarter.

Most of the Fund's portfolio companies continue to report favorable business conditions. During the quarter we recycled some dollars from large successful holdings to smaller, and what we believe to be cheaper, stocks that could enhance long-term returns.

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

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

9

Columbia Acorn Fund

At a Glance (Class A Shares - LACAX)

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

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

through March 31, 2012

Inception 10/16/00		Year to date*			1 year			5 years			10 years
Returns before taxes	NAV POP		15.43 8.81	%		3.97 -2.00	%		3.87 2.65	%		8.89 8.25	%
Returns after taxes on distributions	NAV POP		15.43 8.81			3.31 -2.62			3.33 2.12			8.32 7.68
Returns after taxes on distributions and sale of fund shares	NAV POP		10.03 5.73			3.32 -0.60			3.25 2.20			7.79 7.20
Russell 2500 Index**(pretax)			12.99			1.33			3.03			7.49

All results shown assume reinvestment of distributions.

*Year to date data is not annualized.

**The Fund's primary benchmark.

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

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

The Fund's Class A shares annual operating expense ratio, as stated in the May 1, 2011, prospectus, is 1.07%.

Columbia Acorn Fund Portfolio Diversification

as a percentage of net assets, as of 3/31/12

Columbia Acorn Fund Top 10 Holdings

as a percentage of net assets, as of 3/31/12

1.	lululemon athletica Premium Active Apparel Retailer	2.0	%
2.	Ametek Aerospace/Industrial Instruments	1.8	%
3.	Donaldson Industrial Air Filtration	1.6	%
4.	Mettler Toledo Laboratory Equipment	1.6	%
5.	FMC Technologies Oil & Gas Wellhead Manufacturer	1.5	%
6.	Informatica Enterprise Data Integration Software	1.4	%
7.	Crown Castle International Communications Towers	1.3	%
8.	Alexion Pharmaceuticals Biotech Focused on Orphan Diseases	1.2	%
9.	tw telecom Fiber Optic Telephone/Data Services	1.1	%
10.	Amphenol Electronic Connectors	1.1	%

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

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

October 16, 2000 through March 31, 2012

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: $18.4 billion

*  Class I share value reflects 9/27/10 share class inception date.

10

Columbia Acorn International

In a Nutshell

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

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

Fund's Positions
in Mentioned Holdings

As a percentage of net assets, as of 3/31/12

Melco Crown Entertainment	1.5	%
Gemalto	1.1	%
Localiza Rent A Car	1.1	%
Eurofins Scientific	0.7	%
Start Today	0.5	%
Celtic Exploration	0.2	%
Gree	0.1	%
Manappuram Finance	0.0	%*

*Rounds to less than 0.1%.

Columbia Acorn International regained some of the ground lost in 2011, finishing the first quarter of 2012 up 14.99% (Class A shares, without sales charge). The Fund's primary benchmark, the S&P Global Ex-U.S. Between $500M and $5B Index, gained 13.97% in the quarter. Returns were driven foremost by a reversal of fortune for European and emerging market stocks, which stood out as poor performers in 2011. Investor anxiety regarding the future of the common European currency abated as the European Central Bank's long-term refinancing operations bought policymakers more time to craft fiscal solutions to the sovereign debt crisis. In key emerging markets, where high food inflation in recent years underpinned monetary tightening, the policy bias now appears to be distinctly in the direction of easing, which lowers costs of capital and equity discount rates, and is therefore generally good for equities.

Strong performers in the first quarter included Melco Crown Entertainment, a Macau-based casino that rose over 40% as mainland and Hong Kong gamblers continued to visit the baccarat tables despite fears of an economic slowdown. Brazilian auto rental company, Localiza Rent A Car, appreciated nearly 35% in U.S. dollar terms on the back of strong volume demand and improving financing costs. In Europe, Gemalto, a French provider of digital security solutions, rose 35% as its smart card solutions appeared increasingly well positioned to play an important role in evolving payment technologies. Another French company, Eurofins Scientific, jumped nearly 50% on steadily improving profitability in its core food and pharmaceutical testing business, which led management to revise expectations upwards.

On the downside, Japanese companies Start Today and Gree both fell over 20% on profit-taking after stellar returns in 2011. In India, Manappuram Finance declined 28% in the Fund on the announcement of new Indian regulations designed to constrain the growth of the gold loan industry. We believe there is probably more regulatory bad news in the pipeline and have exited the position. A number of small energy exploration companies declined sharply, including Celtic Exploration in Canada. Celtic Exploration suffered from weak North American natural gas prices and negative sentiment on energy stocks, as relatively high oil prices raised the specter that oil demand could slow.

Our strategy is to generally buy businesses with better-than-average economics and exposure to dislocations in their respective industries that confer an opportunity for growth over a three-year period, or longer. Additionally, we prefer balance sheets that allow businesses fitting this profile to execute a business plan regardless of capital market gyrations. We believe this strategy is well-suited to the present environment, characterized by high macroeconomic uncertainty, but also reasonable valuations.

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

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

11

Columbia Acorn International

At a Glance (Class A Shares - LAIAX)

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

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

through March 31, 2012

Inception 10/16/00		Year to date*			1 year			5 years			10 years
Returns before taxes	NAV POP		14.99 8.39	%		-2.72 -8.31	%		1.59 0.40	%		11.14 10.49	%
Returns after taxes on distributions	NAV POP		14.99 8.39			-3.36 -8.91			1.12 -0.07			10.67 10.02
Returns after taxes on distributions and sale of fund shares	NAV POP		9.75 5.45			-1.56 -5.20			1.33 0.31			9.98 9.37
S&P Global Ex-US Between $500M and $5B Index** (pretax)			13.97			-7.10			0.71			11.92

All results shown assume reinvestment of distributions.

*Year to date data is not annualized.

**The Fund's primary benchmark.

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

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

The Fund's Class A shares annual operating expense ratio, as stated in the May 1, 2011, prospectus, is 1.35%. Effective August 15, 2011, CWAM and its affiliates contractually agreed, through August 14, 2013, to waive a portion of total annual Fund operating expenses 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 3/31/12

Columbia Acorn International Top 10 Holdings

as a percentage of net assets, as of 3/31/12

1.	Melco Crown Entertainment - ADR (Hong Kong) Macau Casino Operator	1.5	%
2.	Hexagon (Sweden) Measurement Equipment	1.2	%
3.	Far EasTone Telecom (Taiwan) Taiwan's Third Largest Mobile Operator	1.2	%
4.	Gemalto (France) Digital Security Solutions	1.1	%
5.	Localiza Rent A Car (Brazil) Car Rental	1.1	%
6.	Naspers (South Africa) Media in Africa & other Emerging Markets	1.0	%
7.	Intertek Group (United Kingdom) Testing, Inspection & Certification Services	0.9	%
8.	Alexion Pharmaceuticals (United States) Biotech Focused on Orphan Diseases	0.9	%
9.	Kansai Paint (Japan) Paint Producer in Japan, India, China & Southeast Asia	0.9	%
10.	Imtech (Netherlands) Electromechanical & ICT Installation & Maintenance	0.9	%

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

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

October 16, 2000 through March 31, 2012

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: $6.3 billion

*  Class I share value reflects 9/27/10 share class inception date. Class R and R5 share value reflects 8/15/11 share class inception date.

12

Columbia Acorn USA

In a Nutshell

Robert A. Mohn

Lead Portfolio Manager

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

Fund's Positions
in Mentioned Holdings

As a percentage of net assets, as of 3/31/12

lululemon athletica	3.1	%
Informatica	2.7	%
Nordson	2.3	%
Mettler Toledo	1.9	%
II-VI	1.7	%
Pentair	1.6	%
IPG Photonics	1.5	%
World Acceptance	1.2	%
Quicksilver Resources	0.2	%
Chelsea Therapeutics International	0.1	%
True Religion Apparel	0.1	%
Houston American Energy	0.1	%

Columbia Acorn USA ended the first quarter of 2012 up 16.27% (Class A shares, without sales charge), outperforming the 12.44% gain of its primary benchmark, the Russell 2000 Index. Several Fund stocks that fell in the fourth quarter of 2011 on general economic fears snapped back in the first quarter of 2012, boosting the Fund's relative return.

Three of the four top contributors to Fund performance in the first quarter were stocks that had missed out on the generally bullish market trend in the fourth quarter: lululemon athletica, Informatica and IPG Photonics. lululemon athletica announced fourth quarter same-store sales growth up 26% over the prior year, as the company continued to benefit from growing awareness of its premium active apparel brand. Its stock was up 60% in the first quarter. Enterprise data integration software provider Informatica fell in the fourth quarter, as a weak sales report from a major competitor brought down the entire sector. But Informatica won back investor confidence in the first quarter after announcing a 23% earnings gain, which sent its stock up 43%. Up 54% in the first quarter, IPG Photonics experienced accelerating sales of its fiber lasers to U.S. automotive manufacturers, driving revenues up 22% over the prior year.

Concerns about the global economy eased in the first quarter, benefitting several Fund industrial stocks, especially those with a significant presence in non-U.S. markets. Nordson manufactures dispensing systems for adhesives and coatings and saw its stock gain 33% in the first quarter. Mettler Toledo, a maker of laboratory equipment, rose 25% in the quarter. II-VI, a manufacturer of laser optics, had a 29% gain in the quarter. Each of these stocks announced better-than-expected earnings for the quarter.

Rounding out the list of first-quarter winners was Pentair, a manufacturer of pumps and water treatment equipment. Its stock rose more than 40% on the announcement of plans to merge with Tyco's flow control business. Generally, the Fund enjoys a boost from merger activity when one of its holdings gets acquired by a larger suitor. In this case, however, Pentair was the suitor and was able to structure a highly accretive deal.

Laggards in the first quarter included personal lender World Acceptance, down 17% on moderating same-store revenue growth and concerns about possible new regulations that could be imposed by the Consumer Financial Protection Bureau. Off 51%, Chelsea Therapeutics International, a biotech company focused on rare diseases, collapsed when its main drug, Northera, was rejected by the FDA. Premium denim retailer True Religion Apparel announced earnings down 10% from the prior year, sending its stock down 20% in the first quarter.

Two of the Fund's oil and gas producers were among the laggards in the first quarter, but for different reasons. Houston American Energy fell 57% after announcing poor results at an important test well in Colombia. Quicksilver Resources, a natural gas and coal seam gas producer, fell 25%, dragged down by the ever-plunging price of natural gas.

Small-cap stocks appear to be reasonably valued, the economic outlook looks favorable, and investor sentiment seems to be fairly sedate. While the past is not a predictor of the future, historically, this combination of factors has, at times, ushered in reasonably good gains for small-cap stocks.

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.

13

Columbia Acorn USA

At a Glance (Class A Shares - LAUAX)

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

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

through March 31, 2012

Inception 10/16/00		Year to date*			1 year			5 years			10 years
Returns before taxes	NAV POP		16.27 9.59	%		2.58 -3.33	%		2.91 1.70	%		6.92 6.29	%
Returns after taxes on distributions	NAV POP		16.27 9.59			2.48 -3.43			2.59 1.39			6.63 6.00
Returns after taxes on distributions and sale of fund shares	NAV POP		10.57 6.24			1.78 -2.07			2.45 1.41			6.06 5.49
Russell 2000 Index**(pretax)			12.44			-0.18			2.13			6.45

All results shown assume reinvestment of distributions.

*Year to date data is not annualized.

**The Fund's primary benchmark.

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

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

The Fund's Class A shares annual operating expense ratio, as stated in the May 1, 2011, prospectus, is 1.30%.

Columbia Acorn USA Portfolio Diversification

as a percentage of net assets, as of 3/31/12

Columbia Acorn USA Top 10 Holdings

as a percentage of net assets, as of 3/31/12

1.	lululemon athletica Premium Active Apparel Retailer	3.1	%
2.	Informatica Enterprise Data Integration Software	2.7	%
3.	Ametek Aerospace/Industrial Instruments	2.4	%
4.	Nordson Dispensing Systems for Adhesives & Coatings	2.3	%
5.	Micros Systems Information Systems for Restaurants & Hotels	2.2	%
6.	Mettler Toledo Laboratory Equipment	1.9	%
7.	Atwood Oceanics Offshore Drilling Contractor	1.8	%
8.	tw telecom Fiber Optic Telephone/Data Services	1.8	%
9.	Donaldson Industrial Air Filtration	1.8	%
10.	II-VI Laser Optics & Specialty Materials	1.7	%

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 USA (Class A)

October 16, 2000 through March 31, 2012

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: $1.8 billion

*  Class I share value reflects 9/27/10 share class inception date.

14

Columbia Acorn International Select

In a Nutshell

Christopher J. Olson

Lead Portfolio Manager

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

Fund's Positions
in Mentioned Holdings

As a percentage of net assets, as of 3/31/12

Ascendas REIT	6.1	%
Kansai Paint	5.6	%
Mapletree Industrial Trust	5.2	%
Rand Merchant Insurance	5.0	%
Seven Bank	4.3	%
Hexagon	3.4	%
Archipelago Resources	2.8	%
Mapletree Logistics Trust	2.4	%
Imtech	2.2	%
Intertek Group	2.1	%
Rheinmetall	1.9	%
Novozymes	1.2	%
Taiwan Mobile	1.0	%
Gree	0.4	%

Columbia Acorn International Select ended the first quarter of 2012 up 11.29% (Class A shares, without sales charge), slightly behind the 11.98% gain of its primary benchmark, the S&P Developed Ex-U.S. Between $2B and $10B Index. Last year's fears of a global recession and a European currency crisis eased in the first quarter as central banks around the world took additional steps to provide liquidity to the global markets, which eased deflationary concerns. Yet the underlying global economic outlook remains questionable and, as a result, the Fund's portfolio remains focused on more defensive, secular growth companies with good dividend yields and strong balance sheets. Also, as much of the global debt problem is centered in developed markets, the Fund is underweight in areas such as Europe, the United Kingdom and Japan, with overweights in Asia ex-Japan and emerging markets.

Fund industrial stocks performed well in the quarter on the back of greater confidence in global economic growth. Based in the Netherlands, Imtech, a provider of electromechanical, information and communication technology services, was up 23% for the quarter on a more optimistic European outlook. UK testing, inspection and certification services provider Intertek Group gained 27% in the first quarter as new regulations and product quality requirements continued to benefit its business and recent acquisitions began to make a significant impact. Finally, Germany's Rheinmetall, a provider of defense and automotive supplies, bounced back after a dismal 2011. Its stock rose 34% in the quarter.

Financial stocks also helped the Fund despite its lack of exposure to commercial banks, which were a primary beneficiary of central bank intervention. Rand Merchant Insurance, a South African insurance company, led gains with a 38% return for the first quarter. The market is just getting to know the company's world-class car and home insurance business after spinning out of Rand Merchant Bank last year. Singapore's Ascendas REIT, Mapletree Industrial Trust and Mapletree Logistics Trust had gains ranging from 8% to 18%. These industrial property landlords benefited from an improved Singaporean economic outlook and investor interest in their roughly 7% dividend yields. Rounding out the list of financial winners, Japan's Seven Bank, a provider of ATM processing services, rose 14% as it continued to expand its ATM network throughout Japan.

Other standouts in the quarter included Hexagon, a Swedish company that manufactures design, measurement and visualization software and equipment. Its stock rose 29% on a very strong earnings report and better-than-expected cash generation. Japanese paint producer Kansai Paint gained 14% in the first quarter as the market began to recognize the quality of the business franchise outside Japan with the recent integration of a newly acquired South African business. Currently, 45% of its business is in emerging markets.

On the downside, Japanese mobile social networking game developer Gree fell 25% in the first quarter. If you recall, this stock was up 173% in 2011, so a retreat after its strong run was not unexpected. Other losses in the quarter were fairly insignificant. Indonesian gold miner Archipelago Resources fell 3%, despite massive increases to its gold reserves, as the markets took a cautious view on gold stocks worldwide. Denmark's Novozymes, a maker of industrial enzymes, fell 5% on expectations of a slowdown in the North American bioethanol market. Taiwanese mobile operator Taiwan Mobile fell 2%, despite an improving earnings outlook, as investors switched into more cyclical stocks in Taiwan.

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

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

15

Columbia Acorn International Select

At a Glance (Class A Shares - LAFAX)

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

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

through March 31, 2012

Inception 10/16/00		Year to date*			1 year			5 years			10 years
Returns before taxes	NAV POP		11.29 4.90	%		-2.39 -8.00	%		1.41 0.22	%		10.35 9.70	%
Returns after taxes on distributions	NAV POP		11.29 4.90			-2.81 -8.39			1.07 -0.13			10.19 9.54
Returns after taxes on distributions and sale of fund shares	NAV POP		7.34 3.18			-0.76 -4.45			1.26 0.24			9.34 8.74
S&P Developed Ex-US Between $2B and $10B Index** (pretax)			11.98			-6.61			-1.92			9.20

All results shown assume reinvestment of distributions.

*Year to date data is not annualized.

**The Fund's primary benchmark.

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

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

The Fund's Class A shares annual operating expense ratio, as stated in the May 1, 2011, prospectus, is 1.56%.

Columbia Acorn International Select Portfolio Diversification

as a percentage of net assets, as of 3/31/12

Columbia Acorn International Select
Top 10 Holdings

as a percentage of net assets, as of 3/31/12

1.	Far EasTone Telecom (Taiwan) Taiwan's Third Largest Mobile Operator	6.6	%
2.	Ascendas REIT (Singapore) Industrial Property Landlord	6.1	%
3.	Kansai Paint (Japan) Paint Producer in Japan, India, China & Southeast Asia	5.6	%
4.	Mapletree Industrial Trust (Singapore) Industrial Property Landlord	5.2	%
5.	Rand Merchant Insurance (South Africa) Directly Sold Property & Casualty Insurance; Holdings in Other Insurers	5.0	%
6.	Seven Bank (Japan) ATM Processing Services	4.3	%
7.	Wirecard (Germany) Online Payment Processing & Risk Management	3.5	%
8.	Hexagon (Sweden) Measurement Equipment	3.4	%
9.	NHN (South Korea) Korean Online Search Services	3.3	%
10.	Adcock Ingram Holdings (South Africa) Manufacturer of Pharmaceuticals & Medical Supplies	2.9	%

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

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

October 16, 2000 through March 31, 2012

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: $343.8 million

*  Class I share value reflects 9/27/10 share class inception date.

16

Columbia Acorn Select

In a Nutshell

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

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

Fund's Positions
in Mentioned Holdings

As a percentage of net assets, as of 3/31/12

Hertz	5.8	%
Discover Financial Services	5.2	%
CNO Financial Group	4.7	%
Sanmina-SCI	3.7	%
WNS	3.5	%
Pacific Rubiales Energy	3.2	%
FMC Corporation	1.2	%
Henry Schein	1.1	%
Associated Banc-Corp	1.1	%
Dupont Fabros Technology	0.9	%
Nordson	0.6	%
Seattle Genetics	0.6	%

Columbia Acorn Select gained 17.65% (Class A shares, without sales charge) in the first quarter of 2012, outperforming the S&P MidCap 400 Index, the Fund's primary benchmark, which was up 13.50% for the same period. The large-cap S&P 500 Index gained 12.59% in the quarter.

As we noted in previous reports, during the second half of last year many of the Fund's opportunistic holdings lagged the market averages, despite having strong earnings growth. While a cause of Fund underperformance last year, we believed these names would continue to have earnings growth in 2012 and so we opted to continue to hold them in anticipation of the market recognizing their solid earnings performance and increasing their valuations accordingly. Our patience started to pay off in the first quarter. Looking at the Fund's top performers, rental car operator Hertz, Colombian oil company Pacific Rubiales Energy, credit card company Discover Financial Services, insurance company CNO Financial Group, Indian business outsourcing company WNS and electronics manufacturer Sanmina-SCI each added between 1% and 2% to the Fund's performance in the quarter. Only seven of the 55 stocks in the Fund's portfolio were down in the quarter, which, when added together, amounted to a little more than 1% of performance loss.

In the second half of last year, we stated that we were working on reducing the Fund's opportunistic holdings within the portfolio but felt they were too cheap to sell at then-current prices. Unfortunately, we watched prices just get cheaper as investors worried about the possibility of a global recession late last year. As noted above, in the first quarter we saw many of these holdings rebound strongly and were able to increase our efforts to transition toward more core holdings. In the first quarter we trimmed the Fund's exposure to Sanmina-SCI, WNS, CNO Financial, Discover and Pacific Rubiales.

During the first quarter, we added six new companies to the portfolio, while exiting from five companies. Our new positions include U.S. bank Associated Banc-Corp, real estate company Dupont Fabros Technology, oil and gas wellhead manufacturer FMC Corporation, healthcare product distributor Henry Schein, dispensing systems manufacturer Nordson and cancer therapies manufacturer Seattle Genetics, all of which are CWAM analysts' best ideas. WW Grainger, JB Hunt, Continental Resources, Oshkosh and Waste Management were sold based on what we believe will be slower future earnings growth at these companies.

We were happy to see some strengthening in the U.S. economic indicators during the first quarter, and it looks like this may continue for a while. But we are still quite concerned with the amount of artificial stimulus in our economy, from interest rates to large budget deficits. Against this backdrop, we expect a continuation of above-average volatility in the stock market.

Risks include stock market fluctuations due to economic and business developments. The Fund also has potentially greater price volatility due to the Fund's concentration in a limited number of stocks of mid-size companies. International investing involves special risks, including foreign taxation, currency risks, risks associated with possible differences in financial standards, operational and settlement risks and other risks associated with future political and economic developments.

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

17

Columbia Acorn Select

At a Glance (Class A Shares - LTFAX)

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

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

through March 31, 2012

Inception 10/16/00		Year to date*			1 year			5 years			10 years
Returns before taxes	NAV POP		17.65 10.88	%		-2.81 -8.40	%		0.54 -0.65	%		7.51 6.88	%
Returns after taxes on distributions	NAV POP		17.65 10.88			-3.30 -8.86			0.29 -0.89			7.26 6.62
Returns after taxes on distributions and sale of fund shares	NAV POP		11.47 7.07			-1.84 -5.47			0.40 -0.61			6.59 6.01
S&P MidCap 400 Index** (pretax)			13.50			1.98			4.78			7.70

All results shown assume reinvestment of distributions.

*Year to date data is not annualized.

**The Fund's primary benchmark.

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

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

The Fund's Class A shares annual operating expense ratio, as stated in the May 1, 2011, prospectus, is 1.28%.

Columbia Acorn Select Portfolio Diversification

as a percentage of net assets, as of 3/31/12

Columbia Acorn Select Top 10 Holdings

as a percentage of net assets, as of 3/31/12

1.	Hertz Largest U.S. Rental Car Operator	5.8	%
2.	Ametek Aerospace/Industrial Instruments	5.3	%
3.	Discover Financial Services Credit Card Company	5.2	%
4.	CNO Financial Group Life, Long-term Care & Medical Supplement Insurance	4.8	%
5.	SBA Communications Communications Towers	3.8	%
6.	Sanmina-SCI Electronic Manufacturing Services	3.7	%
7.	Coach Designer & Retailer of Branded Leather Accessories	3.5	%
8.	WNS - ADR (India) Offshore Business Process Outsourcing Services	3.5	%
9.	Donaldson Industrial Air Filtration	3.3	%
10.	Kennametal Consumable Cutting Tools	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 March 31, 2012

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: $1.4 billion

*  Class I share value reflects 9/27/10 share class inception date.

18

Columbia Thermostat Fund

In a Nutshell

Charles P. McQuaid

Lead Portfolio Manager

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

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

Columbia Thermostat Fund ended the first quarter of 2012 up 8.19% (Class A shares, without sales charge). The Fund's primary equity benchmark, the S&P 500 Index, gained 12.59% for the same period and its primary fixed income benchmark, the Barclays U.S. Aggregate Bond Index, was up just 0.30%.

The Fund hit three reallocation triggers in the first quarter, reducing stock exposure each time on the strength of the equity market. At quarter end, the Fund had a 45% weighting in stock funds and a 55% weighting in its bond funds.

The equity portion of the portfolio provided a 14.33% weighted average return for the first quarter with Columbia Select Large Cap Growth Fund providing top gains of 19.98% for the three months. As we noted in our last report, Columbia Select Large Cap Growth Fund was added to the portfolio late last year. We're now pleased to see its immediate strong contribution.

The bond portion of the Fund provided a 1.86% weighted average gain, with Columbia Income Opportunities Fund leading the performance, up 4.23%. Columbia Income Opportunities Fund, which provides exposure to high-yield securities, had its weighting increased from 20% to 30% late last year, another move that proved beneficial this quarter.

Columbia Thermostat Fund enjoyed a substantial inflow of new assets in the first quarter. At quarter end, the Fund's total net assets were $325 million. We thank you for your investment in the Fund.

Results of the Funds Owned in Columbia Thermostat Fund as of March 31, 2012

Stock Funds Fund	Weightings in category			1st quarter
Columbia Acorn International, Class I		20	%		15.12	%
Columbia Dividend Income Fund, Class I		20	%		8.28	%
Columbia Acorn Fund, Class I		15	%		15.52	%
Columbia Select Large Cap Growth Fund, Class I		10	%		19.98	%
Columbia Acorn Select, Class I		10	%		17.76	%
Columbia Contrarian Core Fund, Class I		15	%		14.68	%
Columbia Large Cap Enhanced Core Fund, Class I		10	%		13.43	%
Weighted Average Equity Gain		100	%		14.33	%
Bond Funds Fund	Weightings in category			1st quarter
Columbia Intermediate Bond Fund, Class I		50	%		1.72	%
Columbia U.S. Treasury Index Fund, Class I		20	%		-1.31	%
Columbia Income Opportunities Fund, Class I		30	%		4.23	%
Weighted Average Income Gain		100	%		1.86	%

Columbia Thermostat Fund
Rebalancing in the First Quarter

January 19, 2012	55% stocks, 45% bonds
February 10, 2012	50% stocks, 50% bonds
March 16, 2012	45% stocks, 55% 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, operational and settlement risks and other risks associated with future political and economic developments. Changes in interest rates and changes in the financial strength of issuers of lower-rated bonds may also affect underlying fund performance. The Fund is also subject to the risk that the investment advisor's decisions regarding asset classes and underlying portfolio funds will not anticipate market trends successfully, resulting in a failure to preserve capital or lower total return. In addition, the Fund may buy and sell shares of the portfolio funds frequently. This may result in higher transaction costs and additional tax liability. This is not an offer of the shares of any other mutual fund mentioned herein.

19

Columbia Thermostat Fund

At a Glance (Class A Shares - CTFAX)

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

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

through March 31, 2012

Inception 3/3/03		Year to date*			1 year			5 years			Life of fund
Returns before taxes	NAV POP		8.19 1.99	%		9.87 3.56	%		5.15 3.91	%		8.22 7.52	%
Returns after taxes on distributions	NAV POP		8.19 1.99			8.87 2.62			4.16 2.93			7.05 6.35
Returns after taxes on distributions and sale of fund shares	NAV POP		5.32 1.29			6.36 2.26			3.90 2.82			6.62 5.99
S&P 500 Index** (pretax)			12.59			8.54			2.01			7.98
Barclays U.S. Aggregate Bond Index** (pretax)			0.30			7.71			6.25			5.11
Lipper Flexible Portfolio Funds Index (pretax)			8.90			2.88			3.42			7.92

All results shown assume reinvestment of distributions.

*Year to date data is not annualized.

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

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

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

The Fund's annual operating expense ratio, as stated in the May 1, 2011, 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 3/31/12

Columbia Thermostat Fund Portfolio Weightings

as a percentage of assets in each investment category, as of 3/31/12

Stock Mutual Funds

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

Bond Mutual Funds

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

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

March 3, 2003 through March 31, 2012

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: $325.0 million

20

Columbia Acorn Emerging Markets Fund

In a Nutshell

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

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

Fund's Positions
in Mentioned Holdings

As a percentage of net assets, as of 3/31/12

Alliance Grain Traders	2.9	%
Nagacorp	2.7	%
Dufry Group	2.5	%
Pirelli	1.4	%
Dürr	1.4	%
Radiant Opto-Electronics	1.2	%
Crew Energy	0.7	%
Madalena Ventures	0.6	%

Columbia Acorn Emerging Markets Fund returned 17.93% (Class A shares, without sales charge) in the first quarter of 2012, slightly behind the 18.46% return of the Fund's primary benchmark, the S&P Emerging Markets Between $500M and $5B Index. We mentioned in our first shareholder report that we have sought to structure the Fund so that it will fall less in downturns but, as a result, it may lag the index in strong up markets. We are encouraged that since the Fund's launch on August 19, 2011, a period that included both a significant market decline followed by a strong emerging markets rally, the Fund has gained 9.20%, outperforming the benchmark gain of 2.52%.

In the first quarter, the Fund benefitted from good stock selection in its consumer discretionary picks. Nagacorp, a casino/entertainment complex operator based in Cambodia, continues to be a strong performer, up 81% on continued robust earnings growth in the Cambodian gaming market. Dufry Group, a Switzerland-based operator of duty free shops, which generates the majority of its earnings in Latin America, gained over 43% as it achieved record margins.

Other key contributors were Radiant Opto-Electronics, which specializes in ultra-thin backlight units for use in tablet computers. Up 54%, the company has benefitted from the growth in tablet computing and its key relationships with market leaders Apple and Samsung. Dürr, a German manufacturer of advanced automatic paint finishing plants, has followed the global auto giants to Latin America and Asia, while winning market share with new Chinese automakers. The stock gained 46% during the quarter. Another auto-related name, premium tire maker Pirelli, was up nearly 43% on robust revenue growth in Latin America. Eighty percent of the company's tires are now made in emerging market countries.

The largest performance detractor for the quarter was Alliance Grain Traders, a Canada-based processor of lentils and peas, down roughly 25%. The company's customers are largely in the Middle East, India and Northern Africa. Political turmoil, currency depreciations and tighter trade finance in those markets caused buying of these pulse crops to shrink. Two energy names listed in Canada, Crew Energy and Madalena Ventures, were each down about 14% for the quarter. Madalena's resources are in Argentina and have traded down as the government has pressured an industry peer, depressing sentiment. Indian gold lender Manappuram Finance fell 9% in the Fund after the government introduced new restrictions on the industry. We believe additional detrimental regulations are coming, and have sold out of the position.

The Fund seeks to benefit by leveraging the global expertise of the CWAM investment team. Three of the Fund's best performers in the quarter, European-listed stocks Dürr, Dufry and Pirelli, were selected by CWAM's Europe analysts. Columbia Acorn Emerging Markets Fund expects to take advantage of CWAM's strength in this area. We hope that CWAM's deep experience may help to identify the best ideas in a wide universe of emerging markets investments.

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

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

21

Columbia Acorn Emerging
Markets Fund

At a Glance (Class A Shares - CAGAX)

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

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

through March 31, 2012

Inception 8/19/11		Year to date*			Life of fund**
Returns before taxes	NAV POP		17.93 11.20	%		9.20 2.92	%
Returns after taxes on distributions	NAV POP		17.93 11.20			9.21 2.93
Returns after taxes on distributions and sale of fund shares	NAV POP		11.65 7.28			5.99 1.91
S&P Emerging Markets Between $500M and $5B Index (pretax)***			18.46			2.52

All results shown assume reinvestment of distributions.

*Year to date data is not annualized.

**Reflects performance from Fund inception on 8/19/11 through 3/31/12.

***The Fund's primary benchmark.

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

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

The Fund's annual operating expense ratio, as stated in the August 19, 2011, prospectus, reflects a contractual fee waiver and expense reimbursement agreement with CWAM that expires April 30, 2013; Class A share expense ratios without and with the contractual fee waiver/reimbursement are 1.96% and 1.85%, respectively.

Columbia Acorn Emerging Markets Fund Portfolio Diversification

as a percentage of net assets, as of 3/31/12

Columbia Acorn Emerging Markets Fund Top 10 Holdings

as a percentage of net assets, as of 3/31/12

1.	Ace Indonesia (Indonesia) Home Improvement Retailer	3.1	%
2.	Tower Bersama Infrastructure (Indonesia) Communications Towers	3.0	%
3.	Rand Merchant Insurance (South Africa) Directly Sold Property & Casualty Insurance; Holdings in Other Insurers	2.8	%
4.	Nagacorp (Cambodia) Casino/Entertainment Complex in Cambodia	2.7	%
5.	Coronation Fund Managers (South Africa) South African Fund Manager	2.6	%
6.	Dufry Group (Switzerland) Operator of Airport Duty Free & Duty Paid Shops	2.5	%
7.	Archipelago Resources (Indonesia) Gold Mining Projects in Indonesia, Vietnam & the Philippines	2.5	%
8.	Alliance Grain Traders (Canada) Global Leader in Pulse Processing & Distribution	2.1	%
9.	Far EasTone Telecom (Taiwan) Taiwan's Third Largest Mobile Operator	2.1	%
10.	Home Product Center (Thailand) Home Improvement Retailer	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 Emerging Markets Fund (Class A)

August 19, 2011 through March 31, 2012

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 Emerging Markets 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 would pay on Fund distributions or on a sale of Fund shares.

Total Net Assets of the Fund:
$5.8 million

22

Columbia Acorn European Fund

In a Nutshell

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

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

Fund's Positions
in Mentioned Holdings

As a percentage of net assets, as of 3/31/12

Gemalto	3.2	%
Eurofins Scientific	3.2	%
1000 mercis	2.8	%
Alliance Grain Traders	1.3	%

Columbia Acorn European Fund returned 17.71% (Class A shares, without sales charge) in the first quarter of 2012, in line with, but slightly less than, its primary benchmark, the S&P Europe Between $500M and $5B Index, which was up 17.80% in the period. Generally, our stock picks in mainland Europe contributed to performance, while stocks listed in the United Kingdom and Ireland were detractors.

The strongest returns came from GlobeOp Financial Services, up almost 60% in the quarter. GlobeOp, an independent financial administrator specializing in middle- and back-office services, became the object of a takeover battle in March, only weeks after listing on the London Stock Exchange. We sold the Fund's shares of the stock.

Eurofins Scientific, a company with its origins in France, headquarters in Brussels and company registration in Luxembourg, was also strong in the quarter. The company provides screening and testing services for foodstuffs, pharmaceuticals, soils and materials and operates worldwide. Having spent the last five years investing heavily in consolidating a very fragmented industry, the company has started to reap the fruit of its labor, reporting much improved operating margins on the back of better capacity utilization. The improved 2011 figures and management's bullish outlook for 2012 and beyond sent the stock up 50% in the first quarter.

Another star performer was Gemalto, a company headquartered in Paris, France, and registered in the Netherlands. The company is a maker of chip cards and digital security solutions with strong market shares in mobile telephone SIM cards, smart credit cards and identification and access control solutions. Gemalto saw demand increase sharply as hardware makers, telecom operators and financial institutions the world over looked at the potential of new payment methods based on mobile telephone and intelligent chip cards. The stock was up more than 35% in the quarter.

On the downside, Alliance Grain Traders, a Canada-listed trader of lentils and peas with large operations in Turkey, suffered from the liquidity squeeze that many of its Middle Eastern clients experienced following political instabilities and currency devaluations. The company had to take write downs on accounts receivables, while suffering foreign currency-related losses in the fourth quarter of 2011. Since then, the situation has slightly improved, with currencies recovering and orders up. Nevertheless, the stock slid almost 25% in the quarter.

Another detractor was 1000 mercis, a specialist marketer and online advertiser. The company reported lower fourth quarter sales than expected, with some sales postponed to the first quarter of 2012 and some cancelled altogether, which scared off investors. After sliding 23% on the news, the stock recovered somewhat and finished the quarter down 18%.

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

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

23

Columbia Acorn
European Fund

At a Glance (Class A Shares - CAEAX)

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

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

through March 31, 2012

Inception 8/19/11		Year to date*			Life of fund**
Returns before taxes	NAV POP		17.71 10.89	%		11.86 5.43	%
Returns after taxes on distributions	NAV POP		17.71 10.89			11.63 5.22
Returns after taxes on distributions and sale of fund shares	NAV POP		11.51 7.08			7.76 3.57
S&P Europe Between $500M and $5B Index (pretax)***			17.80			9.35

All results shown assume reinvestment of distributions.

*Year to date data is not annualized.

**Reflects performance from Fund inception on 8/19/11 through 3/31/12.

***The Fund's primary benchmark.

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

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

The Fund's annual operating expense ratio, as stated in the August 19, 2011, prospectus, reflects a contractual fee waiver and expense reimbursement agreement with CWAM that expires April 30, 2013; Class A share expense ratios without and with the contractual fee waiver/reimbursement are 1.89% and 1.75%, respectively.

Columbia Acorn European Fund Portfolio Diversification

as a percentage of net assets, as of 3/31/12

Columbia Acorn European Fund Top 10 Holdings

as a percentage of net assets, as of 3/31/12

1.	Gemalto (France) Smart Card Products & Solutions	3.2	%
2.	Eurofins Scientific (France) Food, Pharmaceuticals & Materials Screening & Testing	3.2	%
3.	Wirecard (Germany) Online Payment Processing & Risk Management	2.9	%
4.	1000 mercis (France) Interactive Advertising & Marketing	2.8	%
5.	Geberit (Switzerland) Plumbing Supplies	2.6	%
6.	Hexagon (Sweden) Design, Measurement & Visualization Software & Equipment	2.6	%
7.	Marel (Iceland) Largest Manufacturer of Poultry & Fish Processing Equipment	2.5	%
8.	Aalberts Industries (Netherlands) Flow Control & Heat Treatment	2.5	%
9.	UNIT4 (Netherlands) Business Software Development	2.2	%
10.	Intertek Group (United Kingdom) Testing, Inspection & Certification Services	2.2	%

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

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

August 19, 2011 through March 31, 2012

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 Europe 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 would pay on Fund distributions or on a sale of Fund shares.

Total Net Assets of the Fund:
$2.0 million

24

Columbia Acorn Fund

Major Portfolio Changes in the First Quarter (Unaudited)

	Number of Shares
	12/31/11		03/31/12
Purchases
Information
Active Network		0		900,000
Boingo Wireless		1,500,000		1,650,000
Cree		0		380,000
ExlService Holdings		1,145,000		1,435,200
Informatica		4,850,000		5,000,000
ON Semiconductor		6,842,000		7,932,000
Quality Systems		2,333,500		2,350,000
TIBCO		2,139,800		2,150,000
Ultratech		415,000		615,000
WNS - ADR (India)		1,076,353		1,091,353
Industrial Goods & Services
Drew Industries		1,500,000		1,880,000
Fortune Brands Home & Security		1,300,000		1,350,000
Heico		2,250,000		2,450,000
Middleby		123,344		166,419
Nordson		3,000,000		3,125,000
Polypore International		0		900,000
Valmont Industries		100,000		435,000
Consumer Goods & Services
American Eagle Outfitters		0		300,000
Annie's		0		45,500
Caesarstone (Israel)		0		215,000
Deckers Outdoor		1,045,000		1,140,000
Fossil		115,000		392,500
GNC Holdings		0		1,528,500
HomeAway		1,400,000		1,600,000
Shutterfly		3,070,000		3,370,000
Skullcandy		975,000		1,290,000
United Stationers		493,771		625,000
Finance
Alliance Data Systems		400,000		550,000
Allied World Holdings		500,000		833,000
Assured Guaranty		300,000		500,000
Enstar Group		216,766		250,000
First Commonwealth		0		1,000,000
Kemper		762,252		925,000
MB Financial		2,360,000		2,860,000
Oriental Financial Group		0		500,000
Regional Management		0		422,500
Tower Group		1,675,000		2,764,000
TrustCo Bank		1,940,318		2,136,500
Wintrust Financial		0		700,000
Wright Express		180,000		275,000
Health Care
Allscripts Healthcare Solutions		700,000		1,200,000
Anthera Pharmaceuticals		1,740,000		2,990,000
Cepheid		3,200,000		3,900,000

	Number of Shares
	12/31/11		03/31/12
Chelsea Therapeutics International		4,550,000		5,750,000
DENTSPLY International		0		1,136,500
Henry Schein		650,000		950,000
Pacific Biosciences of California		0		2,525,000
PerkinElmer Inc.		0		950,000
Raptor Pharmaceutical		3,455,000		4,200,000
Synageva Biopharma		0		180,167
Techne		0		375,000
Energy & Minerals
Approach Resource		0		200,000
Petroleum Development Corporation		0		340,000
Rowan		0		585,000
Other Industries
Dupont Fabros Technology		3,350,000		3,700,000
Genesee & Wyoming		300,000		400,000
Jones Lang LaSalle		0		325,000
St. Joe		1,000,000		1,300,000
Summit Hotel Properties		1,500,000		2,000,031

25

	Number of Shares
	12/31/11		03/31/12
Sales
Information
Akamai		700,500		250,000
Blackbaud		1,680,198		1,650,000
Crown Castle International		4,600,000		4,465,000
Discovery Series C		2,050,000		1,595,000
Finisar		1,905,000		1,695,000
FTI Consulting		900,000		868,516
Gemalto (France)		230,000		207,000
Global Payments		2,429,000		2,299,000
IMAX (Canada)		1,250,000		1,100,000
Intralinks		550,000		0
Jack Henry & Associates		920,000		750,000
Mail.ru - GDR (Russia)		423,040		400,000
MetroPCS Communications		600,000		0
NetEase.com - ADR (China)		365,000		304,000
Netgear		1,200,000		900,000
Polycom		1,165,000		0
Red Hat		850,000		750,000
Salem Communications		1,527,700		0
Supertex		535,000		0
Industrial Goods & Services
Arcadis (Netherlands)		100,000		0
Expeditors International of Washington		3,200,000		3,050,000
GrafTech International		4,000,000		3,750,000
Imtech (Netherlands)		1,767,165		1,601,465
Interline Brands		2,600,000		2,399,751
Kaydon		1,300,000		501,000
LKQ		1,635,000		1,350,000
Mersen (France)		420,000		260,000
Mine Safety Appliances		566,497		0
Pentair		3,535,000		3,100,000
WABCO Holdings		1,150,000		950,000
WW Grainger		270,000		0
Consumer Goods & Services
Crocs		580,000		0
Diamond Foods		1,050,000		0
Guess?		530,000		0
Hanesbrands		1,000,000		0
Jarden		1,650,000		1,500,000
lululemon athletica		5,740,000		4,922,800
Thor Industries		1,100,000		0
True Religion Apparel		1,507,000		393,452
Vail Resorts		1,680,000		1,430,000
Finance
Aaron's		1,834,695		0
BOK Financial		2,738,000		2,691,414
City National		1,275,000		1,175,000

	Number of Shares
	12/31/11		03/31/12
CVB Financial		4,300,000		3,400,000
Delphi Financial Group		1,200,000		0
Valley National Bancorp		5,450,000		5,070,000
World Acceptance		1,505,202		1,459,555
Health Care
Akorn		4,432,716		4,000,000
Alexion Pharmaceuticals		3,208,000		2,290,000
Community Health Systems		625,000		0
HealthSouth		2,075,000		825,000
Hill-Rom Holdings		1,975,000		1,873,800
HMS Holdings		850,000		0
Micromet		6,702,347		0
Onyx Pharmaceuticals		1,170,000		1,000,000
Sirona Dental Systems		2,075,000		675,000
Energy & Minerals
Core Laboratories (Netherlands)		545,000		442,000
FMC Technologies		6,036,100		5,298,000
GT Solar International		2,800,000		2,000,000
Houston American Energy		900,000		393,600
Kodiak Oil and Gas		2,200,000		1,100,000
Northern Oil & Gas		638,000		0
Oasis Petroleum		840,000		0
Pacific Rubiales Energy (Colombia)		4,300,000		4,250,000
Southwestern Energy Co.		75,071		0
Tullow Oil (United Kingdom)		2,400,000		1,697,000
Other Industries
Biomed Realty Trust		3,000,000		2,450,000
Kilroy Realty		1,120,000		770,000
Macerich		530,000		0
Wisconsin Energy		1,800,000		1,660,000

26

Columbia Acorn Fund

Statement of Investments (Unaudited), March 31, 2012

Number of Shares			Value (000)
			Equities: 97.4%
Information 29.0%
		> Business Software 8.3%
	5,000,000	Informatica (a)	$	264,500
		Enterprise Data Integration Software
	2,550,000	Ansys (a)		165,801
		Simulation Software for Engineers & Designers
	2,700,000	Micros Systems (a)		149,283
		Information Systems for Hotels, Restaurants & Retailers
	1,830,000	Concur Technologies (a)		105,005
		Web Enabled Cost & Expense Management Software
	2,350,000	Quality Systems		102,765
		IT Systems for Medical Groups & Ambulatory Care Centers
	5,164,999	Hexagon (Sweden)		100,243
		Design, Measurement & Visualization Software & Equipment
	2,850,000	Ariba (a)		93,223
		Cost Management Software
	2,350,000	Constant Contact (a)(b)		70,006
		Email & Other Marketing Campaign Management Systems Delivered Over the Web
	2,150,000	TIBCO (a)		65,575
		Datacenter Software
	1,700,000	Tyler Technologies (a)(b)		65,297
		Financial, Tax, Court & Document Management Systems for Local Governments
	1,150,000	NetSuite (a)		57,834
		End to End IT Systems Solution Delivered Over the Web
	1,650,000	Blackbaud		54,830
		Software & Services for Non-profits
	1,700,000	Kenexa (a)(b)		53,108
		Recruiting & Workforce Management Solutions
	750,000	Red Hat (a)		44,918
		Maintenance & Support for Opensource OS & Middleware
	2,500,000	Velti (a)		33,875
		Mobile Marketing Software Platform
	750,000	Jack Henry & Associates		25,590
		Systems Financial Institutions
	900,000	SPS Commerce (a)(b)		24,192
		Supply Chain Management Software Delivered via the Web
	690,000	Advent Software (a)		17,664
		Asset Management & Trading Systems
	900,000	Active Network (a)		15,147
		Web Delivered Software Solutions for Managing Events & Activities
	1,000,000	InContact (a)		5,580
		Call Center Systems Delivered via the Web & Telco Services
	55,000	Solera Holdings		2,524
		Software for Automotive Insurance Claims Processing
				1,516,960

Number of Shares			Value (000)
		> Instrumentation 3.0%
	1,600,000	Mettler Toledo (a)(b)	$	295,600
		Laboratory Equipment
	2,780,000	IPG Photonics (a)(b)		144,699
		Fiber Lasers
	2,035,000	Trimble Navigation (a)		110,745
		GPS-based Instruments
				551,044
		> Computer Hardware & Related Equipment 2.6%
	3,495,000	Amphenol		208,896
		Electronic Connectors
	4,550,000	II-VI (a)(b)		107,607
		Laser Optics & Specialty Materials
	1,605,000	Zebra Technologies (a)		66,094
		Bar Code Printers
	900,000	Netgear (a)		34,380
		Networking Products for Small Business & Home
	800,000	Nice Systems - ADR (Israel) (a)		31,440
		Audio & Video Recording Solutions
	605,000	Stratasys (a)		22,095
		Rapid Prototyping Systems
	207,000	Gemalto (France)		13,663
		Digital Security Solutions
				484,175
		> Semiconductors & Related Equipment 2.4%
	12,300,000	Atmel (a)		121,278
		Microcontrollers, RF & Memory Semiconductors
	7,932,000	ON Semiconductor (a)		71,467
		Mixed Signal & Power Management Semiconductors
	5,000,000	Entegris (a)		46,700
		Semiconductor Materials Management Products
	2,160,000	Microsemi (a)		46,310
		Analog/Mixed Signal Semiconductors
	500,000	Littelfuse		31,350
		Little Fuses
	1,900,000	IXYS (a)(b)		25,080
		Power Semiconductors
	1,165,000	Monolithic Power Systems (a)		22,916
		High Performance Analog & Mixed Signal ICs
	400,000	Hittite Microwave (a)		21,724
		Radio Frequency, Microwave & Millimeterwave Semiconductors
	615,000	Ultratech (a)		17,823
		Semiconductor Equipment
	2,290,000	TriQuint Semiconductor (a)		15,790
		RF Semiconductors
	1,765,000	Pericom Semiconductor (a)(b)		14,279
		Interface ICs & Frequency Control Products
	380,000	Cree (a)		12,019
		LED Lighting, Components & Chips
				446,736

27

Number of Shares			Value (000)
		> Mobile Communications 2.3%
	4,465,000	Crown Castle International (a)	$	238,163
		Communications Towers
	3,700,000	SBA Communications (a)		187,997
		Communications Towers
	1,500,000	Globalstar (a)		1,050
		Satellite Mobile Voice & Data Carrier
				427,210
		> Telephone & Data Services 2.2%
	9,500,000	tw telecom (a)(b)		210,520
		Fiber Optic Telephone/Data Services
	1,400,000	AboveNet (a)(b)		115,920
		Metropolitan Fiber Communications Services
	2,200,000	Cogent Communications (a)		41,976
		Internet Data Pipelines
	1,650,000	Boingo Wireless (a)		19,965
		Wholesale & Retail Wi-Fi Networks
	2,000,000	General Communications (a)(b)		17,440
		Commercial Communication & Consumer CATV, Web & Phone in Alaska
				405,821
		> Computer Services 1.3%
	3,400,000	iGATE (a)(b)		56,984
		IT & Business Process Outsourcing Services
	1,435,200	ExlService Holdings (a)		39,382
		Business Process Outsourcing
	680,000	Syntel		38,080
		Offshore IT Services
	2,125,000	Virtusa (a)(b)		36,699
		Offshore IT Outsourcing
	1,575,000	Genpact (a)		25,672
		Business Process Outsourcing
	3,849,207	Hackett Group (a)(b)		22,980
		IT Integration & Best Practice Research
	1,091,353	WNS - ADR (India) (a)		13,151
		Offshore BPO (Business Process Outsourcing) Services
				232,948
		> Gaming Equipment & Services 1.2%
	3,725,000	Bally Technologies (a)(b)		174,144
		Slot Machines & Software
	1,530,000	WMS Industries (a)		36,307
		Slot Machine Provider
				210,451
		> Internet Related 1.0%
	585,000	Equinix (a)		92,108
		Network Neutral Data Centers
	1,450,000	TripAdvisor (a)		51,722
		Online Travel Research
	304,000	NetEase.com - ADR (China) (a)		17,662
		Chinese Online Gaming Services
	400,000	Mail.ru - GDR (Russia) (a)(c)		15,780
		Internet Social Networking & Games for Russian Speakers
	250,000	Akamai (a)		9,175
		Content Delivery Network (CDN) for Better Delivery of Online Content
				186,447

Number of Shares			Value (000)
		> Telecommunications Equipment 0.9%
	685,000	F5 Networks (a)	$	92,448
		Internet Traffic Management Equipment
	1,695,000	Finisar (a)		34,154
		Optical Subsystems & Components
	2,330,000	Ixia (a)		29,102
		Telecom Network Test Equipment
	1,925,000	Infinera (a)		15,631
		Optical Networking Equipment
				171,335
		> Business Information & Marketing Services 0.9%
	1,900,000	Verisk Analytics (a)		89,243
		Risk & Decision Analytics
	2,800,000	Navigant Consulting (a)(b)		38,948
		Financial Consulting Firm
	868,516	FTI Consulting (a)		32,586
		Financial Consulting Firm
	505,000	RPX (a)		8,565
		Patent Aggregation & Defensive Patent Consulting
				169,342
		> CATV 0.8%
	1,595,000	Discovery Series C (a)		74,773
		CATV Programming
	1,250,000	Liberty Global Series A (a)		62,600
		Cable TV Franchises Outside the USA
	15,770	Jupiter Telecommunications (Japan)		15,795
		Largest Cable Service Provider in Japan
				153,168
		> Financial Processors 0.7%
	2,299,000	Global Payments		108,053
		Credit Card Processor
	5,000,000	Singapore Exchange (Singapore)		27,656
		Singapore Equity & Derivatives Market Operator
				135,709
		> Electronics Distribution 0.6%
	3,125,000	Avnet (a)		113,719
		Electronic Components Distribution
				113,719
		> Contract Manufacturing 0.5%
	3,800,000	Sanmina-SCI (a)		43,510
		Electronic Manufacturing Services
	1,100,000	Plexus (a)		38,489
		Electronic Manufacturing Services
				81,999
		> Entertainment Programming 0.2%
	1,100,000	IMAX (Canada) (a)		26,884
		IMAX Movies, Theatre Equipment & Theatre Joint Ventures
				26,884
		> TV Broadcasting 0.1%
	2,500,000	Entravision Communications		4,275
		Spanish Language TV & Radio Stations
	1,750,000	Gray Television (a)		3,307
		Mid Market Affiliated TV Stations
				7,582

28

Columbia Acorn Fund

Statement of Investments (Unaudited), continued

Number of Shares			Value (000)
		> Radio —%
	164,991	Saga Communications (a)	$	5,907
		Radio Stations in Small & Mid-sized Cities
				5,907
		> Consumer Software —%
	273,500	Carbonite (a)(d)		3,011
		Online File Storage
				3,011
		> Advertising —%
	1,500,000	VisionChina Media - ADR (China) (a)		2,370
		Advertising on Digital Screens in China's Mass Transit System
				2,370
Information: Total				5,332,818
Industrial Goods & Services 18.7%
		> Machinery 11.1%
	6,750,000	Ametek		327,442
		Aerospace/Industrial Instruments
	8,400,000	Donaldson (b)		300,132
		Industrial Air Filtration
	3,125,000	Nordson		170,344
		Dispensing Systems for Adhesives & Coatings
	3,725,000	Kennametal		165,874
		Consumable Cutting Tools
	3,100,000	Pentair		147,591
		Pumps & Water Treatment
	2,775,000	Moog (a)(b)		119,020
		Motion Control Products for Aerospace, Defense & Industrial Markets
	2,325,000	Clarcor		114,134
		Mobile & Industrial Filters
	1,800,000	Pall		107,334
		Filtration & Fluids Clarification
	2,450,000	Heico (b)		98,368
		FAA Approved Aircraft Replacement Parts
	2,200,000	ESCO Technologies (b)		80,894
		Automatic Electric Meter Readers
	2,675,000	Oshkosh Corporation (a)		61,980
		Specialty Truck Manufacturer
	950,000	WABCO Holdings (a)		57,456
		Truck & Bus Component Supplier
	805,000	Toro		57,244
		Turf Maintenance Equipment
	435,000	Valmont Industries		51,073
		Center Pivot Irrigation Systems & Utility Poles
	600,000	Wabtec		45,222
		Freight & Transit Component Supplier
	1,776,000	Generac (a)		43,601
		Standby Power Generators
	900,000	Polypore International (a)(d)		31,644
		Battery Separators & Filtration Media
	166,419	Middleby (a)		16,838
		Manufacturer of Cooking Equipment
	210,000	Neopost (France)		13,505
		Postage Meter Machines
	501,000	Kaydon		12,781
		Specialized Friction & Motion Control Products

Number of Shares			Value (000)
	10,000,000	Marel (Iceland)	$	11,735
		Largest Manufacturer of Poultry & Fish Processing Equipment
	3,450,000	Jain Irrigation Systems (India)		6,656
	172,500	Jain Irrigation Systems - DVR (India) (a)		162
		Agricultural Micro-irrigation Systems & Food Processing
	1,000,000	Spartan Motors		5,290
		Specialty Truck & Chassis Manufacturer
				2,046,320
		> Industrial Materials & Specialty Chemicals 2.1%
	1,750,000	Albemarle		111,860
		Refinery Catalysts & Other Specialty Chemicals
	760,000	FMC Corporation		80,454
		Niche Specialty Chemicals
	1,880,000	Drew Industries (a)(b)		51,343
		RV & Manufactured Home Components
	1,525,000	Novozymes (Denmark)		44,415
		Industrial Enzymes
	673,000	Sociedad Quimica y Minera de Chile - ADR (Chile)		39,485
		Producer of Specialty Fertilizers, Lithium & Iodine
	2,218,700	Kansai Paint (Japan)		22,493
		Paint Producer in Japan, India, China & Southeast Asia
	900,000	Albany International		20,655
		Paper Machine Clothing & Advanced Textiles
	260,000	Mersen (France)		9,215
		Advanced Industrial Materials
	200,000	Silgan Holdings		8,840
		Metal & Plastic Packaging
				388,760
		> Other Industrial Services 1.9%
	3,050,000	Expeditors International of Washington		141,855
		International Freight Forwarder
	1,601,465	Imtech (Netherlands)		51,197
		Electromechanical & ICT Installation & Maintenance
	1,300,000	Forward Air		47,671
		Freight Transportation Between Airports
	1,350,000	LKQ (a)		42,079
		Alternative Auto Parts Distribution
	1,600,000	Mobile Mini (a)		33,792
		Portable Storage Units Leasing
	1,500,000	Acorn Energy (b)		16,305
		Frac Well Exploration/Monitoring Device, Sonar Security, Electric Grid Monitoring
	750,000	UTI Worldwide		12,923
		Freight Forwarding & Logistics
				345,822
		> Construction 0.9%
	1,725,000	Chicago Bridge & Iron		74,503
		Engineering & Construction for LNG & Petrochemicals

29

Number of Shares			Value (000)
		> Construction—continued
	66,000	NVR (a)	$	47,938
		DC Homebuilder
	1,350,000	Fortune Brands Home & Security (a)		29,794
		Home Building Supplies & Small Locks
	1,800,000	Mills Estruturas e Servicos de Engenharia (Brazil)		22,877
		Civil Engineering & Construction
				175,112
		> Electrical Components 0.7%
	1,440,000	Acuity Brands		90,475
		Commercial Lighting Fixtures
	1,500,000	Ushio (Japan)		21,249
		Industrial Light Sources
	351,000	Saft Batteries (France)		11,375
		Niche Battery Manufacturer
				123,099
		> Waste Management 0.6%
	2,400,000	Waste Connections		78,072
		Solid Waste Management
	560,000	Clean Harbors (a)		37,705
		Hazardous Waste Services & Disposal
				115,777
		> Outsourcing Services 0.6%
	2,800,000	Quanta Services (a)		58,520
		Electrical & Telecom Construction Services
	1,210,000	Insperity		37,074
		Professional Employer Organization
	600,000	GP Strategies (a)		10,500
		Training Programs
				106,094
		> Industrial Distribution 0.3%
	2,399,751	Interline Brands (a)(b)		51,859
		Industrial Distribution
				51,859
		> Conglomerates 0.3%
	2,263,654	Aalberts Industries (Netherlands)		46,795
		Flow Control & Heat Treatment
				46,795
		> Steel 0.2%
	3,750,000	GrafTech International (a)		44,775
		Industrial Graphite Materials Producer
				44,775
Industrial Goods & Services: Total				3,444,413
Consumer Goods & Services 16.4%
		> Retail 5.0%
	4,922,800	lululemon athletica (a)		367,635
		Premium Active Apparel Retailer
	3,460,000	Abercrombie & Fitch		171,651
		Teen Apparel Retailer
	3,370,000	Shutterfly (a)(b)		105,582
		Internet Photo-centric Retailer
	5,600,000	Pier 1 Imports (a)(b)		101,808
		Home Furnishing Retailer

Number of Shares			Value (000)
	5,225,000	Saks (a)	$	60,662
		Luxury Department Store Retailer
	392,500	Fossil (a)		51,802
		Watch Designer & Retailer
	525,000	DSW		28,754
		Branded Footwear Retailer
	971,500	Teavana (a)(d)		19,158
		Specialty Tea Retailer
	1,371,366	Gaiam (a)(b)		5,458
		Healthy Living Catalogs & E-Commerce
	300,000	American Eagle Outfitters		5,157
		Teen Apparel Retailer
	66,000	The Fresh Market (a)		3,165
		Specialty Food Retailer
				920,832
		> Apparel 3.0%
	2,100,000	Coach		162,288
		Designer & Retailer of Branded Leather Accessories
	1,660,000	PVH		148,288
		Apparel Wholesaler & Retailer
	2,190,000	Warnaco Group (a)(b)		127,896
		Global Branded Apparel Manufacturer
	1,140,000	Deckers Outdoor (a)		71,877
		Fashion Footwear Wholesaler
	600,000	Steven Madden (a)		25,650
		Wholesaler/Retailer of Fashion Footwear
	393,452	True Religion Apparel (a)		10,780
		Premium Denim
				546,779
		> Travel 2.5%
	3,850,000	Gaylord Entertainment (a)(b)		118,580
		Convention Hotels
	1,430,000	Vail Resorts		61,847
		Ski Resort Operator & Developer
	3,750,000	Hertz (a)		56,400
		Largest U.S. Rental Car Operator
	3,800,000	Avis Budget Group (a)		53,770
		Second Largest Car Rental Company
	1,450,000	Expedia (d)		48,488
		Online Travel Services Company
	1,600,000	HomeAway (a)		40,592
		Vacation Rental Online Marketplace
	2,000,000	Localiza Rent A Car (Brazil)		36,813
		Car Rental
	970,000	Choice Hotels		36,220
		Franchisor of Budget Hotel Brands
				452,710
		> Food & Beverage 1.2%
	2,340,000	Monster Beverage (a)		145,290
		Alternative Beverages
	32,000,000	Olam International (Singapore)		60,136
		Agriculture Supply Chain Manager
	240,000	Snyder's-Lance		6,204
		Snack Foods
	45,500	Annie's (a)		1,585
		Developer & Marketer of Natural & Organic Food

30

Columbia Acorn Fund

Statement of Investments (Unaudited), continued

Number of Shares			Value (000)
		> Food & Beverage—continued
	1,678,125	GLG Life Tech (Canada) (a)(b)(d)	$	1,326
		Produce an All-natural Sweetener Extracted from the Stevia Plant
				214,541
		> Other Consumer Services 0.8%
	2,190,000	Lifetime Fitness (a)(b)		110,748
		Sport & Fitness Club Operator
	13,500,000	Lifestyle International (Hong Kong)		34,392
		Mid to High-end Department Store Operator in Hong Kong & China
	1,062,500	Move (a)		10,317
		Real Estate Internet Websites
	1,325,000	IFM Investments (Century 21 China RE) - ADR (China) (a)		954
		Provide Real Estate Services in China
				156,411
		> Furniture & Textiles 0.8%
	4,200,000	Knoll (b)		69,888
		Office Furniture
	2,250,000	Herman Miller		51,660
		Office Furniture
	1,750,000	Interface		24,413
		Modular & Broadloom Carpet
	215,000	Caesarstone (Israel) (a)		2,511
		Quartz Countertops
				148,472
		> Consumer Goods Distribution 0.8%
	2,015,000	Pool		75,401
		Distributor of Swimming Pool Supplies & Equipment
	1,528,500	GNC Holdings		53,329
		Specialty Retailer of Health + Wellness Products
	625,000	United Stationers		19,394
		Wholesale Distributor of Business Products
				148,124
		> Casinos & Gaming 0.8%
	3,950,000	Pinnacle Entertainment (a)(b)		45,464
		Regional Casino Operator
	3,000,000	Melco Crown Entertainment - ADR (Hong Kong) (a)		40,830
		Macau Casino Operator
	850,000	Penn National Gaming (a)		36,533
		Regional Casino Operator
	12,000,000	MGM China Holdings (Hong Kong) (d)		21,906
		Macau Casino Operator
				144,733
		> Other Durable Goods 0.5%
	1,500,000	Jarden		60,345
		Branded Household Products
	460,000	Cavco Industries (a)(b)		21,427
		Manufactured Homes
	400,000	Tesla Motors (a)		14,896
		Design, Manufacture and Sell High-performance Electric Vehicles
				96,668

Number of Shares			Value (000)
		> Restaurants 0.3%
	2,000,000	AFC Enterprises (a)(b)	$	33,920
		Popeye's Restaurants
	675,000	Bravo Brio Restaurant Group (a)		13,473
		Upscale Casual Italian Restaurants
	450,000	Cheesecake Factory (a)		13,226
		Casual Dining Restaurants
				60,619
		> Nondurables 0.3%
	1,600,000	Helen of Troy (a)(b)		54,416
		Personal Care, Housewares, Healthcare & Home Environment Products
				54,416
		> Educational Services 0.3%
	800,000	New Oriental Education & Technology - ADR (China) (a)		21,968
		Education Service Provider
	300,000	ITT Educational Services (a)(d)		19,842
		Postsecondary Degree Services
	612,205	Universal Technical Institute		8,075
		Vocational Training
	2,000,000	Voyager Learning, Contingent Value Rights (a)(e)(f)		220
		Education Services for the K-12 Market
				50,105
		> Leisure Products 0.1%
	1,290,000	Skullcandy (a)(d)		20,421
		Lifestyle Branded Headphones
				20,421
		> Other Entertainment —%
	265,000	CTS Eventim (Germany)		9,154
		Event Ticket Sales
				9,154
Consumer Goods & Services: Total				3,023,985
Finance 10.2%
		> Banks 4.2%
	2,691,414	BOK Financial		151,473
		Tulsa-based S.W. Bank
	6,287,800	Associated Banc-Corp		87,778
		Midwest Bank
	2,337,313	Hancock Holding		82,998
		Gulf Coast Bank
	5,070,000	Valley National Bancorp		65,657
		New Jersey/New York Bank
	1,175,000	City National		61,652
		Bank & Asset Manager
	2,860,000	MB Financial (b)		60,031
		Chicago Bank
	810,000	SVB Financial Group (a)		52,115
		Bank to Venture Capitalists
	3,400,000	CVB Financial		39,916
		Inland Empire Business Bank
	2,200,000	TCF Financial		26,158
		Great Lakes Bank
	700,000	Wintrust Financial		25,053
		Chicago & Milwaukee Full Service Bank

31

Number of Shares			Value (000)
		> Banks—continued
	1,350,000	TriCo Bancshares (b)	$	23,517
		California Central Valley Bank
	4,299,507	First Busey		21,240
		Illinois Bank
	1,121,188	Sandy Spring Bancorp		20,372
		Baltimore, D.C. Bank
	811,295	Hudson Valley		13,086
		Metro New York City Bank
	2,136,500	TrustCo Bank		12,199
		New York State Bank
	706,559	Eagle Bancorp (a)		11,828
		Metro D.C. Bank
	1,000,000	First Commonwealth		6,120
		Western Pennsylvania Bank
	500,000	Oriental Financial Group		6,050
		Puerto Rican Bank
	246,505	Pacific Continental Bank		2,322
		Pacific N.W. Bank
	152,569	Green Bankshares (a)		258
		Tennessee Bank
				769,823
		> Insurance 2.6%
	2,820,000	Leucadia National		73,602
		Insurance Holding Company
	8,900,000	CNO Financial Group (a)		69,242
		Life, Long Term Care & Medical Supplement Insurance
	2,764,000	Tower Group (b)		61,997
		Commercial & Personal Lines Insurance
	833,000	Allied World Holdings		57,202
		Commercial Lines Insurance/Reinsurance
	1,120,000	The Hanover Insurance Group		46,054
		Personal & Commercial Lines Insurance
	2,050,000	Selective Insurance Group		36,100
		Commercial & Personal Lines Insurance
	1,100,000	HCC Insurance Holdings		34,287
		Specialty Insurance
	832,000	Willis Group (Ireland)		29,103
		Insurance Broker
	925,000	Kemper		28,009
		Multi-line Insurance
	250,000	Enstar Group (a)		24,748
		Insurance/Reinsurance & Related Services
	900,000	Brown & Brown		21,402
		Insurance Broker
	500,000	Assured Guaranty		8,260
		Global Muni Bond Insurance
				490,006
		> Finance Companies 1.4%
	1,459,555	World Acceptance (a)(b)		89,398
		Personal Loans
	2,150,000	McGrath Rentcorp (b)		69,037
		Temporary Space & IT Rentals
	3,400,000	H & E Equipment Services (a)(b)		64,328
		Heavy Equipment Leasing
	1,123,400	CAI International (a)(b)		20,423
		International Container Leasing

Number of Shares			Value (000)
	1,091,000	Marlin Business Services (b)	$	16,430
		Small Equipment Leasing
	422,500	Regional Management (a)		7,098
		Consumer Loans
	78,500	Textainer Group Holdings		2,661
		Top International Container Leaser
				269,375
		> Brokerage & Money Management 1.3%
	6,198,000	SEI Investments		128,237
		Mutual Fund Administration & Investment Management
	3,700,000	Eaton Vance		105,746
		Specialty Mutual Funds
	1,000,000	Artio Global Investors (d)		4,770
		International Asset Manager
				238,753
		> Credit Cards 0.5%
	550,000	Alliance Data Systems (a)		69,278
		Diversified Credit Card Provider
	275,000	Wright Express (a)		17,801
		Pay Card Processor
				87,079
		> Savings & Loans 0.2%
	400,000	Financial Engines (a)		8,944
		Asset Management for 401k Plans
	1,010,000	Provident New York Bancorp		8,545
		New York State Thrift
	470,000	ViewPoint Financial		7,229
		Texas Thrift
	452,146	Kaiser Federal		6,325
		Los Angeles Savings & Loan
	65,991	Berkshire Hills Bancorp		1,512
		Northeast Thrift
				32,555
Finance: Total				1,887,591
Health Care 8.7%
		> Biotechnology & Drug Delivery 4.1%
	2,290,000	Alexion Pharmaceuticals (a)		212,649
		Biotech Focused on Orphan Diseases
	4,315,000	BioMarin Pharmaceutical (a)		147,789
		Biotech Focused on Orphan Diseases
	6,153,000	Seattle Genetics (a)(b)(d)		125,398
		Antibody-based Therapies for Cancer
	3,250,000	Auxilium Pharmaceuticals (a)(b)		60,352
		Biotech Focused on Niche Disease Areas
	2,950,000	InterMune (a)		43,277
		Drugs for Pulmonary Fibrosis & Hepatitis C
	6,000,000	NPS Pharmaceuticals (a)(b)		41,040
		Orphan Drugs & Healthy Royalties
	1,000,000	Onyx Pharmaceuticals (a)		37,680
		Commercial-stage Biotech Focused on Cancer
	3,430,000	Isis Pharmaceuticals (a)		30,081
		Biotech Pioneer in Antisense Drugs
	4,200,000	Raptor Pharmaceutical (a)(b)(d)		28,392
		Orphan Drug Company

32

Columbia Acorn Fund

Statement of Investments (Unaudited), continued

Number of Shares			Value (000)
		> Biotechnology & Drug Delivery—continued
	5,750,000	Chelsea Therapeutics International (a)(b)	$	14,720
		Biotech Focused on Rare Diseases
	2,990,000	Anthera Pharmaceuticals (a)(b)		6,608
		Biotech Focused on Cardiovascular, Cancer & Immunology
	180,167	Synageva Biopharma (a)		6,463
		Biotech Focused on Orphan Diseases
	359,944	MicroDose Therapeutx (a)(e)(f)		270
		Drug Inhaler Development
				754,719
		> Medical Supplies 2.1%
	3,900,000	Cepheid (a)(b)		163,137
		Molecular Diagnostics
	950,000	Henry Schein (a)		71,896
		Largest Distributor of Healthcare Products
	2,126,000	Patterson Companies		71,008
		Dental/Vet/Med Distributor
	1,136,500	DENTSPLY International		45,608
		Leading Dental Supplies Manufacturer
	375,000	Techne		26,287
		Cytokines, Antibodies & Other Reagents for Life Science
				377,936
		> Medical Equipment & Devices 1.3%
	1,873,800	Hill-Rom Holdings		62,604
		Hospital Beds/Patient Handling
	760,000	Gen-Probe (a)		50,472
		Molecular In-vitro Diagnostics
	550,000	Haemonetics (a)		38,324
		Blood & Plasma Collection Equipment
	675,000	Sirona Dental Systems (a)		34,789
		Manufacturer of Dental Equipment
	950,000	PerkinElmer Inc.		26,277
		Analytical Instruments for Life Sciences
	570,000	Orthofix International (a)		21,421
		Bone Fixation & Stimulation Devices
	2,525,000	Pacific Biosciences of California (a)		8,635
		Genome Sequencing
				242,522
		> Health Care Services 0.7%
	665,000	Mednax (a)		49,456
		Physician Management for Pediatric & Anesthesia Practices
	4,900,000	eResearch Technology (a)(b)		38,318
		Clinical Research Services
	1,200,000	Allscripts Healthcare Solutions (a)		19,920
		IT for Physician Offices & Hospitals
	825,000	HealthSouth (a)		16,896
		Inpatient Rehabilitation Facilities
	1,875,000	Health Management Associates (a)		12,600
		Non-urban Hospitals
				137,190
		> Pharmaceuticals 0.5%
	4,000,000	Akorn (a)		46,800
		Develops, Manufactures & Sells Specialty Generic Drugs

Number of Shares			Value (000)
	3,388,000	Adcock Ingram Holdings (South Africa)	$	25,926
		Manufacturer of Pharmaceuticals & Medical Supplies
	2,040,000	Alimera Sciences (a)(b)		6,895
		Ophthalmology-focused Pharmaceutical Company
	1,095,000	Horizon Pharma (a)		4,533
		Specialty Pharmaceutical Company
				84,154
Health Care: Total				1,596,521
Energy & Minerals 8.6%
		> Oil Services 3.9%
	5,298,000	FMC Technologies (a)		267,125
		Oil & Gas Well Head Manufacturer
	1,988,054	Fugro (Netherlands)		141,641
		Sub-sea Oilfield Services
	2,114,000	Atwood Oceanics (a)		94,898
		Offshore Drilling Contractor
	743,000	Oil States International (a)		57,999
		Diversified North American Oil Service Provider
	1,670,000	ShawCor (Canada)		52,572
		Oil & Gas Pipeline Products
	1,000,000	Hornbeck Offshore (a)		42,030
		Supply Vessel Operator in U.S. Gulf of Mexico
	1,056,600	Black Diamond Group (Canada)		21,059
		Provides Accommodations/Equipment for Oil Sands Development
	585,000	Rowan (a)		19,264
		Contract Offshore Driller
	2,890,900	Horizon North Logistics (Canada)		18,114
		Provides Diversified Oil Service Offering in Northern Canada
	4,435,000	Tuscany International Drilling (Colombia) (a)		3,335
		South America-based Drilling Rig Contractor
				718,037
		> Oil & Gas Producers 3.1%
	4,250,000	Pacific Rubiales Energy (Colombia)		124,162
		Oil Production & Exploration in Colombia
	900,000	SM Energy		63,693
		Oil & Gas Producer
	2,700,000	Denbury Resources (a)		49,221
		Oil Producer Using Co2 Injection
	974,000	Rosetta Resources (a)		47,492
		Oil & Gas Producer Exploring in South Texas & Montana
	1,697,000	Tullow Oil (United Kingdom)		41,448
		Oil & Gas Producer
	695,000	Range Resources		40,407
		Oil & Gas Producer
	650,000	Baytex (Canada)		33,749
		Oil & Gas Producer in Canada
	2,160,000	Athabasca Oil Sands (Canada) (a)		24,016
		Oil Sands SAGD & Alberta Deep Basin Development
	1,140,000	Celtic Exploration (Canada) (a)		16,618
		Canadian Oil & Gas Producer

33

Number of Shares			Value (000)
		> Oil & Gas Producers—continued
	550,000	Swift Energy (a)	$	15,966
		Oil & Gas Exploration & Production
	500,000	Cabot Oil and Gas		15,585
		Large Natural Gas Producer in Appalachia & Gulf Coast
	1,547,000	Crew Energy (Canada) (a)		14,765
		Canadian Oil & Gas Producer
	340,000	Petroleum Development Corporation (a)		12,611
		Oil & Gas Producer in U.S.
	7,582,928	PetroMagdalena Energy (Colombia) (a)(b)(d)		12,164
		Oil & Gas Exploration/Production in Colombia
	1,100,000	Kodiak Oil and Gas (a)		10,956
		Bakken Oil & Gas Producer
	37,500,000	Petromanas (Canada) (a)(b)		8,647
	18,750,000	Petromanas - Warrants (Canada) (a)(e)		92
		Exploring for Oil in Albania
	200,000	Approach Resource (a)		7,390
		Oil & Gas Producer in West Texas Permian
	27,000,000	Shamaran Petroleum (Iraq) (a)		6,903
		Oil Exploration in Kurdistan
	26,000,000	Petrodorado (Colombia) (a)(b)		5,995
	24,000,000	Petrodorado - Warrants (Colombia) (a)(e)(f)		941
		Oil & Gas Exploration & Production in Colombia, Peru & Paraguay
	1,198,100	Pan Orient (Canada) (a)		4,889
		Growth-oriented, Return-focused Asian Explorer
	5,917,100	Canacol (Colombia) (a)		4,686
		Oil Producer in South America
	25,000,000	Petroamerica (Colombia) (a)		4,010
		Oil Exploration & Production in Colombia
	41,100,000	Quetzal Energy (Colombia) (a)(b)(e)		2,176
	8,900,000	Quetzal Energy (Colombia) (a)(b)		491
		Explores for Oil & Gas in Latin America
	393,600	Houston American Energy (a)		2,054
		Oil & Gas Exploration/Production in Colombia
	8,400,000	Canadian Overseas Petroleum (United Kingdom) (a)(e)		1,779
	4,200,000	Canadian Overseas Petroleum - Warrants (United Kingdom) (a)(e)(f)		106
		Oil & Gas Exploration/Production in the North Sea
				573,012
		> Mining 1.3%
	442,000	Core Laboratories (Netherlands)		58,154
		Oil & Gas Reservoir Consulting
	1,600,000	Silver Wheaton (Canada)		53,120
		Silver Mining Royalty Company
	15,000,000	Zhaojin Mining Industry (China)		25,231
		Gold Mining & Refining in China
	4,432,000	Northam Platinum (South Africa)		19,713
		Platinum Mining in South Africa
	2,800,000	Alexco Resource (a)		19,544
		Mining, Exploration & Environmental Services

Number of Shares			Value (000)
	1,150,000	Ivanhoe Mines (Mongolia) (a)	$	18,090
		Copper Mine Project in Mongolia
	7,500,000	Duluth Metals (Canada) (a)(b)(d)		17,068
		Copper & Nickel Miner
	920,000	Kirkland Lake Gold (Canada) (a)		13,300
		Gold Mining
	12,000,000	Mongolian Mining (Mongolia) (a)		11,421
		Coking Coal Mining in Mongolia
	800,000	Augusta Resource (a)		2,184
		US Copper/Moly Mine
	4,000,000	Wolverine Minerals (Canada) (a)(b)(e)		674
	2,000,000	Wolverine Minerals - Warrants (Canada) (a)(e)(f)		30
		Gold Miner
	500,000	Duluth Exploration - Special Warrants (Canada) (a)(e)(f)		45
		Copper & Nickel Miner
				238,574
		> Alternative Energy 0.1%
	2,000,000	GT Solar International (a)		16,540
		Largest Manufacturer of Furnaces & Reactors to Produce & Cast Polysilicon
	1,210,300	Synthesis Energy Systems (China) (a)		1,779
		Owner/Operator of Gasification Plants
				18,319
		> Oil Refining, Marketing & Distribution 0.1%
	300,000	Vopak (Netherlands)		17,283
		World's Largest Operator of Petroleum & Chemical Storage Terminals
				17,283
		> Agricultural Commodities 0.1%
	1,250,000	Union Agriculture Group (Argentina) (a)(e)(f)		13,275
		Farmland Operator in Uruguay
				13,275
Energy & Minerals: Total				1,578,500
Other Industries 5.8%
		> Real Estate 3.6%
	3,700,000	Dupont Fabros Technology (b)		90,465
		Technology-focused Office Buildings
	750,000	Federal Realty Investment Trust		72,592
		Shopping Centers
	3,700,000	Associated Estates Realty (b)		60,458
		Multifamily Properties
	1,850,000	Extra Space Storage		53,262
		Self Storage Facilities
	720,000	Digital Realty Trust		53,258
		Technology-focused Office Buildings
	2,450,000	Biomed Realty Trust		46,501
		Life Science-focused Office Buildings
	975,000	Post Properties		45,689
		Multifamily Properties
	770,000	Kilroy Realty		35,890
		West Coast Office & Industrial Properties
	3,000,000	Education Realty Trust		32,520
		Student Housing

34

Columbia Acorn Fund

Statement of Investments (Unaudited), continued

Number of Shares			Value (000)
		> Real Estate—continued
	43,000,000	Mapletree Logistics Trust (Singapore)	$	32,348
		Industrial Property Landlord
	325,000	Jones Lang LaSalle		27,076
		Real Estate Services
	1,300,000	St. Joe (a)(d)		24,713
		Florida Panhandle Landowner
	15,000,000	Ascendas REIT (Singapore)		24,130
		Industrial Property Landlord
	3,750,000	DCT Industrial Trust		22,125
		Industrial Properties
	3,500,000	Kite Realty Group (b)		18,445
		Community Shopping Centers
	2,000,031	Summit Hotel Properties (b)		15,160
		Owner of Select Service Hotels
	2,800	Orix JREIT (Japan)		13,084
		Diversified REIT
				667,716
		> Transportation 1.3%
	1,155,000	JB Hunt Transport Services		62,797
		Truck & Intermodal Carrier
	2,800,000	Rush Enterprises, Class A (a)(b)		59,416
	550,000	Rush Enterprises, Class B (a)(b)		9,565
		Truck Sales & Service
	1,260,000	World Fuel Services		51,660
		Global Fuel Broker
	2,400,000	Heartland Express		34,704
		Regional Trucker
	400,000	Genesee & Wyoming (a)		21,832
		Short-line Operator
				239,974
		> Regulated Utilities 0.9%
	2,000,000	Northeast Utilities		74,240
		Regulated Electric Utility
	1,660,000	Wisconsin Energy		58,399
		Wisconsin Utility
	500,000	Allete		20,745
		Regulated Electric Utility in Minnesota
	200,000	Red Eléctrica de España (Spain)		9,786
		Spanish Power Transmission
				163,170
Other Industries: Total				1,070,860
Total Equities: 97.4% (Cost: $10,807,922)				17,934,688

Number of Shares			Value (000)
Securities Lending Collateral 0.9%
	169,250,625	Dreyfus Government Cash Management Fund (7 day yield of 0.01%) (g)	$	169,251
Total Securities Lending Collateral: (Cost: $169,251)				169,251
Total Investments: 98.3% (Cost: $10,977,173)(h)(i)				18,103,939	(j)
Obligation to Return Collateral for Securities Loaned: (0.9)%				(169,251	)
Cash and Other Assets Less Liabilities: 2.6%				480,744
Total Net Assets: 100.0%			$	18,415,432

ADR - American Depositary Receipts

DVR - Differential Voting Right Equity Shares

GDR - Global Depositary Receipts

35

> 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 three months ended March 31, 2012, are as follows:

Affiliates	Balance of Shares Held at 12/31/11		Purchases/ Additions		Sales/ Reductions		Balance of Shares Held at 3/31/12		Value		Dividend
AboveNet		1,400,000		-		-		1,400,000	$	115,920	$	-
Acorn Energy		1,500,000		-		-		1,500,000		16,305		128
AFC Enterprises		2,000,000		-		-		2,000,000		33,920		-
Alimera Sciences		2,040,000		-		-		2,040,000		6,895		-
Anthera Pharmaceuticals		1,740,000		1,250,000		-		2,990,000		6,608		-
Associated Estates Realty		3,700,000		-		-		3,700,000		60,458		629
Auxilium Pharmaceuticals		3,033,715		216,285		-		3,250,000		60,352		-
Bally Technologies		3,725,000		-		-		3,725,000		174,144		-
CAI International		1,123,400		-		-		1,123,400		20,423		-
Cavco Industries		460,000		-		-		460,000		21,427		-
Cepheid		3,200,000		700,000		-		3,900,000		163,137		-
Chelsea Therapeutics International		4,550,000		1,200,000		-		5,750,000		14,720		-
Cogent Communications*		2,520,000		-		320,000		2,200,000		41,976		-
Constant Contact		2,350,000		-		-		2,350,000		70,006		-
Donaldson**		4,200,000		4,200,000		-		8,400,000		300,132		672
Drew Industries		1,500,000		380,000		-		1,880,000		51,343		-
Duluth Metals		7,500,000		-		-		7,500,000		17,068		-
Dupont Fabros Technology		3,350,000		350,000		-		3,700,000		90,465		378
eResearch Technology		4,900,000		-		-		4,900,000		38,318		-
ESCO Technologies		2,200,000		-		-		2,200,000		80,894		176
Gaiam		1,371,366		-		-		1,371,366		5,458		-
Gaylord Entertainment		3,850,000		-		-		3,850,000		118,580		-
General Communications		2,000,000		-		-		2,000,000		17,440		-
GLG Life Tech		1,750,000		-		71,875		1,678,125		1,326		-
H & E Equipment Services		3,400,000		-		-		3,400,000		64,328		-
Hackett Group+		4,500,000		-		650,793		3,849,207		22,980		-
Heico		2,250,000		200,000		-		2,450,000		98,368		135
Helen of Troy		1,600,000		-		-		1,600,000		54,416		-
Horizon Pharma*		1,095,000		-		-		1,095,000		4,533		-
iGATE		3,400,000		-		-		3,400,000		56,984		-
II-VI		4,550,000		-		-		4,550,000		107,607		-
Interline Brands		2,600,000		-		200,249		2,399,751		51,859		-
IPG Photonics		2,780,000		-		-		2,780,000		144,699		-
IXYS		1,900,000		-		-		1,900,000		25,080		-
Kenexa		1,700,000		-		-		1,700,000		53,108		-
Kite Realty Group		3,500,000		-		-		3,500,000		18,445		210
Knoll		4,200,000		-		-		4,200,000		69,888		420
Lifetime Fitness		2,190,000		-		-		2,190,000		110,748		-
lululemon athletica*		5,740,000		-		817,200		4,922,800		367,635		-
Marlin Business Services		1,091,000		-		-		1,091,000		16,430		65
MB Financial		2,360,000		500,000		-		2,860,000		60,031		26
McGrath Rentcorp		2,150,000		-		-		2,150,000		69,037		495
Mettler Toledo		1,600,000		-		-		1,600,000		295,600		-
Micromet*		6,702,347		64,547		6,766,894		-		-		-
Moog		2,775,000		-		-		2,775,000		119,020		-
Navigant Consulting		2,800,000		-		-		2,800,000		38,948		-
NPS Pharmaceuticals		6,000,000		-		-		6,000,000		41,040		-
Pericom Semiconductor		1,765,000		-		-		1,765,000		14,279		-
Petroamerica*		30,275,000		-		5,275,000		25,000,000		4,010		-
Petrodorado		26,000,000		-		-		26,000,000		5,995		-
PetroMagdalena Energy		7,582,928		-		-		7,582,928		12,164		-
Petromanas		37,500,000		-		-		37,500,000		8,647		-
Pier 1 Imports		5,600,000		-		-		5,600,000		101,808		-
Pinnacle Entertainment		3,950,000		-		-		3,950,000		45,464		-
Quetzal Energy		50,000,000		-		-		50,000,000		2,667		-
Raptor Pharmaceutical		3,455,000		745,000		-		4,200,000		28,392		-
Rush Enterprises		3,350,000		-		-		3,350,000		68,981		-
Salem Communications*		1,527,700		-		1,527,700		-		-		-

36

Columbia Acorn Fund

Statement of Investments (Unaudited), continued

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

Affiliates	Balance of Shares Held at 12/31/11		Purchases/ Additions		Sales/ Reductions		Balance of Shares Held at 3/31/12		Value		Dividend
Seattle Genetics		6,153,000		-		-		6,153,000	$	125,398	$	-
Shutterfly		3,070,000		300,000		-		3,370,000		105,582		-
SPS Commerce		900,000		-		-		900,000		24,192		-
Summit Hotel Properties		1,500,000		500,031		-		2,000,031		15,160		188
Tower Group		1,675,000		1,089,000		-		2,764,000		61,997		518
TriCo Bancshares		1,350,000		-		-		1,350,000		23,517		122
True Religion Apparel*		1,507,000		-		1,113,548		393,452		10,780		-
tw telecom		9,500,000		-		-		9,500,000		210,520		-
Tyler Technologies		1,700,000		-		-		1,700,000		65,297		-
Virtusa		2,125,000		-		-		2,125,000		36,699		-
Warnaco Group		2,190,000		-		-		2,190,000		127,896		-
Wolverine Minerals		4,000,000		-		-		4,000,000		674		-
World Acceptance		1,505,202		-		45,647		1,459,555		89,398		-
Total of Affiliated Transactions		345,027,658		11,694,863		16,788,906		339,933,615	$	4,607,616	$	4,162

*  At March 31, 2012, the Fund owned less than five percent of the company's outstanding voting shares.

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

+  Includes the effects of a corporate action.

  The aggregate cost and value of these companies at March 31, 2012, were $2,743,348 and $4,178,682, respectively. Investments in affiliated companies represented 22.69% of the Fund's total net assets at March 31, 2012.

(c)  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 March 31, 2012, this security had an aggregate value of $15,780, which represented 0.09% of total net assets.

(d)  All or a portion of this security was on loan at March 31, 2012. The total market value of securities on loan at March 31, 2012 was $166,411.

(e)  Denotes a restricted security, which is subject to restrictions on resale under federal securities laws. These securities are valued at fair value determined in good faith under consistently applied procedures established by the Board of Trustees. At March 31, 2012, the market value of these securities amounted to $19,608, which represented 0.11% of total net assets.

  Additional information on these securities is as follows:

Security	Acquisition Dates	Shares		Cost		Value
Union Agriculture Group	12/8/10-12/16/11		1,250,000	$	15,000	$	13,275
Quetzal Energy	1/14/11		41,100,000		5,193		2,176
Canadian Overseas Petroleum	11/24/10		8,400,000		3,591		1,779
Petrodorado - Warrants	11/20/09		24,000,000		2,965		941
Wolverine Minerals	6/3/11		4,000,000		2,005		674
MicroDose Therapeutx	11/24/00		359,944		2,005		270
Voyager Learning, Contingent Value Rights	12/24/09		2,000,000		-		220
Canadian Overseas Petroleum - Warrants	11/24/10		4,200,000		526		106
Petromanas - Warrants	5/20/10		18,750,000		1,086		92
Duluth Exploration - Special Warrants	8/19/11		500,000		-		45
Wolverine Minerals - Warrants	6/3/11		2,000,000		243		30
				$	32,614	$	19,608

(f)  Illiquid security.

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

(h)  At March 31, 2012, for federal income tax purposes, the cost of investments was $10,977,173 and net unrealized appreciation was $7,126,766 consisting of gross unrealized appreciation of $7,687,302 and gross unrealized depreciation of $(560,536).

37

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

(i)  On March 31, 2012, the market value of foreign securities represented 9.36% of total net assets. The Fund's foreign portfolio was diversified as follows:

	Value		Percentage of Net Assets
Netherlands	$	315,070		1.71
Canada		306,968		1.67
Colombia		157,960		0.86
Singapore		144,270		0.78
Sweden		100,243		0.54
Hong Kong		97,128		0.53
Japan		72,621		0.39
China		69,964		0.38
Brazil		59,690		0.32
France		47,758		0.26
South Africa		45,639		0.25
Denmark		44,415		0.24
United Kingdom		43,333		0.24
	Value		Percentage of Net Assets
Chile	$	39,485		0.21
Israel		33,951		0.18
Mongolia		29,511		0.16
Ireland		29,103		0.16
India		19,969		0.12
Russia		15,780		0.09
Argentina		13,275		0.07
Iceland		11,735		0.06
Spain		9,786		0.05
Germany		9,154		0.05
Iraq		6,903		0.04
Total Foreign Portfolio	$	1,723,711		9.36

(j)  Securities are valued using policies described in the Notes to Financial Statements in the most recent shareholder report.

  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.

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

  The Committee meets at least quarterly to review and approve valuation matters, which may include a description of fair value actions, data regarding pricing information received from approved pricing vendors and brokers and the results of Board-approved valuation control policies and procedures (the Policies). The Policies address, among other things, instances when market quotations are readily available, including recommendation of third party pricing vendors and determining appropriate pricing methodologies; events that require fair valuation and assessment of fair value techniques; securities with a potential for stale pricing, including those that are illiquid, restricted, or in default; and the effectiveness of third-party pricing vendors. The Committee meets more frequently, as needed, to discuss additional valuation matters, which may include the need to review back-testing results, review time-sensitive information or approve related valuation actions.

  For investments categorized as Level 3, the Committee monitors information similar to that described above, which may include: (i) data specific to the issuer or comparable issuers, (ii) general market or specific sector news and (iii) quoted prices and specific or similar security transactions. The Committee considers this data and any changes from prior periods in order to assess the reasonableness of observable and unobservable inputs, any assumptions or internal models used to value those securities and changes in fair value. This data is also used to corroborate, when available, information received from approved pricing vendors. Various factors impact the frequency of monitoring (which may occur as often as daily), however the Committee may determine that changes to inputs, assumptions and models are not required with the same frequency.

38

Columbia Acorn Fund

Statement of Investments (Unaudited), continued

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

  The following table summarizes the inputs used, as of March 31, 2012, in valuing the Fund's assets:

Investment Type	Quoted Prices (Level 1)		Other Significant Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)		Total
Equities
Information	$	5,051,628	$	281,190	$	-	$	5,332,818
Industrial Goods & Services		3,205,616		238,797		-		3,444,413
Consumer Goods & Services		2,898,177		125,588		220		3,023,985
Finance		1,887,591		-		-		1,887,591
Health Care		1,570,325		25,926		270		1,596,521
Energy & Minerals		1,302,645		262,535		13,320		1,578,500
Other Industries		991,512		79,348		-		1,070,860
Total Equities		16,907,494		1,013,384		13,810		17,934,688
Total Securities Lending Collateral		169,251		-		-		169,251
Total Investments	$	17,076,745	$	1,013,384	$	13,810	$	18,103,939

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

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

Transfers In				Tranfers Out
Level 1		Level 2		Level 1		Level 2
$	-	$	115,086	$	115,086	$	-

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

  The following table reconciles asset balances for the period ending March 31, 2012, in which significant unobservable inputs (Level 3) were used in determining value:

Investments in Securities	Balance as of December 31, 2011		Realized Gain/(Loss)		Change in Unrealized Appreciation (Depreciation)		Purchases		Sales		Transfers into Level 3		Transfers out of Level 3		Balance as of March 31, 2012
Equities
Consumer Goods & Services	$	180	$	-	$	40	$	-	$	-	$	-	$	-	$	220
Health Care		270		-		-		-		-		-		-		270
Energy & Minerals		12,507		-		813		-		-		-		-		13,320
	$	12,957	$	-	$	853	$	-	$	-	$	-	$	-	$	13,810

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

  The change in unrealized appreciation attributed to securities owned at March 31, 2012, which were valued using significant unobservable inputs (Level 3) amounted to $853.

39

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

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

  Certain common stock classified as Level 3 are valued using a market approach. To determine fair value for these securities, management considered various factors which may have included, but were not limited to, trades of similar securities, estimated earnings of the respective company, market multiples derived from a set of comparable companies, and the position of the security within the respective company's capital structure. Significant increases (decreases) to any of these inputs would result in a significantly lower (higher) fair value measurement. Generally, a change in estimated earnings of the respective company may result in a change to the comparable companies and market multiples utilized.

40

Columbia Acorn International

Major Portfolio Changes in the First Quarter (Unaudited)

	Number of Shares
	12/31/11		03/31/12
Purchases
Asia
> Japan
Daiseki		1,277,429		1,427,129
Disco		306,000		480,000
Doshisha		24,000		750,600
FP Corporation		254,000		339,000
Glory		1,055,562		1,694,562
Horiba		0		257,800
Nihon Parkerizing		0		145,700
Park24		2,263,000		3,029,900
Sanrio		0		500,000
Start Today		527,001		1,718,724
> Taiwan
Chroma Ate		9,857,400		10,277,000
CTCI Corp		13,957,000		18,571,200
MStar Semiconductor		0		2,930,000
St. Shine Optical		2,450,000		2,492,300
Taiwan Hon Chuan		10,357,000		11,200,000
Taiwan Mobile		6,647,000		10,329,000
Tripod Technologies		10,147,270		12,218,270
> Hong Kong
Lifestyle International		17,000,000		18,000,000
Melco International		7,419,000		8,000,000
Sasa International		37,703,800		38,000,000
> Singapore
CDL Hospitality Trust		18,000,000		20,000,000
Mapletree Commercial Trust		32,300,000		35,000,000
> China
Digital China		12,446,800		13,570,200
Want Want		19,410,400		26,565,000
> India
Redington India		0		1,477,269
United Breweries		1,500,251		2,262,300
> Korea
Grand Korea Leisure		0		1,134,000
Hana Tour Service		0		182,000
Handsome		61,600		471,971
Hyundai Home Shopping		0		10,090
iMarketKorea		0		570,990
> Mongolia
Mongolian Mining		35,923,500		42,636,400
> Indonesia
Tower Bersama Infrastructure		13,942,000		48,560,000
> Cambodia
Nagacorp		42,522,600		50,000,000

	Number of Shares
	12/31/11		03/31/12
Europe
> United Kingdom
BBA Aviation		0		3,167,139
Greggs		467,193		1,060,885
Rightmove		0		548,000
> Netherlands
TKH Group		0		403,800
> Switzerland
Dufry Group		324,000		360,000
Geberit		225,650		255,000
Partners Group		265,000		280,000
Zehnder		0		236,217
> Italy
Geox		5,300,000		5,800,000
Pirelli		1,756,000		2,661,000
> Denmark
Solar A/S		0		130,651
> Spain
Red Eléctrica de España		494,320		618,320
> Portugal
Redes Energéticas Nacionais		7,770,405		8,531,175
> Kazakhstan
Halyk Savings Bank of Kazakhstan - GDR		1,770,000		3,319,000
Other Countries
> South Africa
Coronation Fund Managers		10,271,492		11,763,907
Northam Platinum		6,943,940		8,679,940
> Canada
Alliance Grain Traders		868,000		984,500
Americas Petrogas		0		1,611,000
> Australia
Challenger Financial		0		4,546,885
Commonwealth Property Office Fund		0		17,451,906
> Israel
Caesarstone		0		125,000
Israel Chemicals		3,085,527		4,706,527
Latin America
> Argentina
Madalena Ventures		0		2,475,000
> Chile
Viña Concha y Toro		0		4,016,878

41

	Number of Shares
	12/31/11		03/31/12
Sales
Asia
> Japan
Gree		1,139,000		246,300
Hamamatsu Photonics		479,854		0
Hoshizaki Electric		1,697,200		1,582,200
Kansai Paint		7,044,100		5,582,600
Miura		636,250		511,450
Pigeon		469,500		0
Shinsei Bank		25,769,649		18,673,649
> Taiwan
Formosa International Hotels		468,917		0
President Chain Store		7,000,000		3,181,000
> Singapore
Ascendas REIT		21,600,000		20,000,000
Mapletree Industrial Trust		39,000,000		28,000,000
Mapletree Logistics Trust		50,000,000		35,000,000
Olam International		33,000,000		27,000,000
> China
China Yurun Food		12,047,000		0
ENN Energy		5,000,000		0
Noah Holdings - ADR		493,398		0
Zhaojin Mining Industry		34,745,554		18,920,554
> India
Manappuram Finance		16,621,332		1,668,793
> Korea
MegaStudy		63,916		0
Woongjin Coway		1,242,590		623,410
> Thailand
Home Product Center		120,000,000		118,000,000
> Philippines
SM Prime Holdings		69,967,000		58,577,000
Europe
> United Kingdom
Chemring		5,700,000		5,654,735
GlobeOp Financial Services		4,150,000		0
Intertek Group		1,480,000		1,460,000
Kesa Electricals		2,533,060		0
Next		446,300		262,300
> Netherlands
Core Laboratories		228,095		177,395
Imtech		1,955,311		1,763,611
Koninklijke TenCate		1,371,573		1,181,073
> Switzerland
Bank Sarasin & Cie		696,331		580,000

	Number of Shares
	12/31/11		03/31/12
> Germany
CTS Eventim		819,889		625,000
Dürr		636,800		500,000
> France
Eurofins Scientific		532,368		418,000
Gemalto		1,193,000		1,073,700
Neopost		555,324		430,000
> Italy
CIR		13,547,300		12,503,754
> Ireland
United Drug		9,074,112		6,750,000
Other Countries
> South Africa
Mr. Price		3,722,083		3,175,083
> United States
FMC Technologies		606,253		461,213
Latin America
> Brazil
Localiza Rent A Car		4,000,000		3,700,000
Mills Estruturas e Servicos de Engenharia		2,303,200		1,880,200
Suzano		6,344,043		0
> Mexico
Grupo Aeroportuario del Sureste - ADR		624,168		600,000
> Chile
Sociedad Quimica y Minera de Chile - ADR		362,996		0

42

Columbia Acorn International

Statement of Investments (Unaudited), March 31, 2012

Number of Shares			Value (000)
			Equities: 95.7%
Asia 42.3%
		> Japan 17.3%
	5,582,600	Kansai Paint	$	56,596
		Paint Producer in Japan, India, China & Southeast Asia
	22,694,000	Seven Bank		49,767
		ATM Processing Services
	22,300	Wacom (a)		46,834
		Computer Graphic Illustration Devices
	2,981,100	Kuraray		42,398
		Special Resin, Fine Chemical, Fibers & Textures
	3,029,900	Park24		40,971
		Parking Lot Operator
	1,860,438	Aeon Delight		39,233
		Facility Maintenance & Management
	1,582,200	Hoshizaki Electric		37,531
		Commercial Kitchen Equipment
	1,694,562	Glory		37,164
		Currency Handling Systems & Related Equipment
	7,780	Orix JREIT		36,356
		Diversified REIT
	2,400,000	NGK Insulators		34,575
		Ceramic Products for Auto, Power & Electronics
	937,651	Kintetsu World Express		32,758
		Airfreight Logistics
	589,792	Ain Pharmaciez		31,834
		Dispensing Pharmacy/Drugstore Operator
	1,718,724	Start Today		31,742
		Online Japanese Apparel Retailer
	295,762	Nakanishi		31,399
		Dental Tools & Machinery
	16,005	Advance Residence Investment		30,405
		Residential REIT
	2,137,272	Japan Airport Terminal		28,174
		Airport Terminal Operator at Haneda
	480,000	Disco		26,729
		Semiconductor Dicing & Grinding Equipment
	1,427,129	Daiseki		26,533
		Waste Disposal & Recycling
	25,979	Jupiter Telecommunications		26,020
		Largest Cable Service Provider in Japan
	855,604	Tsumura		24,732
		Traditional Chinese/Japanese Herbal Rx Drugs (Kampo)
	18,673,649	Shinsei Bank		24,582
		Commercial Bank
	2,600,000	Shimadzu		23,663
		Analytical Instrument, Medical & Industrial Equipment
	6,140	Kenedix Realty Investment		22,592
		Tokyo Mid-size Office REIT
	1,885,600	Asahi Diamond Industrial		22,292
		Consumable Diamond Tools
	857,144	Ibiden		22,164
		Electronic Parts & Ceramics

Number of Shares			Value (000)
	5,540	Mori Hills REIT Investment	$	22,162
		Tokyo-centric Diversified REIT
	1,940,200	Sintokogio		21,723
		Automated Casting Machines, Surface Treatment System & Consumables
	750,600	Doshisha		21,581
		Wholesaler
	339,000	FP Corporation		21,373
		Disposable Food Trays & Containers
	880,474	Aeon Mall		20,567
		Suburban Shopping Mall Developer, Owner & Operator
	1,405,739	Ushio		19,914
		Industrial Light Sources
	500,000	Sanrio (b)		19,528
		Character Goods & Licensing
	772,000	Misumi Group		18,870
		Industrial Components Distributor
	1,346,963	Torishima Pump Manufacturing		18,472
		Industrial Pump for Power Generation & Water Supply Systems
	732,108	Icom		17,800
		Two Way Radio Communication Equipment
	2,417	Fukuoka REIT		17,371
		Diversified REIT in Fukuoka
	1,603	Japan Real Estate Investment		14,134
		Office REIT in Tokyo
	511,450	Miura		13,302
		Industrial Boiler
	257,800	Horiba		8,898
		Measuring Instruments & Analyzers
	246,300	Gree (b)		6,206
		Mobile Social Networking Game Developer/Platform
	145,700	Nihon Parkerizing		2,166
		Metal Surface Treatment Agents & Processing
				1,091,111
		> Taiwan 6.5%
	36,606,000	Far EasTone Telecom		75,238
		Taiwan's Third Largest Mobile Operator
	5,614,530	Simplo Technology		42,547
		Battery Packs for Notebook & Tablet PCs
	12,218,270	Tripod Technologies		41,172
		Printed Circuit Boards (PCB)
	2,492,300	St. Shine Optical		32,412
		World's Leading Disposable Contact Lens OEM
	10,329,000	Taiwan Mobile		31,491
		Taiwan's Second-largest Mobile Operator
	18,571,200	CTCI Corp		30,790
		International Engineering Firm
	5,910,000	Radiant Opto-Electronics		26,393
		LCD Back Light Units & Modules
	10,277,000	Chroma Ate		26,310
		Automatic Test Systems, Testing & Measurement Instruments
	11,200,000	Taiwan Hon Chuan		25,449
		Beverage Packaging (Bottles, Caps, Labels) Manufacturer

43

Number of Shares			Value (000)
		> Taiwan—continued
	6,603,000	Advantech	$	22,973
		Industrial PC & Components
	2,930,000	MStar Semiconductor		17,953
		ICs for TV, Digital Set-top-box & Handset
	3,181,000	President Chain Store		17,745
		Taiwan's Number One Convenience Chain Store Operator
	2,595,000	PC Home		14,671
		Taiwanese Internet Retail Company
	2,468,300	Lung Yen		7,895
		Funeral Services & Columbaria
				413,039
		> Hong Kong 4.0%
	7,000,000	Melco Crown Entertainment - ADR (c)		95,270
		Macau Casino Operator
	18,000,000	Lifestyle International		45,856
		Mid to High-end Department Store Operator in Hong Kong & China
	15,625,000	L'Occitane International		37,052
		Skin Care & Cosmetics Producer
	8,475,000	AAC Technologies		23,083
		Miniature Acoustic Components
	12,500,000	MGM China Holdings		22,819
		Macau Casino Operator
	38,000,000	Sasa International		22,050
		Cosmetics Retailer
	8,000,000	Melco International (c)		7,642
		Macau Casino Operator
				253,772
		> Singapore 3.6%
	27,000,000	Olam International		50,740
		Agriculture Supply Chain Manager
	20,000,000	Ascendas REIT		32,174
		Industrial Property Landlord
	20,000,000	CDL Hospitality Trust		27,648
		Hotel Owner/Operator
	35,000,000	Mapletree Logistics Trust		26,329
		Industrial Property Landlord
	28,000,000	Mapletree Industrial Trust		24,477
		Industrial Property Landlord
	35,000,000	Mapletree Commercial Trust		24,406
		Retail & Office Property Landlord
	15,000,000	Goodpack Limited		21,186
		International Bulk Container Leasing
	3,500,000	Singapore Exchange		19,359
		Singapore Equity & Derivatives Market Operator
				226,319
		> China 3.3%
	644,000	NetEase.com - ADR (c)		37,416
		Chinese Online Gaming Services
	18,920,554	Zhaojin Mining Industry		31,826
		Gold Mining & Refining in China
	1,100,000	New Oriental Education & Technology - ADR (c)		30,206
		Education Service Provider
	26,565,000	Want Want		29,725
		Chinese Branded Consumer Food Company

Number of Shares			Value (000)
	13,570,200	Digital China	$	26,998
		IT Distribution & Systems Integration Services
	220,000,000	RexLot Holdings (b)		19,557
		Lottery Equipment Supplier in China
	28,763,700	AMVIG Holdings		15,604
		Chinese Tobacco Packaging Material Supplier
	263,700	51job - ADR (b)(c)		14,994
		Integrated Human Resource Services
				206,326
		> India 2.1%
	2,262,300	United Breweries		23,890
		India's Largest Brewer
	341,652	Asian Paints		21,739
		India's Largest Paint Company
	11,163,303	Jain Irrigation Systems		21,537
	558,165	Jain Irrigation Systems - DVR (c)		525
		Agricultural Micro-irrigation Systems & Food Processing
	8,052,053	Adani Ports & Special Economic Zone		20,442
		Indian West Coast Shipping Port
	1,550,000	Shriram Transport Finance		18,232
		Used Truck Finance
	32,642,905	REI Agro		7,849
		Basmati Rice Processing
	10,249,300	S. Kumars Nationwide		6,646
		Textiles, Clothing & Retail
	791,352	Titan Industries		3,549
		Jewelry, Watches, Eyeglasses
	1,650,000	SKIL Ports and Logistics (c)		3,220
		Indian Container Port Project
	1,477,269	Redington India		2,555
		Supply Chain Solutions for IT & Mobile Handsets in Emerging Markets
	1,668,793	Manappuram Finance		997
		Short-term Lending Collateralized by Household Gold
				131,181
		> Korea 1.6%
	101,150	NHN		23,216
		Korean Online Search Services
	1,134,000	Grand Korea Leisure		21,907
		Largest 'Foreigner Only' Casino Group in Korea
	623,410	Woongjin Coway		20,729
		Korean Household Appliance Rental Service Provider
	471,971	Handsome		13,873
		Korea's Leading High-end Apparel Company
	570,990	iMarketKorea		9,865
		Procurement, Distribution of MRO (Maintenance, Repair, Operations) Goods
	182,000	Hana Tour Service		7,244
		Korea's Largest Wholesale Tour Provider
	10,090	Hyundai Home Shopping		1,198
		TV Home Shopping Company
				98,032

44

Columbia Acorn International

Statement of Investments (Unaudited), continued

Number of Shares			Value (000)
		> Mongolia 1.1%
	42,636,400	Mongolian Mining (c)	$	40,577
		Coking Coal Mining in Mongolia
	1,049,943	Ivanhoe Mines (c)		16,516
		Copper Mine Project in Mongolia
	914,678	Ivanhoe Mines (c)(d)		14,397
		Copper Mine Project in Mongolia
				71,490
		> Indonesia 0.9%
	29,063,787	Archipelago Resources (a)(c)		30,217
		Gold Mining Projects in Indonesia, Vietnam & the Philippines
	48,560,000	Tower Bersama Infrastructure		15,696
		Communications Towers
	10,000,000	Ace Indonesia		4,872
		Home Improvement Retailer
	6,937,300	Jasa Marga		3,914
		Largest Toll Road Operator in Indonesia
	6,217,500	Southern Arc Minerals (a)(c)(e)		2,663
		Gold & Copper Exploration in Indonesia
				57,362
		> Thailand 0.8%
	118,000,000	Home Product Center		53,181
		Home Improvement Retailer
				53,181
		> Philippines 0.7%
	58,577,000	SM Prime Holdings		23,053
		Shopping Mall Operator
	7,931,700	Int'l Container Terminal		12,116
		Container Handling Terminals & Port Management
	19,454,700	Manila Water Company		10,535
		Water Utility Company in the Philippines
				45,704
		> Cambodia 0.4%
	50,000,000	Nagacorp		22,733
		Casino/Entertainment Complex in Cambodia
				22,733
Asia: Total				2,670,250
Europe 33.0%
		> United Kingdom 5.8%
	1,460,000	Intertek Group		58,639
		Testing, Inspection, Certification Services
	5,654,735	Chemring		36,857
		Defense Manufacturer of Countermeasures & Energetics
	3,000,000	JLT Group		33,518
		International Business Insurance Broker
	3,305,000	Serco		28,678
		Facilities Management
	7,500,000	Workspace Group (a)		28,221
		UK Real Estate
	730,000	Rotork		23,925
		Valve Actuators for Oil & Water Pipelines

Number of Shares			Value (000)
	740,581	Tullow Oil	$	18,088
		Oil & Gas Producer
	1,761,742	Smith and Nephew		17,851
		Medical Equipment & Supplies
	2,497,000	Domino's Pizza United Kingdom & Ireland		17,238
		Pizza Delivery in the United Kingdom, Ireland & Germany
	2,636,932	Premier Oil (c)		16,546
		Oil & Gas Producer in Europe, Pakistan & Asia
	2,950,000	Abcam		16,468
		Online Sales of Antibodies
	1,773,408	Shaftesbury		13,970
		London Prime Retail REIT
	548,000	Rightmove		12,727
		Internet Real Estate Listings
	262,300	Next		12,515
		Clothes & Home Retailer in the UK
	3,167,139	BBA Aviation		10,841
		Aviation Support Services
	1,060,885	Greggs		8,832
		Bakery
	4,163,948	PureCircle (b)(c)		7,127
		Natural Sweeteners
	2,840,000	Sterling Resources (c)		4,556
		Oil & Gas Exploration in Europe
				366,597
		> Netherlands 5.1%
	1,763,611	Imtech		56,380
		Electromechanical & ICT Installation & Maintenance
	2,479,123	Aalberts Industries		51,249
		Flow Control & Heat Treatment
	687,967	Fugro		49,015
		Sub-sea Oilfield Services
	1,591,702	UNIT4 (a)		46,172
		Business Software Development
	1,181,073	Koninklijke TenCate (a)		41,034
		Advanced Textiles & Industrial Fabrics
	1,252,514	Arcadis		26,176
		Engineering Consultants
	177,395	Core Laboratories		23,340
		Oil & Gas Reservoir Consulting
	317,424	Vopak		18,287
		World's Largest Operator of Petroleum & Chemical Storage Terminals
	403,800	TKH Group		10,968
		Dutch Industrial Conglomerate
				322,621
		> Switzerland 4.1%
	280,000	Partners Group		54,623
		Private Markets Asset Management
	255,000	Geberit (c)		53,362
		Plumbing Supplies
	360,000	Dufry Group (c)		47,059
		Operates Airport Duty Free & Duty Paid Shops
	15,500	Sika		33,551
		Chemicals for Construction & Industrial Applications

45

Number of Shares			Value (000)
		> Switzerland—continued
	245,000	Kuehne & Nagel	$	33,139
		Freight Forwarding/Logistics
	580,000	Bank Sarasin & Cie		18,183
		Private Banking
	236,217	Zehnder		17,506
		Radiators & Ventilation Systems
				257,423
		> Germany 3.9%
	2,500,000	Wirecard		47,596
		Online Payment Processing & Risk Management
	679,600	Rheinmetall		40,239
		Defense & Automotive
	148,295	Rational		34,681
		Commercial Ovens
	1,600,000	Rhoen-Klinikum		32,126
		Health Care Services
	500,000	Dürr		31,829
		Automotive Plant Engineering & Associated Capital Equipment
	625,000	CTS Eventim		21,589
		Event Ticket Sales
	555,700	Elringklinger		15,912
		Automobile Components
	165,400	Bertrandt		12,464
		Outsourced Engineering
	338,886	Deutsche Beteiligungs (b)		7,690
		Private Equity Investment Management
				244,126
		> France 3.8%
	1,073,700	Gemalto		70,869
		Digital Security Solutions
	418,000	Eurofins Scientific		45,602
		Food, Pharmaceuticals & Materials Screening & Testing
	971,800	Saft Batteries		31,495
		Niche Battery Manufacturer
	430,000	Neopost		27,654
		Postage Meter Machines
	353,648	Rubis		20,680
		Tank Storage & LPG Distribution
	232,400	Norbert Dentressangle		20,643
		Leading European Logistics & Transport Group
	460,000	Mersen		16,304
		Advanced Industrial Materials
	1,831,204	Hi-Media (b)(c)		6,399
		Online Advertiser in Europe
				239,646
		> Sweden 2.4%
	4,056,007	Hexagon		78,720
		Design, Measurement & Visualization Software & Equipment
	4,150,024	Sweco (a)		45,008
		Engineering Consultants

Number of Shares			Value (000)
	658,700	Unibet	$	18,469
		European Online Gaming Operator
	905,452	East Capital Explorer		7,630
		Sweden-based RUS/CEE Investment Fund
				149,827
		> Italy 1.8%
	2,661,000	Pirelli		31,657
		Global Tire Supplier
	2,621,149	Ansaldo STS		26,009
		Railway Systems Integrator
	5,800,000	Geox		18,952
		Apparel & Shoe Maker
	166,200	Tod's (b)		18,697
		Leather Shoes & Bags
	12,503,754	CIR		17,693
		Italian Holding Company
				113,008
		> Denmark 1.3%
	1,648,800	Novozymes		48,020
		Industrial Enzymes
	168,042	SimCorp		29,365
		Software for Investment Managers
	130,651	Solar A/S		7,189
		Technical Wholesaler of Electrical, Plumbing & HVAC Equipment
				84,574
		> Russia 0.7%
	629,642	Mail.ru - GDR (c)(f)		24,839
		Internet Social Networking & Games for Russian Speakers
	2,109,700	Petropavlovsk		18,796
		Gold & Iron Ore Mining in Russia
				43,635
		> Iceland 0.6%
	35,982,499	Marel		41,095
		Largest Manufacturer of Poultry & Fish Processing Equipment
				41,095
		> Ireland 0.6%
	6,750,000	United Drug		19,085
		Irish Pharmaceutical Wholesaler & Outsourcer
	289,400	Paddy Power		18,226
		Irish Betting Services
				37,311
		> Spain 0.5%
	618,320	Red Eléctrica de España		30,257
		Spanish Power Transmission
				30,257
		> Norway 0.5%
	2,403,664	Atea		29,018
		Leading Nordic IT Hardware/Software Reseller & Installation Company
				29,018

46

Columbia Acorn International

Statement of Investments (Unaudited), continued

Number of Shares			Value (000)
		> Czech Republic 0.4%
	130,682	Komercni Banka	$	26,023
		Leading Czech Universal Bank
				26,023
		> Portugal 0.4%
	8,531,175	Redes Energéticas Nacionais		25,828
		Portuguese Power Transmission & Gas Transportation
				25,828
		> Belgium 0.4%
	438,880	EVS Broadcast Equipment		22,758
		Digital Live Mobile Production Software & Systems
				22,758
		> Finland 0.3%
	1,039,429	Stockmann		22,402
		Department Store & Fashion Retailer in Scandinavia & Russia
				22,402
		> Kazakhstan 0.3%
	3,319,000	Halyk Savings Bank of Kazakhstan - GDR (c)		21,574
		Largest Retail Bank & Insurer in Kazakhstan
				21,574
		> Greece 0.1%
	6,954,400	Intralot		6,623
		Lottery & Gaming Systems & Services
				6,623
Europe: Total				2,084,346
Other Countries 16.2%
		> South Africa 4.6%
	1,170,188	Naspers		65,748
		Media in Africa, China, Russia & Other Emerging Markets
	11,763,907	Coronation Fund Managers		43,707
		South African Fund Manager
	19,098,300	Rand Merchant Insurance		42,847
		Directly Sold Property & Casualty Insurance; Holdings in Other Insurers
	3,175,083	Mr. Price		39,048
		South African Retailer of Apparel, Household & Sporting Goods
	8,679,940	Northam Platinum		38,608
		Platinum Mining in South Africa
	4,992,200	Adcock Ingram Holdings		38,201
		Manufacturer of Pharmaceuticals & Medical Supplies
	1,025,504	Massmart Holdings		21,649
		General Merchandise, Food & Home Improvement Stores; Wal-Mart Subsidiary
				289,808
		> United States 4.5%
	627,431	Alexion Pharmaceuticals (c)		58,263
		Biotech Focused on Orphan Diseases
	952,080	Atwood Oceanics (c)		42,739
		Offshore Drilling Contractor

Number of Shares			Value (000)
	1,229,871	BioMarin Pharmaceutical (c)	$	42,123
		Biotech Focused on Orphan Diseases
	987,228	World Fuel Services		40,476
		Global Fuel Broker
	965,297	Textainer Group Holdings		32,724
		Top International Container Leaser
	555,500	Hornbeck Offshore (c)		23,348
		Supply Vessel Operator in U.S. Gulf of Mexico
	461,213	FMC Technologies (c)		23,254
		Oil & Gas Well Head Manufacturer
	270,000	Oil States International (c)		21,076
		Diversified North American Oil Service Provider
				284,003
		> Canada 4.4%
	1,403,772	CCL Industries		51,369
		Leading Global Label Manufacturer
	1,212,597	ShawCor		38,173
		Oil & Gas Pipeline Products
	615,857	Baytex		31,977
		Oil & Gas Producer in Canada
	582,942	AG Growth (b)		24,377
		Leading Manufacturer of Augers & Grain Handling Equipment
	653,200	Onex Capital		24,040
		Private Equity
	1,049,576	Black Diamond Group		20,919
		Provides Accommodations/Equipment for Oil Sands Development
	984,500	Alliance Grain Traders		15,121
		Global Leader in Pulse Processing & Distribution
	2,411,514	Horizon North Logistics		15,110
		Provides Diversified Oil Service Offering in Northern Canada
	2,919,000	DeeThree Exploration (a)(c)(e)		12,734
	1,142,377	DeeThree Exploration (a)(c)		5,085
		Canadian Oil & Gas Producer
	721,000	Celtic Exploration (c)		10,510
		Canadian Oil & Gas Producer
	1,043,000	Crew Energy (c)		9,955
		Canadian Oil & Gas Producer
	731,000	Athabasca Oil Sands (c)		8,127
		Oil Sands SAGD & Alberta Deep Basin Development
	1,607,306	Pan Orient (c)		6,558
		Growth-oriented, Return-focused Asian Explorer
	1,611,000	Americas Petrogas (c)		5,750
		Oil & Gas Exploration in Argentina, Potash in Peru
	6,250,000	Petromanas - Warrants (c)(e)		31
		Exploring for Oil in Albania
				279,836
		> Australia 1.6%
	2,653,389	UGL		36,352
		Engineering & Facilities Management
	498,560	Cochlear		31,939
		Cochlear Implants

47

Number of Shares			Value (000)
		> Australia—continued
	4,546,885	Challenger Financial	$	17,908
		Largest Annuity Provider
	17,451,906	Commonwealth Property Office Fund		17,814
		Australia Prime Office REIT
				104,013
		> Israel 0.9%
	4,706,527	Israel Chemicals		54,374
		Producer of Potash, Phosphates, Bromine & Specialty Chemicals
	125,000	Caesarstone (c)		1,460
		Quartz Countertops
				55,834
		> Senegal 0.2%
	45,237	Sonatel		11,681
		Leading Telecoms Operator in Western Africa
				11,681
Other Countries: Total				1,025,175
Latin America 4.2%
		> Brazil 2.6%
	3,700,000	Localiza Rent A Car		68,104
		Car Rental
	1,500,000	Odontoprev		25,226
		Dental Insurance
	1,200,000	Multiplus		24,849
		Loyalty Program Operator in Brazil
	1,880,200	Mills Estruturas e Servicos de Engenharia		23,896
		Civil Engineering & Construction
	2,917,000	MRV Engenharia		20,661
		Brazilian Property Developer
				162,736
		> Mexico 0.7%
	600,000	Grupo Aeroportuario del Sureste - ADR		41,112
		Mexican Airport Operator
				41,112
		> Argentina 0.3%
	1,250,000	Union Agriculture Group (c)(e)(g)		13,275
		Farmland Operator in Uruguay
	4,950,000	Madalena Ventures (c)(e)		4,474
	2,475,000	Madalena Ventures (c)		2,283
		Oil & Gas Exploration in Argentina
				20,032
		> Guatemala 0.3%
	932,600	Tahoe Resources (c)		19,653
		Silver Project in Guatemala
				19,653
		> Colombia 0.2%
	8,353,169	Canacol (c)		6,616
		Oil Producer in South America
	22,525,000	Gulf United (c)(e)		2,595
		Prospecting for Oil Alongside Large Producers in Colombia
				9,211

Number of Shares			Value (000)
		> Chile 0.1%
	4,016,878	Viña Concha y Toro	$	9,208
		Global Branded Wine Manufacturer
				9,208
Latin America: Total				261,952
Total Equities: 95.7% (Cost: $4,641,672)				6,041,723
Securities Lending Collateral 0.5%
	32,332,947	Dreyfus Government Cash Management Fund (7 day yield of 0.01%) (h)		32,333
Total Securities Lending Collateral: (Cost: $32,333)				32,333
Total Investments: 96.2% (Cost: $4,674,005)(i)(j)				6,074,056	(k)
Obligation to Return Collateral for Securities Loaned: (0.5)%				(32,333	)
Cash and Other Assets Less Liabilities: 4.3%				272,701
Total Net Assets: 100.0%			$	6,314,424

ADR - American Depositary Receipts

DVR - Differential Voting Right Equity Shares

GDR - Global Depositary Receipts

48

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 three months ended March 31, 2012, are as follows:

Affiliates	Balance of Shares Held 12/31/11		Purchases/ Additions		Sales/ Reductions		Balance of Shares Held 3/31/12		Value		Dividend
Archipelago Resources		29,063,787		-		-		29,063,787	$	30,217	$	-
DeeThree Exploration		4,061,377		-		-		4,061,377		17,819		-
Koninklijke TenCate*		1,371,573		-		190,500		1,181,073		41,034		-
Southern Arc Minerals		6,217,500		-		-		6,217,500		2,663		-
Sweco		4,150,024		-		-		4,150,024		45,008		-
UNIT4		1,591,702		-		-		1,591,702		46,172		-
Wacom		23,790		-		1,490		22,300		46,834		-
Workspace Group		8,000,000		-		500,000		7,500,000		28,221		372,696
Total of Affiliated Transactions		54,479,753		-		691,990		53,787,763	$	257,968	$	372,696

*  At March 31, 2012, the Fund owned less than five percent of the company's outstanding voting shares.

  The aggregate cost and value of these companies at March 31, 2012, were $149,124 and $216,934, respectively. Investments in affiliated companies represented 3.44% of the Fund's total net assets at March 31, 2012.

(b)  All or a portion of this security was on loan at March 31, 2012. The total market value of securities on loan at March 31, 2012 was $30,746.

(c)  Non-income producing security.

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

(e)  Denotes a restricted security, which is subject to restrictions on resale under federal securities laws. These securities are valued at fair value determined in good faith under consistently applied procedures established by the Board of Trustees. At March 31, 2012, the market value of these securities amounted to $35,772, which represented 0.57% of total net assets.

  Additional information on these securities is as follows:

Security	Acquisition Dates	Shares		Cost		Value
Union Agriculture Group	12/8/10-12/16/11		1,250,000	$	15,000	$	13,275
DeeThree Exploration	9/7/10-3/8/11		2,919,000		10,228		12,734
Madalena Ventures	10/21/10		4,950,000		3,136		4,474
Southern Arc Minerals	2/16/11		6,217,500		10,087		2,663
Gulf United	2/11/11		22,525,000		6,758		2,595
Petromanas - Warrants	5/20/10		6,250,000		362		31
				$	45,571	$	35,772

(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 March 31, 2012, this security had an aggregate value of $24,839, which represented 0.39% of total net assets.

(g)  Illiquid security.

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

(i)  At March 31, 2012, for federal income tax purposes, the cost of investments was $4,674,005 and net unrealized appreciation was $1,400,051 consisting of gross unrealized appreciation of $1,708,166 and gross unrealized depreciation of $(308,115).

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

Currency	Value		Percentage of Net Assets
Japanese Yen	$	1,091,111		17.3
Euro		1,041,240		16.5
U.S. Dollar		604,481		9.6
British Pound		414,274		6.6
Taiwan Dollar		413,039		6.5
Hong Kong Dollar		345,522		5.5
Canadian Dollar		336,597		5.3
Other currencies less than 5% of total net assets		1,795,459		28.4
	$	6,041,723		95.7

(k)  Securities are valued using policies described in the Notes to Financial Statements in the most recent shareholder report.

49

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

  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.

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

  The Committee meets at least quarterly to review and approve valuation matters, which may include a description of fair value actions, data regarding pricing information received from approved pricing vendors and brokers and the results of Board-approved valuation control policies and procedures (the Policies). The Policies address, among other things, instances when market quotations are readily available, including recommendation of third party pricing vendors and determining appropriate pricing methodologies; events that require fair valuation and assessment of fair value techniques; securities with a potential for stale pricing, including those that are illiquid, restricted, or in default; and the effectiveness of third-party pricing vendors. The Committee meets more frequently, as needed, to discuss additional valuation matters, which may include the need to review back-testing results, review time-sensitive information or approve related valuation actions.

  For investments categorized as Level 3, the Committee monitors information similar to that described above, which may include: (i) data specific to the issuer or comparable issuers, (ii) general market or specific sector news and (iii) quoted prices and specific or similar security transactions. The Committee considers this data and any changes from prior periods in order to assess the reasonableness of observable and unobservable inputs, any assumptions or internal models used to value those securities and changes in fair value. This data is also used to corroborate, when available, information received from approved pricing vendors. Various factors impact the frequency of monitoring (which may occur as often as daily), however the Committee may determine that changes to inputs, assumptions and models are not required with the same frequency.

The following table summarizes the inputs used, as of March 31, 2012, in valuing the Fund's assets:

Investment Type	Quoted Prices (Level 1)		Other Significant Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)		Total
Equities
Asia	$	208,799	$	2,461,451	$	-	$	2,670,250
Europe		27,896		2,056,450		-		2,084,346
Other Countries		552,534		472,641		-		1,025,175
Latin America		241,608		7,069		13,275		261,952
Total Equities		1,030,837		4,997,611		13,275		6,041,723
Total Securities Lending Collateral		32,333		-		-		32,333
Total Investments	$	1,063,170	$	4,997,611	$	13,275	$	6,074,056

  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, in accordance with the policy adopted by the Board of Trustees, provided by an independent third party to value securities principally traded in foreign markets in order to adjust for possible stale pricing that may occur between the close of the foreign exchanges and the time for valuation. These models take into account available market data including intraday index, ADR, and ETF movements. Securities acquired via private placement that have a holding period or an extended settlement period are valued at a discount to the same shares that are trading freely on the market. These discounts are determined by the investment manager's experience with similar securities or situations. Factors may include, but are not limited to, trade volume, shares outstanding and stock price.

50

Columbia Acorn International

Statement of Investments (Unaudited), continued

> 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				Transfers Out
Level 1		Level 2		Level 1		Level 2
$	1,843	$	-	$	-	$	1,843

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

  The following table reconciles asset balances for the three months ending March 31, 2012, in which significant unobservable inputs (Level 3) were used in determining value:

Investments in Securities	Balance as of December 31, 2011		Realized Gain/(Loss)		Change in Unrealized Appreciation (Depreciation)		Purchases		Sales		Transfers into Level 3		Transfers out of Level 3		Balance as of March 31, 2012
Equities
Latin America	$	12,462	$	-	$	813	$	-	$	-	$	-	$	-	$	13,275
	$	12,462	$	-	$	813	$	-	$	-	$	-	$	-	$	13,275

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

  The change in unrealized appreciation attributed to securities owned at March 31, 2012, which were valued using significant unobservable inputs (Level 3) amounted to $813.

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

  Certain common stock classified as Level 3 are valued using a market approach. To determine fair value for these securities, management considered various factors which may have included, but were not limited to, trades of similar securities, estimated earnings of the respective company, market multiples derived from a set of comparable companies, and the position of the security within the respective company's capital structure. Significant increases (decreases) to any of these inputs would result in a significantly lower (higher) fair value measurement. Generally, a change in estimated earnings of the respective company may result in a change to the comparable companies and market multiples utilized.

51

Columbia Acorn International

Portfolio Diversification (Unaudited)

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

	Value (000)		Percentage of Net Assets
> Industrial Goods & Services
Other Industrial Services	$	521,450		8.3
Machinery		396,343		6.3
Industrial Materials & Specialty Chemicals		394,522		6.3
Electrical Components		122,840		1.9
Construction		108,048		1.7
Conglomerates		102,075		1.6
Outsourcing Services		51,983		0.8
Industrial Distribution		38,240		0.6
		1,735,501		27.5
> Consumer Goods & Services
Retail		341,207		5.4
Casinos & Gaming		233,246		3.7
Food & Beverage		162,219		2.6
Nondurables		107,117		1.7
Other Consumer Services		89,473		1.4
Travel		75,348		1.2
Apparel		61,874		1.0
Other Durable Goods		49,163		0.8
Educational Services		30,206		0.4
Consumer Goods Distribution		24,136		0.4
Other Entertainment		21,589		0.3
Restaurants		17,238		0.3
Furniture & Textiles		1,460		0.0	*
		1,214,276		19.2
> Information
Computer Hardware & Related Equipment		296,628		4.7
Internet Related		163,947		2.6
Business Software		154,256		2.5
Mobile Communications		140,225		2.2
Financial Processors		66,955		1.1
Instrumentation		58,871		0.9
Semiconductors & Related Equipment		44,681		0.7
Computer Services		29,018		0.5
Electronics Distribution		26,998		0.4
CATV		26,020		0.4
Telephone & Data Services		11,681		0.2
Advertising		6,399		0.1
Gaming Equipment & Services		6,206		0.1
		1,031,885		16.4

	Value (000)			Percentage of Net Assets
> Energy & Minerals
Mining	$	236,593			3.7
Oil Services		233,634			3.7
Oil & Gas Producers		145,885			2.3
Oil Refining Marketing & Distribution		38,967			0.6
Agricultural Commodities		28,396			0.5
		683,475			10.8
> Other Industries
Real Estate		381,775			6.0
Transportation		134,319			2.1
Regulated Utilities		66,619			1.1
		582,713			9.2
> Finance
Brokerage & Money Management		131,833			2.1
Banks		121,946			1.9
Insurance		119,499			1.9
Finance Companies		75,993			1.2
		449,271			7.1
> Health Care
Biotechnology & Drug Delivery		100,387			1.6
Pharmaceuticals		82,019			1.3
Medical Equipment & Devices		81,190			1.3
Medical Supplies		48,880			0.8
Health Care Services		32,126			0.5
		344,602			5.5
Total Equities:		6,041,723			95.7
Securities Lending Collateral:		32,333			0.5
Total Investments:		6,074,056			96.2
Obligation to Return Collateral for Securities Loaned:		(32,333	)		(0.5	)
Cash and Other Assets Less Liabilities:		272,701			4.3
Net Assets:	$	6,314,424			100.0

*  Rounds to less than 0.1%.

52

Columbia Acorn USA

Major Portfolio Changes in the First Quarter (Unaudited)

	Number of Shares
	12/31/11		03/31/12
Purchases
Information
Ultratech		0		262,000
WNS - ADR (India)		0		359,000
Industrial Goods & Services
Polypore International		0		100,000
Consumer Goods & Services
Avis Budget Group		1,175,950		1,300,950
Helen of Troy		0		106,000
Shutterfly		289,000		356,000
Skullcandy		140,000		230,000
Finance
Associated Banc-Corp		923,000		1,053,000
City National		144,000		211,000
First Commonwealth		0		556,000
Hudson Valley		26,935		105,700
MB Financial		480,000		833,000
McGrath Rentcorp		210,000		346,000
Health Care
Cepheid		439,600		488,600
Chelsea Therapeutics International		790,000		948,000
Pacific Biosciences of California		0		385,000
Raptor Pharmaceutical		0		374,000
Synageva Biopharma		0		29,671
Techne		0		53,000
Other Industries
Dupont Fabros Technology		191,000		519,000
St. Joe		0		200,000
Energy & Minerals
Approach Resource		0		100,000
Hornbeck Offshore		0		83,000
Petroleum Development Corporation		57,184		117,000

	Number of Shares
	12/31/11		03/31/12
Sales
Information
Amphenol		159,000		0
Constant Contact		198,000		0
Netgear		196,000		107,000
Nice Systems - ADR (Israel)		252,000		177,000
Polycom		330,000		165,000
Salem Communications		460,100		0
Industrial Goods & Services
Ametek		941,250		876,300
Consumer Goods & Services
Diamond Foods		72,000		0
True Religion Apparel		163,000		82,300
Finance
Aaron's		231,320		0
Health Care
Alexion Pharmaceuticals		275,000		251,000
Community Health Systems		151,000		0
Gen-Probe		126,000		72,000
HealthSouth		205,000		0
Micromet		843,689		0
Other Industries
Biomed Realty Trust		739,200		561,200
Kilroy Realty		159,000		77,000
Energy & Minerals
FMC Technologies		844,600		167,000
Houston American Energy		300,000		262,200
Northern Oil & Gas		115,000		0
Oasis Petroleum		107,800		0
Quicksilver Resources		773,400		567,000

53

Columbia Acorn USA

Statement of Investments (Unaudited), March 31, 2012

Number of Shares			Value (000)
			Equities: 99.5%
Information 32.5%
		> Business Software 10.2%
	910,000	Informatica (a)	$	48,139
		Enterprise Data Integration Software
	698,000	Micros Systems (a)		38,592
		Information Systems for Hotels, Restaurants & Retailers
	375,000	Ansys (a)		24,383
		Simulation Software for Engineers & Designers
	281,000	NetSuite (a)		14,131
		End to End IT Systems Solution Delivered Over the Web
	243,000	Concur Technologies (a)		13,943
		Web Enabled Cost & Expense Management Software
	408,000	Ariba (a)		13,346
		Cost Management Software
	300,000	Blackbaud		9,969
		Software & Services for Non-profits
	322,000	SPS Commerce (a)		8,655
		Supply Chain Management Software Delivered via the Web
	400,000	Velti (a)		5,420
		Mobile Marketing Software Platform
	198,000	Advent Software (a)		5,069
		Asset Management & Trading Systems
				181,647
		> Semiconductors & Related Equipment 4.1%
	1,958,000	Atmel (a)		19,306
		Microcontrollers, RF & Memory Semiconductors
	690,000	Microsemi (a)		14,794
		Analog/Mixed Signal Semiconductors
	1,061,750	ON Semiconductor (a)		9,566
		Mixed Signal & Power Management Semiconductors
	426,000	Monolithic Power Systems (a)		8,379
		High Performance Analog & Mixed Signal ICs
	262,000	Ultratech (a)		7,593
		Semiconductor Equipment
	1,075,000	TriQuint Semiconductor (a)		7,412
		RF Semiconductors
	390,000	Pericom Semiconductor (a)		3,155
		Interface ICs & Frequency Control Products
	50,000	Hittite Microwave (a)		2,716
		Radio Frequency, Microwave & Millimeterwave Semiconductors
				72,921
		> Instrumentation 3.9%
	180,000	Mettler Toledo (a)		33,255
		Laboratory Equipment
	525,000	IPG Photonics (a)		27,326
		Fiber Lasers
	168,000	Trimble Navigation (a)		9,143
		GPS-based Instruments
				69,724

Number of Shares			Value (000)
		> Computer Hardware & Related Equipment 3.0%
	1,317,000	II-VI (a)	$	31,147
		Laser Optics & Specialty Materials
	292,000	Zebra Technologies (a)		12,025
		Bar Code Printers
	177,000	Nice Systems - ADR (Israel) (a)		6,956
		Audio & Video Recording Solutions
	107,000	Netgear (a)		4,087
		Networking Products for Small Business & Home
				54,215
		> Telephone & Data Services 2.8%
	1,457,000	tw telecom (a)		32,287
		Fiber Optic Telephone/Data Services
	148,000	AboveNet (a)		12,254
		Metropolitan Fiber Communications Services
	400,000	Boingo Wireless (a)		4,840
		Wholesale & Retail Wi-Fi Networks
				49,381
		> Gaming Equipment & Services 2.0%
	660,000	Bally Technologies (a)		30,855
		Slot Machines & Software
	235,000	WMS Industries (a)		5,576
		Slot Machine Provider
				36,431
		> Telecommunications Equipment 2.0%
	732,000	Finisar (a)		14,750
		Optical Subsystems & Components
	903,000	Ixia (a)		11,278
		Telecom Network Test Equipment
	752,000	Infinera (a)(b)		6,106
		Optical Networking Equipment
	165,000	Polycom (a)		3,147
		Video Conferencing Equipment
				35,281
		> Computer Services 1.9%
	556,000	ExlService Holdings (a)		15,257
		Business Process Outsourcing
	97,000	Syntel		5,432
		Offshore IT Services
	776,766	Hackett Group (a)		4,637
		IT Integration & Best Practice Research
	359,000	WNS - ADR (India) (a)		4,326
		Offshore BPO (Business Process Outsourcing) Services
	640,000	RCM Technologies (a)(c)		3,565
		Technology & Engineering Services
				33,217
		> Mobile Communications 1.6%
	560,000	SBA Communications (a)		28,454
		Communications Towers
				28,454
		> Contract Manufacturing 0.5%
	236,000	Plexus (a)		8,258
		Electronic Manufacturing Services
				8,258

54

Columbia Acorn USA

Statement of Investments (Unaudited), continued

Number of Shares			Value (000)
		> Financial Processors 0.4%
	170,000	Global Payments	$	7,990
		Credit Card Processor
				7,990
		> TV Broadcasting 0.1%
	875,000	Entravision Communications		1,496
		Spanish Language TV & Radio Stations
				1,496
Information: Total				579,015
Industrial Goods & Services 17.8%
		> Machinery 13.5%
	876,300	Ametek		42,509
		Aerospace/Industrial Instruments
	747,200	Nordson		40,730
		Dispensing Systems for Adhesives & Coatings
	890,000	Donaldson		31,800
		Industrial Air Filtration
	835,000	ESCO Technologies		30,703
		Automatic Electric Meter Readers
	585,000	Pentair		27,852
		Pumps & Water Treatment
	504,665	Heico		20,262
		FAA Approved Aircraft Replacement Parts
	355,000	Moog (a)		15,226
		Motion Control Products for Aerospace, Defense & Industrial Markets
	166,219	Toro		11,820
		Turf Maintenance Equipment
	226,000	Kennametal		10,064
		Consumable Cutting Tools
	100,000	Polypore International (a)(b)		3,516
		Battery Separators & Filtration Media
	146,000	Oshkosh Corporation (a)		3,383
		Specialty Truck Manufacturer
	25,327	Middleby (a)		2,562
		Manufacturer of Cooking Equipment
				240,427
		> Electrical Components 1.0%
	280,000	Acuity Brands		17,592
		Commercial Lighting Fixtures
				17,592
		> Industrial Materials & Specialty Chemicals 1.0%
	496,000	Drew Industries (a)		13,546
		RV & Manufactured Home Components
	170,000	Albany International		3,901
		Paper Machine Clothing & Advanced Textiles
				17,447
		> Other Industrial Services 0.8%
	600,000	Acorn Energy (b)		6,522
		Frac Well Exploration/Monitoring Device, Sonar Security, Electric Grid Monitoring
	240,000	TrueBlue (a)		4,291
		Temporary Manual Labor
	109,000	Forward Air		3,997
		Freight Transportation Between Airports
				14,810

Number of Shares			Value (000)
		> Waste Management 0.6%
	176,000	Waste Connections	$	5,725
		Solid Waste Management
	65,000	Clean Harbors (a)		4,377
		Hazardous Waste Services & Disposal
				10,102
		> Steel 0.4%
	686,000	GrafTech International (a)		8,191
		Industrial Graphite Materials Producer
				8,191
		> Industrial Distribution 0.3%
	233,400	Interline Brands (a)		5,044
		Industrial Distribution
				5,044
		> Construction 0.2%
	200,000	Fortune Brands Home & Security (a)		4,414
		Home Building Supplies & Small Locks
				4,414
Industrial Goods & Services: Total				318,027
Consumer Goods & Services 16.2%
		> Retail 6.5%
	730,000	lululemon athletica (a)		54,516
		Premium Active Apparel Retailer
	468,500	Abercrombie & Fitch		23,242
		Teen Apparel Retailer
	805,000	Pier 1 Imports (a)		14,635
		Home Furnishing Retailer
	356,000	Shutterfly (a)		11,153
		Internet Photo-centric Retailer
	790,000	Saks (a)		9,172
		Luxury Department Store Retailer
	161,500	Teavana (a)(b)		3,185
		Specialty Tea Retailer
	9,000	The Fresh Market (a)		432
		Specialty Food Retailer
				116,335
		> Travel 3.5%
	849,700	Gaylord Entertainment (a)		26,171
		Convention Hotels
	1,300,950	Avis Budget Group (a)		18,408
		Second Largest Car Rental Company
	750,000	Hertz (a)		11,280
		Largest U.S. Rental Car Operator
	140,000	HomeAway (a)		3,552
		Vacation Rental Online Marketplace
	64,000	Vail Resorts		2,768
		Ski Resort Operator & Developer
				62,179
		> Furniture & Textiles 1.5%
	880,000	Knoll		14,643
		Office Furniture
	540,000	Interface		7,533
		Modular & Broadloom Carpet
	148,000	Herman Miller		3,398
		Office Furniture
	20,000	Caesarstone (Israel) (a)		234
		Quartz Countertops
				25,808

55

Number of Shares			Value (000)
		> Apparel 1.2%
	222,000	Warnaco Group (a)	$	12,965
		Global Branded Apparel Manufacturer
	81,000	Deckers Outdoor (a)		5,107
		Fashion Footwear Wholesaler
	82,300	True Religion Apparel (a)		2,255
		Premium Denim
				20,327
		> Consumer Goods Distribution 1.0%
	472,000	Pool		17,662
		Distributor of Swimming Pool Supplies & Equipment
				17,662
		> Other Durable Goods 0.8%
	206,000	Cavco Industries (a)		9,596
		Manufactured Homes
	126,000	Jarden		5,069
		Branded Household Products
				14,665
		> Other Consumer Services 0.7%
	259,000	Lifetime Fitness (a)		13,098
		Sport & Fitness Club Operator
				13,098
		> Casinos & Gaming 0.5%
	775,000	Pinnacle Entertainment (a)		8,920
		Regional Casino Operator
				8,920
		> Leisure Products 0.2%
	230,000	Skullcandy (a)(b)		3,641
		Lifestyle Branded Headphones
				3,641
		> Nondurables 0.2%
	106,000	Helen of Troy (a)		3,605
		Personal Care, Housewares, Healthcare & Home Environment Products
				3,605
		> Educational Services 0.1%
	37,350	ITT Educational Services (a)(b)		2,470
		Postsecondary Degree Services
				2,470
		> Food & Beverage —%
	4,900	Annie's (a)		171
		Developer & Marketer of Natural & Organic Food
				171
Consumer Goods & Services: Total				288,881
Finance 12.3%
		> Banks 7.1%
	833,000	MB Financial		17,485
		Chicago Bank
	1,053,000	Associated Banc-Corp		14,700
		Midwest Bank
	431,597	Lakeland Financial		11,234
		Indiana Bank

Number of Shares			Value (000)
	211,000	City National	$	11,071
		Bank & Asset Manager
	170,000	SVB Financial Group (a)		10,938
		Bank to Venture Capitalists
	278,678	Hancock Holding		9,896
		Gulf Coast Bank
	675,000	Valley National Bancorp		8,741
		New Jersey/New York Bank
	1,478,200	First Busey		7,302
		Illinois Bank
	594,000	TCF Financial		7,063
		Great Lakes Bank
	513,755	Pacific Continental Bank		4,840
		Pacific N.W. Bank
	844,000	TrustCo Bank		4,819
		New York State Bank
	269,600	Eagle Bancorp (a)		4,513
		Metro D.C. Bank
	556,000	First Commonwealth		3,403
		Western Pennsylvania Bank
	178,826	Sandy Spring Bancorp		3,249
		Baltimore, D.C. Bank
	210,000	CVB Financial		2,465
		Inland Empire Business Bank
	105,700	Hudson Valley		1,705
		Metro New York City Bank
	851,247	Guaranty Bancorp (a)		1,694
		Colorado Bank
	90,000	TriCo Bancshares		1,568
		California Central Valley Bank
				126,686
		> Finance Companies 3.4%
	345,000	World Acceptance (a)		21,131
		Personal Loans
	345,000	Textainer Group Holdings		11,696
		Top International Container Leaser
	346,000	McGrath Rentcorp		11,110
		Temporary Space & IT Rentals
	397,172	H & E Equipment Services (a)		7,515
		Heavy Equipment Leasing
	330,000	CAI International (a)		5,999
		International Container Leasing
	100,000	Marlin Business Services		1,506
		Small Equipment Leasing
	45,500	Regional Management (a)		764
		Consumer Loans
				59,721
		> Savings & Loans 0.9%
	602,487	ViewPoint Financial		9,266
		Texas Thrift
	194,000	Berkshire Hills Bancorp		4,447
		Northeast Thrift
	173,073	Kaiser Federal		2,421
		Los Angeles Savings & Loan
				16,134

56

Columbia Acorn USA

Statement of Investments (Unaudited), continued

Number of Shares			Value (000)
		> Brokerage & Money Management 0.5%
	340,500	Eaton Vance	$	9,732
		Specialty Mutual Funds
				9,732
		> Insurance 0.4%
	39,000	Enstar Group (a)		3,860
		Insurance/Reinsurance & Related Services
	55,000	Allied World Holdings		3,777
		Commercial Lines Insurance/Reinsurance
				7,637
Finance: Total				219,910
Health Care 8.9%
		> Biotechnology & Drug Delivery 5.2%
	251,000	Alexion Pharmaceuticals (a)		23,308
		Biotech Focused on Orphan Diseases
	520,000	BioMarin Pharmaceutical (a)		17,810
		Biotech Focused on Orphan Diseases
	682,000	Seattle Genetics (a)(b)		13,899
		Antibody-based Therapies for Cancer
	421,000	Auxilium Pharmaceuticals (a)		7,818
		Biotech Focused on Niche Disease Areas
	1,055,000	NPS Pharmaceuticals (a)		7,216
		Orphan Drugs & Healthy Royalties
	160,000	Onyx Pharmaceuticals (a)		6,029
		Commercial-stage Biotech Focused on Cancer
	643,000	Isis Pharmaceuticals (a)		5,639
		Biotech Pioneer in Antisense Drugs
	313,000	InterMune (a)		4,592
		Drugs for Pulmonary Fibrosis & Hepatitis C
	374,000	Raptor Pharmaceutical (a)(b)		2,528
		Orphan Drug Company
	948,000	Chelsea Therapeutics International (a)		2,427
		Biotech Focused on Rare Diseases
	530,000	Anthera Pharmaceuticals (a)		1,172
		Biotech Focused on Cardiovascular, Cancer & Immunology
	29,671	Synageva Biopharma (a)		1,064
		Biotech Focused on Orphan Diseases
	18,181	Metabolex, Series A-1 (a)(d)(e)		11
		Diabetes Drug Development
				93,513
		> Medical Equipment & Devices 1.5%
	224,000	Sirona Dental Systems (a)		11,545
		Manufacturer of Dental Equipment
	268,000	Hill-Rom Holdings		8,954
		Hospital Beds/Patient Handling
	72,000	Gen-Probe (a)		4,781
		Molecular In-vitro Diagnostics
	385,000	Pacific Biosciences of California (a)		1,317
		Genome Sequencing
				26,597
		> Medical Supplies 1.4%
	488,600	Cepheid (a)		20,438
		Molecular Diagnostics
	53,000	Techne		3,716
		Cytokines, Antibodies & Other Reagents for Life Science
				24,154

Number of Shares			Value (000)
		> Pharmaceuticals 0.5%
	733,000	Akorn (a)	$	8,576
		Develops, Manufactures & Sells Specialty Generic Drugs
	150,000	Horizon Pharma (a)		621
		Specialty Pharmaceutical Company
	133,180	Alimera Sciences (a)		450
		Ophthalmology-focused Pharmaceutical Company
				9,647
		> Health Care Services 0.3%
	738,900	Health Management Associates (a)		4,965
		Non-urban Hospitals
				4,965
Health Care: Total				158,876
Other Industries 6.5%
		> Real Estate 5.3%
	915,000	Extra Space Storage		26,343
		Self Storage Facilities
	519,000	Dupont Fabros Technology		12,689
		Technology-focused Office Buildings
	561,200	Biomed Realty Trust		10,651
		Life Science-focused Office Buildings
	600,000	Associated Estates Realty		9,804
		Multifamily Properties
	870,000	Education Realty Trust		9,431
		Student Housing
	1,380,000	Kite Realty Group		7,273
		Community Shopping Centers
	958,000	DCT Industrial Trust		5,652
		Industrial Properties
	100,000	Post Properties		4,686
		Multifamily Properties
	200,000	St. Joe (a)(b)		3,802
		Florida Panhandle Landowner
	77,000	Kilroy Realty		3,589
		West Coast Office & Industrial Properties
				93,920
		> Transportation 1.2%
	256,000	World Fuel Services		10,496
		Global Fuel Broker
	410,091	Rush Enterprises, Class A (a)		8,702
	115,000	Rush Enterprises, Class B (a)		2,000
		Truck Sales & Service
				21,198
Other Industries: Total				115,118
Energy & Minerals 5.3%
		> Oil Services 2.5%
	725,000	Atwood Oceanics (a)		32,545
		Offshore Drilling Contractor
	167,000	FMC Technologies (a)		8,420
		Oil & Gas Well Head Manufacturer
	83,000	Hornbeck Offshore (a)		3,489
		Supply Vessel Operator in U.S. Gulf of Mexico
				44,454

57

Number of Shares			Value (000)
		> Oil & Gas Producers 1.9%
	133,000	SM Energy	$	9,412
		Oil & Gas Producer
	143,000	Rosetta Resources (a)		6,973
		Oil & Gas Producer Exploring in South Texas & Montana
	168,000	Swift Energy (a)		4,877
		Oil & Gas Exploration & Production
	117,000	Petroleum Development Corporation (a)		4,339
		Oil & Gas Producer in U.S.
	100,000	Approach Resource (a)		3,695
		Oil & Gas Producer in West Texas Permian
	567,000	Quicksilver Resources (a)(b)		2,858
		Natural Gas & Coal Seam Gas Producer
	262,200	Houston American Energy (a)		1,369
		Oil & Gas Exploration/Production in Colombia
				33,523
		> Mining 0.9%
	85,000	Core Laboratories (Netherlands)		11,184
		Oil & Gas Reservoir Consulting
	600,000	Alexco Resource (a)		4,188
		Mining, Exploration & Environmental Services
	180,000	Augusta Resource (a)		491
		US Copper/Moly Mine
				15,863
Energy & Minerals: Total				93,840
Total Equities: 99.5% (Cost: $1,166,642)				1,773,667

Number of Shares			Value (000)
Securities Lending Collateral 1.3%
	22,953,025	Dreyfus Government Cash Management Fund (7 day yield of 0.01%) (f)	$	22,953
Total Securities Lending Collateral: (Cost: $22,953)				22,953
Total Investments: 100.8% (Cost: $1,189,595)(g)(h)				1,796,620	(i)
Obligation to Return Collateral for Securities Loaned: (1.3)%				(22,953	)
Cash and Other Assets Less Liabilities: 0.5%				8,134
Total Net Assets: 100.0%			$	1,781,801

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 March 31, 2012. The total market value of securities on loan at March 31, 2012 was $22,452.

(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 three months ended March 31, 2012, are as follows:

Affiliates	Balance of Shares Held at 12/31/11		Purchases/ Additions		Sales/ Reductions		Balance of Shares Held at 3/31/12		Value		Dividend
RCM Technologies		640,000		-		-		640,000	$	3,565	$	-
Total of Affiliated Transactions		640,000		-		-		640,000	$	3,565	$	-

  The aggregate cost and value of this company at March 31, 2012, were $3,624 and $3,565, respectively. Investments in affiliated companies represented 0.20% of the Fund's total net assets at March 31, 2012.

(d)  Denotes a restricted security, which is subject to restrictions on resale under federal securities laws. These securities are valued at fair value determined in good faith under consistently applied procedures established by the Board of Trustees. At March 31, 2012, the market value of this security amounted to $11, 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	$	11
				$	2,000	$	11

(e)  Illiquid security.

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

58

Columbia Acorn USA

Statement of Investments (Unaudited), continued

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

(g)  At March 31, 2012, for federal income tax purposes, the cost of investments was $1,189,595 and net unrealized appreciation (depreciation) was $607,025 consisting of gross unrealized appreciation of $685,305 and gross unrealized depreciation of $(78,280).

(h)  On March 31, 2012, the market value of foreign securities represented 1.27% of total net assets. The Fund's foreign portfolio was diversified as follows:

	Value		Percentage of Net Assets
Netherlands	$	11,183		0.63
Israel		7,190		0.40
India		4,326		0.24
Total Foreign Portfolio	$	22,699		1.27

(i)  Securities are valued using polices described in the Notes to Financial Statements in the most recent shareholder report.

Fair Value Measurements

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

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

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

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

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

  Examples of the types of securities in which the Fund would typically invest and how they are classified within this hierarchy are as follows. Typical Level 1 securities include exchange traded domestic equities, mutual funds whose NAVs are published each day and exchange traded foreign equities that are not statistically fair valued. Typical Level 2 securities include exchange traded foreign equities that are statistically fair valued, forward foreign currency exchange contracts and short-term investments valued at amortized cost. Additionally, securities fair valued by the Valuation Committee 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.

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

  The Committee meets at least quarterly to review and approve valuation matters, which may include a description of fair value actions, data regarding pricing information received from approved pricing vendors and brokers and the results of Board-approved valuation control policies and procedures (the Policies). The Policies address, among other things, instances when market quotations are readily available, including recommendation of third party pricing vendors and determining appropriate pricing methodologies; events that require fair valuation and assessment of fair value techniques; securities with a potential for stale pricing, including those that are illiquid, restricted, or in default; and the effectiveness of third-party pricing vendors. The Committee meets more frequently, as needed, to discuss additional valuation matters, which may include the need to review back-testing results, review time-sensitive information or approve related valuation actions.

  For investments categorized as Level 3, the Committee monitors information similar to that described above, which may include: (i) data specific to the issuer or comparable issuers, (ii) general market or specific sector news and (iii) quoted prices and specific or similar security transactions. The Committee considers this data and any changes from prior periods in order to assess the reasonableness of observable and unobservable inputs, any assumptions or internal models used to value those securities and changes in fair value. This data is also used to corroborate, when available, information received from approved pricing vendors. Various factors impact the frequency of monitoring (which may occur as often as daily), however the Committee may determine that changes to inputs, assumptions and models are not required with the same frequency.

The following table summarizes the inputs used, as of March 31, 2012, in valuing the Fund's assets:

Investment Type	Quoted Prices (Level 1)		Other Significant Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)		Total
Equities
Information	$	571,025	$	7,990	$	-	$	579,015
Industrial Goods & Services		318,027		-		-		318,027
Consumer Goods & Services		288,881		-		-		288,881
Finance		219,910		-		-		219,910
Health Care		158,865		-		11		158,876
Other Industries		115,118		-		-		115,118
Energy & Minerals		93,840		-		-		93,840
Total Equities		1,765,666		7,990		11		1,773,667
Total Securities Lending Collateral		22,953		-		-		22,953
Total Investments	$	1,788,619	$	7,990	$	11	$	1,796,620

59

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

  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. Securities which have halted or temporarily stopped trading are valued at the last sale and adjusted by a premium or a discount to account for the anticipated re-opening price. These adjustments are determined by the investment manager's experience with similar securities or situations.

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

Transfers In				Transfers Out
Level 1		Level 2		Level 1		Level 2
$	-	$	8,055	$	8,055	$	-

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

  The following table reconciles asset balances for the three months ending March 31, 2012, in which significant unobservable inputs (Level 3) were used in determining value:

Investments in Securities	Balance as of December 31, 2011		Realized Gain/(Loss)		Change in Unrealized Appreciation (Depreciation)			Purchases		Sales		Transfers into Level 3		Transfers out of Level 3		Balance as of March 31, 2012
Equities
Health Care	$	27	$	-	$	(16	)	$	-	$	-	$	-	$	-	$	11
	$	27	$	-	$	(16	)	$	-	$	-	$	-	$	-	$	11

  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 March 31, 2012, which were valued using significant unobservable inputs (Level 3) amounted to $(16).

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

  Certain common stock classified as Level 3 are valued using a market approach. To determine fair value for these securities, management considered various factors which may have included, but were not limited to, trades of similar securities, estimated earnings of the respective company, market multiples derived from a set of comparable companies, and the position of the security within the respective company's capital structure. Significant increases (decreases) to any of these inputs would result in a significantly lower (higher) fair value measurement. Generally, a change in estimated earnings of the respective company may result in a change to the comparable companies and market multiples utilized.

60

Columbia Acorn International Select

Major Portfolio Changes in the First Quarter (Unaudited)

	Number of Shares
	12/31/11		03/31/12
Purchases
Other Countries
> South Africa
Adcock Ingram Holdings		1,220,200		1,317,200
Naspers		80,700		112,700
Northam Platinum		0		1,146,000
Rand Merchant Insurance		7,415,000		7,601,015
> Australia
Challenger Financial		0		826,355
Commonwealth Property Office Fund		0		3,170,358

	Number of Shares
	12/31/11		03/31/12
Sales
Other Countries
> Japan
Ain Pharmaciez		105,000		74,000
Gree		181,000		59,400
Kansai Paint		2,100,000		1,911,000
> Korea
Woongjin Coway		111,000		0
Europe
> United Kingdom
Intertek Group		210,000		178,000
JLT Group		665,000		314,000
Shaftesbury		432,000		0
Workspace Group		897,000		0
> Sweden
Hexagon		658,666		595,666
> Netherlands
Imtech		277,519		239,919
> Ireland
United Drug		1,329,400		0
Other Countries
> Canada
AG Growth		125,000		89,000
CCL Industries		210,400		106,400

61

Columbia Acorn International Select

Statement of Investments (Unaudited), March 31, 2012

Number of Shares			Value (000)
			Equities: 95.1%
Asia 49.3%
		> Japan 16.0%
	1,911,000	Kansai Paint	$	19,374
		Paint Producer in Japan, India, China & Southeast Asia
	6,753,000	Seven Bank		14,809
		ATM Processing Services
	8,970	Jupiter Telecommunications		8,984
		Largest Cable Service Provider in Japan
	528,000	Asahi Diamond Industrial		6,242
		Consumable Diamond Tools
	74,000	Ain Pharmaciez		3,994
		Dispensing Pharmacy/Drugstore Operator
	59,400	Gree (a)		1,496
		Mobile Social Networking Game Developer/Platform
				54,899
		> Singapore 13.8%
	13,130,000	Ascendas REIT		21,122
		Industrial Property Landlord
	20,395,000	Mapletree Industrial Trust		17,829
		Industrial Property Landlord
	11,142,000	Mapletree Logistics Trust		8,382
		Industrial Property Landlord
				47,333
		> Taiwan 9.0%
	11,103,000	Far EasTone Telecom		22,821
		Taiwan's Third Largest Mobile Operator
	2,789,400	CTCI Corp		4,625
		International Engineering Firm
	1,179,000	Taiwan Mobile		3,594
		Taiwan's Second-largest Mobile Operator
				31,040
		> China 4.4%
	4,146,000	Zhaojin Mining Industry		6,974
		Gold Mining & Refining in China
	84,000	NetEase.com - ADR (b)		4,880
		Chinese Online Gaming Services
	3,044,000	Want Want		3,406
		Chinese Branded Consumer Food Company
				15,260
		> Korea 3.3%
	49,830	NHN		11,437
		Korean Online Search Services
				11,437
		> Indonesia 2.8%
	9,272,000	Archipelago Resources (b)		9,640
		Gold Mining Projects in Indonesia, Vietnam & the Philippines
				9,640
Asia: Total				169,609

Number of Shares			Value (000)
Europe 25.7%
		> Germany 6.4%
	630,000	Wirecard	$	11,994
		Online Payment Processing & Risk Management
	109,500	Rheinmetall		6,484
		Defense & Automotive
	175,000	Rhoen-Klinikum		3,514
		Health Care Services
				21,992
		> United Kingdom 6.2%
	178,000	Intertek Group		7,149
		Testing, Inspection, Certification Services
	659,000	Serco		5,719
		Facilities Management
	772,800	Chemring		5,037
		Defense Manufacturer of Countermeasures & Energetics
	314,000	JLT Group		3,508
		International Business Insurance Broker
				21,413
		> Sweden 3.4%
	595,666	Hexagon		11,561
		Design, Measurement & Visualization Software & Equipment
				11,561
		> Netherlands 3.3%
	239,919	Imtech		7,670
		Electromechanical & ICT Installation & Maintenance
	28,100	Core Laboratories		3,697
		Oil & Gas Reservoir Consulting
				11,367
		> Switzerland 2.5%
	24,000	Partners Group		4,682
		Private Markets Asset Management
	28,000	Kuehne & Nagel		3,787
		Freight Forwarding/Logistics
				8,469
		> Iceland 1.6%
	4,800,000	Marel		5,633
		Largest Manufacturer of Poultry & Fish Processing Equipment
				5,633
		> Denmark 1.2%
	145,000	Novozymes		4,223
		Industrial Enzymes
				4,223
		> Belgium 1.1%
	74,000	EVS Broadcast Equipment		3,837
		Digital Live Mobile Production Software & Systems
				3,837
Europe: Total				88,495

62

Columbia Acorn International Select

Statement of Investments (Unaudited), continued

Number of Shares			Value (000)
Other Countries 19.2%
		> South Africa 11.2%
	7,601,015	Rand Merchant Insurance	$	17,053
		Directly Sold Property & Casualty Insurance; Holdings in Other Insurers
	1,317,200	Adcock Ingram Holdings		10,080
		Manufacturer of Pharmaceuticals & Medical Supplies
	112,700	Naspers		6,332
		Media in Africa, China, Russia & Other Emerging Markets
	1,146,000	Northam Platinum		5,097
		Platinum Mining in South Africa
				38,562
		> United States 2.3%
	94,000	Atwood Oceanics (b)		4,220
		Offshore Drilling Contractor
	52,000	SM Energy		3,680
		Oil & Gas Producer
				7,900
		> Canada 2.2%
	106,400	CCL Industries		3,893
		Leading Global Label Manufacturer
	89,000	AG Growth		3,722
		Leading Manufacturer of Augers & Grain Handling Equipment
				7,615
		> Australia 1.9%
	826,355	Challenger Financial		3,255
		Largest Annuity Provider
	3,170,358	Commonwealth Property Office Fund		3,236
		Australia Prime Office REIT
				6,491
		> Israel 1.6%
	460,000	Israel Chemicals		5,314
		Producer of Potash, Phosphates, Bromine & Specialty Chemicals
	10,000	Caesarstone (b)		117
		Quartz Countertops
				5,431
Other Countries: Total				65,999
Latin America 0.9%
		> Argentina 0.6%
	183,333	Union Agriculture Group (b)(c)(d)		1,947
		Farmland Operator in Uruguay
				1,947
		> Colombia 0.3%
	18,800,000	Quetzal Energy (b)(c)		995
		Explores for Oil & Gas in Latin America
				995
Latin America: Total				2,942
Total Equities: 95.1% (Cost: $265,888)				327,045

Number of Shares			Value (000)
Securities Lending Collateral 0.8%
	2,658,332	Dreyfus Government Cash Management Fund (7 day yield of 0.01%) (e)	$	2,658
Total Securities Lending Collateral: (Cost: $2,658)				2,658
Total Investments: 95.9% (Cost: $268,546)(f)(g)				329,703	(h)
Obligation to Return Collateral for Securities Loaned: (0.8)%				(2,658	)
Cash and Other Assets Less Liabilities: 4.9%				16,804
Total Net Assets: 100.0%			$	343,849

ADR - American Depositary Receipts

63

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

(a)  All or a portion of this security was on loan at March 31, 2012. The total market value of securities on loan at March 31, 2012 was $2,531.

(b)  Non-income producing security.

(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 March 31, 2012, the market value of these securities amounted to $2,942 which represented 0.86% of total net assets.

  Additional information on these securities is as follows:

Security	Acquisition Dates	Shares		Cost		Value
Union Agriculture Group	12/8/10-12/16/11		183,333	$	2,200	$	1,947
Quetzal Energy	1/14/11		18,800,000		2,376		995
				$	4,576	$	2,942

(d)  Illiquid security.

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

(f)  At March 31, 2012, for federal income tax purposes, the cost of investments was $268,546 and net unrealized appreciation was $61,157 consisting of gross unrealized appreciation of $74,081 and gross unrealized depreciation of $(12,924).

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

Currency	Value		Percentage of Net Assets
Japanese Yen	$	54,900		16.0
Singapore Dollar		47,333		13.8
South African Rand		38,562		11.2
Euro		33,499		9.7
Pound Sterling		31,052		9.0
Taiwan Dollar		31,040		9.0
U.S. Dollar		18,541		5.4
Other currencies less than 5% of total net assets		72,118		21.0
	$	327,045		95.1

(h)  Securities are valued using policies described in the Notes to Financial Statements in the most recent shareholder report.

  At March 31, 2012, the Fund had entered into the following forward foreign currency exchange contracts:

Forward Foreign Currency Exchange Contracts to Buy	Forward Foreign Currency Exchange Contracts to Sell	Principal Amount in Foreign Currency		Principal Amount in U.S. Dollar		Settlement Date	Unrealized Depreciation
USD	ZAR		200,400	$	26,000	04/13/12	$	(86	)

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

USD = United States Dollar

ZAR = South African Rand

Fair Value Measurements

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

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

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

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

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

  Examples of the types of securities in which the Fund would typically invest and how they are classified within this hierarchy are as follows. Typical Level 1 securities include exchange traded domestic equities, mutual funds whose NAVs are published each day and exchange traded foreign equities that are not statistically fair valued. Typical Level 2 securities include exchange traded foreign equities that are statistically fair valued, forward foreign currency exchange contracts and short-term investments valued at amortized cost. Additionally, securities fair valued by the Valuation Committee 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.

64

Columbia Acorn International Select

Statement of Investments (Unaudited), continued

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

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

  The Committee meets at least quarterly to review and approve valuation matters, which may include a description of fair value actions, data regarding pricing information received from approved pricing vendors and brokers and the results of Board-approved valuation control policies and procedures (the Policies). The Policies address, among other things, instances when market quotations are readily available, including recommendation of third party pricing vendors and determining appropriate pricing methodologies; events that require fair valuation and assessment of fair value techniques; securities with a potential for stale pricing, including those that are illiquid, restricted, or in default; and the effectiveness of third-party pricing vendors. The Committee meets more frequently, as needed, to discuss additional valuation matters, which may include the need to review back-testing results, review time-sensitive information or approve related valuation actions.

  For investments categorized as Level 3, the Committee monitors information similar to that described above, which may include: (i) data specific to the issuer or comparable issuers, (ii) general market or specific sector news and (iii) quoted prices and specific or similar security transactions. The Committee considers this data and any changes from prior periods in order to assess the reasonableness of observable and unobservable inputs, any assumptions or internal models used to value those securities and changes in fair value. This data is also used to corroborate, when available, information received from approved pricing vendors. Various factors impact the frequency of monitoring (which may occur as often as daily), however the Committee may determine that changes to inputs, assumptions and models are not required with the same frequency.

The following table summarizes the inputs used, as of March 31, 2012, in valuing the Fund's assets:

Investment Type	Quoted Prices (Level 1)		Other Significant Observable Inputs (Level 2)			Significant Unobservable Inputs (Level 3)		Total
Equities
Asia	$	4,880	$	164,729		$	-	$	169,609
Europe		3,697		84,798			-		88,495
Other Countries		15,632		50,367			-		65,999
Latin America		-		995			1,947		2,942
Total Equities		24,209		300,889			1,947		327,045
Total Securities Lending Collateral		2,658		-			-		2,658
Total Investments	$	26,867	$	300,889		$	1,947	$	329,703
Unrealized Depreciation of Forward Foreign Currency Exchange Contracts		-		(86	)		-		(86	)
Total	$	26,867	$	300,803		$	1,947	$	329,617

  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, in accordance with the policy adopted by the Board of Trustees, provided by an independent third party to value securities principally traded in foreign markets in order to adjust for possible stale pricing that may occur between the close of the foreign exchanges and the time for valuation. These models take into account available market data including intraday index, ADR, and ETF movements. Forward foreign currency exchange contracts are valued at the prevailing forward exchange rate of the underlying currencies. Securities acquired via private placement that have a holding period or an extended settlement period are valued at a discount to the same shares that are trading freely on the market. These discounts are determined by the investment manager's experience with similar securities or situations. Factors may include, but are not limited to, trade volume, shares outstanding and stock price.

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

The following table reconciles asset balances for the three months ending March 31, 2012, in which significant unobservable inputs (Level 3) were used in determining value:

Investment Type	Balance as of December 31, 2011		Realized Gain/(Loss)		Change in Unrealized Appreciation (Depreciation)		Purchases		Sales		Transfers Into Level 3		Transfers out of Level 3		Balance as of March 31, 2012
Latin America
Argentina	$	1,828	$	-	$	119	$	-	$	-	$	-	$	-	$	1,947
	$	1,828	$	-	$	119	$	-	$	-	$	-	$	-	$	1,947

65

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

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

  The change in unrealized appreciation attributed to securities owned at March 31, 2012, which were valued using significant unobservable inputs (Level 3) amounted to $119.

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

  Certain common stock classified as Level 3 are valued using a market approach. To determine fair value for these securities, management considered various factors which may have included, but were not limited to, trades of similar securities, estimated earnings of the respective company, market multiples derived from a set of comparable companies, and the position of the security within the respective company's capital structure. Significant increases (decreases) to any of these inputs would result in a significantly lower (higher) fair value measurement. Generally, a change in estimated earnings of the respective company may result in a change to the comparable companies and market multiples utilized.

66

Columbia Acorn International Select

Portfolio Diversification (Unaudited)

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

	Value (000)		Percentage of Net Assets
> Information
Mobile Communications	$	26,415		7.7
Internet Related		22,649		6.6
Financial Processors		11,994		3.5
Business Software		11,561		3.4
CATV		8,984		2.6
Computer Hardware & Related Equipment		3,837		1.1
Gaming Equipment & Services		1,497		0.4
		86,937		25.3
> Industrial Goods & Services
Industrial Materials & Specialty Chemicals		28,911		8.4
Machinery		22,080		6.4
Other Industrial Services		18,607		5.4
Outsourcing Services		5,718		1.7
Electrical Components		5,037		1.5
Construction		4,625		1.3
		84,978		24.7
> Other Industries
Real Estate		50,569		14.7
> Finance
Insurance		23,816		6.9
Banks		14,809		4.3
Brokerage & Money Management		4,682		1.4
		43,307		12.6
> Energy & Minerals
Mining		25,408		7.4
Oil & Gas Producers		4,675		1.4
Oil Services		4,220		1.2
Agricultural Commodities		1,947		0.5
		36,250		10.5
> Health Care
Pharmaceuticals		10,079		3.0
Health Care Services		3,514		1.0
		13,593		4.0

	Value (000)			Percentage of Net Assets
> Consumer Goods & Services
Retail	$	3,994			1.2
Nondurables		3,894			1.1
Food & Beverage		3,406			1.0
Furniture & Textiles		117			0.0	*
		11,411			3.3
Total Equities:		327,045			95.1
Securities Lending Collateral:		2,658			0.8
Total Investments:		329,703			95.9
Obligation to Return Collateral for Securities Loaned:		(2,658	)		(0.8	)
Cash and Other Assets Less Liabilities:		16,804			4.9
Net Assets:	$	343,849			100.0

*  Rounds to less than 0.1%.

67

Columbia Acorn Select

Major Portfolio Changes in the First Quarter (Unaudited)

	Number of Shares
	12/31/11		03/31/12
Purchases
Information
Atmel		825,000		1,175,000
Globalstar		13,184,322		15,000,000
Industrial Goods & Services
FMC Corporation		0		150,000
Nordson		0		160,000
Finance
Associated Banc-Corp		0		1,075,000
Regional Management		0		84,500
Energy & Minerals
Tuscany International Drilling (Colombia)		10,600,000		12,700,000
Other Industries
Dupont Fabros Technology		0		475,000
Health Care
Henry Schein		0		190,000
Seattle Genetics		0		395,000

	Number of Shares
	12/31/11		03/31/12
Sales
Consumer Goods & Services
Abercrombie & Fitch		830,000		555,000
Coach		650,000		615,000
Gaylord Entertainment		1,060,000		1,020,000
lululemon athletica		417,900		390,000
RexLot Holdings (China)		300,000,000		260,000,000
Safeway		2,000,000		1,100,000
Information
Amphenol		670,000		645,000
Crown Castle International		825,000		770,000
Sanmina-SCI		6,100,000		4,375,000
SBA Communications		1,100,000		1,010,000
WNS - ADR (India)		4,254,230		3,940,000
Industrial Goods & Services
Ametek		1,550,000		1,490,000
Expeditors International of Washington		620,000		600,000
Kennametal		1,035,000		975,000
Oshkosh Corporation		250,000		0
Pall		740,000		690,000
Quanta Services		1,470,000		1,420,000
Waste Management		500,000		0
WW Grainger		135,000		0
Finance
CNO Financial Group		9,100,000		8,325,000
Discover Financial Services		3,225,000		2,115,000
SEI Investments		1,000,000		965,000
Energy & Minerals
Continental Resources		65,000		0
Eacom Timber (Canada)		36,000,000		33,572,000
Houston American Energy		1,060,000		826,400
Kirkland Lake Gold (Canada)		900,000		870,000
Pacific Rubiales Energy (Colombia)		2,150,000		1,480,000
Other Industries
JB Hunt Transport Services		115,000		0
Health Care
Akorn		1,802,464		1,400,000

68

Columbia Acorn Select

Statement of Investments (Unaudited), March 31, 2012

Number of Shares			Value (000)
			Equities: 98.8%
Consumer Goods & Services 21.7%
		> Travel 8.1%
	5,225,000	Hertz (a)	$	78,584
		Largest U.S. Rental Car Operator
	1,020,000	Gaylord Entertainment (a)		31,416
		Convention Hotels
				110,000
		> Retail 6.8%
	390,000	lululemon athletica (a)		29,125
		Premium Active Apparel Retailer
	555,000	Abercrombie & Fitch		27,534
		Teen Apparel Retailer
	1,100,000	Safeway (b)		22,231
		Supermarkets
	200,000	Tiffany & Co.		13,826
		Luxury Good Retailer
				92,716
		> Apparel 3.5%
	615,000	Coach		47,527
		Designer & Retailer of Branded Leather Accessories
				47,527
		> Casinos & Gaming 1.7%
	260,000,000	RexLot Holdings (China) (b)		23,113
		Lottery Equipment Supplier in China
				23,113
		> Educational Services 1.3%
	270,000	ITT Educational Services (a)(b)		17,858
		Postsecondary Degree Services
				17,858
		> Other Consumer Services 0.2%
	3,430,000	IFM Investments (Century 21 China RE) - ADR (China) (a)(b)(c)		2,469
		Provide Real Estate Services in China
				2,469
		> Food & Beverage 0.1%
	1,500,000	GLG Life Tech (Canada) (a)(b)		1,185
		Produce an All-natural Sweetener Extracted from the Stevia Plant
	9,100	Annie's (a)		317
		Developer & Marketer of Natural & Organic Food
				1,502
Consumer Goods & Services: Total				295,185
Information 21.4%
		> Mobile Communications 7.5%
	1,010,000	SBA Communications (a)		51,318
		Communications Towers
	770,000	Crown Castle International (a)		41,072
		Communications Towers
	15,000,000	Globalstar (a)(c)		10,500
		Satellite Mobile Voice & Data Carrier
				102,890

Number of Shares			Value (000)
		> Contract Manufacturing 3.7%
	4,375,000	Sanmina-SCI (a)(c)	$	50,094
		Electronic Manufacturing Services
				50,094
		> Computer Services 3.5%
	3,940,000	WNS - ADR (India) (a)(c)		47,477
		Offshore BPO (Business Process Outsourcing) Services
				47,477
		> Computer Hardware & Related Equipment 2.8%
	645,000	Amphenol		38,552
		Electronic Connectors
				38,552
		> Instrumentation 1.5%
	110,000	Mettler Toledo (a)		20,322
		Laboratory Equipment
				20,322
		> Semiconductors & Related Equipment 0.8%
	1,175,000	Atmel (a)		11,586
		Microcontrollers, RF & Memory Semiconductors
				11,586
		> Business Software 0.8%
	182,000	Concur Technologies (a)		10,443
		Web Enabled Cost & Expense Management Software
				10,443
		> Advertising 0.7%
	6,108,437	VisionChina Media - ADR (China) (a)(c)		9,651
		Advertising on Digital Screens in China's Mass Transit System
				9,651
Information: Total				291,015
Industrial Goods & Services 20.8%
		> Machinery 15.4%
	1,490,000	Ametek		72,280
		Aerospace/Industrial Instruments
	1,260,000	Donaldson		45,020
		Industrial Air Filtration
	975,000	Kennametal		43,417
		Consumable Cutting Tools
	690,000	Pall		41,145
		Filtration & Fluids Clarification
	160,000	Nordson		8,721
		Dispensing Systems for Adhesives & Coatings
				210,583
		> Outsourcing Services 2.2%
	1,420,000	Quanta Services (a)		29,678
		Electrical & Telecom Construction Services
				29,678

69

Number of Shares			Value (000)
		> Other Industrial Services 2.0%
	600,000	Expeditors International of Washington	$	27,906
		International Freight Forwarder
				27,906
		> Industrial Materials & Specialty Chemicals 1.2%
	150,000	FMC Corporation		15,879
		Niche Specialty Chemicals
				15,879
Industrial Goods & Services: Total				284,046
Finance 15.0%
		> Credit Cards 5.2%
	2,115,000	Discover Financial Services		70,514
		Credit Card Company
				70,514
		> Insurance 4.7%
	8,325,000	CNO Financial Group (a)		64,768
		Life, Long Term Care & Medical Supplement Insurance
				64,768
		> Banks 3.5%
	630,000	City National		33,056
		Bank & Asset Manager
	1,075,000	Associated Banc-Corp		15,007
		Midwest Bank
				48,063
		> Brokerage & Money Management 1.5%
	965,000	SEI Investments		19,966
		Mutual Fund Administration & Investment Management
				19,966
		> Finance Companies 0.1%
	84,500	Regional Management (a)		1,420
		Consumer Loans
				1,420
Finance: Total				204,731
Energy & Minerals 11.5%
		> Oil & Gas Producers 7.3%
	1,480,000	Pacific Rubiales Energy (Colombia)		43,238
		Oil Production & Exploration in Colombia
	30,872,300	Canacol (Colombia) (a)		24,452
		Oil Producer in South America
	36,500,000	Shamaran Petroleum (Iraq) (a)		9,331
		Oil Exploration in Kurdistan
	34,700,000	Petrodorado (Colombia) (a)(c)		8,001
	17,144,000	Petrodorado - Warrants (Colombia) (a)(d)(e)		672
		Oil & Gas Exploration & Production in Colombia, Peru & Paraguay

Number of Shares			Value (000)
	24,000,000	Canadian Overseas Petroleum (United Kingdom) (a)(c)(d)	$	5,082
	12,000,000	Canadian Overseas Petroleum - Warrants (United Kingdom) (a)(d)(e)		302
		Oil & Gas Exploration/Production in the North Sea
	826,400	Houston American Energy (a)		4,314
		Oil & Gas Exploration/Production in Colombia
	18,125,000	Petromanas (Canada) (a)		4,179
	6,562,500	Petromanas - Warrants (Canada) (a)(d)		32
		Exploring for Oil in Albania
				99,603
		> Agricultural Commodities 1.6%
	1,666,667	Union Agriculture Group (Argentina) (a)(d)(e)		17,700
		Farmland Operator in Uruguay
	33,572,000	Eacom Timber (Canada) (a)(c)		3,702
		Canadian Lumber Producer
				21,402
		> Alternative Energy 1.0%
	2,700,000	Canadian Solar (China) (a)(b)(c)		8,586
		Solar Cell & Module Manufacturer
	2,500,000	Synthesis Energy Systems (China) (a)		3,675
		Owner/Operator of Gasification Plants
	1,200,000	Real Goods Solar (a)		1,740
		Residential Solar Energy Installer
				14,001
		> Mining 0.9%
	870,000	Kirkland Lake Gold (Canada) (a)		12,578
		Gold Mining
				12,578
		> Oil Services 0.7%
	12,700,000	Tuscany International Drilling (Colombia) (a)		9,549
		South America-based Drilling Rig Contractor
				9,549
Energy & Minerals: Total				157,133
Other Industries 4.3%
		> Real Estate 3.2%
	1,660,000	Biomed Realty Trust		31,507
		Life Science-focused Office Buildings
	475,000	Dupont Fabros Technology		11,614
		Technology-focused Office Buildings
				43,121
		> Regulated Utilities 1.1%
	435,000	Wisconsin Energy		15,303
		Wisconsin Utility
				15,303
Other Industries: Total				58,424

70

Columbia Acorn Select

Statement of Investments (Unaudited), continued

Number of Shares			Value (000)
Health Care 4.1%
		> Biotechnology & Drug Delivery 1.8%
	2,510,000	NPS Pharmaceuticals (a)	$	17,169
		Orphan Drugs & Healthy Royalties
	395,000	Seattle Genetics (a)(b)		8,050
		Antibody-based Therapies for Cancer
				25,219
		> Pharmaceuticals 1.2%
	1,400,000	Akorn (a)		16,380
		Develops, Manufactures & Sells Specialty Generic Drugs
				16,380
		> Medical Supplies 1.1%
	190,000	Henry Schein (a)		14,379
		Largest Distributor of Healthcare Products
				14,379
Health Care: Total				55,978
Total Equities: 98.8% (Cost: $979,694)				1,346,512

Number of Shares			Value (000)
Securities Lending Collateral 3.5%
	47,277,255	Dreyfus Government Cash Management Fund (7 day yield of 0.01%) (f)	$	47,277
Total Securities Lending Collateral: (Cost: $47,277)				47,277
Total Investments: 102.3% (Cost: $1,026,971)(g)(h)				1,393,789	(i)
Obligation to Return Collateral for Securities Loaned: (3.5)%				(47,277	)
Cash and Other Assets Less Liabilities: 1.2%				16,749
Total Net Assets: 100.0%			$	1,363,261

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 March 31, 2012. The total market value of securities on loan at March 31, 2012 was $45,804.

(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 three months ended March 31, 2012, are as follows:

Affiliates	Balance of Shares Held 12/30/11		Purchases/ Additions		Sales/ Reductions		Balance of Shares Held 3/30/12		Value		Dividend
Canacol*		31,372,300		-		500,000		30,872,300	$	24,452	$	-
Canadian Overseas Petroleum		24,000,000		-		-		24,000,000		5,082		-
Canadian Solar		2,700,000		-		-		2,700,000		8,586		-
Eacom Timber		36,000,000		-		2,428,000		33,572,000		3,702		-
GLG Life Tech*		1,850,000		-		350,000		1,500,000		1,185		-
Globalstar		13,184,322		1,815,678		-		15,000,000		10,500		-
IFM Investments (Century 21 China RE) - ADR		3,430,000		-		-		3,430,000		2,469		-
Petrodorado		34,700,000		-		-		34,700,000		8,001		-
Real Goods Solar*		1,500,000		-		300,000		1,200,000		1,740		-
Sanmina-SCI		6,100,000		-		1,725,000		4,375,000		50,094		-
Synthesis Energy Systems*		2,950,372		-		450,372		2,500,000		3,675		-
VisionChina Media - ADR		7,000,000		-		891,563		6,108,437		9,651		-
WNS - ADR		4,254,230		-		314,230		3,940,000		47,477		-
Total of Affiliated Transactions		169,041,224		1,815,678		6,959,165		163,897,737	$	176,614	$	-

*  At March 31, 2012, the Fund owned less than five percent of the company's outstanding voting shares.

  The aggregate cost and value of these companies at March 31, 2012, were $219,738 and $145,562, respectively. Investments in affiliated companies represented 10.68% of the Fund's total net assets at March 31, 2012.

(d)  Denotes a restricted security, which is subject to restrictions on resale under federal securities laws. These securities are valued at a fair value determined in good faith under consistenly applied procedures established by the Board of Trustees. At March 31, 2012, the market value of these securities amounted to $23,788 which represented 1.74% of total net assets.

71

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

Security	Acquisition Dates	Shares		Cost		Value
Union Agriculture Group	12/8/10-12/16/11		1,666,667	$	20,000	$	17,700
Canadian Overseas Petroleum	11/24/10		24,000,000		10,260		5,082
Petrodorado - Warrants	11/20/09		17,144,000		2,118		672
Canadian Overseas Petroleum - Warrants	11/24/10		12,000,000		1,502		302
Petromanas - Warrants	5/20/10		6,562,500		380		32
				$	34,260	$	23,788

(e)  Illiquid security.

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

(g)  At March 31, 2012, for federal income tax purposes, the cost of investments was $1,026,971 and net unrealized appreciation was $366,818 consisting of gross unrealized appreciation of $495,701 and gross unrealized depreciation of $(128,883).

(h)  On March 31, 2012, the market value of foreign securities represented 17.24% of total net assets. The Fund's foreign portfolio was diversified as follows:

	Value		Percentage of Net Assets
Colombia	$	85,912		6.30
China		47,494		3.49
India		47,477		3.48
Canada		21,676		1.59
Argentina		17,700		1.30
Iraq		9,331		0.68
United Kingdom		5,384		0.40
Total Foreign Portfolio	$	234,974		17.24

(i)  Securities are valued using policies described in the Notes to Financial Statements in the most recent shareholder report.

  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.

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

  The Committee meets at least quarterly to review and approve valuation matters, which may include a description of fair value actions, data regarding pricing information received from approved pricing vendors and brokers and the results of Board-approved valuation control policies and procedures (the Policies). The Policies address, among other things, instances when market quotations are readily available, including recommendation of third party pricing vendors and determining appropriate pricing methodologies; events that require fair valuation and assessment of fair value techniques; securities with a potential for stale pricing, including those that are illiquid, restricted, or in default; and the effectiveness of third-party pricing vendors. The Committee meets more frequently, as needed, to discuss additional valuation matters, which may include the need to review back-testing results, review time-sensitive information or approve related valuation actions.

  For investments categorized as Level 3, the Committee monitors information similar to that described above, which may include: (i) data specific to the issuer or comparable issuers, (ii) general market or specific sector news and (iii) quoted prices and specific or similar security transactions. The Committee considers this data and any changes from prior periods in order to assess the reasonableness of observable and unobservable inputs, any assumptions or internal models used to value those securities and changes in fair value. This data is also used to corroborate, when available, information received from approved pricing vendors. Various factors impact the frequency of monitoring (which may occur as often as daily), however the Committee may determine that changes to inputs, assumptions and models are not required with the same frequency.

72

Columbia Acorn Select

Statement of Investments (Unaudited), continued

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

The following table summarizes the inputs used, as of March 31, 2012, in valuing the Fund's assets:

Investment Type	Quoted Prices (Level 1)		Other Significant Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)		Total
Equities
Consumer Goods & Services	$	272,072	$	23,113	$	-	$	295,185
Information		291,015		-		-		291,015
Industrial Goods & Services		284,046		-		-		284,046
Finance		204,731		-		-		204,731
Energy & Minerals		133,345		6,088		17,700		157,133
Other Industries		58,424		-		-		58,424
Health Care		55,978		-		-		55,978
Total Equities		1,299,611		29,201		17,700		1,346,512
Total Securities Lending Collateral		47,277		-		-		47,277
Total Investments	$	1,346,888	$	29,201	$	17,700	$	1,393,789

  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, in accordance with the policy adopted by the Board of Trustees, provided by an independent third party to value securities principally traded in foreign markets in order to adjust for possible stale pricing that may occur between the close of the foreign exchanges and the time for valuation. These models take into account available market data including intraday index, ADR, and ETF movements. Securities acquired via private placement that have a holding period or an extended settlement period are valued at a discount to the same shares that are trading freely on the market. These discounts are determined by the investment manager's experience with similar securities or situations. Factors may include, but are not limited to, trade volume, shares outstanding and stock price. Warrants which do not trade are valued as a percentage of the actively trading common stock using a model, based on Black Scholes.

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

  The following table reconciles asset balances for the six months ending March 31, 2012, in which significant unobservable inputs (Level 3) were used in determining value:

Investments in Securities	Balance as of December 31, 2011		Realized Gain/(Loss)		Change in Unrealized Appreciation (Depreciation)		Purchases		Sales		Transfers into Level 3		Transfers out of Level 3		Balance as of March 31, 2012
Equities
Energy & Minerals	$	16,617	$	-	$	1,083	$	-	$	-	$	-	$	-	$	17,700
	$	16,617	$	-	$	1,083	$	-	$	-	$	-	$	-	$	17,700

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

  The change in unrealized appreciation attributed to securities owned at March 31, 2012, which were valued using significant unobservable inputs (Level 3) amounted to $1,083.

  Quantitative information pertaining to Level 3 unobservable fair value measurements

	Fair Value at 03/31/12		Valuation Technique(s)	Unobservable Input (s)	Range (Weighted Average)
Equities		17,700	Market comparable companies	Discount for lack of marketability	-6% - +16% (-9%)

  Certain common stock classified as Level 3 are valued using a market approach. To determine fair value for these securities, management considered various factors which may have included, but were not limited to, trades of similar securities, estimated earnings of the respective company, market multiples derived from a set of comparable companies, and the position of the security within the respective company's capital structure. Significant increases (decreases) to any of these inputs would result in a significantly lower (higher) fair value measurement. Generally, a change in estimated earnings of the respective company may result in a change to the comparable companies and market multiples utilized.

73

Columbia Thermostat Fund

Statement of Investments (Unaudited), March 31, 2012

Number of Shares			Value (000)
		> Affiliated Bond Funds: 53.4%
	9,295,325	Columbia Intermediate Bond Fund, Class I	$	86,725
	5,457,987	Columbia Income Opportunities Fund, Class I		52,233
	2,987,862	Columbia U.S. Treasury Income Fund, Class I		34,629
Total Bond Funds (Cost: $171,419)				173,587
		> Affiliated Stock Funds: 43.8%
	725,247	Columbia Acorn International Fund, Class I		28,662
	1,946,023	Columbia Dividend Income Fund, Class I		28,529
	1,353,681	Columbia Contrarian Core Fund, Class I		21,361
	668,359	Columbia Acorn Fund, Class I		21,287

Number of Shares			Value (000)
	1,014,784	Columbia Large Cap Enhanced Core Fund, Class I	$	14,227
	981,120	Columbia Select Large Cap Growth Fund, Class I (a)		14,197
	509,047	Columbia Acorn Select Fund, Class I		14,177
Total Stock Funds (Cost: $114,924)				142,440
Total Investments: 97.2% (Cost: $286,343)(b)				316,027	(c)
Cash and Other Assets Less Liabilities: 2.8%				8,998
Total Net Assets: 100.0%			$	325,025

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

(a)  Non-income producing security.

(b)  At March 31, 2012, for federal income tax purposes, the cost of investments was $286,343 and net unrealized appreciation was $29,684 consisting of gross unrealized appreciation of $29,684 and gross unrealized depreciation of $(—).

(c)  Securities are valued using policies described in the Notes to Financial Statements in the most recent shareholder report.

Fair Value Measurements

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

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

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

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

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

  Examples of the types of securities in which the Fund would typically invest and how they are classified within this hierarchy are as follows. Typical Level 1 securities include exchange traded domestic equities, mutual funds whose NAVs are published each day and exchange traded foreign equities that are not statistically fair valued. Typical Level 2 securities include exchange traded foreign equities that are statistically fair valued, forward foreign currency exchange contracts and short-term investments valued at amortized cost. Additionally, securities fair valued by the Valuation Committee 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.

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

  The Committee meets at least quarterly to review and approve valuation matters, which may include a description of fair value actions, data regarding pricing information received from approved pricing vendors and brokers and the results of Board-approved valuation control policies and procedures (the Policies). The Policies address, among other things, instances when market quotations are readily available, including recommendation of third party pricing vendors and determining appropriate pricing methodologies; events that require fair valuation and assessment of fair value techniques; securities with a potential for stale pricing, including those that are illiquid, restricted, or in default; and the effectiveness of third-party pricing vendors. The Committee meets more frequently, as needed, to discuss additional valuation matters, which may include the need to review back-testing results, review time-sensitive information or approve related valuation actions.

  For investments categorized as Level 3, the Committee monitors information similar to that described above, which may include: (i) data specific to the issuer or comparable issuers, (ii) general market or specific sector news and (iii) quoted prices and specific or similar security transactions. The Committee considers this data and any changes from prior periods in order to assess the reasonableness of observable and unobservable inputs, any assumptions or internal models used to value those securities and changes in fair value. This data is also used to corroborate, when available, information received from approved pricing vendors. Various factors impact the frequency of monitoring (which may occur as often as daily), however the Committee may determine that changes to inputs, assumptions and models are not required with the same frequency.

74

Columbia Thermostat Fund

Statement of Investments (Unaudited), continued

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

The following table summarizes the inputs used, as of March 31, 2012, in valuing the Fund's assets:

Investment Type	Quoted Prices (Level 1)		Other Significant Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)		Total
Total Bond Funds	$	173,587	$	-	$	-	$	173,587
Total Stock Funds		142,440		-		-		142,440
Total Investments	$	316,027	$	-	$	-	$	316,027

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

75

Columbia Acorn Emerging Markets Fund

Major Portfolio Changes in the First Quarter (Unaudited)

	Number of Shares
	12/31/11		03/31/12
Purchases
Asia
> Taiwan
Advantech		12,000		19,169
Chroma Ate		26,990		38,990
CTCI Corp		33,200		64,762
Far EasTone Telecom		43,700		58,126
Lung Yen		11,000		16,500
MStar Semiconductor		0		9,800
PC Home		3,900		13,700
Radiant Opto-Electronics		11,277		15,277
Simplo Technology		7,730		10,342
St. Shine Optical		5,800		7,200
Taiwan Hon Chuan		15,385		21,689
Tripod Technologies		0		30,000
> Indonesia
Ace Indonesia		178,989		369,019
Archipelago Resources		76,959		137,500
Jasa Marga		67,000		109,911
Surya Citra Media		44,000		93,264
Tower Bersama Infrastructure		241,000		535,709
> Hong Kong
AAC Technologies		13,000		18,027
Lifestyle International		16,865		28,089
Melco Crown Entertainment - ADR		4,137		5,150
Melco International		33,000		118,462
Sasa International		65,652		89,999
> China
51job - ADR		741		1,154
Digital China		34,651		45,651
NetEase.com - ADR		1,000		1,277
RexLot Holdings		451,892		823,246
> India
Adani Ports & Special Economic Zone		12,250		22,500
Jain Irrigation Systems		20,800		30,249
Redington India		0		7,562
Titan Industries		2,200		13,040
United Breweries		4,180		7,835
> Philippines
Int'l Container Terminal		25,567		40,787
Manila Water Company		88,382		100,465
> Cambodia
Nagacorp		229,035		340,000
> Thailand
Home Product Center		134,348		249,018
> Mongolia
Mongolian Mining		48,909		98,500

	Number of Shares
	12/31/11		03/31/12
> Japan
Kansai Paint		3,860		7,060
Other Countries
> South Africa
Adcock Ingram Holdings		9,580		15,850
Coronation Fund Managers		24,626		42,926
Massmart Holdings		1,945		3,197
Mr. Price		5,370		6,597
Northam Platinum		11,354		15,354
Rand Merchant Insurance		39,175		71,200
> Canada
Alliance Grain Traders		3,565		10,801
Americas Petrogas		0		17,500
> United States
Atwood Oceanics		752		952
Hornbeck Offshore		1,000		1,509
Textainer Group Holdings		1,200		2,204
Europe
> Sweden
East Capital Explorer		6,072		8,806
Hexagon		3,498		7,231
> Switzerland
Dufry Group		675		1,116
> Kazakhstan
Halyk Savings Bank of Kazakhstan - GDR		4,332		17,800
> Italy
Pirelli		3,000		7,000
> Germany
Dürr		824		1,229
> France
Rubis		780		965
Latin America
> Brazil
Localiza Rent A Car		4,436		5,490
MRV Engenharia		11,121		11,325
Multiplus		1,884		3,144
> Mexico
Grupo Aeroportuario del Sureste - ADR		1,203		1,647
> Chile
Viña Concha y Toro		0		16,500

76

Columbia Acorn Emerging Markets Fund

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

	Number of Shares
	12/31/11		03/31/12
Sales
Asia
> Taiwan
Formosa International Hotels		949		0
President Chain Store		5,000		0
> China
ENN Energy		7,538		0
> India
Manappuram Finance		35,100		0
> Singapore
Goodpack Limited		27,403		0
Latin America
> Brazil
Suzano		7,431		0
> Argentina
Madalena Ventures		56,433		40,200

77

Columbia Acorn Emerging Markets Fund

Statement of Investments (Unaudited), March 31, 2012

Number of Shares			Value (000)
			Equities: 96.1%
Asia 55.2%
		> Taiwan 16.8%
	58,126	Far EasTone Telecom	$	120
		Taiwan's Third Largest Mobile Operator
	64,762	CTCI Corp		107
		International Engineering Firm
	30,000	Tripod Technologies		101
		Printed Circuit Boards (PCB)
	38,990	Chroma Ate		100
		Automatic Test Systems, Testing & Measurement Instruments
	7,200	St. Shine Optical		94
		World's Leading Disposable Contact Lens OEM
	10,342	Simplo Technology		78
		Battery Packs for Notebook & Tablet PCs
	13,700	PC Home		77
		Taiwanese Internet Retail Company
	15,277	Radiant Opto-Electronics		68
		LCD Back Light Units & Modules
	19,169	Advantech		67
		Industrial PC & Components
	9,800	MStar Semiconductor		60
		ICs for TV, Digital Set-top-box & Handset
	16,500	Lung Yen		53
		Funeral Services & Columbaria
	21,689	Taiwan Hon Chuan		49
		Beverage Packaging (Bottles, Caps, Labels) Manufacturer
				974
		> Indonesia 11.1%
	369,019	Ace Indonesia		180
		Home Improvement Retailer
	535,709	Tower Bersama Infrastructure		173
		Communications Towers
	137,500	Archipelago Resources (a)		143
		Gold Mining Projects in Indonesia, Vietnam & the Philippines
	93,264	Surya Citra Media		82
		Free to Air TV in Indonesia
	109,911	Jasa Marga		62
		Largest Toll Road Operator in Indonesia
				640
		> Hong Kong 6.2%
	118,462	Melco International (a)		113
		Macau Casino Operator
	28,089	Lifestyle International		72
		Mid to High-end Department Store Operator in Hong Kong & China
	5,150	Melco Crown Entertainment - ADR (a)		70
		Macau Casino Operator
	89,999	Sasa International		52
		Cosmetics Retailer
	18,027	AAC Technologies		49
		Miniature Acoustic Components
				356

Number of Shares			Value (000)
		> China 6.1%
	45,651	Digital China	$	91
		IT Distribution & Systems Integration Services
	1,277	NetEase.com - ADR (a)		74
		Chinese Online Gaming Services
	823,246	RexLot Holdings		73
		Lottery Equipment Supplier in China
	1,154	51job - ADR (a)(b)		66
		Integrated Human Resource Services
	89,275	AMVIG Holdings		48
		Chinese Tobacco Packaging Material Supplier
				352
		> India 4.7%
	7,835	United Breweries		83
		India's Largest Brewer
	13,040	Titan Industries		59
		Jewelry, Watches, Eyeglasses
	30,249	Jain Irrigation Systems		58
		Agricultural Micro-irrigation Systems & Food Processing
	22,500	Adani Ports & Special Economic Zone		57
		Indian West Coast Shipping Port
	7,562	Redington India		13
		Supply Chain Solutions for IT & Mobile Handsets in Emerging Markets
				270
		> Philippines 2.9%
	40,787	Int'l Container Terminal		62
		Container Handling Terminals & Port Management
	100,465	Manila Water Company		54
		Water Utility Company in the Philippines
	128,155	SM Prime Holdings		51
		Shopping Mall Operator
				167
		> Cambodia 2.7%
	340,000	Nagacorp		155
		Casino/Entertainment Complex in Cambodia
				155
		> Thailand 1.9%
	249,018	Home Product Center		112
		Home Improvement Retailer
				112
		> Mongolia 1.6%
	98,500	Mongolian Mining (a)		94
		Coking Coal Mining in Mongolia
				94
		> Japan 1.2%
	7,060	Kansai Paint		72
		Paint Producer in Japan, India, China & Southeast Asia
				72
Asia: Total				3,192

78

Columbia Acorn Emerging Markets Fund

Statement of Investments (Unaudited), continued

Number of Shares			Value (000)
Other Countries 19.1%
		> South Africa 11.4%
	71,200	Rand Merchant Insurance	$	160
		Directly Sold Property & Casualty Insurance; Holdings in Other Insurers
	42,926	Coronation Fund Managers		159
		South African Fund Manager
	15,850	Adcock Ingram Holdings		121
		Manufacturer of Pharmaceuticals & Medical Supplies
	6,597	Mr. Price		81
		South African Retailer of Apparel, Household & Sporting Goods
	15,354	Northam Platinum		68
		Platinum Mining in South Africa
	3,197	Massmart Holdings		68
		General Merchandise, Food & Home Improvement Stores; Wal-Mart Subsidiary
				657
		> Canada 4.6%
	10,801	Alliance Grain Traders		166
		Global Leader in Pulse Processing & Distribution
	17,500	Americas Petrogas (a)		62
		Oil & Gas Exploration in Argentina, Potash in Peru
	4,172	Crew Energy (a)		40
		Canadian Oil & Gas Producer
				268
		> United States 3.1%
	2,204	Textainer Group Holdings		75
		Top International Container Leaser
	1,509	Hornbeck Offshore (a)		63
		Supply Vessel Operator in U.S. Gulf of Mexico
	952	Atwood Oceanics (a)		43
		Offshore Drilling Contractor
				181
Other Countries: Total				1,106
Europe 13.5%
		> Sweden 3.7%
	7,231	Hexagon		141
		Design, Measurement & Visualization Software & Equipment
	8,806	East Capital Explorer		74
		Sweden-based RUS/CEE Investment Fund
				215
		> Switzerland 2.5%
	1,116	Dufry Group (a)		146
		Operates Airport Duty Free & Duty Paid Shops
				146
		> Kazakhstan 2.0%
	17,800	Halyk Savings Bank of Kazakhstan - GDR (a)		116
		Largest Retail Bank & Insurer in Kazakhstan
				116

Number of Shares			Value (000)
		> Czech Republic 1.5%
	434	Komercni Banka	$	86
		Leading Czech Universal Bank
				86
		> Italy 1.4%
	7,000	Pirelli		83
		Global Tire Supplier
				83
		> Germany 1.4%
	1,229	Dürr		78
		Automotive Plant Engineering & Associated Capital Equipment
				78
		> France 1.0%
	965	Rubis		57
		Tank Storage & LPG Distribution
				57
Europe: Total				781
Latin America 8.3%
		> Brazil 5.0%
	5,490	Localiza Rent A Car		101
		Car Rental
	11,325	MRV Engenharia		80
		Brazilian Property Developer
	3,144	Multiplus		65
		Loyalty Program Operator in Brazil
	3,361	Mills Estruturas e Servicos de Engenharia		43
		Civil Engineering & Construction
				289
		> Mexico 2.0%
	1,647	Grupo Aeroportuario del Sureste - ADR		113
		Mexican Airport Operator
				113
		> Chile 0.7%
	16,500	Viña Concha y Toro		38
		Global Branded Wine Manufacturer
				38
		> Argentina 0.6%
	40,200	Madalena Ventures (a)		37
		Oil & Gas Exploration in Argentina
				37
Latin America: Total				477
Total Equities: 96.1% (Cost: $5,066)				5,556

79

Number of Shares			Value (000)
Securities Lending Collateral 0.6%
	35,100	Dreyfus Government Cash Management Fund (7 day yield of 0.01%) (c)	$	35
Total Securities Lending Collateral: (Cost: $35)				35
Total Investments: 96.7% (Cost: $5,101)(d)(e)				5,591	(f)
Obligation to Return Collateral for Securities Loaned: (0.6)%				(35	)
Cash and Other Assets Less Liabilities: 3.9%				226
Total Net Assets: 100.0%			$	5,782

ADR - American Depositary Receipts

GDR - Global Depositary Receipts

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

(a)  Non-income producing security.

(b)  All or a portion of this security was on loan at March 31, 2012. The total market value of securities on loan at March 31, 2012 was $34.

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

(d)  At March 31, 2012, for federal income tax purposes, the cost of investments was $5,101 and net unrealized appreciation was $490 consisting of gross unrealized appreciation of $630 and gross unrealized depreciation of $(140).

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

Currency	Value		Percentage of Net Assets
Taiwan Dollar	$	974		16.8
South African Rand		657		11.4
Indonesian Rupiah		640		11.1
Hong Kong Dollar		356		6.2
Brazilain Real		289		5.0
U.S. Dollar		181		3.1
Other currencies less than 5% of total net assets		2,459		42.5
	$	5,556		96.1

(f)  Securities are valued using policies described in the Notes to Financial Statements in the most recent shareholder report.

  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.

80

Columbia Acorn Emerging Markets Fund

Statement of Investments (Unaudited), continued

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

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

  The Committee meets at least quarterly to review and approve valuation matters, which may include a description of fair value actions, data regarding pricing information received from approved pricing vendors and brokers and the results of Board-approved valuation control policies and procedures (the Policies). The Policies address, among other things, instances when market quotations are readily available, including recommendation of third party pricing vendors and determining appropriate pricing methodologies; events that require fair valuation and assessment of fair value techniques; securities with a potential for stale pricing, including those that are illiquid, restricted, or in default; and the effectiveness of third-party pricing vendors. The Committee meets more frequently, as needed, to discuss additional valuation matters, which may include the need to review back-testing results, review time-sensitive information or approve related valuation actions.

  For investments categorized as Level 3, the Committee monitors information similar to that described above, which may include: (i) data specific to the issuer or comparable issuers, (ii) general market or specific sector news and (iii) quoted prices and specific or similar security transactions. The Committee considers this data and any changes from prior periods in order to assess the reasonableness of observable and unobservable inputs, any assumptions or internal models used to value those securities and changes in fair value. This data is also used to corroborate, when available, information received from approved pricing vendors. Various factors impact the frequency of monitoring (which may occur as often as daily), however the Committee may determine that changes to inputs, assumptions and models are not required with the same frequency.

The following table summarizes the inputs used, as of March 31, 2012, in valuing the Fund's assets:

Investment Type	Quoted Prices (Level 1)		Other Significant Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)		Total
Equities
Asia	$	210	$	2,982	$	-	$	3,192
Other Countries		449		657		-		1,106
Europe		-		781		-		781
Latin America		477		-		-		477
Total Equities		1,136		4,420		-		5,556
Total Securities Lending Collateral		35		-		-		35
Total Investments	$	1,171	$	4,420	$	-	$	5,591

  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, in accordance with the policy adopted by the Board of Trustees, provided by an independent third party to value securities principally traded in foreign markets in order to adjust for possible stale pricing that may occur between the close of the foreign exchanges and the time for valuation. These models take into account available market data including intraday index, ADR, and ETF movements.

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

81

Columbia Acorn Emerging Markets Fund

Portfolio Diversification (Unaudited)

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

	Value (000)		Percentage of Net Assets
>Consumer Goods & Services
Retail	$	775		13.5
Casinos & Gaming		411		7.1
Other Consumer Services		190		3.3
Food & Beverage		186		3.2
Travel		101		1.7
Other Durable Goods		83		1.4
Consumer Goods Distribution		13		0.2
		1,759		30.4
> Information
Computer Hardware & Related Equipment		363		6.3
Mobile Communications		293		5.1
Business Software		140		2.4
Instrumentation		100		1.7
Electronics Distribution		91		1.6
TV Broadcasting		82		1.4
Internet Related		74		1.3
Semiconductors & Related Equipment		60		1.0
		1,203		20.8
> Energy & Minerals
Mining		305		5.3
Agricultural Commodities		166		2.9
Oil & Gas Producers		139		2.4
Oil Services		106		1.8
Oil Refining, Marketing & Distribution		57		1.0
		773		13.4
> Finance
Brokerage & Money Management		234		4.0
Banks		202		3.5
Insurance		160		2.8
Finance Companies		75		1.3
		671		11.6
> Industrial Goods & Services
Industrial Materials & Specialty Chemicals		169		2.9
Construction		150		2.6
Machinery		137		2.4
Other Industrial Services		119		2.1
		575		10.0
> Other Industries
Transportation		175		3.0
Real Estate		131		2.3
Regulated Utilities		54		0.9
		360		6.2

	Value (000)			Percentage of Net Assets
> Health Care
Pharmaceuticals	$	121			2.1
Medical Supplies		94			1.6
		215			3.7
Total Equities:		5,556			96.1
Securities Lending Collateral:		35			0.6
Total Investments:		5,591			96.7
Obligation to Return Collateral for Securities Loaned:		(35	)		(0.6	)
Cash and Other Assets Less Liabilities:		226			3.9
Net Assets:	$	5,782			100.0

82

Columbia Acorn European Fund

Major Portfolio Changes in the First Quarter (Unaudited)

	Number of Shares
	12/31/11		03/31/12
Purchases
Europe
> United Kingdom
Rightmove		0		1,000
> France
1000 mercis		700		1,200
> Netherlands
TKH Group		0		400
> Switzerland
Zehnder		0		243
> Sweden
Hexagon		2,570		2,670
> Denmark
Solar A/S		0		300

	Number of Shares
	12/31/11		03/31/12
Sales
Europe
> United Kingdom
GlobeOp Financial Services		6,480		0
> France
Gemalto		1,100		1,000
> Germany
Elringklinger		810		0

83

Columbia Acorn European Fund

Statement of Investments (Unaudited), March 31, 2012

Number of Shares			Value (000)
			Equities: 94.0%
Europe 91.7%
		> United Kingdom 16.2%
	1,100	Intertek Group	$	44
		Testing, Inspection, Certification Services
	15,220	Charles Taylor		37
		Insurance Services
	2,927	JLT Group		33
		International Business Insurance Broker
	4,900	Chemring		32
		Defense Manufacturer of Countermeasures & Energetics
	3,180	Shaftesbury		25
		London Prime Retail REIT
	3,610	Domino's Pizza United Kingdom & Ireland		25
		Pizza Delivery in the United Kingdom, Ireland & Germany
	1,000	Rightmove		23
		Internet Real Estate Listings
	5,800	Workspace Group		22
		UK Real Estate
	660	Rotork		22
		Valve Actuators for Oil & Water Pipelines
	2,480	Serco		21
		Facilities Management
	2,870	Premier Oil (a)		18
		Oil & Gas Producer in Europe, Pakistan & Asia
	3,190	Abcam		18
		Online Sales of Antibodies
	999	Greggs		8
		Bakery
				328
		> France 16.1%
	1,000	Gemalto		66
		Digital Security Solutions
	600	Eurofins Scientific		65
		Food, Pharmaceuticals & Materials Screening & Testing
	1,200	1000 mercis		57
		Interactive Advertising & Marketing
	360	Norbert Dentressangle		32
		Leading European Logistics & Transport Group
	790	Saft Batteries		26
		Niche Battery Manufacturer
	352	Neopost		23
		Postage Meter Machines
	600	Mersen		21
		Advanced Industrial Materials
	310	Rubis		18
		Tank Storage & LPG Distribution
	5,030	Hi-Media (a)		18
		Online Advertiser in Europe
				326
		> Netherlands 14.0%
	2,420	Aalberts Industries		50
		Flow Control & Heat Treatment
	1,530	UNIT4		44
		Business Software Development

Number of Shares			Value (000)
	330	Core Laboratories	$	44
		Oil & Gas Reservoir Consulting
	1,160	Koninklijke TenCate		40
		Advanced Textiles & Industrial Fabrics
	1,260	Imtech		40
		Electromechanical & ICT Installation & Maintenance
	410	Fugro		29
		Sub-sea Oilfield Services
	1,280	Arcadis		27
		Engineering Consultants
	400	TKH Group		11
		Dutch Industrial Conglomerate
				285
		> Germany 11.1%
	3,080	Wirecard		59
		Online Payment Processing & Risk Management
	170	Rational		40
		Commercial Ovens
	560	Rheinmetall		33
		Defense & Automotive
	520	Dürr		33
		Automotive Plant Engineering & Associated Capital Equipment
	300	Bertrandt		23
		Outsourced Engineering
	590	CTS Eventim		20
		Event Ticket Sales
	450	Stratec Biomedical Systems		18
		Diagnostic Instrumentation
				226
		> Switzerland 7.7%
	250	Geberit (a)		52
		Plumbing Supplies
	15	Sika		33
		Chemicals for Construction & Industrial Applications
	160	Partners Group		31
		Private Markets Asset Management
	170	Dufry Group (a)		22
		Operates Airport Duty Free & Duty Paid Shops
	243	Zehnder		18
		Radiators & Ventilation Systems
				156
		> Sweden 6.1%
	2,670	Hexagon		52
		Design, Measurement & Visualization Software & Equipment
	4,070	Sweco		44
		Engineering Consultants
	1,000	Unibet		28
		European Online Gaming Operator
				124
		> Italy 4.4%
	2,000	Pirelli		24
		Global Tire Supplier
	7,000	Geox		23
		Apparel & Shoe Maker

84

Columbia Acorn European Fund

Statement of Investments (Unaudited), continued

Number of Shares			Value (000)
		> Italy—continued
	200	Tod's	$	22
		Leather Shoes & Bags
	13,860	CIR		20
		Italian Holding Company
				89
		> Iceland 2.5%
	43,750	Marel		51
		Largest Manufacturer of Poultry & Fish Processing Equipment
				51
		> Ireland 2.2%
	9,300	United Drug		26
		Irish Pharmaceutical Wholesaler & Outsourcer
	300	Paddy Power		19
		Irish Betting Services
				45
		> Portugal 2.0%
	13,480	Redes Energéticas Nacionais		41
		Portuguese Power Transmission & Gas Transportation
				41
		> Norway 2.0%
	3,310	Atea		40
		Leading Nordic IT Hardware/Software Reseller & Installation Company
				40
		> Russia 1.9%
	1,000	Mail.ru - GDR (a)(b)		39
		Internet Social Networking & Games for Russian Speakers
				39
		> Belgium 1.6%
	630	EVS Broadcast Equipment		33
		Digital Live Mobile Production Software & Systems
				33
		> Czech Republic 1.4%
	140	Komercni Banka		28
		Leading Czech Universal Bank
				28
		> Poland 1.1%
	4,000	FX Energy (a)		22
		Oil & Gas Producer in Poland
				22
		> Denmark 0.8%
	300	Solar A/S		17
		Technical Wholesaler of Electrical, Plumbing & HVAC Equipment
				17
		> Greece 0.6%
	12,800	Intralot		12
		Lottery & Gaming Systems & Services
				12
Europe: Total				1,862

Number of Shares			Value (000)
Other Countries 1.3%
		> Canada 1.3%
	1,670	Alliance Grain Traders	$	26
		Global Leader in Pulse Processing & Distribution
				26
Other Countries: Total				26
Asia 1.0%
		> Hong Kong 1.0%
	9,000	L'Occitane International		21
		Skin Care & Cosmetics Producer
				21
Asia: Total				21
Total Equities: 94.0% (Cost: $1,708)				1,909
Total Investments: 94.0% (Cost: $1,708)(c)(d)				1,909	(e)
Cash and Other Assets Less Liabilities: 6.0%				122
Total Net Assets: 100.0%			$	2,031

GDR - Global Depositary Receipts

85

> 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 March 31, 2012, this security had an aggregate value of $39, which represented 1.92% of total net assets.

(c)  At March 31, 2012, for federal income tax purposes, the cost of investments was $1,708 and net unrealized appreciation was $201 consisting of gross unrealized appreciation of $249 and gross unrealized depreciation of $(48).

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

Currency	Value		Percentage of Net Assets
Euro	$	1,014		49.9
British Pound		328		16.2
Swiss Franc		156		7.7
Swedish Krona		124		6.1
U.S. Dollar		105		5.1
Other currencies less than 5% of total net assets		182		9.0
	$	1,909		94.0

(e)  Securities are valued using policies described in the Notes to Financial Statements in the most recent shareholder report.

  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.

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

  The Committee meets at least quarterly to review and approve valuation matters, which may include a description of fair value actions, data regarding pricing information received from approved pricing vendors and brokers and the results of Board-approved valuation control policies and procedures (the Policies). The Policies address, among other things, instances when market quotations are readily available, including recommendation of third party pricing vendors and determining appropriate pricing methodologies; events that require fair valuation and assessment of fair value techniques; securities with a potential for stale pricing, including those that are illiquid, restricted, or in default; and the effectiveness of third-party pricing vendors. The Committee meets more frequently, as needed, to discuss additional valuation matters, which may include the need to review back-testing results, review time-sensitive information or approve related valuation actions.

  For investments categorized as Level 3, the Committee monitors information similar to that described above, which may include: (i) data specific to the issuer or comparable issuers, (ii) general market or specific sector news and (iii) quoted prices and specific or similar security transactions. The Committee considers this data and any changes from prior periods in order to assess the reasonableness of observable and unobservable inputs, any assumptions or internal models used to value those securities and changes in fair value. This data is also used to corroborate, when available, information received from approved pricing vendors. Various factors impact the frequency of monitoring (which may occur as often as daily), however the Committee may determine that changes to inputs, assumptions and models are not required with the same frequency.

86

Columbia Acorn European Fund

Statement of Investments (Unaudited), continued

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

The following table summarizes the inputs used, as of March 31, 2012, in valuing the Fund's assets:

Investment Type	Quoted Prices (Level 1)		Other Significant Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)		Total
Equities
Europe	$	65	$	1,797	$	-	$	1,862
Other Countries		26		-		-		26
Asia		-		21		-		21
Total Equities		91		1,818		-		1,909
Total Investments	$	91	$	1,818	$	-	$	1,909

  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, in accordance with the policy adopted by the Board of Trustees, provided by an independent third party to value securities principally traded in foreign markets in order to adjust for possible stale pricing that may occur between the close of the foreign exchanges and the time for valuation. These models take into account available market data including intraday index, ADR, and ETF movements.

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

87

Columbia Acorn European Fund

Portfolio Diversification (Unaudited)

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

	Value (000)		Percentage of Net Assets
>Industrial Goods & Services
Other Industrial Services	$	221		10.9
Machinery		202		9.9
Industrial Materials & Specialty Chemicals		94		4.6
Conglomerates		80		3.9
Electrical Components		58		2.9
Construction		52		2.6
Outsourcing Services		44		2.2
Industrial Distribution		16		0.8
		767		37.8
>Information
Internet Related		99		4.9
Instrumentation		96		4.7
Financial Processors		63		3.1
CATV		59		2.9
Gaming Equipment & Services		57		2.8
Business Software		40		2.0
Advertising		17		0.8
		431		21.2
>Consumer Goods & Services
Casinos & Gaming		59		2.9
Nondurables		44		2.2
Other Durable Goods		42		2.1
Restaurants		25		1.2
Apparel		23		1.1
Retail		22		1.1
Other Entertainment		20		1.0
Food & Beverage		8		0.4
		243		12.0
>Energy & Minerals
Mining		43		2.1
Oil & Gas Producers		40		2.0
Oil Services		29		1.4
Agricultural Commodities		26		1.3
Oil Refining, Marketing & Distribution		18		0.9
		156		7.7
>Finance
Insurance		70		3.4
Brokerage & Money Management		31		1.5
Banks		28		1.4
		129		6.3
>Other Industries
Real Estate		47		2.3
Regulated Utilities		41		2.0
Transportation		32		1.6
		120		5.9

	Value (000)		Percentage of Net Assets
>Health Care
Pharmaceuticals	$	26		1.3
Medical Equipment & Devices		19		0.9
Medical Supplies		18		0.9
		63		3.1
Total Equities:		1,909		94.0
Total Investments:		1,909		94.0
Cash and Other Assets Less Liabilities:		122		6.0
Net Assets:	$	2,031		100.0

88

Columbia Acorn Family of Funds

First Quarter Class A, B, C, I, R and R5 Expense Information (Unaudited)

Columbia Acorn Fund	Class A			Class B*			Class C			Class I
Management Fees		0.64	%		0.64	%		0.64	%		0.64	%
Distribution and Services (12b-1) Fees		0.25	%		0.75	%		1.00	%		0.00	%
Other Expenses		0.16	%		0.26	%		0.16	%		0.08	%
Net Expense Ratio		1.05	%		1.65	%		1.80	%		0.72	%
Columbia Acorn International	Class A			Class B*			Class C			Class I			Class R†			Class R5†
Management Fees		0.76	%		0.76	%		0.76	%		0.76	%		0.76	%		0.76	%
Distribution and Services (12b-1) Fees		0.25	%		0.75	%		1.00	%		0.00	%		0.50	%		0.00	%
Other Expenses		0.24	%		0.46	%		0.25	%		0.10	%		0.15	%		0.12	%
Net Expense Ratio		1.25	%		1.97	%		2.01	%		0.86	%		1.41	%		0.88	%
Columbia Acorn USA	Class A			Class B*			Class C			Class I
Management Fees		0.86	%		0.86	%		0.86	%		0.86	%
Distribution and Services (12b-1) Fees		0.25	%		0.75	%		1.00	%		0.00	%
Other Expenses		0.17	%		0.39	%		0.18	%		0.11	%
Net Expense Ratio		1.28	%		2.00	%		2.04	%		0.97	%
Columbia Acorn International Select	Class A			Class B*			Class C			Class I
Management Fees		0.94	%		0.94	%		0.94	%		0.94	%
Distribution and Services (12b-1) Fees		0.25	%		0.75	%		1.00	%		0.00	%
Other Expenses		0.33	%		0.44	%		0.38	%		0.20	%
Net Expense Ratio		1.52	%		2.13	%		2.32	%		1.14	%
Columbia Acorn Select	Class A			Class B*			Class C			Class I
Management Fees		0.83	%		0.83	%		0.83	%		0.83	%
Distribution and Services (12b-1) Fees		0.25	%		0.75	%		1.00	%		0.00	%
Other Expenses		0.21	%		0.25	%		0.19	%		0.10	%
Net Expense Ratio		1.29	%		1.83	%		2.02	%		0.93	%
Columbia Thermostat Fund	Class A			Class B*			Class C
Management Fees		0.10	%		0.10	%		0.10	%
Distribution and Services (12b-1) Fees		0.25	%		0.75	%		1.00	%
Other Expenses		0.15	%		0.15	%		0.15	%
Net Expense Ratio		0.50	%		1.00	%		1.25	%
Columbia Acorn Emerging Markets Fund	Class A			Class C			Class I
Management Fees		1.25	%		1.25	%		1.25	%
Distribution and Services (12b-1) Fees		0.25	%		1.00	%		0.00	%
Other Expenses**		0.35	%		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 Services (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.

    Fees and expenses are for the three months ended March 31, 2012. The fees and expenses of Columbia Acorn Select and Columbia Acorn International Select include the effect of the voluntary undertaking by Columbia Wanger Asset Management, LLC (CWAM) to waive fees and/or reimburse the Funds for any ordinary operating expenses (exclusive of brokerage commissions, interest, taxes and extraordinary expenses, but inclusive of custodian charges relating to overdrafts, if any), after giving effect to any balance credits from the Funds' custodian, in excess of the following annual rates:

Fund	Class A			Class B			Class C			Class I
Columbia Acorn International Select		1.70	%		2.20	%		2.45	%		1.30	%
Columbia Acorn Select		1.60	%		2.10	%		2.35	%		1.25	%

    These arrangements may be modified or terminated by either the Funds or CWAM upon 30 days notice.

Columbia Thermostat Fund's fees and expenses include the effect of CWAM's contractual undertaking to waive fees and/or reimburse the Fund for any ordinary operating expenses (exclusive of distribution and service fees, interest and fees on borrowings and expenses associated with the Fund's investments in other investment companies, but including custodian charges relating to overdrafts, if any), after giving effect to any balance credits from the Fund's custodian, in excess of the annual rate of 0.25% of the average daily net assets. Columbia Thermostat Fund's waiver/reimbursement arrangement is contractual through April 30, 2012. There is no guarantee that this arrangement will continue thereafter.

    The fees and expenses of Columbia Acorn Emerging Markets Fund and Columbia Acorn European Fund also include the effect of fee waivers/reimbursement. CWAM has contractually undertaken to waive fees and/or reimburse Columbia Acorn Emerging Markets Fund so that the Fund's ordinary operating expenses (excluding interest and fees on borrowings and expenses associated with the Fund's investment in other investment companies, if any) do not exceed the annual rates of 1.85%, 2.60% and 1.41% of the Fund's average daily net assets attributable to Class A, Class C and Class I shares, respectively, through April 30, 2013. There is no guarantee that this arrangement will continue thereafter. CWAM has contractually undertaken to waive fees and/or reimburse Columbia Acorn European Fund so that the Fund's ordinary operating expenses (excluding interest and fees on borrowings and expenses associated with the Fund's investment in other investment companies, if any) do not exceed the annual rates of 1.75%, 2.50% and 1.31% of the Fund's average daily net assets attributable to Class A, Class C and Class I shares, respectively, through April 30, 2013. There is no guarantee that this arrangement will continue thereafter.

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

  *  The Funds generally no longer accept investments by new or existing investors in Class B shares, except in connection with the reinvestment of any dividend and/or capital gain distributions in Class B shares of the Funds and exchanges by existing Class B shareholders of certain other funds within the Columbia Family of Funds.

  **  Does not include estimated fees and expenses of 0.62% 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.

89

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90

Columbia Acorn Family of Funds

Trustees

Laura M. Born

Chair of the Board

Steven N. Kaplan

Vice Chair of the Board

Michelle L. Collins

Maureen M. Culhane

Margaret M. Eisen

John C. Heaton

Charles P. McQuaid

David J. Rudis

David B. Small

Ralph Wanger (Trustee Emeritus)

Officers

Charles P. McQuaid

President

Ben Andrews

Vice President

Robert A. Chalupnik

Vice President

Michael G. Clarke

Assistant Treasurer

Joseph F. DiMaria

Assistant Treasurer

P. Zachary Egan

Vice President

Fritz Kaegi

Vice President

John M. Kunka

Assistant Treasurer

Stephen Kusmierczak

Vice President

Joseph C. LaPalm

Vice President

Bruce H. Lauer

Vice President, Secretary and Treasurer

Louis J. Mendes III

Vice President

Robert A. Mohn

Vice President

Christopher J. Olson

Vice President

Christopher O. Petersen

Assistant Secretary

Scott R. Plummer

Assistant Secretary

Andreas Waldburg-Wolfegg

Vice President

Linda K. Roth-Wiszowaty

Assistant Secretary

Robert P. Scales

Chief Compliance Officer, Chief Legal Officer,
Senior Vice President and General Counsel

Investment Manager

Columbia Wanger Asset Management, LLC
227 West Monroe Street, Suite 3000
Chicago, Illinois 60606

1-800-922-6769

Distributor

Columbia Management Investment Distributors, Inc.
225 Franklin Street
Boston, Massachusetts 02110

Transfer Agent, Dividend Disbursing Agent

Columbia Management Investment Services Corp.
P. O. Box 8081
Boston, Massachusetts 02266-8081

1-800-345-6611

Legal Counsel to the Funds

Perkins Coie LLP
Washington, DC

Legal Counsel to the Independent Trustees

Drinker Biddle & Reath LLP
Philadelphia, Pennsylvania

Independent Registered Public Accounting Firm

PricewaterhouseCoopers LLP
Chicago, Illinois

This report, including the schedules of investments, is submitted for the general information of the shareholders of Columbia Acorn Trust.

A description of the policies and procedures that the Funds use to determine how to vote proxies and a copy of the Funds' voting record are available (i) without charge, upon request, by calling 800-922-6769 and (ii) on the Securities and Exchange Commission's website at www.sec.gov. Information regarding how the Funds voted proxies relating to portfolio securities during the 12-month period ended June 30, is available from the SEC's website. Information regarding how the Funds voted proxies relating to portfolio securities is also available at www.columbiamanagement.com under "About Us." From there, click on "Disclosures."

The Funds file a complete schedule of portfolio holdings with the SEC for the first and third quarters of each fiscal year on Form N-Q. The Funds' Form N-Q is available on the SEC's website at www.sec.gov and may be reviewed and copied at the SEC's Public Reference Room in Washington, D.C. Information on the operation of the Public Reference Room may be obtained by calling 1-800-SEC-0330.

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.

91

This document contains Global Industry Classification Standard data. The Global Industry Classification Standard ("GICS") was developed by and is the exclusive property and a service mark of MSCI Inc. ("MSCI") and Standard & Poor's Financial Services LLC ("S&P") and is licensed for use by Columbia Wanger Asset Management, LLC. Neither MSCI, S&P, nor any other party involved in making or compiling the GICS or any GICS classifications makes any express or implied warranties or representations with respect to such standard or classification (or the results to be obtained by the use thereof), and all such parties hereby expressly disclaim all warranties of originality, accuracy, completeness, merchantability and fitness for a particular purpose with respect to any of such standard or classification. Without limiting any of the foregoing, in no event shall MSCI, S&P, any of their affiliates or any third party involved in making or compiling the GICS or any GICS classifications have any liability for any direct, indirect, special, punitive, consequential or any other damages (including lost profits) even if notified of the possibility of such damages.

Columbia Management^®

Columbia Acorn Family of Funds
Class A, B, C, I, R and R5 Shares

First Quarter Report, March 31, 2012

For More Information

You'll find more information about the Columbia Acorn Family of Funds in the documents described below. Contact Columbia Funds as follows to obtain these documents free of charge:

By Mail:  Columbia Funds
c/o Columbia Management Investment Services Corp.
P.O. Box 8081
Boston, MA 02266-8081

By Telephone: 800.345.6611

Online: www.columbiamanagement.com

Shareholder Communications with the Board

The Funds' Board of Trustees has adopted procedures by which shareholders may communicate with the Board. Shareholders who wish to communicate with the Board should send their written communications to the Board by mail, c/o Columbia Wanger Asset Management, LLC, 227 West Monroe Street, Suite 3000, Chicago, Illinois 60606, Attention: Secretary. Shareholder communications must (i) be in writing, (ii) identify the Columbia Acorn Fund to which the communication relates and (iii) state the particular class of shares and number of shares held by the communicating shareholder.

Prospectuses and the Statement of Additional Information (SAI)

The prospectuses and the SAI provide more detailed information about the Funds and their policies. The SAI is legally part of each prospectus (it's incorporated by reference). A copy of each has been filed with the SEC.

Information Provided by the SEC

You can review and copy information about the Funds (including their prospectuses, the SAI and shareholder reports) at the SEC's Public Reference Room in Washington, DC. To find out more about the operation of the Public Reference Room, call the SEC at 202.551.8090. Reports and other information about the Fund are also available in the EDGAR Database on the SEC's website at http://www.sec.gov, or you can receive copies of this information, for a fee, by electronic request at the following e-mail address: publicinfo@sec.gov. You can also obtain copies of this information by writing the Public Reference Section, Securities and Exchange Commission, Washington, DC 20549-0102.

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

© 2012 Columbia Management Investment Advisers, LLC. All rights reserved.

225 Franklin Street, Boston, MA 02110

800.345.6611 www.columbiamanagement.com

C-1448 C (5/12) 138036