N-30B-2 1 a15-21323_1n30b2.htm N-30B-2

THIRD QUARTER REPORT

September 30, 2015

COLUMBIA ACORN FAMILY OF FUNDS

Class A, B, C, I, R, R4, R5, Y and Z Shares
Managed by Columbia Wanger Asset Management, LLC

Columbia Acorn® Fund

Columbia Acorn International®

Columbia Acorn USA®

Columbia Acorn International Select^SM

Columbia Acorn Select^SM

Columbia Thermostat Fund^SM

Columbia Acorn Emerging Markets Fund^SM

Columbia Acorn European Fund^SM

COLUMBIA ACORN FAMILY OF FUNDS

NET ASSET VALUE PER SHARE as of 9/30/15

	Columbia Acorn® Fund		Columbia Acorn International®		Columbia Acorn USA®		Columbia Acorn International Select^SM		Columbia Acorn Select^SM		Columbia Thermostat Fund^SM		Columbia Acorn Emerging Markets Fund^SM		Columbia Acorn European Fund^SM
Class A	$	27.61	$	39.02	$	27.23	$	20.59	$	18.66	$	14.38	$	10.21	$	14.33
Class B	$	23.84	$	37.55	$	23.28	$	19.30	$	15.67	$	14.43		N/A		N/A
Class C	$	23.28	$	37.41	$	23.12	$	19.16	$	15.35	$	14.40	$	10.10	$	14.14
Class I	$	29.35	$	39.21	$	29.30	$	20.88	$	20.02		N/A	$	10.27	$	14.35
Class R		N/A	$	38.91		N/A		N/A		N/A		N/A		N/A		N/A
Class R4	$	29.78	$	39.40	$	29.76	$	21.02	$	20.35	$	14.29	$	10.32	$	14.42
Class R5	$	29.84	$	39.14	$	29.79	$	21.01	$	20.39	$	14.31	$	10.32	$	14.49
Class Y	$	29.91	$	39.46	$	29.88	$	21.01	$	20.48	$	14.29	$	10.23		N/A
Class Z	$	29.27	$	39.15	$	29.11	$	20.88	$	19.91	$	14.22	$	10.25	$	14.36

Class I shares are available only to the Columbia funds, such as Columbia Thermostat Fund, and are not available to individual investors. Class R, R4, R5, Y and Z shares are sold at net asset value and have limited eligibility. Please see the Funds' prospectuses for details. The Columbia Acorn Family of Funds offer multiple share classes, not all necessarily available through all financial intermediaries, and the ratings assigned to the various share classes by mutual fund rating agencies may vary. Contact us for details.

ESTIMATED YEAR-END DISTRIBUTIONS as of 10/31/15

To help with your tax planning, following are the estimated year-end capital gain distributions for the Columbia Acorn Funds. With the exception of Columbia Thermostat Fund, the expected record date is December 8, 2015, and the expected ex-dividend and payable date is December 9, 2015. For Columbia Thermostat Fund, the expected record date is December 21, 2015, and the expected ex-dividend and payable date is December 22, 2015. Distribution information is not final and should not be considered final until after the record date. The board of trustees will determine the actual distributions the Funds will pay. We have not provided estimates for income distributions, but some Funds may pay such distributions on the same dates noted above.

	Short-term Capital Gains		Long-term Capital Gains
Columbia Acorn Fund		None	$	9.70-$10.70
Columbia Acorn International		None	$	1.20-$1.40
Columbia Acorn USA		None	$	6.80-$7.30
Columbia Acorn International Select		None		None
Columbia Acorn Select	$	0.75-$0.85	$	4.75-$5.25
Columbia Thermostat Fund		None	$	0.00-$0.05
Columbia Acorn Emerging Markets Fund		None		None
Columbia Acorn European Fund		None		None

The views expressed in the report 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 a 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 ACORN FAMILY OF FUNDS

TABLE OF CONTENTS

Message From Director of International Research					2
Descriptions of Indexes					3
Share Class Performance					4
Fund Performance vs. Benchmarks					5
Columbia Acorn® Fund
In a Nutshell					6
At a Glance					7
Major Portfolio Changes					26
Statement of Investments					28
Columbia Acorn International®
In a Nutshell					8
At a Glance					9
Major Portfolio Changes					36
Statement of Investments					39
Portfolio Diversification					47
Columbia Acorn USA®
In a Nutshell					10
At a Glance					11
Major Portfolio Changes					48
Statement of Investments					49
Columbia Acorn International Select^SM
In a Nutshell					12
At a Glance					13
Major Portfolio Changes					54
Statement of Investments					55
Portfolio Diversification					59
Columbia Acorn Select^SM
In a Nutshell					14
At a Glance					15
Major Portfolio Changes					60
Statement of Investments					61

Columbia Thermostat Fund^SM
In a Nutshell					16
At a Glance					17
Statement of Investments					65
Columbia Acorn Emerging Markets Fund^SM
In a Nutshell					18
At a Glance					19
Major Portfolio Changes					67
Statement of Investments					69
Portfolio Diversification					74
Columbia Acorn European Fund^SM
In a Nutshell					20
At a Glance					21
Major Portfolio Changes					75
Statement of Investments					77
Portfolio Diversification					81
Squirrel Chatter: Fannie Mae, Freddie Mac and the Housing Market Collapse					22
Columbia Acorn Family of Funds
Expense Information					83

A COMMENT ON TRADING VOLUMES

Market conditions are always changing and vary by country and industry sector, and investing in international markets involves unique risks. In the wake of the 2007-2009 financial crisis, trading volumes in both emerging and developed international markets declined significantly and have stayed at generally reduced levels since then. Although it is difficult to accurately assess trends in trading volumes in foreign markets, because some amount of activity has migrated to alternative trading venues, a reduction in trading volumes poses challenges to the Funds. This is particularly so because the Funds focus on small- and mid-cap companies that usually have lower trading volumes and often take sizeable positions in portfolio companies. As a result of lower trading volumes, it may take longer to buy or sell securities, which can exacerbate a Fund's exposure to volatile markets. A Fund may also be limited in its ability to execute favorable trades in portfolio securities in response to changes in company prices and fundamentals. If a Fund is forced to sell securities to meet redemption requests or other cash needs, or in the case of an event affecting liquidity in a particular market or markets, it may be forced to dispose of those securities under disadvantageous circumstances and at a loss. As a Fund grows in size, these considerations take on increasing significance and may adversely impact performance.

MESSAGE FROM DIRECTOR OF INTERNATIONAL RESEARCH

DEAR SHAREHOLDERS:

Effective January 1, 2016, the primary benchmarks for all Columbia Acorn international products will be changed from their current S&P benchmark indices to the more commonly used MSCI family of benchmark indices. After a comprehensive review of various indices, and taking into account input from various investors and intermediaries, we believe the MSCI family of indices are most representative of the international Funds' target opportunity sets and provide the best comparison of your Funds to their peer funds. MSCI is the most widely used benchmark family for international funds in both the Lipper and Morningstar peer groups of mutual funds. These changes will have no effect on our investment philosophy and process at Columbia Wanger, and they do not affect the domestic Columbia Acorn Fund product offerings.

Specifically, the benchmark changes are as follows:

Fund	Current primary benchmark	Primary benchmark effective January 1, 2016
Columbia Acorn International	S&P Global Ex-U.S. Between $500M-$5B	MSCI ACWI Ex USA SMID Cap
Columbia Acorn International Select	S&P Developed Ex-U.S. Between $2B-$10B	MSCI ACWI Ex USA
Columbia Acorn Emerging Markets Fund	S&P Emerging Markets Between $500M-$5B	MSCI Emerging Markets SMID Cap
Columbia Acorn European Fund	S&P Europe Between $500M-$5B	MSCI AC Europe Small Cap

The difference in composition between the current and new benchmarks varies from Fund to Fund, and Fund portfolio composition may be adjusted in connection with the transition to the new benchmarks. For example, the average weighted market capitalization for the new benchmark is greater than that of the current benchmark for Columbia Acorn International, Columbia Acorn International Select and Columbia Acorn European Fund, and is less than that of the current benchmark for Columbia Acorn Emerging Markets Fund. The regional geographic weightings will differ between the current and new benchmarks for all Funds other than Columbia Acorn European Fund, which invests in one region. Industry sector weightings may also vary between the current and new benchmarks. As an active manager, we have always been benchmark aware, but we have regularly deviated from the benchmark average weighted market capitalizations, and from benchmark sector and geography weightings, where we believed this was in the interest of Fund shareholders. We will continue to do so going forward.

In managing the international Funds, we will of course continue to seek to outperform the new benchmarks in keeping with the Funds' investment strategies and our overall investment approach. As provided in SEC rules relating to mutual funds, for one year after the change, Fund performance will be shown against both the current and the new benchmarks.

Louis J. Mendes
Director of International Research and Portfolio Manager
Columbia Wanger Asset Management, LLC

COLUMBIA ACORN FAMILY OF FUNDS

DESCRIPTIONS OF INDEXES INCLUDED IN THIS REPORT

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

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

• Euromoney Smaller European Companies (inc. UK) Index is an index of smaller companies in Europe including the UK market. The Euromoney Smaller European Companies Index covers companies of small- and mid-cap market capitalization in Europe's developed markets. The index is rebalanced on a quarterly basis.

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

• MSCI Europe, Australasia and Far East (EAFE) Index (Net) is a capitalization-weighted index that tracks the total return of common stocks in 21 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 (Net), a widely recognized international benchmark, is a free float-adjusted market capitalization index that is designed to measure small-cap emerging market equity performance in 23 emerging market countries, as determined by MSCI. The MSCI Emerging Markets Small Cap Index (Net) currently consists of the following emerging market country indexes: Brazil, Chile, China, Colombia, Czech Republic, Egypt, Greece, Hungary, India, Indonesia, Korea, Malaysia, Mexico, Peru, Philippines, Poland, Qatar, Russia, South Africa, Taiwan, Thailand, Turkey and United Arab Emirates.

• 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.

• 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 that represents the mid-cap developed market, excluding the United States.

• S&P Emerging Markets Between $500M and $5B® Index represents the institutionally investable capital of 23 emerging market countries, as determined by S&P, with market caps ranging between $500 million to $5 billion. The index currently consists of the following emerging market country indexes: Brazil, Chile, China, Colombia, Czech Republic, Egypt, Greece, Hungary, India, Indonesia, Malaysia, Mexico, Morocco, Peru, Philippines, Poland, Qatar, Russia, South Africa, Taiwan, Thailand, Turkey and United Arab Emirates.

• S&P Europe Between $500M and $5B® Index represents the institutionally investable capital of 16 European countries, as determined by S&P, with market caps ranging between $500 million to $5 billion. The index consists of the following European countries: Austria, Belgium, Denmark, Finland, France, Germany, 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 that represents 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.

COLUMBIA ACORN FAMILY OF FUNDS

SHARE CLASS PERFORMANCE Average Annual Total Returns through 9/30/15

	Class A						Class B						Class C						Class I			Class R			Class R4			Class R5			Class Y			Class Z
	Without Sales Charge			With Sales Charge			Without Sales Charge			With Sales Charge			Without Sales Charge			With Sales Charge
Columbia Acorn® Fund
Year to date*		-4.05	%		-9.57	%		-4.64	%		-9.13	%		-4.55	%		-5.45	%		-3.79	%		N/A			-3.90	%		-3.83	%		-3.79	%		-3.80	%
1 year		-0.38	%		-6.11	%		-1.20	%		-5.13	%		-1.10	%		-1.88	%		-0.03	%		N/A			-0.16	%		-0.07	%		-0.01	%		-0.07	%
5 years		10.02	%		8.73	%		9.34	%		9.07	%		9.23	%		9.23	%		10.41	%		N/A			10.32	%		10.37	%		10.40	%		10.35	%
10 years		6.66	%		6.03	%		5.99	%		5.99	%		5.85	%		5.85	%		7.01	%		N/A			6.96	%		6.98	%		7.00	%		6.97	%
Columbia Acorn International®
Year to date*		-5.58	%		-11.00	%		-6.18	%		-10.83	%		-6.11	%		-7.04	%		-5.30	%		-5.82	%		-5.44	%		-5.36	%		-5.29	%		-5.38	%
1 year		-8.11	%		-13.40	%		-8.89	%		-13.20	%		-8.79	%		-9.65	%		-7.75	%		-8.45	%		-7.93	%		-7.81	%		-7.76	%		-7.84	%
5 years		4.35	%		3.12	%		3.60	%		3.25	%		3.58	%		3.58	%		4.77	%		4.00	%		4.64	%		4.70	%		4.73	%		4.68	%
10 years		6.35	%		5.72	%		5.63	%		5.63	%		5.54	%		5.54	%		6.74	%		6.02	%		6.68	%		6.71	%		6.73	%		6.70	%
Columbia Acorn USA®
Year to date*		-3.97	%		-9.50	%		-4.94	%		-9.55	%		-4.47	%		-5.40	%		-3.67	%		N/A			-3.77	%		-3.71	%		-3.69	%		-3.79	%
1 year		3.42	%		-2.53	%		2.09	%		-1.95	%		2.71	%		1.89	%		3.84	%		N/A			3.68	%		3.75	%		3.80	%		3.65	%
5 years		11.45	%		10.14	%		10.54	%		10.27	%		10.66	%		10.66	%		11.88	%		N/A			11.75	%		11.79	%		11.82	%		11.74	%
10 years		5.89	%		5.27	%		5.12	%		5.12	%		5.11	%		5.11	%		6.25	%		N/A			6.19	%		6.21	%		6.23	%		6.19	%
Columbia Acorn International Select^SM
Year to date*		-6.19	%		-11.56	%		-6.66	%		-11.32	%		-6.72	%		-7.65	%		-5.94	%		N/A			-5.98	%		-5.95	%		-5.90	%		-5.98	%
1 year		-13.95	%		-18.90	%		-14.58	%		-18.35	%		-14.65	%		-15.40	%		-13.68	%		N/A			-13.72	%		-13.70	%		-13.60	%		-13.72	%
5 years		3.39	%		2.18	%		2.73	%		2.44	%		2.59	%		2.59	%		3.79	%		N/A			3.71	%		3.74	%		3.77	%		3.73	%
10 years		5.55	%		4.93	%		4.86	%		4.86	%		4.72	%		4.72	%		5.93	%		N/A			5.88	%		5.90	%		5.91	%		5.89	%
Columbia Acorn Select^SM
Year to date*		-3.65	%		-9.17	%		-4.22	%		-8.56	%		-4.19	%		-5.05	%		-3.37	%		N/A			-3.50	%		-3.45	%		-3.39	%		-3.43	%
1 year		-0.96	%		-6.65	%		-1.73	%		-5.42	%		-1.66	%		-2.39	%		-0.59	%		N/A			-0.71	%		-0.62	%		-0.57	%		-0.63	%
5 years		7.89	%		6.61	%		7.14	%		6.94	%		7.09	%		7.09	%		8.30	%		N/A			8.17	%		8.22	%		8.25	%		8.21	%
10 years		6.22	%		5.59	%		5.50	%		5.50	%		5.39	%		5.39	%		6.57	%		N/A			6.51	%		6.53	%		6.55	%		6.53	%
Columbia Thermostat Fund^SM
Year to date*		-1.25	%		-6.95	%		-1.65	%		-6.47	%		-1.78	%		-2.75	%		N/A			N/A			-1.06	%		-0.99	%		-1.06	%		-1.06	%
1 year		0.50	%		-5.31	%		-0.01	%		-4.80	%		-0.26	%		-1.22	%		N/A			N/A			0.75	%		0.77	%		0.76	%		0.70	%
5 years		7.63	%		6.36	%		7.10	%		6.79	%		6.82	%		6.82	%		N/A			N/A			7.88	%		7.91	%		7.92	%		7.88	%
10 years		5.82	%		5.20	%		5.29	%		5.29	%		5.04	%		5.04	%		N/A			N/A			6.09	%		6.11	%		6.11	%		6.09	%
Columbia Acorn Emerging Markets Fund^SM
Year to date*		-19.73	%		-24.37	%		N/A			N/A			-20.16	%		-20.96	%		-19.45	%		N/A			-19.56	%		-19.50	%		-19.51	%		-19.54	%
1 year		-21.63	%		-26.14	%		N/A			N/A			-22.25	%		-23.03	%		-21.32	%		N/A			-21.40	%		-21.38	%		-21.33	%		-21.44	%
Life of Fund		0.96	%		-0.48	%		N/A			N/A			0.24	%		0.24	%		1.37	%		N/A			1.30	%		1.33	%		1.34	%		1.25	%
Columbia Acorn European Fund^SM
Year to date*		0.36	%		-5.38	%		N/A			N/A			-0.14	%		-1.14	%		0.57	%		N/A			0.56	%		0.56	%		N/A			0.57	%
1 year		-0.42	%		-6.11	%		N/A			N/A			-1.12	%		-2.11	%		-0.11	%		N/A			-0.15	%		-0.17	%		N/A			-0.15	%
Life of Fund		9.90	%		8.33	%		N/A			N/A			9.10	%		9.10	%		10.21	%		N/A			10.19	%		10.18	%		N/A			10.19	%

*Not annualized.

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

All results shown assume reinvestment of distributions during the period. Returns do not reflect the deduction of taxes that a shareholder may pay on Fund distributions or on the redemption of Fund shares. Performance results may reflect the effect of any fee waivers or reimbursements of Fund expenses by the investment manager and/or any of its affiliates. Absent these fee waivers and/or expense reimbursement arrangements, performance results may have been lower. Please see Page 83 of this report for information on contractual fee waiver and expense reimbursement agreements in place on September 30, 2015, for Columbia Thermostat Fund, Columbia Acorn Emerging Markets Fund and Columbia Acorn European Fund and voluntary fee waiver and expense reimbursement arrangements in place for Columbia Acorn International, Columbia Acorn International Select and Columbia Acorn Select.

The performance information shown represents past performance and is not a guarantee of future results. The investment return and principal value of your investment will fluctuate so that shares, when redeemed, may be worth more or less than their original cost. Current performance may be lower or higher than the performance data shown. You may obtain performance information current to the most recent month-end by contacting your financial intermediary, visiting columbiathreadneedle.com/us or calling 800.922.6769.

The returns shown include the returns of each Fund's Class Z shares, each Fund's oldest share class, in cases where the inception date of the Fund is earlier than the inception date of the particular share class or where a period shown dates to before the inception date of the share class. These returns are adjusted to reflect any higher class-related operating expenses of the newer share classes, as applicable. Please visit columbiathreadneedleus.com/investment-products/mutual-funds/appended-performance for more information.

Continued on Page 5.

FUND PERFORMANCE VS. BENCHMARKS Class Z Average Annual Total Returns through 9/30/15

Class Z Shares	3rd quarter*			Year to date*			1 year			5 years			10 years			Life of Fund
Columbia Acorn® Fund (ACRNX) (6/10/70)		-9.77	%		-3.80	%		-0.07	%		10.35	%		6.97	%		14.23	%
Russell 2500 Index		-10.30	%		-5.98	%		0.38	%		12.69	%		7.40	%		N/A
S&P 500 Index**		-6.44	%		-5.29	%		-0.61	%		13.34	%		6.80	%		10.73	%
Russell 2000 Index		-11.92	%		-7.73	%		1.25	%		11.73	%		6.55	%		N/A
Lipper Mid-Cap Growth Funds Index		-9.25	%		-4.22	%		1.35	%		11.53	%		7.76	%		N/A
Columbia Acorn International® (ACINX) (9/23/92)		-10.04	%		-5.38	%		-7.84	%		4.68	%		6.70	%		10.24	%
S&P Global Ex-U.S. Between $500M and $5B Index		-11.49	%		-4.44	%		-7.76	%		3.71	%		5.61	%		7.81	%
S&P Global Ex-U.S. SmallCap Index		-9.70	%		-2.10	%		-5.34	%		4.72	%		5.61	%		7.40	%
MSCI EAFE Index (Net)		-10.23	%		-5.28	%		-8.66	%		3.98	%		2.97	%		5.52	%
Lipper International Small/Mid Growth Funds Index		-7.20	%		2.23	%		-0.72	%		7.79	%		6.64	%		N/A
Columbia Acorn USA® (AUSAX) (9/4/96)		-10.29	%		-3.79	%		3.65	%		11.74	%		6.19	%		10.14	%
Russell 2000 Index		-11.92	%		-7.73	%		1.25	%		11.73	%		6.55	%		7.88	%
Lipper Small-Cap Growth Funds Index		-11.20	%		-4.50	%		2.97	%		11.99	%		6.51	%		6.67	%
Columbia Acorn Int'l Select^SM (ACFFX) (11/23/98)		-9.49	%		-5.98	%		-13.72	%		3.73	%		5.89	%		7.99	%
S&P Developed Ex-U.S. Between $2B and $10B Index		-8.78	%		-1.48	%		-3.90	%		5.29	%		4.80	%		6.98	%
MSCI EAFE Index (Net)		-10.23	%		-5.28	%		-8.66	%		3.98	%		2.97	%		3.63	%
Lipper International Small/Mid Growth Funds Index		-7.20	%		2.23	%		-0.72	%		7.79	%		6.64	%		9.70	%
Columbia Acorn Select^SM (ACTWX) (11/23/98)		-8.96	%		-3.43	%		-0.63	%		8.21	%		6.53	%		9.58	%
S&P MidCap 400 Index		-8.50	%		-4.66	%		1.40	%		12.93	%		8.25	%		9.81	%
S&P 500 Index**		-6.44	%		-5.29	%		-0.61	%		13.34	%		6.80	%		4.96	%
Lipper Mid-Cap Core Funds Index		-9.32	%		-6.20	%		-1.31	%		11.49	%		7.10	%		8.37	%
Columbia Thermostat Fund^SM (COTZX) (9/25/02)		-2.27	%		-1.06	%		0.70	%		7.88	%		6.09	%		7.42	%
S&P 500 Index		-6.44	%		-5.29	%		-0.61	%		13.34	%		6.80	%		8.96	%
Barclays U.S. Aggregate Bond Index		1.23	%		1.13	%		2.94	%		3.10	%		4.64	%		4.49	%
Lipper Flexible Portfolio Funds Index		-6.03	%		-5.08	%		-4.83	%		6.58	%		5.12	%		7.12	%
50/50 Blended Benchmark		-2.62	%		-1.98	%		1.32	%		8.31	%		6.02	%		6.99	%
Columbia Acorn Emerging Markets Fund^SM (CEFZX) (8/19/11)		-17.21	%		-19.54	%		-21.44	%		—			—			1.25	%
S&P Emerging Markets Between $500M and $5B Index		-17.85	%		-15.34	%		-18.15	%		—			—			-1.37	%
MSCI Emerging Markets Small Cap Index		-16.67	%		-9.80	%		-15.23	%		—			—			-1.55	%
Lipper Emerging Markets Index		-16.71	%		-15.28	%		-19.72	%		—			—			-2.23	%
Columbia Acorn European Fund^SM (CAEZX) (8/19/11)		-5.84	%		0.57	%		-0.15	%		—			—			10.19	%
S&P Europe Between $500M and $5B Index		-5.34	%		4.71	%		3.18	%		—			—			12.41	%
Euromoney Smaller European Companies Index		-5.17	%		4.45	%		0.88	%		—			—			10.66	%
Lipper European Region Index		-7.28	%		-1.32	%		-3.80	%		—			—			9.45	%

The inception dates for Class A, B and C shares (if offered) are as follows: Columbia Acorn Fund, Columbia Acorn International, Columbia Acorn USA, Columbia Acorn International Select and Columbia Acorn Select, 10/16/00; Columbia Thermostat Fund, 3/3/03; Columbia Acorn Emerging Markets Fund and Columbia Acorn European Fund, 8/19/11. The inception dates for Class I shares are as follows: Columbia Acorn Fund, Columbia Acorn International, Columbia Acorn USA, Columbia Acorn International Select and Columbia Acorn Select, 9/27/10; Columbia Acorn Emerging Markets Fund and Columbia Acorn European Fund, 8/19/11. The inception date for Class R shares for Columbia Acorn International is 8/2/11. The inception date for Class R4, R5 and Y shares (if offered) is as follows: Columbia Acorn Fund, Columbia Acorn USA, Columbia Acorn International Select, Columbia Acorn Select, Columbia Thermostat Fund, Columbia Acorn Emerging Markets Fund and Columbia Acorn European Fund, 11/8/12, except that Class Y shares of Columbia Acorn Emerging Markets Fund commenced operations on 6/13/13 and Class R4 shares of Columbia Acorn European Fund commenced operations on 6/25/14. The inception date for Class R5 shares of Columbia Acorn International is 8/2/11. The inception date for Class R4 and Y shares of Columbia Acorn International is 11/8/12. The inception date for Class Z shares is as follows: Columbia Acorn Fund, 6/10/70; Columbia Acorn International, 9/23/92; Columbia Acorn USA, 9/4/96; Columbia Acorn International Select and Columbia Acorn Select, 11/23/98; Columbia Thermostat Fund, 9/25/02; Columbia Acorn Emerging Markets Fund and Columbia Acorn European Fund, 8/19/11.

*Not annualized.

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

Please see Page 3 for a description of the indexes listed above.

COLUMBIA ACORN® FUND

IN A NUTSHELL


Robert A. Mohn* Co-Portfolio Manager				P. Zachary Egan Co-Portfolio Manager

Fritz Kaegi Co-Portfolio Manager				David L. Frank Co-Portfolio Manager

Market risk may affect a single issuer, sector of the economy, industry or the market as a whole. Investments in small- and mid-cap companies involve risks and volatility and possible illiquidity greater than investments in larger, more established companies. Foreign investments subject the Fund to political, economic, market, social and other risks within a particular country, as well as to potential currency instabilities and less stringent financial and accounting standards generally applicable to U.S. issuers. Risks are enhanced for emerging market issuers. The Fund may invest significantly in issuers within a particular sector, which may be negatively affected by market, economic or other conditions, making the Fund more vulnerable to unfavorable developments in the sector.

In the third quarter of 2015, Columbia Acorn Fund Class Z shares fell 9.77%, outperforming the Fund's primary benchmark, the Russell 2500 Index, which declined 10.30%. Year to date through September, the Fund had a 3.80% loss versus a 5.98% decline for the benchmark.

During the third quarter, we continued to concentrate the portfolio modestly by reducing the number of holdings in the Fund to 174 positions, down 10 names from the end of the second quarter. As we have made adjustments, our actions have been consistent with our growth-at-a-reasonable-price (GARP) approach, which focuses on allocating capital to companies that we believe have excellent business models and solid growth prospects, and that are available at reasonable prices. In addition to selling several positions to further concentrate the portfolio in the quarter, we selectively trimmed names that had reached our valuation targets and reallocated the proceeds into new positions that we believe meet our GARP standards. These additions were largely made in the consumer discretionary and information technology (IT) sectors. We maintained the Fund's overweight in industrials, its roughly benchmark weight in health care, and its underweight in financials, as discussed below.

Within the IT sector, one of our themes is investing in software developers offering product via the cloud for a monthly rental fee. This is a transition away from the older approach that requires customers to buy software outright and have it installed on site. The big implication for investors is that the software company will benefit from smooth revenues achieved through the rental arrangement, though upfront revenues will be lower. This newer model has created new businesses and is attracting takeouts from older developers who are trying to keep up. Under this theme, we added Cvent to the portfolio late in the second quarter. A developer of software used in corporate event planning, Cvent is dominating its niche and gained 34% in the third quarter. Other IT winners outside of the cloud theme included Solera Holdings, a software developer for automotive insurance claims processing, which gained 21% following the September announcement of its agreement to be acquired by Vista Equity Partners. We opted to take our gains and sold the position, using some of the proceeds to buy Coupons.com, a company that allows businesses to distribute coupons, advertising and trade promotions online. The Fund had a 28% weighting in the IT sector at quarter end, while the benchmark weight was 15%.

Industrials continue to be among the Fund's largest sector overweights, representing 23% of the Fund and 15% of the benchmark. During the third quarter, our stock selection within the sector was positive relative to the benchmark,

but we lost some ground due to the Fund's overweight in a down quarter for the sector. U.S. dollar strength continued to negatively impact global names like Donaldson, a maker of industrial air filtration equipment, and Nordson, a manufacturer of dispensing systems for adhesives and coatings. Both names fell around 20% in the quarter. While the dollar headwind has had an impact, the majority of the industrial stocks the Fund owns have a more natural linkage to the U.S. market. For example, NVR, a homebuilder with operations in 14 states, was up 14% in the quarter. In addition to being largely U.S.-focused, Fund holdings within the industrial sector are also much broader than the machines and tools that the industrials name evokes; they include rental cars, trucking companies, consulting services and distributors, to name a few.

After a tremendous run in the first half of the year, the health care sector cooled in the third quarter. Despite the reversal, the Fund maintained its strong outperformance in the sector year to date, posting a 14% gain in the sector versus the benchmark's 1% return for the first nine months of the year. Much of the Fund's strength in health care has been driven by the outperformance of biotech and pharmaceutical names. Due to the higher valuations we are seeing now in biotechs and pharmaceuticals, we did some selective trimming within this segment during the quarter. Laggards in the health care sector during the quarter included Cepheid, a provider of molecular diagnostic supplies, which fell 26% due to softer-than-expected June quarter results. Akorn, a developer, manufacturer and distributor of specialty generic drugs, fell 35% in the quarter primarily due to accounting errors that caused a delay in the company's filings with the SEC. Akorn hired a new chief financial officer, and we don't anticipate future problems.

The Fund's financial sector performance was a relative detractor in the quarter. The Federal Reserve opted not to raise interest rates at their meeting in September but implied a hike would come before year end. We continue to be leery of rate-sensitive names in this current environment. We maintained our underweight in real estate investment trusts (REITs) because of the potential negative impact of a rate increase on many of these companies. Banks, on the other hand, are expected to benefit from a rate hike, but we think any advantage would be modest, as banks struggle with fierce competition and heavy regulation. Bucking the downward trend in the quarter in REITs, Extra Space Storage, a self-storage facility operator, gained 19%. This name exemplifies what we are looking for in the REIT space—companies with strong growth potential and pricing power.

*In our first quarter shareholder report, we announced that Robert Mohn would be retiring later this year. Mr. Mohn formally retired effective October 1, 2015.

Fund holdings are as of the date given, are subject to change at any time, and are not recommendations to buy or sell any security.

COLUMBIA ACORN® FUND

AT A GLANCE

Total Net Assets of the Fund:
$9.1 billion

Performance data shown below represents past performance, does not guarantee future results, assumes reinvestment of dividends and distributions and does not reflect the deduction of taxes that a shareholder may pay on Fund distributions or the redemption of Fund shares. 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 data reflects fee waivers or reimbursements of Fund expenses, if any; in their absence, performance results would have been lower. Indexes are unmanaged; their results do not reflect the effect of expenses or sales charges. Securities in the Fund may not match those in an index. Please visit columbiathreadneedle.com/us for performance data current to the most recent month-end.

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

June 10, 1970 (Fund inception) through September 30, 2015

This chart shows the change in value of a hypothetical $10,000 investment in Class Z shares of the Fund during the stated time period. 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.

Average Annual Total Returns for period ended September 30, 2015

	3rd quarter			Year to date			1 year			5 years			10 years			Life of Fund
Class Z (6/10/70 inception)		-9.77	%		-3.80	%		-0.07	%		10.35	%		6.97	%		14.23	%
Class A (10/16/00 inception)
without sales charge		-9.86			-4.05			-0.38			10.02			6.66			13.86
with sales charge		-15.05			-9.57			-6.11			8.73			6.03			13.72
Russell 2500 Index*		-10.30			-5.98			0.38			12.69			7.40			N/A

Results for other share classes can be found on Page 4.

*The Fund's primary benchmark. Please see Page 3 for index descriptions.

Returns for Class A shown with and without the maximum initial sales charge of 5.75%. As stated in the May 1, 2015, prospectus, the Fund's annual operating expense ratio is 0.79% for Class Z shares and 1.08% for Class A shares. The returns shown for periods prior to the inception of the Fund's Class A shares append the returns of the Fund's Class Z shares, the Fund's oldest share class. These returns are adjusted to reflect any higher class-related operating expenses of the newer share classes, as applicable. Please visit columbiathreadneedleus.com/investment-products/mutual-funds/appended-performance for more information.

Portfolio Diversification

as a percentage of net assets, as of 9/30/15

Top 10 Holdings

as a percentage of net assets, as of 9/30/15

1.	Donaldson Industrial Air Filtration	2.4	%
2.	Ametek Aerospace/Industrial Instruments	2.1	%
3.	LKQ Alternative Auto Parts Distribution	1.9	%
4.	Cepheid Molecular Diagnostics	1.7	%
5.	Amphenol Electronic Connectors	1.7	%
6.	Mettler-Toledo International Laboratory Equipment	1.6	%
7.	SEI Investments Mutual Fund Administration & Investment Management	1.5	%
8.	Nordson Dispensing Systems for Adhesives & Coatings	1.4	%
9.	HEICO FAA-approved Aircraft Replacement Parts	1.4	%
10.	Associated Banc-Corp Midwest Bank	1.4	%

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

COLUMBIA ACORN INTERNATIONAL®

IN A NUTSHELL


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

Market risk may affect a single issuer, sector of the economy, industry or the market as a whole. International investing involves certain risks and volatility due to potential political, economic or currency instabilities and different, potentially less stringent, financial and accounting standards than those generally applicable to U.S. issuers. Risks are enhanced for emerging market issuers. Investments in small- and mid-cap companies involve risks and volatility and possible illiquidity greater than investments in larger, more established companies. Please also see "A Comment on Trading Volumes" on Page 1 of this report.

Columbia Acorn International Class Z shares fell 10.04% in the third quarter of 2015, compared to an 11.49% decline of the Fund's primary benchmark, the S&P Global ex-U.S. Between $500M and $5B® Index. Year to date through September, the Fund had a 5.38% loss versus a 4.44% decline for the benchmark. While the Fund outperformed in the quarter, the strain put on most global markets by decelerating economic growth in China created a difficult environment for international investors.

The third quarter saw a dramatic reversal of enthusiasm for Chinese stocks. Following China's market collapse in June and unexpected relaxation of the currency peg to the U.S. dollar, which resulted in modest devaluation in mid-August, its benchmark Shanghai Composite index declined 8.5% on August 24, wiping out all gains made in the year and closing down 38% from its June peak. China's steady growth has historically bolstered emerging markets in Asia and elsewhere because these markets are a source of commodities. This economic link drove emerging markets down along with China in the quarter, particularly when expressed in U.S. dollar terms, as commodity-tied currencies lost ground. For example, in Brazil, a country struggling against high inflation, unemployment and corruption, the real hit a 12-year low against the U.S. dollar in the quarter. The Fund had less than a 1% weight in Brazil at quarter end.

Against this backdrop, Fund holdings in Asia ex-Japan fell 14%, outperforming the benchmark in the region. In Latin America EMEA (Europe, Middle East, Africa), Fund holdings fell 25%, underperforming the benchmark. Coronation Fund Managers, a South African investment manager, was the largest detractor in the period, falling 30% on lower performance fees compared to those earned the prior year, and on reduced prospects for emerging markets, which could hurt future inflows.

While the news from Asia was bleak, European markets fared far better, as quantitative easing policies continued to provide a floor for European equities. Posting a relatively benign 3% loss, the Fund's overweight exposure to Europe benefited the Fund in the quarter versus the benchmark. The top three contributors to Fund gains were European companies and included Sweden's Unibet, a European online gaming operator, which gained 37% in the quarter.

We increased the liquidity of the Fund by moving into some larger market-cap positions in the quarter. We reduced the Fund's exposure to emerging markets and put that capital to work in Western Europe. European small- to mid-cap stocks have outperformed relative to other world markets and, despite this strong run, we believe valuations are only

modestly above historical averages, which may be warranted by the outlook for interest rates in the Eurozone.

Within emerging markets, we have concerns about the impact of a continued slowdown in China and a weakness in consumption across Southeast Asia and Latin America. While we have reduced Fund exposure to emerging markets, we are not moving away from these economies completely. Not all emerging markets are impacted in the same way by global events, so we take a country-by-country view to discover the local drivers of growth and the unique opportunities available in each market. In India, for example, our holdings were down only 4% in local currency in the quarter and positive that amount year to date, strongly outperforming the largely double-digit declines of other emerging markets. In Korea, holdings in the Fund were up slightly in local currency terms in the quarter and had a 17% gain for the first nine months of the year. We will continue to hold and make strategic investments within the emerging market space.

We believe we can no longer rely on consistent 7% or 8% growth from China to power the factories of Europe and Japan or the commodity markets of the emerging markets. With a slower Chinese growth rate, we believe emerging markets will continue to be fairly volatile. Our focus within China continues to be on businesses addressing the country's domestic needs, such as environmental companies, infrastructure development businesses, and providers of health care management services. In the broader international markets, we are putting fresh capital in higher growth companies and companies where near-term fundamental progress is masked by accounting factors or other issues, but that we believe have solid long-term earnings prospects. We are steering clear of modestly growing businesses where volatility of earnings is very low but valuations are high.

Fund holdings are as of the date given, are subject to change at any time, and are not recommendations to buy or sell any security.

COLUMBIA ACORN INTERNATIONAL®

AT A GLANCE

Total Net Assets of the Fund:
$6.9 billion

The Growth of a $10,000 Investment in Columbia Acorn International® Class Z Shares

September 23, 1992 (Fund inception) through September 30, 2015

This chart shows the change in value of a hypothetical $10,000 investment in Class Z shares of the Fund during the stated time period.

Average Annual Total Returns for period ended September 30, 2015

	3rd quarter			Year to date			1 year			5 years			10 years			Life of Fund
Class Z (9/23/92 inception)		-10.04	%		-5.38	%		-7.84	%		4.68	%		6.70	%		10.24	%
Class A (10/16/00 inception)
without sales charge		-10.11			-5.58			-8.11			4.35			6.35			9.83
with sales charge		-15.28			-11.00			-13.40			3.12			5.72			9.54
S&P Global Ex-U.S. Between $500M® and $5B*		-11.49			-4.44			-7.76			3.71			5.61			7.81

Results for other share classes can be found on Page 4.

*The Fund's primary benchmark. Please see Page 3 for index descriptions.

Returns for Class A shown with and without the maximum initial sales charge of 5.75%. As stated in the May 1, 2015, prospectus, the Fund's annual operating expense ratio is 0.93% for Class Z shares and 1.26% for Class A shares. The returns shown for periods prior to the inception of the Fund's Class A shares append the returns of the Fund's Class Z shares, the Fund's oldest share class. These returns are adjusted to reflect any higher class-related operating expenses of the newer share classes, as applicable. Please visit columbiathreadneedleus.com/investment-products/mutual-funds/appended-performance for more information.

Portfolio Diversification

as a percentage of net assets, as of 9/30/15

Top 10 Holdings

as a percentage of net assets, as of 9/30/15

1.	SimCorp (Denmark) Software for Investment Managers	1.4	%
2.	CCL Industries (Canada) Global Label Converter	1.3	%
3.	Spotless (Australia) Facility Management & Catering Company	1.3	%
4.	Wirecard (Germany) Online Payment Processing & Risk Management	1.2	%
5.	Distribuidora Internacional de Alimentación (Spain) Discount Retailer in Spain & Latin America	1.2	%
6.	Zee Entertainment Enterprises (India) Indian Programmer of Pay Television Content	1.2	%
7.	Unibet (Sweden) European Online Gaming Operator	1.1	%
8.	Partners Group (Switzerland) Private Markets Asset Management	1.0	%
9.	Novozymes (Denmark) Industrial Enzymes	1.0	%
10.	Geberit (Switzerland) Plumbing Systems	1.0	%

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

COLUMBIA ACORN USA®

IN A NUTSHELL


Robert A. Mohn* Co-Portfolio Manager				William J. Doyle Co-Portfolio Manager

Columbia Acorn USA Class Z shares outperformed the Fund's primary benchmark, the Russell 2000 Index, by 1.63% in the third quarter. In a volatile quarter, the Fund fell 10.29%, while the Russell 2000 Index fell 11.92%. Year to date through September, the Fund declined 3.79%, outperforming the 7.73% decline of the benchmark. Stock selection across most industries contributed positively to the Fund's performance versus the benchmark.

We continue to see the effects of increased takeover activity on Columbia Acorn USA. The Fund had 11 of its stocks acquired by strategic or financial buyers in the first nine months of the year, or nearly 10% of the number of holdings in the portfolio. While there is no guarantee that this trend will continue and not all of these transactions were at large premiums like Synageva BioPharma, which we mentioned last quarter, we do think this activity reinforces our view that we are succeeding in finding strategically important or financially attractive businesses in the markets in which they operate. In the third quarter, two of our three top contributors to performance gained on acquisition announcements. Solera Holdings, a software developer for automotive insurance claims processing, gained 21% on news that it would be acquired by Vista Equity Partners. Zulily, an e-commerce retailer offering flash sale events, gained 41% after Liberty Interactive extended an exchange offer to acquire all of the outstanding shares of its stock. We exited both positions on the announcements.

We did not make significant adjustments to Columbia Acorn USA in the quarter. Using the proceeds from sales of takeovers, or from the trimming of existing positions, we did redeploy some cash into the consumer discretionary sector and have also made some additions in the information technology (IT) space. At the period end, we remained underweight in financial stocks versus the benchmark, and we had an overweight position in the IT sector. Industrials continue to be the Fund's largest overweight, while its health care weight is below benchmark.

Within the IT sector, one of the areas that we have been focusing on is cloud computing, which provides access to software applications and computing power via the Internet for a monthly fee. Cvent, a developer of software used in corporate event planning, is a newer position in the Fund purchased following this theme. Cvent has a dominant position in its market niche, and its stock was up 34% in the quarter. Other IT winners outside of the cloud theme included Solera Holdings, mentioned above, and ExlService Holdings, a provider of business process outsourcing services, which was up 7% in the quarter after reporting stronger-than-expected June quarter results and

on management's upward revision of its 2015 forecast amid healthy demand.

In the industrials sector, Fund stock selection was a positive but the Fund's heavy overweight worked against us as the sector declined in the quarter. Nordson, a manufacturer of dispensing systems for adhesives and coatings, and Donaldson, a maker of industrial air filtration equipment, were both down around 20%. The strong U.S. dollar has negatively impacted these global companies, but we are seeing stronger results from the Fund's more domestic-oriented industrial names like Toro, a provider of turf maintenance equipment, which gained 4% in the quarter.

After a strong run in the first half of the year, health care stocks reversed in the third quarter. Despite these shorter-term declines, the Fund has maintained its strong outperformance in this sector year to date versus the benchmark. As we mentioned last quarter, we've done some trimming of the Fund's health care weight and this did prove to be modestly beneficial this quarter. Our biggest detractors in the sector included Cepheid, a provider of molecular diagnostic supplies, which fell 26% due to softer-than-expected June quarter results. Akorn, a developer, manufacturer and distributor of specialty generic drugs, fell 35% after disclosing that accounting errors caused a delay in the company's filings with the SEC. Akorn hired a new chief financial officer, and we don't anticipate future problems.

Relative to the benchmark, stock selection in the financial sector was a positive for the Fund in the quarter, but the sector as a whole underperformed. World Acceptance, a provider of personal loans, fell 56% on news of possible action to be taken against the company by the Consumer Financial Protection Bureau. SVB Financial Group, a bank to venture capitalists, ended the quarter down 20%. SVB's large deposit base positions it to benefit from an increase in interest rates, but the Federal Reserve's decision to delay a rate increase dampened investor sentiment around the stock.

*In our first quarter shareholder report, we announced that Robert Mohn would be retiring later this year. Mr. Mohn formally retired effective October 1, 2015.

Fund holdings are as of the date given, are subject to change at any time, and are not recommendations to buy or sell any security.

COLUMBIA ACORN USA®

AT A GLANCE

Total Net Assets of the Fund:
$1.1 billion

The Growth of a $10,000 Investment in Columbia Acorn USA® Class Z Shares

September 4, 1996 (Fund inception) through September 30, 2015

This chart shows the change in value of a hypothetical $10,000 investment in Class Z shares of the Fund during the stated time period.

Average Annual Total Returns for period ended September 30, 2015

	3rd quarter			Year to date			1 year			5 years			10 years			Life of Fund
Class Z (9/4/96 inception)		-10.29	%		-3.79	%		3.65	%		11.74	%		6.19	%		10.14	%
Class A (10/16/00 inception)
without sales charge		-10.37			-3.97			3.42			11.45			5.89			9.78
with sales charge		-15.51			-9.50			-2.53			10.14			5.27			9.44
Russell 2000 Index*		-11.92			-7.73			1.25			11.73			6.55			7.88

Results for other share classes can be found on Page 4.

*The Fund's primary benchmark. Please see Page 3 for index descriptions.

Returns for Class A shown with and without the maximum initial sales charge of 5.75%. As stated in the May 1, 2015, prospectus, the Fund's annual operating expense ratio is 1.08% for Class Z shares and 1.34% for Class A shares. The returns shown for periods prior to the inception of the Fund's Class A shares append the returns of the Fund's Class Z shares, the Fund's oldest share class. These returns are adjusted to reflect any higher class-related operating expenses of the newer share classes, as applicable. Please visit columbiathreadneedleus.com/investment-products/mutual-funds/appended-performance for more information.

Portfolio Diversification

as a percentage of net assets, as of 9/30/15

Top 10 Holdings

as a percentage of net assets, as of 9/30/15

1.	Extra Space Storage Self Storage Facilities	3.7	%
2.	Ametek Aerospace/Industrial Instruments	3.4	%
3.	HEICO FAA-approved Aircraft Replacement Parts	3.0	%
4.	Nordson Dispensing Systems for Adhesives & Coatings	2.9	%
5.	Donaldson Industrial Air Filtration	2.4	%
6.	Mettler-Toledo International Laboratory Equipment	2.0	%
7.	Drew Industries RV & Manufactured Home Components	1.9	%
8.	ExlService Holdings Business Process Outsourcing	1.9	%
9.	Cepheid Molecular Diagnostics	1.8	%
10.	Ansys Simulation Software for Engineers & Designers	1.8	%

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.

COLUMBIA ACORN INTERNATIONAL SELECT^SM

IN A NUTSHELL


Christopher J. Olson Co-Portfolio Manager				Andreas Waldburg-Wolfegg Co-Portfolio Manager

Market risk may affect a single issuer, sector of the economy, industry or the market as a whole. Foreign investments subject the Fund to political, economic, market, social and other risks within a particular country, as well as to potential currency instabilities and less stringent financial and accounting standards generally applicable to U.S. issuers. Risks are enhanced for emerging market issuers. Investments in small- and mid-cap companies involve risks and volatility and possible illiquidity greater than investments in larger, more established companies. The Fund may invest significantly in issuers within a particular sector, which may be negatively affected by market, economic or other conditions, making the Fund more vulnerable to unfavorable developments in the sector. Please also see "A Comment on Trading Volumes" on Page 1 of this report.

Columbia Acorn International Select Class Z shares ended the third quarter of 2015 down 9.49%, underperforming the 8.78% drop of the Fund's primary benchmark, the S&P Developed Ex-U.S. Between $2B and $10B® Index. Year to date through September, the Fund was down 5.98% versus a benchmark decline of 1.48%. Most world markets were negatively impacted by China's reversal, making it a difficult quarter for international investors. On a regional basis, Fund stock selection in Europe, North America and Australasia outpaced the benchmark in the quarter, but the Fund's overweight exposure to Latin America and select emerging markets was a detractor.

During the quarter, we moved some Fund assets away from Asia (excluding Japan) and put that money to work in Europe, where the Fund has historically been underweight. Compass Group, a UK provider of catering and support services, and Essilor International, a French manufacturer of eyeglass lenses, were two new names added to the Fund in the quarter. We also increased the Fund's exposure to some existing positions including Whitbread, a UK hotelier and coffee shop owner. At quarter end, the Fund was modestly overweight in Europe versus the benchmark.

We have put more emphasis on the mid-cap space within the portfolio since the beginning of the year. As market valuations have continued to grow, we are seeing opportunities in mid-cap names similar to those historically available in the small-mid cap area. Additionally, focusing on mid-caps gives us the opportunity to continue to invest in names that we have known for a long time, but that have outgrown the smaller cap space. Also in the quarter, we reduced the Fund's weighting in the basic materials sector by selling holdings in precious metal stocks. Gold miners Tahoe Resources and Goldcorp, down 33% and 23%, respectively in the quarter, were among the Fund's detractors and were sold before the period end.

Within Europe and North America, top contributors in the quarter included Wirecard, a German online payment processor, which gained 25%. Wirecard announced continued high revenue growth and operating profit. CCL Industries, a global label converter based in Canada, gained 15% on improved margins in all of its business segments, which beat market expectations. Partners Group, a Swiss private markets asset management company, gained 13% in the quarter on strong asset flows that are expected to be substantially higher than were anticipated at the beginning of the year. As noted above, the Fund benefited from its stock selection in Europe. In North America and Australasia, the Fund's underweight and stock selection were both beneficial relative to its benchmark.

Leading detractors in the period were heavily impacted by China's decline. While we made adjustments away from Asia (excluding Japan) during the quarter, the region remained an overweight in the Fund at quarter end and was a detractor relative to the benchmark. The Fund's one position listed in Hong Kong, the Hong Kong equity and derivatives market operator Hong Kong Exchanges and Clearing, declined 34%, dropping with the Chinese market. CapitaLand Mall Trust, a Singaporean commercial property real estate investment trust (REIT), fell 15%, as most emerging market economies were also down substantially in the quarter. As long-term investors, we generally try to hold or build positions in companies with good fundamentals when stock weakness occurs due to near-term factors.

Also an overweight in the Fund, Latin America and EMEA (Europe, Middle East, Africa) regional exposure was the largest detractor relative to the benchmark during the quarter. Naspers, a South African provider of media to emerging markets, fell 20% due to a 17% fall in Hong Kong-listed social networking platform TenCent. TenCent is Naspers' primary investment and it declined on concerns about the Chinese economy.

Fund holdings are as of the date given, are subject to change at any time, and are not recommendations to buy or sell any security.

COLUMBIA ACORN INTERNATIONAL SELECT^SM

AT A GLANCE

Total Net Assets of the Fund:
$180.7 million

The Growth of a $10,000 Investment in Columbia Acorn International Select^SM Class Z Shares

November 23, 1998 (Fund inception) through September 30, 2015

This chart shows the change in value of a hypothetical $10,000 investment in Class Z shares of the Fund during the stated time period.

Average Annual Total Returns for period ended September 30, 2015

	3rd quarter			Year to date			1 year			5 years			10 years			Life of Fund
Class Z (11/23/98 inception)		-9.49	%		-5.98	%		-13.72	%		3.73	%		5.89	%		7.99	%
Class A (10/16/00 inception)
without sales charge		-9.53			-6.19			-13.95			3.39			5.55			7.64
with sales charge		-14.74			-11.56			-18.90			2.18			4.93			7.26
S&P Developed Ex-U.S. Between $2B and $10B® Index*		-8.78			-1.48			-3.90			5.29			4.80			6.98

Results for other share classes can be found on Page 4.

*The Fund's primary benchmark. Please see Page 3 for index descriptions.

Returns for Class A shown with and without the maximum initial sales charge of 5.75%. As stated in the May 1, 2015, prospectus, the Fund's annual operating expense ratio is 1.18% for Class Z shares and 1.47% for Class A shares. The returns shown for periods prior to the inception of the Fund's Class A shares append the returns of the Fund's Class Z shares, the Fund's oldest share class. These returns are adjusted to reflect any higher class-related operating expenses of the newer share classes, as applicable. Please visit columbiathreadneedleus.com/investment-products/mutual-funds/appended-performance for more information.

Portfolio Diversification

as a percentage of net assets, as of 9/30/15

Top 10 Holdings

as a percentage of net assets, as of 9/30/15

1.	KDDI (Japan) Mobile & Fixed Line Communication Service Provider in Japan	4.9	%
2.	Naspers (South Africa) Media in Africa, China, Russia & other Emerging Markets	4.2	%
3.	Secom (Japan) Security Services	4.0	%
4.	Partners Group (Switzerland) Private Markets Asset Management	3.9	%
5.	Recruit Holdings (Japan) Recruitment & Media Services	3.9	%
6.	CCL Industries (Canada) Global Label Converter	3.8	%
7.	Telefonica Deutschland (Germany) Mobile & Fixed-line Communications in Germany	3.3	%
8.	CapitaLand Mall Trust (Singapore) Singapore Commercial Property Real Estate Investment Trust	3.2	%
9.	Distribuidora Internacional de Alimentación (Spain) Discount Retailer in Spain & Latin America	3.1	%
10.	WH Smith (United Kingdom) Newsprint, Books & General Stationery Retailer	3.0	%

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

COLUMBIA ACORN SELECT^SM

IN A NUTSHELL


Robert A. Chalupnik Lead Portfolio Manager				Matthew S. Szafranski Co-Portfolio Manager

Market risk may affect a single issuer, sector of the economy, industry or the market as a whole. Investments in small- and mid-cap companies involve risks and volatility and possible illiquidity greater than investments in larger, more established companies. Foreign investments subject the Fund to risks, including political, economic, market, social and other risks, within a particular country, as well as to potential currency instabilities and less stringent financial and accounting standards generally applicable to U.S. issuers. Risks are enhanced for emerging market issuers. The Fund may invest significantly in issuers within a particular sector, which may be negatively affected by market, economic or other conditions, making the Fund more vulnerable to unfavorable developments in the sector.

Columbia Acorn Select Class Z shares ended the third quarter of 2015 down 8.96%, slightly behind the 8.50% decline of its primary benchmark, the S&P MidCap 400 Index. Year to date through September, the Fund was down 3.43%, outperforming the 4.66% decline of the benchmark. Fund performance in the information technology (IT) sector was strong in the quarter, while certain holdings in the industrials and consumer staples sectors were relative detractors.

We ended the quarter with 41 holdings in Columbia Acorn Select. This is somewhat below the average number of Fund positions in recent years, and is roughly where we intend to keep the portfolio going forward. We've made adjustments to concentrate Fund assets in higher-conviction names. During the quarter, for example, we reduced the Fund's exposure to biotech, an area that has performed well for the Fund but where we currently feel valuations are stretched. In general, we are opting for companies with better balance sheets, higher return on capital, and a solid competitive advantage.

Strong performance in the IT sector was led by Solera Holdings, a software developer for automotive insurance claims processing that gained 21% following the announcement of its agreement to be acquired by Vista Equity Partners. Ultimate Software, a provider of human capital management systems, gained 9% on strong earnings news and strength in new bookings. Vonage, a provider of business and consumer Internet telephone services, benefited from strong quarterly earnings and growth in business customers. Its stock gained 20% in the quarter.

Reacting favorably to the Federal Reserve's September decision not to raise interest rates, Fund holdings in real estate investment trusts (REITs) were also strong contributors in the quarter. Extra Space Storage, a self-storage facility operator, Post Properties, an owner of multifamily properties, and EdR, a provider of student housing at universities, had gains ranging from 6% to 19%. Overall, the Fund's relative underweight in the financial sector detracted from performance in the quarter but stock selection in the sector topped the benchmark.

Fund stocks in the industrial sector did not keep pace with the benchmark in the quarter. Donaldson, a maker of industrial air filtration equipment, and Nordson, a maker of dispensing systems for adhesives and coatings, detracted from relative performance, as both declined around 20%. U.S. dollar strength continued to hurt these global businesses, but Donaldson's stock also came under pressure following a close competitor's announcement of an earnings miss. While external factors have weighed

heavily on Donaldson, the company continues to take market share from competitors because they have better-performing products (filters) and have expanded their distribution.

Within the consumer staples sector, specialty food retailer The Fresh Market and organic food distributor United Natural Foods continued to struggle, ending the quarter down 32% and 24%, respectively. The Fresh Market is facing increased competition and is also feeling the impact of lower produce prices on its bottom line. While we did some trimming of this position in the quarter, we continue to feel confident in its business model and believe its current valuation is quite appealing. We decided to sell the Fund's position in United Natural Foods because of slower growth prospects for the industry.

We added two new positions to the Fund in the quarter: Polaris and Align Technology. Polaris manufactures leisure vehicles and related products and we feel the company is well positioned to benefit from improving U.S. consumer spending and lower gas prices. Align Technology, which manufactures the Invisalign system used to straighten teeth, is a leader in non-invasive orthodontics and is taking share from traditional orthodontic solutions. While adding Align, we decided to exit Henry Schein, a distributor of dental, veterinary and other medical products, because we believe Align has higher growth prospects and a better business model. In the current low-price environment, we opted to reduce the Fund's energy exposure and sold Gulfport Energy and Petromanas.

Fund holdings are as of the date given, are subject to change at any time, and are not recommendations to buy or sell any security.

COLUMBIA ACORN SELECT^SM

AT A GLANCE

Total Net Assets of the Fund:
$468.5 million

The Growth of a $10,000 Investment in Columbia Acorn Select^SM Class Z Shares

November 23, 1998 (Fund inception) through September 30, 2015

This chart shows the change in value of a hypothetical $10,000 investment in Class Z shares of the Fund during the stated time period.

Average Annual Total Returns for period ended September 30, 2015

	3rd quarter			Year to date			1 year			5 years			10 years			Life of Fund
Class Z (11/23/98 inception)		-8.96	%		-3.43	%		-0.63	%		8.21	%		6.53	%		9.58	%
Class A (10/16/00 inception)
without sales charge		-9.06			-3.65			-0.96			7.89			6.22			9.23
with sales charge		-14.29			-9.17			-6.65			6.61			5.59			8.85
S&P MidCap 400® Index*		-8.50			-4.66			1.40			12.93			8.25			9.81

Results for other share classes can be found on Page 4.

*The Fund's primary benchmark. Please see Page 3 for index descriptions.

Returns for Class A shown with and without the maximum initial sales charge of 5.75%. As stated in the May 1, 2015, prospectus, the Fund's annual operating expense ratio is 0.84% for Class Z shares and 1.12% for Class A shares. The returns shown for periods prior to the inception of the Fund's Class A shares append the returns of the Fund's Class Z shares, the Fund's oldest share class. These returns are adjusted to reflect any higher class-related operating expenses of the newer share classes, as applicable. Please visit columbiathreadneedleus.com/investment-products/mutual-funds/appended-performance for more information.

Portfolio Diversification

as a percentage of net assets, as of 9/30/15

Top 10 Holdings

as a percentage of net assets, as of 9/30/15

1.	Ametek Aerospace/Industrial Instruments	6.5	%
2.	LKQ Alternative Auto Parts Distribution	4.8	%
3.	Donaldson Industrial Air Filtration	4.7	%
4.	SEI Investments Mutual Fund Administration & Investment Management	3.6	%
5.	Nordson Dispensing Systems for Adhesives & Coatings	3.6	%
6.	Vail Resorts Ski Resort Operator & Developer	3.5	%
7.	The Fresh Market Specialty Food Retailer	3.0	%
8.	Gentex Manufacturer of Auto Parts	3.0	%
9.	CNO Financial Group Life, Long-term Care & Medical Supplement Insurance	3.0	%
10.	Expeditors International of Washington International Freight Forwarder	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.

COLUMBIA THERMOSTAT FUND^SM

IN A NUTSHELL


Charles P. McQuaid Lead Portfolio Manager				Christopher J. Olson Co-Portfolio Manager

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 a fund that invests and trades directly in financial instruments under the direction of a single manager.

The value of an investment in the Fund is based primarily on the performance of the underlying funds in which it invests. The Fund is subject to the risk that the investment manager's decisions regarding asset classes and underlying funds will not anticipate market trends successfully, resulting in a failure to preserve capital or lower total return. The Investment Manager may prefer an underlying fund in the Columbia Acorn Family of Funds over alternative investments. There can be no assurance that the Columbia Acorn Funds will outperform similar funds managed by the Investment Manager's affiliates. This is not an offer of the shares of any other mutual fund mentioned herein.

Class Z shares of our fund of funds, Columbia Thermostat Fund, ended the third quarter of 2015 down 2.27%, compared to the 6.44% loss of the Fund's primary equity benchmark, the S&P 500® Index, and the 1.23% gain of the Fund's primary debt benchmark, the Barclays U.S. Aggregate Bond Index. Year to date through September, the Fund fell 1.06%, while the S&P 500 fell 5.29%. The Barclay's benchmark gained 1.13% for the same period. The Fund's custom 50/50 Blended Benchmark fell 2.62% in the quarter and ended the nine months down 1.98%.

In a volatile quarter for stocks, the Fund's equity portfolio had a weighted average loss of 7.93%. Columbia Dividend Income Fund was the Fund's best performer on the equity side, but declined 5.14%. Columbia Acorn International was at the bottom of the performance list with a 10.01% loss in the quarter.

The bond portion of the Fund had a slight loss in the third quarter, falling 0.37%. Three of the Fund's four underlying bond funds had a positive return, with Columbia Intermediate Bond Fund in the lead, up 1.03%. Columbia Income Opportunities Fund was the worst detractor on the bond side, falling 3.53%.

Columbia Thermostat Fund continues to faithfully execute its "buy low, sell high" strategy. When stocks appeared expensive through June 30, the Fund was just 10% to 20% invested in stocks. During the late summer swoon in stocks, the Fund bought stocks, hitting a 35% exposure, where it remained through the quarter end. As a result, the Fund dropped much less than the stock market year to date. As of the end of the quarter, Columbia Thermostat was poised to moderately profit on a stock market recovery but also to buy more on a market drop.

Results of the Funds Owned in Columbia Thermostat Fund

as of September 30, 2015

Stock Funds

Fund	Weightings in category			3rd quarter performance			Year to date performance
Columbia Acorn International, Class I		20	%		-10.01	%		-5.30	%
Columbia Contrarian Core Fund, Class I		20	%		-7.17	%		-4.30	%
Columbia Dividend Income Fund, Class I		20	%		-5.14	%		-6.24	%
Columbia Acorn Fund, Class I		10	%		-9.78	%		-3.79	%
Columbia Acorn Select, Class I		10	%		-9.00	%		-3.37	%
Columbia Large Cap Enhanced Core Fund, Class I		10	%		-6.80	%		-5.99	%
Columbia Select Large Cap Growth Fund, Class I		10	%		-9.16	%		-1.58	%
Weighted Average Equity Loss		100	%		-7.93	%		-4.57	%

Bond Funds

Fund	Weightings in category			3rd quarter performance			Year to date performance
Columbia Short Term Bond Fund, Class I		40	%		0.14	%		0.87	%
Columbia Intermediate Bond Fund, Class I		20	%		1.03	%		1.33	%
Columbia Income Opportunities Fund, Class I		20	%		-3.53	%		-0.94	%
Columbia U.S. Government Mortgage Fund, Class I		20	%		0.38	%		1.70	%
Weighted Average Income Gain/Loss		100	%		-0.37	%		0.77	%

Columbia Thermostat Fund Rebalancing in the Third Quarter

July 31, 2015				20% stocks, 80% bonds
August 31, 2015				30% stocks, 70% bonds
September 2, 2015				35% stocks, 65% bonds

The Fund's investments in the underlying funds may present certain risks, including the following. Market risk may affect a single issuer, sector of the economy, industry or the market as a whole. The Fund's investment in other funds subjects it to the investment performance (positive or negative), risks and expenses of these underlying funds. Investments in small- and mid-cap companies involve risks and volatility and possible illiquidity greater than in investments in larger, more established companies. There are risks associated with fixed income investments, including credit risk, market risk, interest rate risk and prepayment and extension risk. In general, bond prices fall when interest rates rise and vice versa. This effect is more pronounced for longer term securities. Non-investment-grade (high-yield or junk) securities present greater price volatility and more risk to principal and income than higher rated securities. Foreign investments subject the Fund to political, economic, market, social and other risks within a particular country, as well as to potential currency instabilities and less stringent financial and accounting standards generally applicable to U.S. issuers. Risks are enhanced for emerging market issuers.

COLUMBIA THERMOSTAT FUND^SM

AT A GLANCE

Total Net Assets of the Fund:
$1.1 billion

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

September 25, 2002 (Fund inception) through September 30, 2015

This chart shows the change in value of a hypothetical $10,000 investment in Class Z shares of the Fund during the stated time period.

Average Annual Total Returns for period ended September 30, 2015

	3rd quarter			Year to date			1 year			5 years			10 years			Life of Fund
Class Z (9/25/02 inception)		-2.27	%		-1.06	%		0.70	%		7.88	%		6.09	%		7.42	%
Class A (3/3/03 inception)
without sales charge		-2.31			-1.25			0.50			7.63			5.82			7.15
with sales charge		-7.94			-6.95			-5.31			6.36			5.20			6.67
S&P 500® Index*		-6.44			-5.29			-0.61			13.34			6.80			8.96
Barclays U.S. Aggregate Bond Index*		1.23			1.13			2.94			3.10			4.64			4.49

Results for other share classes can be found on Page 4.

*The Fund's primary benchmarks. Please see Page 3 for index descriptions.

Returns for Class A shown with and without the maximum initial sales charge of 5.75%. As stated in the May 1, 2015, prospectus, the Fund's annual operating expense ratio is 0.77% for Class Z shares and 1.02% for Class A shares. The returns shown for periods prior to the inception of the Fund's Class A shares append the returns of the Fund's Class Z shares, the Fund's oldest share class. These returns are adjusted to reflect any higher class-related operating expenses of the newer share classes, as applicable. Please visit columbiathreadneedleus.com/investment-products/mutual-funds/appended-performance for more information.

Asset Allocation

as a percentage of net assets, as of 9/30/15

Portfolio Weightings

as a percentage of assets in each investment category, as of 9/30/15

Stock Mutual Funds

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

Bond Mutual Funds

Columbia Short Term Bond Fund, Class I	40	%
Columbia Intermediate Bond Fund, Class I	20	%
Columbia Income Opportunities Fund, Class I	20	%
Columbia U.S. Government Mortgage Fund, Class I	20	%

COLUMBIA ACORN EMERGING MARKETS FUND^SM

IN A NUTSHELL


Fritz Kaegi Co-Portfolio Manager				Stephen Kusmierczak Co-Portfolio Manager

Louis J. Mendes Co-Portfolio Manager				Satoshi Matsunaga Co-Portfolio Manager

Market risk may affect a single issuer, sector of the economy, industry or the market as a whole. International investing involves certain risks and volatility due to potential political, economic or currency instabilities and different, potentially less stringent, financial and accounting standards than those generally applicable to U.S. issuers. Risks are enhanced for emerging and frontier market issuers. Investments in small- and mid-cap companies involve risks and volatility and possible illiquidity greater than investments in larger, more established companies. Please also see "A Comment on Trading Volumes" on Page 1 of this report.

Columbia Acorn Emerging Markets Fund Class Z shares lost 17.21% in the third quarter of 2015, slightly outperforming the 17.85% decline of the Fund's primary benchmark, the S&P Emerging Markets Between $500M and $5B® Index. Year to date through September, the Fund was down 19.54%, trailing the benchmark's 15.34% drop for the same period.

Much of the Fund's decline in the quarter was tied to weakness in China, which experienced further slowdowns in economic growth. The Fund's exposure to China was roughly 23% at quarter end, attributable to direct investment in China and Hong Kong, and to investments in companies operating in China but listed elsewhere in Asia. The Fund's weighting was in line with the benchmark's Greater China weight and was an area of modest relative outperformance in the quarter. Given China's greater focus on its domestic needs, we've added an emphasis in environmental companies, health care and select infrastructure names within this market.

Emerging markets that serve as a source of raw materials or commodities for China experienced similar declines in their markets and in their currencies. In Brazil, South Africa and Kazakhstan, where the Fund has a combined weighting of 10%, currencies have declined significantly against the U.S. dollar, and stocks in these markets have experienced greatly diminished returns when stated in dollar terms. We do not hedge the Fund's exposure to these currencies in order to provide shareholders exposure to local markets and currency diversification, and we expect emerging market currencies to be volatile. Hurt by the currency headwind and broader economic concerns in Brazil, car rental company Localiza Rent a Car ended the quarter down 38%. Coronation Fund Managers, a South African investment manager, fell 30% on lower fees compared to the prior year and on general concerns about future inflows given emerging market uncertainty. These portfolio companies were among the Fund's largest detractors in the quarter.

While it was a difficult quarter in some emerging market countries, not all of these markets were impacted in the same way by global events. Looking at each country individually, we can focus on what influenced growth locally. The Fund's second-largest country weight at quarter end was in India, a country that has very different drivers when compared to China, and that performed very differently in this volatile quarter. Within the Fund, India was down 2% for the quarter in local currency terms, which compared to a 22% decline for China for the same period. We are focusing on Indian companies positioned to benefit from an advancing consumer class and expected economic reforms. Zee Entertainment Enterprises, an

Indian programmer of pay television content, was a top contributor in the quarter, gaining 5%. Amara Raja, a maker of auto and industrial batteries, was another top Indian contributor, gaining 14% in the quarter. The Fund's 14% exposure to India at quarter end was just above the 13% weight of the benchmark, and was a modest detractor from performance during the quarter.

Another way to differentiate the emerging market space is to look at a country's stage of development. Both Taiwan and Korea have deeper domestic capital markets and a large current account surplus, which are not common in many other emerging countries. Taiwan is largely a manufacturer of technology hardware and semiconductors sold in developed markets. With a relatively affluent, urbanized and stable population, Taiwan does not possess the same growth opportunities as less developed countries that are benefiting from improving demographics, growing consumer incomes, better education, urbanization and higher workforce participation. Still, we believe that while the opportunity set may be smaller in more developed emerging markets, valuations may, at times, offer greater value. Strong stock selection resulted in Fund holdings in Taiwan outpacing the benchmark and was an overall contributor to performance in the quarter, despite the Fund's below benchmark weighting. Korea is also further along in development versus most emerging markets. Like Taiwan, Korea has strong export-oriented industries (such as technology hardware and automotive), but it has a larger domestic economy. We took advantage of favorable stock valuations and added three new Korean names in the quarter, bringing the Fund's weighting in Korea to 3%.

Emerging markets are some of the most dynamic economies in the world, evolving rapidly and poised for growth to reflect the underlying demographics. The quality of life for half of the world's population is improving as these markets advance and new companies are formed to meet the needs of a stronger consumer base. While there will continue to be volatility and currency fluctuations within these markets, as we have seen recently, emerging market downturns can provide compelling investment opportunities for long-term, bottom-up investors like Columbia Wanger Asset Management. With valuations down across many of these markets and currencies at multi-year lows against the U.S. dollar, we see many excellent businesses attractively priced in U.S. dollar terms. As we allocate Fund capital to these opportunities, we will continue to focus on companies that we believe have strong balance sheets and the ability to survive the volatility in these markets and position themselves for strong growth as local conditions improve.

Fund holdings are as of the date given, are subject to change at any time, and are not recommendations to buy or sell any security.

Columbia Acorn Emerging Markets Fund is closed to most new investors and new accounts with certain exceptions. Refer to the Fund's prospectus for details.

COLUMBIA ACORN EMERGING MARKETS FUND^SM

AT A GLANCE

Total Net Assets of the Fund:
$305.4 million

The Growth of a $10,000 Investment in Columbia Acorn Emerging Markets Fund^SM Class Z Shares

August 19, 2011 (Fund inception) through September 30, 2015

This chart shows the change in value of a hypothetical $10,000 investment in Class Z shares of the Fund during the stated time period.

Average Annual Total Returns for period ended September 30, 2015

	3rd quarter			Year to date			1 year			Life of Fund
Class Z (8/19/11 inception)		-17.21	%		-19.54	%		-21.44	%		1.25	%
Class A (8/19/11 inception)
without sales charge		-17.26			-19.73			-21.63			0.96
with sales charge		-22.00			-24.37			-26.14			-0.48
S&P Emerging Markets Between $500M and $5B® Index*		-17.85			-15.34			-18.15			-1.37

Results for other share classes can be found on Page 4.

*The Fund's primary benchmark. Please see Page 3 for index descriptions.

Returns for Class A shown with and without the maximum initial sales charge of 5.75%. As stated in the May 1, 2015, prospectus, the Fund's annual operating expense ratio is 1.33% for Class Z shares and 1.57% for Class A shares.

Portfolio Diversification

as a percentage of net assets, as of 9/30/15

Top 10 Holdings

as a percentage of net assets, as of 9/30/15

1.	Zee Entertainment Enterprises (India) Indian Programmer of Pay Television Content	4.8	%
2.	Adani Ports & Special Economic Zone (India) Indian West Coast Shipping Port	2.6	%
3.	Coronation Fund Managers (South Africa) South African Fund Manager	2.6	%
4.	Halyk Savings Bank of Kazakhstan–GDR (Kazakhstan) Retail Bank & Insurer in Kazakhstan	2.5	%
5.	Koh Young Technology (Korea) Inspection Systems for Printed Circuit Boards	2.3	%
6.	Commercial International Bank of Egypt (Egypt) Private Universal Bank in Egypt	2.2	%
7.	Far EasTone Telecom (Taiwan) Mobile Operator in Taiwan	2.2	%
8.	Cable and Wireless (United Kingdom) Telecommunications Service Provider in the Caribbean	2.0	%
9.	MNC Sky Vision (Indonesia) Satellite Pay TV Operator in Indonesia	2.0	%
10.	Rand Merchant Insurance (South Africa) Directly Sold Property & Casualty Insurance; Holdings in other Insurers	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.

COLUMBIA ACORN EUROPEAN FUND^SM

IN A NUTSHELL


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

Columbia Acorn European Fund Class Z shares fell 5.84% in the third quarter of 2015, slightly underperforming the 5.34% drop of the Fund's primary benchmark, the S&P Europe Between $500M and $5B Index. Year to date through September, the Fund was up 0.57%, while the benchmark gained 4.71% for the same period. Underperformance for both periods was due in part to significant declines in several of the Fund's largest positions.

Munksjo, a Finnish specialty paper retailer and the Fund's second largest position at quarter end, was also the second largest detractor. Its stock continued to give back the gains made early in the year, falling an additional 21% in the third quarter. Markets are worried that the company will not be able to offset higher hardwood pulp input prices. We think this is a short-term issue, which will ease with recently implemented price increases of the company's release liner and décor paper products. We have, therefore, added to the Fund's position in the company since the beginning of the year. Distribuidora Internacional de Alimentación (DIA), a discount retailer in Spain and Latin America, was the third largest position in the Fund at quarter end and also ranked among the Fund's main detractors. While DIA's stock was down 19% in the quarter, we believe strengthening food prices in Spain should help the company increase its margins and gain market share. We took advantage of the decline and added to the Fund's position. The company's emerging market exposure is a concern in the current environment, but we believe the outlook for DIA is positive overall.

Looking at the Fund's regional weightings, the overweight in the Nordic region (Denmark, Finland, Norway and Sweden) was a positive in the third quarter relative to the benchmark. Nordic winners included Sweden's Unibet, an online gaming operator, which gained 37% as the company continues to take market share in European markets. SimCorp, a Danish developer of software for investment managers, was also strong in the quarter, gaining 26%. The company has enjoyed a recovery in new license sales, as asset managers respond to new compliance rules put in place in the wake of the financial crisis.

In Northern and Central Europe (Austria, Belgium, Germany, Luxembourg, the Netherlands and Switzerland), the Fund's average weight and performance were largely in line with the benchmark at quarter end. Gaining nearly 25%, German online payment processor Wirecard announced continued high revenue growth and operating profit, and also benefited from its increased attention to the financial technology sector. Partners Group, a Swiss

private markets asset management company, gained 13% on strong asset flows that beat expectations.

Performance of Fund stocks held in the Mediterranean region (France, Greece, Italy, Portugal and Spain) were a significant detractor relative to the benchmark. The Fund was below the benchmark weight in this region at the end of the quarter. French online advertiser Hi-Media fell 72%, as its decision to separate from its sister company (HiPay) raised liquidity concerns. We elected to sell the Fund's position in the stock. French postage machine manufacturer Neopost continued to struggle in the third quarter, falling 36%. Neopost's revenues have suffered from decreasing mail volumes and weak European demand in its core equipment business.

Columbia Acorn European Fund reached its four-year anniversary in August and, at the end of the third quarter, had a 10.19% annualized return since its inception. We are pleased that the Fund has provided our shareholders with a solid gain, while taking on less average risk than its benchmark. Today, we are increasingly concerned by the asylum crisis in Europe, and while it seems to receive less media attention than the Greek euro exit worries of this summer, we believe that the impact on Europe could be decidedly more detrimental. European trade and travel have benefited enormously since the introduction of the Schengen open border zone three decades ago. Certainly one of the important accomplishments of the European Union, borderless travel has increased intra-European trade and travel, and enabled more economically efficient dispersion of manufacturing and logistics across the continent. However, if border controls are re-introduced, trade will be impaired and companies may face meaningfully higher transport and working capital costs. We are seeing evidence that growing negative public sentiment will force new restrictions on refugee entrance to the European Union, thus preserving the Schengen area. In the event that immigration curbs are not imposed and countries re-establish intra-Schengen border controls, we are ready to make portfolio changes to reflect higher trade and travel restrictions for Europe.

Fund holdings are as of the date given, are subject to change at any time, and are not recommendations to buy or sell any security.

COLUMBIA ACORN EUROPEAN FUND^SM

AT A GLANCE

Total Net Assets of the Fund:
$57.9 million

The Growth of a $10,000 Investment in Columbia Acorn European Fund^SM Class Z Shares

August 19, 2011 (Fund inception) through September 30, 2015

This chart shows the change in value of a hypothetical $10,000 investment in Class Z shares of the Fund during the stated time period.

Average Annual Total Returns for period ended September 30, 2015

	3rd quarter			Year to date			1 year			Life of Fund
Class Z (8/19/11 inception)		-5.84	%		0.57	%		-0.15	%		10.19	%
Class A (8/19/11 inception)
without sales charge		-5.91			0.36			-0.42			9.90
with sales charge		-11.32			-5.38			-6.11			8.33
S&P Europe Between $500M and $5B® Index*		-5.34			4.71			3.18			12.41

Results for other share classes can be found on Page 4.

*The Fund's primary benchmark. Please see Page 3 for index descriptions.

Returns for Class A shown with and without the maximum initial sales charge of 5.75%. As stated in the May 1, 2015, prospectus, the Fund's annual operating expense ratio is 1.50% for Class Z shares and 1.75% for Class A shares.

Portfolio Diversification

as a percentage of net assets, as of 9/30/15

Top 10 Holdings

as a percentage of net assets, as of 9/30/15

1.	Assura (United Kingdom) UK Primary Health Care Property Developer	2.8	%
2.	Munksjo (Finland)† Specialty Paper Maker	2.8	%
3.	Distribuidora Internacional de Alimentación (Spain) Discount Retailer in Spain & Latin America	2.7	%
4.	Partners Group (Switzerland) Private Markets Asset Management	2.6	%
5.	Aurelius (Germany) European Turnaround Investor	2.5	%
6.	Charles Taylor (United Kingdom) Insurance Services	2.5	%
7.	Wirecard (Germany) Online Payment Processing & Risk Management	2.3	%
8.	SimCorp (Denmark) Software for Investment Managers	2.2	%
9.	Unibet (Sweden) European Online Gaming Operator	2.2	%
10.	William Demant Holding (Denmark) Manufacture & Distribution of Hearing Aids & Diagnostic Equipment	2.1	%

†The Fund holds shares traded on both the Finnish and Swedish exchanges.

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.

SQUIRREL CHATTER: FANNIE MAE, FREDDIE MAC AND THE HOUSING MARKET COLLAPSE

American Enterprise Institute scholar and member of the Financial Crisis Inquiry Commission, Peter Wallison, published a book this year called Hidden in Plain Sight, in which he states that there would not have been a housing bubble and collapse without the specific U.S. Department of Housing and Urban Development (HUD) targets mandated for Fannie Mae (Fannie) and Freddie Mac¹ (Freddie) to support housing. Because it contradicts the popularly accepted belief that the financial crisis was caused by Wall Street greed and poor regulation of the financial system, Wallison's stance piqued my interest and led me to do some further research on the subject.

Fannie and Freddie Become Aggressive Lenders

After years of expanding and evolving, Fannie's and Freddie's share of residential mortgages reached 28.4% in 1991.² The Housing and Community Development Act of 1992 (the Act) created a safety and soundness regulator for Fannie and Freddie, the Office of Federal Housing Enterprise Oversight (OFHEO).³ OFHEO ended up being part of HUD, an agency intended to support housing, and the OFHEO generally regulated Fannie and Freddie lightly.

As a result of pressure from community activists,⁴ the Act also mandated that HUD set specific targets to support housing for low- and middle-income loan applicants, including loans for inner-city, affordable housing.⁵ Low- and middle-income loan targets began at 30% for 1995, below what was already being achieved.⁶ Lending standards initially remained high.⁷

The affordability goal was raised to 42% in 1996 and 50% in 2001.⁸ Congress specifically instructed Fannie and Freddie to consider loans with down payments of 5% or less, and loans to borrowers whose credit was good for only the last year.⁹ A 1996 study by the Federal Reserve indicated that such affordable housing loans had default rates of 51 times those with 20% down payments and good credit scores.¹⁰

Fannie and Freddie grew their overall mortgage holdings more than five-fold in the eight years between 1992 and 2000, to $993 billion. Including guarantees, their combined mortgage exposure was nearly $2.3 trillion.¹¹ Competitors and free-market advocates questioned their

unique advantages, such as implicit guarantees on their debt and low taxes,¹² but subsequent attempts to more vigorously regulate Freddie and Fannie failed as allied politicians supported them as enablers of affordable home ownership.¹³

A HUD study in 2002 confirmed that Fannie and Freddie had adopted more "flexible" underwriting standards with respect to down payments and credit histories, including down payments as low as 3%, in order to reach the targets. By 2002, Fannie and Freddie held $1.21 trillion of mortgages and guaranteed $1.52 trillion more, achieving a 44.7% market share.¹⁴

Former Fannie chief financial officer Timothy Howard admitted that in order for Fannie to grow, it had to "extend the reach of our affordable housing activities by proportionately much more."¹⁵ Howard denied, however, taking excessive risk to meet the HUD goals, and credit losses on Fannie's mortgages remained low through the year 2000.¹⁶

According to Howard, Fannie tightened up its risk discipline in the summer of 2003 in response to rising interest rates, painful losses from loans for manufactured housing, and risks being accepted by its competitors.¹⁷ Fannie lost market share in 2004, as outstanding mortgages grew 14% and its portfolio grew just 5%, down from the double-digit growth experienced since 1986.¹⁸

Through 2003, Fannie and Freddie dominated mortgage securitization.¹⁹ Buyers of Fannie and Freddie securities took only interest rate and early repayment risks, as the implicit government guarantees purportedly eliminated credit risk. Private label—not Government backed—securitization accounted for just 12% of mortgage securitizations in 1996 and 17% in 2003.²⁰

Private Mortgage Securitization Accelerates

Post 2003, private label securitizers became more aggressive in issuing mortgage-backed securities, offering higher yields in exchange for minimal credit guarantees.²¹ Pools of mortgages were securitized into risk tranches, with senior tranches receiving cash flows prior to junior tranches and interest rates reflecting perceived risks. By 2006, private label securitizations accounted for 50% of mortgage securitizations.²² All of the top five securitizers were mortgage companies such as Countrywide; none were Wall Street firms or commercial banks.²³

There was substantial "moral hazard" in this business, as profits were made via securitization regardless of whether the loans ended up being sound. Loan quality plunged. Adjustable rate mortgages with low initial "teaser" rates jumped to a 45% share by 2006.²⁴ A similar percentage of loans made to first-time homebuyers had no down payments, and low or no documentation fraud-prone loans also surged.²⁵ Indeed, in 2006, 80% of new subprime mortgage loans were securitized.²⁶ "Conforming" (high quality) loans dropped to just 33% of new mortgage loans that year.²⁷

Rating agencies used statistical models based on low historical mortgage default ratios in rating mortgage-backed securities. While there had been regional drops in housing prices, nationwide declines had occurred only during the Great Depression. Mortgage securitizations included diversified geographies, so most of the tranches were rated AAA. The rating agencies seemed blind to decreasing mortgage quality and an apparent housing bubble. Critics noted the conflict of interest of rating agencies being paid by the securitizers, who shopped for high ratings.²⁸

Bank regulations encouraged holdings of securitized mortgage debt because banks had to hold just 1.6% capital reserves on AA or higher rated private mortgage-backed securities, compared to 4.0% reserves on residential mortgages and 8.0% reserves on commercial loans.²⁹ Regulators also allowed some capital relief if securitized debt was insured.³⁰ Utilizing models similar to those used by rating agencies, AIG, an international insurance company, believed there was little risk and by the end of 2006 had insured $527 billion of credit.³¹

Accordingly, many large financial institutions bought AAA-rated tranches on their own balance sheets. The top five commercial banks and the top five investment banks roughly doubled balance sheet assets from 2003 to 2007.³² Many of them also set up special investment vehicles (SIVs), funded off balance sheet, to place securitized mortgages and other loans.³³ However, SIVs tended to have liquidity or credit guarantees.³⁴

Howard noted that Fannie continued to be under attack by competitors and free market advocates, and management's relationship with its regulator grew contentious. In December 2004, Fannie management was forced out due to an accounting controversy. The account-

ing rules for derivatives were complex and ambiguous, and ultimately Fannie and nearly 300 other companies restated their derivative results and earnings.³⁵ The disallowance of hedge accounting resulted in a $9 billion reported loss from derivatives and left Fannie undercapitalized.³⁶

The new Fannie management was forced to hire a chief risk officer independent of other corporate responsibilities, who had an oversight role.³⁷ In addition to his role as CFO, Howard had been chief risk officer and had actual authority to veto the decisions of marketing executives. Within the new management structure, this role did not have veto power, and Fannie's risk management process deteriorated. Of $76 billion in single family credit losses Fannie ultimately recorded from 2008 to 2012, 87% came from loans purchased or guaranteed after 2004.³⁸

Meanwhile, HUD phased in higher affordability goals, from 52% in 2005 to 56% in 2008.³⁹ Dan Mudd, Fannie's new chairman, said Fannie had to devote a great deal of resources to running its business to satisfy HUD targets.⁴⁰ In 2006, Fannie's newer management decided to increase market share, including share of subprime mortgages.⁴¹

Fannie and Freddie ended up being the largest buyers of securitized mortgage loans backed by low-quality mortgages, which helped them meet their affordable home mortgage targets.⁴² Home mortgage debt jumped from 54% of gross domestic product (GDP) to 89% of GDP in the 10 years through year-end 2006,⁴³ and hit $11 trillion in 2008, exceeding the federal government debt.⁴⁴

Spurred by cheap and high-risk loans, home prices surged, creating an unprecedented bubble. The S&P/Case-Shiller 10 City Index⁴⁵ nearly tripled in the 10 years to June 2006.⁴⁶ As long as home prices were rising, there were few defaults, as deadbeat borrowers could sell at a profit or refinance.

The Bubble Bursts

The home ownership rate in the United States reached 64% of households in the 1960s, stayed about there for the next 30 years,⁴⁷ and then grew. At the height of the housing boom, the home ownership rate hit nearly 70%.⁴⁸ At that time, there were 31 million low down payment, poor credit and poor documentation loans, accounting for 56% of mortgage loans.⁴⁹

Home sales peaked in 2005 and prices peaked in 2006.⁵⁰ The S&P/Case-Shiller Housing Price Index fell 40%

in the next three years.⁵¹ Mortgage delinquencies soared. Fannie's rose to 0.98% in 2007, 2.42% in 2008 and 5.4% in 2009.⁵² Fannie lost $2.2 billion in both of the first two quarters of 2008, and then in the third quarter lost $29.0 billion; Freddie's results were similar.⁵³ Millions lost their homes to foreclosure.⁵⁴ Banks were compelled to take back onto their balance sheets hundreds of billions of dollars of asset-backed securities.⁵⁵

Regulators were blindsided. In their financial statements, Fannie and Freddie had reported that their exposures to subprime loans were under 1% of their portfolios.⁵⁶ As of May 2007, the Federal Reserve apparently believed those reports and estimated that there were only about 7.5 million subprime loans outstanding.⁵⁷ In July 2008, economist Paul Krugman wrote that Fannie and Freddie "didn't do any subprime lending..."⁵⁸ As a result of a 2011 U.S. Securities and Exchange Commission lawsuit, Fannie and Freddie subsequently admitted holding or guaranteeing 13.6 million subprime loans.⁵⁹

Fannie and Freddie had $1.7 trillion debt outstanding as of September 2008, including $520 million maturing within a year.⁶⁰ Foreign entities held over $1 trillion of Fannie and Freddie debt, and made it clear to the U.S. Department of the Treasury (the Treasury) that if those debts defaulted, no government debt would be rolled over. Unable to roll over debt and deemed "too big to fail," Fannie and Freddie were placed into conservatorship on September 7, 2008.⁶¹ Fannie and Freddie eventually received $187 billion of bailout funds, and AIG received $152 billion.⁶²

In 2004, HUD stated that it had created "a revolution in affordable lending," as "conventional loans to low income and minority families increased at much faster rates than loans to upper-income and nonminority families." Wallison points out the irony in that claim, as the "revolution" drove up home prices such that only 33% of U.S. housing markets were affordable (home prices three times incomes or less) in 2005, down from 90% in 1989, prior to the standards being created.⁶³

Former congressman and chair of the House Financial Services Committee Barney Frank had been a vocal supporter of affordable housing, but he admitted in 2010 that "it was a great mistake to push lower-income people into housing they couldn't afford" and "I had been too sanguine about Fannie and Freddie."⁶⁴

While Wallison makes good points, lots of bad loans were also made and securitized by the private sector, which gained market share from 2003 to 2006, the most precarious time for the housing bubble. I agree with the four Columbia University professors who wrote Guaranteed to Fail. They wrote, "The subprime mortgage mess was in part [emphasis added] due to government guarantees for Fannie and Freddie that distorted a level playing field, resulting in the debacle of mortgage finance."⁶⁵

Bailouts

The Federal Reserve bailouts that followed the collapse provided short- and intermediate-term liquidity to companies who were deemed strategic to the economy. On the campaign trail in 2012, President Obama said that the banks paid back in full all federal bailout money. PolitiFact agreed that, in aggregate, the statement was true. A January 3, 2015 Washington Post story reported that the Treasury declared that the entire bailout was actually marginally profitable, as Fannie, Freddie, AIG and others had also paid back, with interest and profit, the money they received. The story added that "in many cases shareholders of bailed-out firms—especially AIG, Fannie and Freddie—were essentially wiped out, as they should have been."

One reason that the bailouts were paid back was that most subprime residential first mortgage-backed securities substantially recovered after the panic. Of those securities issued from 2005 to 2007, about 82% were originally rated AAA, and just 4.4% of this tranche became impaired through 2009, which was far better than expected.⁶⁶ Most of the securities had been subject to mark-to-market accounting, and when their prices plunged, financial firms had to write them down, making them look far worse than the ultimate economic reality.

In hindsight, it seems that bad policies and incentives caused the housing bubble and financial crisis. While the economy, homeowners and shareholders were hurt, many purveyors of bad loans walked away wealthy, even after sanctions, in some cases. Yet regulations to prevent a recurrence could be much simpler than those created after Dodd-Frank's 2010 passage.⁶⁷ Companies deemed strategically essential that needed bailouts could be broken up, bailouts that resulted in taxpayer losses could trigger claw-backs of top management compensation, fraud and predatory lending abuses could be fully prosecuted, and shareholders of surviving companies could not be subjected

to the negative impact of huge settlements many years after a financial crisis.

Charles P. McQuaid

Portfolio Manager, Analyst and Advisor
Columbia Wanger Asset Management, LLC

The information and data provided in this analysis are derived from sources that we deem to be reliable and accurate. These views are not guarantees of future performance and involve certain risks, uncertainties and assumptions that are difficult to predict so actual outcomes and results may differ significantly from the views expressed. The views/opinions expressed here are those of the author and not of the Columbia Acorn Trust Board of Trustees, 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 The Federal National Mortgage Association (later dubbed Fannie Mae) was created in 1938 to purchase Federal Housing Administration-insured mortgages; later it was allowed to also buy U.S. Department of Veterans Affairs mortgages and was made exempt from state and local income taxes. Fannie was privatized in 1968. The Federal Home Loan Mortgage Corporation (Freddie Mac) was created in 1970, originally to purchase mortgages from the Savings & Loan industry and was privatized two decades later.

² Viral V. Acharya, Matthew Richardson, Stijn Van Nieuwerburgh and Lawrence J. White, Guaranteed to Fail, Fannie Mae, Freddie Mac and the Debacle of Mortgage Finance (Princeton, New Jersey, Princeton University Press, 2011), p. 20.

³Ibid., p. 32.

⁴ Peter J. Wallison, Hidden In Plain Sight, What Really Caused the World's Worst Financial Crisis and Why It Could Happen Again (New York, Encounter Books, 2015), p. 113.

⁵ Acharya, op. cit., p. 33.

⁶ Wallison, op. cit., p. 128-129.

⁷ Timothy Howard, The Mortgage Wars, Inside Fannie Mae, Big-Money Politics, and the Collapse of the American Dream (New York, McGraw-Hill Education, 2014), p. 46.

⁸ Wallison, op. cit., p. 129.

⁹ Ibid., p. 119.

¹⁰ Ibid., p. 164

¹¹ Acharya, op. cit., p. 62

¹² Howard, op. cit., p. 13.

¹³ Wallison, op. cit., p. 172.

¹⁴ Acharya, op. cit., p. 20.

¹⁵ Howard, op. cit., p. 65.

¹⁶ Ibid., p. 65-67.

¹⁷ Ibid., p. 157-163, 178.

¹⁸ Ibid., p. 177.

¹⁹ Acharya, op. cit., p. 42. A mortgage-backed security (MBS) is a type of asset-backed security that is secured by a mortgage or a collection of mortgages. The mortgages are sold to a government agency or investment bank that securitizes, or packages, the loans together into a security that investors can buy.

²⁰ Ibid., p. 48.

²¹ Ibid., p. 42.

²² Ibid., p. 48.

²³ Wallison, op. cit., p. 195. While mortgage companies created securitized mortgages, Wall Street did participate in the bubble. Wall Street Firms repackaged securitized mortgages and other debt instruments into collateralized debt obligations (CDO). According to McLean/Nocera (p126) revenues from underwriting such securities were

$5 billion in 2006. Wall Street also made money from associated derivatives and trading all types of debt. But mortgage-backed securities underpinned the CDOs, derivatives, and ultimately the housing collapse and Great Recession.

²⁴ Acharya, op. cit., p. 47.

²⁵ Wallison, op. cit., p. 222.

²⁶ Acharya, op. cit., p. 48.

²⁷ Ibid., p. 44.

²⁸ Bethany McLean and Joe Nocera, All The Devils Are Here, The Hidden History of the Financial Crisis (New York, Penguin Group, 2010), p. 118.

²⁹ Wallison, op. cit., p. 19.

³⁰ McLean, op. cit., p. 78.

³¹ Ibid., p. 329.

³² Acharya, op. cit., p. 51.

³³ Ibid., p. 49-50.

³⁴ Ibid., p. 70.

³⁵ Howard, op. cit., p. 220.

³⁶ Ibid., p. 213.

³⁷ Ibid., p. 229-233.

³⁸ Ibid., p. 262.

³⁹ Ibid., p. 193.

⁴⁰ Wallison, op. cit., p. 168.

⁴¹ Howard, op. cit., p. 237.

⁴² Wallison, op. cit., p. 224.

⁴³ Acharya, op. cit., p. 44.

⁴⁴ Howard, op. cit., p. 11.

⁴⁵ The S&P/Case-Shiller Home Price Indices are the leading measures of U.S. residential real estate prices, tracking changes in the value of residential real estate both nationally, as well as in 20 metropolitan regions.

⁴⁶ Acharya, op. cit., p. 43.

⁴⁷ Wallison, op. cit., p. 102.

⁴⁸ Ibid., p. 219.

⁴⁹ Ibid., p. 41.

⁵⁰ Howard, op. cit., p. 15.

⁵¹ Acharya, op. cit., p. 85.

⁵² Ibid., p. 90.

⁵³ Ibid., p. 89.

⁵⁴ Howard, op. cit., p. 258.

⁵⁵ Wallison, op. cit., p. 22. An asset-backed security (ABS) is a security whose income payments and hence value are derived from and collateralized (or "backed") by a specified pool of underlying assets. The pool of assets is typically a group of small and illiquid assets which are unable to be sold individually.

⁵⁶ Ibid., p. 248.

⁵⁷ Ibid., p. 249.

⁵⁸ Ibid., p. 257.

⁵⁹ Peter J. Wallison, "The 'Big Lie' Defense, The Painful Task of Taking on the Left," The American Spectator, April 2012, p. 21.

⁶⁰ Acharya, op. cit., p. 73.

⁶¹ Ibid., p. 77, 83.

⁶² Chris Isidore, "We're Almost Break Even on the Bailout," CNNMoney (New York) September 15, 2013. http://money.cnn.com/2013/09/15/news/economy/bailout-profit/. Accessed October 12, 2015.

⁶³ Wallison, op. cit., p. 157-158.

⁶⁴ Wallison, op. cit., p. 25.

⁶⁵ Acharya, op. cit., p. 98.

⁶⁶ Wallison, op. cit., p. 91.

⁶⁷ The Dodd-Frank Wall Street Reform and Consumer Protection Act is a compendium of federal regulations, primarily affecting financial institutions and their customers, that the Obama administration passed in 2010 in an attempt to prevent the recurrence of events that caused the 2008 financial crisis.

COLUMBIA ACORN® FUND

MAJOR PORTFOLIO CHANGES IN THE THIRD QUARTER (UNAUDITED)

	Number of Shares
	6/30/15		9/30/15
Purchases
Information
CoreLogic		1,005,000		1,138,000
Cvent		205,225		1,364,000
DemandWare		0		550,000
Genpact		1,419,083		1,714,083
Lamar Advertising		550,749		628,184
RetailMeNot		1,830,000		2,768,000
Sanmina		3,467,599		3,572,799
Starz		0		951,000
Industrial Goods & Services
Robert Half International		1,798,000		1,911,000
Consumer Goods & Services
Avis Budget Group		1,806,776		2,017,776
Cato		0		719,860
Coupons.com		0		2,697,000
Fiesta Restaurant Group		856,484		997,484
Gentex		4,350,000		6,505,000
Hertz		2,800,000		3,635,000
HRG Group		0		1,608,005
Mattress Firm		0		390,000
Polaris Industries		0		192,000
Tenneco		411,825		649,825
Health Care
Align Technology		777,276		914,276
Celldex Therapeutics		1,902,687		2,162,687
Other Industries
Heartland Express		2,296,684		2,816,684
Energy & Minerals
Carrizo Oil & Gas		944,733		1,216,733
Cimarex Energy		402,497		528,771

		Number of Shares
		6/30/15		9/30/15
Sales
Information
Amphenol			3,468,610		3,102,522
Ansys			1,530,948		1,307,860
Belden			427,810		0
Cadence Design Systems			4,514,783		4,174,029
CalAmp			1,269,759		1,255,089
Cogent Communications			769,047		0
Crown Castle International			747,504		655,865
Discovery Communications Series C			402,028		0
F5 Networks			491,008		450,102
FLIR Systems			1,596,221		1,440,913
Global Eagle Entertainment			1,808,895		1,767,570
Global Payments			941,314		446,868
Gogo			2,208,178		2,138,621
GTT Communications			2,502,088		1,838,844
inContact			2,244,897		2,190,721
Infinera			1,940,827		1,896,961
IPG Photonics			1,143,460		1,051,460
Liberty Global Series A			661,980		623,626
Liquidity Services			1,600,000		0
Littelfuse			319,938		300,258
Mettler-Toledo International			532,255		500,314
NetSuite			570,149		505,397
Rogers			494,334		466,375
RP	X		1,908,954		1,780,644
Rubicon Technology			2,371,155		2,024,886
SBA Communications			839,317		557,169
Solera Holdings			1,650,392		0
SPS Commerce			940,526		738,167
Trimble Navigation			2,575,640		1,765,318
Ultimate Software			543,708		531,160
VeriFone Holdings			1,003,359		978,966
Verint Systems			1,258,046		1,228,326
Verisign			887,506		706,197
Verisk Analytics			1,170,274		1,019,873
Virtusa			1,263,525		1,078,328
Industrial Goods & Services
Airgas			823,571		760,291
Allegion			609,008		560,477
Ametek			4,569,066		3,759,949
Donaldson			7,949,116		7,758,932
Dorman Products			954,332		921,458
Drew Industries			1,434,286		1,341,286
ESCO Technologies			1,489,000		1,438,756
Expeditors International of Washington			1,674,435		1,614,150
Forward Air			1,359,907		1,310,342
HEICO			2,962,178		2,863,648

	Number of Shares
	6/30/15		9/30/15
Sales (continued)
Industrial Goods & Services—continued
LKQ		6,748,927		6,088,786
Middleby		803,972		576,889
Moog		1,440,787		1,296,026
Nordson		2,147,586		2,096,519
Oshkosh Corporation		1,942,945		1,875,197
Toro		1,353,698		1,148,893
WABCO Holdings		595,235		376,496
Wabtec		625,474		0
Consumer Goods & Services
Caesarstone (Israel)		540,000		0
Casey's General Stores		596,335		328,705
Choice Hotels		720,955		695,884
Fossil		874,735		857,573
HomeAway		2,160,506		2,108,589
Knoll		2,520,350		2,285,817
Pool		1,274,436		968,373
Select Comfort		2,158,630		2,082,715
United Natural Foods		1,192,643		0
Vail Resorts		817,499		696,739
Williams-Sonoma		567,295		517,835
Zulily		2,405,817		0
Finance
Allied World Assurance Company Holdings		864,371		761,549
Associated Banc-Corp		7,931,448		7,020,624
BOK Financial		1,799,411		1,693,009
CAI International		839,000		46,177
Eaton Vance		2,914,581		2,744,774
First Busey		1,370,960		1,150,982
Hancock Holding		1,350,879		1,255,879
Leucadia National		3,760,346		3,510,346
MB Financial		1,790,025		1,665,025
McGrath Rentcorp		1,167,476		1,018,222
RLI		606,457		0
Sandy Spring Bancorp		1,014,983		920,302
SEI Investments		6,522,307		2,926,928
SVB Financial Group		677,700		585,706
TrustCo Bank		3,089,176		2,400,880
World Acceptance		530,000		284,817
Health Care
Agios Pharmaceuticals		346,692		278,315
Akorn		2,503,151		2,343,909
Allscripts Healthcare Solutions		1,749,965		0
Bio-Techne		1,123,116		940,171
Cepheid		4,065,050		3,544,076
Envision Healthcare Holdings		1,155,575		953,559
HealthSouth		1,647,700		1,564,880

	Number of Shares
	6/30/15		9/30/15
Intercept Pharmaceuticals		220,978		167,157
Sarepta Therapeutics		2,404,789		1,465,091
Seattle Genetics		1,823,556		1,406,314
Sirona Dental Systems		435,820		410,018
Ultragenyx Pharmaceutical		1,712,134		881,105
VWR		1,850,600		1,742,943
Wright Medical Group		1,829,940		1,764,061
Other Industries
EdR		2,325,332		2,277,125
Extra Space Storage		1,002,619		915,342
Federal Realty		658,669		599,049
Genesee & Wyoming		380,000		0
JB Hunt Transport Services		578,406		545,660
Post Properties		1,316,297		1,040,362
Rush Enterprises, Class A		2,173,034		1,998,351
Rush Enterprises, Class B		460,172		0
Energy & Minerals
Alamos Gold (Canada)		3,421,322		0
Argonaut Gold (Canada)		8,582,916		1,001,900
Clayton Williams		265,636		0
Core Labs (Netherlands)		407,938		385,377
Energen Corporation		501,139		0
Gulfport Energy		774,708		0
Hornbeck Offshore		1,147,145		0

COLUMBIA ACORN® FUND

STATEMENT OF INVESTMENTS (UNAUDITED), SEPTEMBER 30, 2015

Number of Shares			Value
			Equities: 95.5%
Information 28.2%
		> Business Software 6.1%
	1,307,860	Ansys (a)	$	115,274,780
		Simulation Software for Engineers & Designers
	531,160	Ultimate Software (a)		95,082,951
		Human Capital Management Systems
	4,174,029	Cadence Design Systems (a)		86,318,920
		Electronic Design Automation Software
	1,228,326	Verint Systems (a)		53,002,267
		Contact Center & Security Software
	738,167	SPS Commerce (a)		50,114,158
		Supply Chain Management Software Delivered via the Web
	1,364,000	Cvent (a)		45,912,240
		Software for Corporate Event Planners & Marketing Platform for Hotels
	505,397	NetSuite (a)		42,402,808
		Enterprise Software Delivered via the Web
	1,134,283	Textura (a)(b)		29,309,873
		Construction Vendor Management Software
	550,000	DemandWare (a)		28,424,000
		E-Commerce Website Platform for Retailers & Apparel Manufacturers
	2,190,721	inContact (a)(b)		16,452,315
		Call Center Systems Delivered via the Web & Telco Services
				562,294,312
		> Instrumentation 3.2%
	500,314	Mettler-Toledo International (a)		142,459,408
		Laboratory Equipment
	1,051,460	IPG Photonics (a)		79,879,416
		Fiber Lasers
	1,440,913	FLIR Systems		40,331,155
		Infrared Cameras
	1,765,318	Trimble Navigation (a)		28,986,522
		GPS-based Instruments
				291,656,501
		> Business Information & Marketing Services 2.7%
	7,500,000	Bankrate (a)(c)		77,625,000
		Internet Advertising for the Insurance, Credit Card & Banking Markets
	1,019,873	Verisk Analytics (a)		75,378,813
		Risk & Decision Analytics
	3,041,462	Navigant Consulting (a)(c)		48,389,660
		Financial Consulting Firm
	1,780,644	RPX (a)		24,430,436
		Patent Aggregation & Defensive Patent Consulting
	223,000	Dun & Bradstreet		23,415,000
		Commercial Data Provider
				249,238,909
		> Computer Hardware & Related Equipment 2.6%
	3,102,522	Amphenol		158,104,521
		Electronic Connectors

Number of Shares			Value
	430,258	Zebra Technologies (a)	$	32,936,250
		Bar Code Printers & Mobile Computers
	978,966	VeriFone Holdings (a)		27,146,727
		Point of Sale Systems
	466,375	Rogers (a)		24,801,823
		Printed Circuit Materials & High Performance Foams
				242,989,321
		> Computer Services 2.6%
	2,021,597	WNS - ADR (a)		56,503,636
		Offshore Business Process Outsourcing Services
	1,078,328	Virtusa (a)		55,329,010
		Offshore IT Outsourcing
	1,256,334	ExlService Holdings (a)		46,396,414
		Business Process Outsourcing
	1,714,083	Genpact (a)		40,469,500
		Business Process Outsourcing
	2,588,645	Hackett Group (c)		35,593,869
		IT Integration & Best Practice Research
				234,292,429
		> Mobile Communications 2.4%
	557,169	SBA Communications (a)		58,357,881
		Communications Towers
	34,500,000	Globalstar (a)		54,165,000
		Satellite Mobile Voice & Data Carrier
	655,865	Crown Castle International		51,728,072
		Communications Towers
	2,138,621	Gogo (a)(b)		32,678,129
		Provider of Wi-Fi on Airplanes
	1,767,570	Global Eagle Entertainment (a)(b)		20,291,704
		Provider of Entertainment & Wi-Fi on Airplanes
				217,220,786
		> Internet Related 1.7%
	14,475,223	Vonage (a)(c)		85,114,311
		Business & Consumer Internet Telephony
	706,197	Verisign (a)(b)		49,829,260
		Internet Domain Registry for .com/.net (Approximately 50% of World Domains)
	2,768,000	RetailMeNot (a)(c)		22,808,320
		Digital Coupon Marketplace
				157,751,891
		> Telecommunications Equipment 1.2%
	450,102	F5 Networks (a)		52,121,812
		Internet Traffic Management Equipment
	1,896,961	Infinera (a)		37,104,557
		Optical Networking Equipment
	1,255,089	CalAmp (a)		20,194,382
		Machine-to-machine Communications
				109,420,751
		> Financial Processors 1.0%
	446,868	Global Payments		51,269,166
		Credit Card Processor
	1,138,000	CoreLogic (a)		42,367,740
		Data Processing Services for Real Estate, Insurance, & Mortgages
				93,636,906

Number of Shares			Value
		> Telephone & Data Services 1.0%
	1,838,844	GTT Communications (a)(c)	$	42,771,511
		Provider of High Capacity Data Transit
	2,727,319	Boingo Wireless (a)(c)		22,582,201
		Wi-Fi & Cellular Communications Networks
	867,000	Zayo Group Holdings (a)		21,987,120
		Fiber Optic Data Communications
	3,775,680	Towerstream (a)(b)(c)		4,039,978
		High Speed Wireless, Rooftop Antenna Space & Wi-Fi Offload
				91,380,810
		> Semiconductors & Related Equipment 0.9%
	3,736,317	Atmel		30,152,078
		Microcontrollers, Radio Frequency & Memory Semiconductors
	300,258	Littelfuse		27,368,517
		Little Fuses
	378,172	Monolithic Power Systems		19,362,406
		High Performance Analog & Mixed Signal Integrated Circuits
	2,024,886	Rubicon Technology (a)(b)(c)		2,085,633
		Producer of Sapphire for the Lighting, Electronics & Automotive Industries
				78,968,634
		> Contract Manufacturing 0.8%
	3,572,799	Sanmina (a)		76,350,715
		Electronic Manufacturing Services
		> Cable TV 0.8%
	951,000	Starz (a)		35,510,340
		Premium CATV Channel Network
	623,626	Liberty Global Series A (a)		26,778,500
	230,253	Liberty Global Series C (a)		9,444,978
		Cable TV Franchises Outside of the United States
				71,733,818
		> Electronics Distribution 0.5%
	1,092,454	Avnet		46,625,937
		Electronic Components Distribution
		> Advertising 0.4%
	628,184	Lamar Advertising		32,778,641
		Outdoor Advertising
		> Entertainment Programming 0.3%
	860,159	IMAX (Canada) (a)		29,064,773
		IMAX Movies, Theater Equipment & Theater Joint Ventures
Information: Total				2,585,405,134
Industrial Goods & Services 22.6%
		> Machinery 13.1%
	7,758,932	Donaldson (c)		217,870,810
		Industrial Air Filtration
	3,759,949	Ametek		196,720,532
		Aerospace/Industrial Instruments
	2,096,519	Nordson		131,954,906
		Dispensing Systems for Adhesives & Coatings

Number of Shares			Value
	2,863,648	HEICO (c)	$	130,038,256
		FAA-approved Aircraft Replacement Parts
	1,148,893	Toro		81,042,912
		Turf Maintenance Equipment
	2,563,598	Generac (a)		77,138,664
		Standby Power Generators
	1,296,026	Moog (a)		70,076,126
		Motion Control Products for Aerospace, Defense & Industrial Markets
	1,875,197	Oshkosh Corporation		68,125,907
		Specialty Truck Manufacturer
	576,889	Middleby (a)		60,682,954
		Manufacturer of Cooking Equipment
	1,438,756	ESCO Technologies (c)		51,651,340
		Industrial Filtration & Advanced Measurement Equipment
	921,458	Dorman Products (a)(b)		46,892,997
		Aftermarket Auto Parts Distributor
	376,496	WABCO Holdings (a)		39,468,076
		Truck & Bus Component Supplier
	1,344,966	Kennametal		33,476,204
		Consumable Cutting Tools
				1,205,139,684
		> Other Industrial Services 4.3%
	6,088,786	LKQ (a)		172,677,971
		Alternative Auto Parts Distribution
	1,911,000	Robert Half International		97,766,760
		Temporary & Permanent Staffing in Finance, Accounting & other Professions
	1,614,150	Expeditors International of Washington		75,945,757
		International Freight Forwarder
	1,310,342	Forward Air		54,366,090
		Freight Transportation Between Airports
				400,756,578
		> Construction 1.9%
	71,780	NVR (a)		109,480,291
		Homebuilder
	2,865,200	PGT (a)(c)		35,184,656
		Wind Resistant Windows & Doors
	560,477	Allegion		32,317,104
		Mechanical & Electronic Security Systems
				176,982,051
		> Industrial Distribution 1.2%
	760,291	Airgas		67,916,795
		Industrial Gas Distributor
	851,347	WESCO International (a)		39,562,095
		Industrial Distributor
				107,478,890
		> Outsourcing Services 0.9%
	3,357,357	Quanta Services (a)		81,281,613
		Electrical Transmission & Pipeline Contracting Services
		> Industrial Materials & Specialty Chemicals 0.8%
	1,341,286	Drew Industries (c)		73,247,629
		RV & Manufactured Home Components

COLUMBIA ACORN® FUND

STATEMENT OF INVESTMENTS (UNAUDITED), CONTINUED

Number of Shares			Value
		> Electrical Components 0.4%
	1,639,635	Thermon (a)(c)	$	33,694,499
		Global Engineered Thermal Solutions
Industrial Goods & Services: Total				2,078,580,944
Consumer Goods & Services 13.2%
		> Travel 3.4%
	2,017,776	Avis Budget Group (a)		88,136,456
		Car Rental Company
	696,739	Vail Resorts		72,934,638
		Ski Resort Operator & Developer
	3,635,000	Hertz (a)		60,813,550
		U.S. Rental Car Operator
	2,108,589	HomeAway (a)		55,961,952
		Vacation Rental Online Marketplace
	695,884	Choice Hotels		33,158,873
		Franchisor of Budget Hotel Brands
				311,005,469
		> Retail 2.5%
	2,561,000	The Fresh Market (a)(b)(c)		57,852,990
		Specialty Food Retailer
	857,573	Fossil (a)		47,921,179
		Watch Designer & Retailer
	517,835	Williams-Sonoma		39,536,702
		Home Goods & Furnishing Retailer
	328,705	Casey's General Stores		33,830,319
		Owner/Operator of Convenience Stores
	719,860	Cato		24,496,836
		Women's Apparel Retailing, Focusing on Private Labels & Low Prices
	492,129	Urban Outfitters (a)		14,458,750
		Multi-channel Apparel & Accessory Retailer
	2,100,000	Gaiam (a)(c)		12,915,000
		Promoter of Healthy Living through Catalogs, E-Commerce & Gaiam TV
				231,011,776
		> Restaurants 2.3%
	937,570	Papa John's International		64,204,794
		Franchisor of Pizza Restaurants
	997,484	Fiesta Restaurant Group (a)		45,255,849
		Owner/Operator of Two Restaurant Chains: Pollo Tropical & Taco Cabana
	403,000	Domino's Pizza		43,487,730
		Franchisor of Pizza Restaurants
	576,000	Dunkin Brands		28,224,000
		Franchisor of Quick Service Restaurants
	454,079	Popeyes Louisiana Kitchen (a)		25,591,892
		Popeyes Restaurants
				206,764,265
		> Other Durable Goods 2.2%
	6,505,000	Gentex		100,827,500
		Manufacturer of Auto Parts
	2,082,715	Select Comfort (a)		45,569,804
		Specialty Mattresses
	455,025	Cavco Industries (a)(c)		30,982,653
		Manufactured Homes

Number of Shares			Value
	649,825	Tenneco (a)	$	29,092,665
		Auto Parts for Emission Control, Suspension
				206,472,622
		> Consumer Goods Distribution 0.9%
	968,373	Pool		70,013,368
		Swimming Pool Supplies & Equipment Distributor
	863,000	The Chefs' Warehouse (a)		12,220,080
		Distributor of Specialty Foods to Fine Dining Restaurants
				82,233,448
		> Furniture & Textiles 0.7%
	2,285,817	Knoll		50,242,258
		Office Furniture
	390,000	Mattress Firm (a)(b)		16,286,400
		Mattress Retailer
				66,528,658
		> Other Consumer Services 0.7%
	978,253	Blackhawk Network (a)		41,468,145
		Third-party Distributor of Prepaid Content, Mostly Gift Cards
	2,697,000	Coupons.com (a)(b)		24,273,000
		Allows CPGs to Digitally Distribute Coupons, Advertising, & Trade Promotion
				65,741,145
		> Leisure Products 0.3%
	192,000	Polaris Industries		23,015,040
		Leisure Vehicles & Related Products
		> Nondurables 0.2%
	1,608,005	HRG Group (a)		18,861,898
		Holding Company
Consumer Goods & Services: Total				1,211,634,321
Finance 11.0%
		> Banks 4.9%
	7,020,624	Associated Banc-Corp		126,160,613
		Midwest Bank
	1,693,009	BOK Financial (b)		109,554,613
		Tulsa-based Southwest Bank
	585,706	SVB Financial Group (a)		67,672,471
		Bank to Venture Capitalists
	1,665,025	MB Financial		54,346,416
		Chicago Bank
	1,255,879	Hancock Holding		33,971,527
		Gulf Coast Bank
	920,302	Sandy Spring Bancorp		24,093,507
		Baltimore & Washington, D.C. Bank
	1,150,982	First Busey		22,870,012
		Illinois Bank
	2,400,880	TrustCo Bank		14,021,139
		New York State Bank
				452,690,298
		> Brokerage & Money Management 2.7%
	2,926,928	SEI Investments		141,165,737
		Mutual Fund Administration & Investment Management
	2,744,774	Eaton Vance		91,730,347
		Specialty Mutual Funds

Number of Shares			Value
		> Brokerage & Money Management—continued
	11,000,000	Sprott (Canada) (b)	$	19,535,407
		Asset Manager Focused on Resources, Particularly Gold & Silver
				252,431,491
		> Insurance 1.5%
	5,651,291	CNO Financial Group		106,300,784
		Life, Long-term Care & Medical Supplement Insurance
	761,549	Allied World Assurance Company Holdings		29,068,325
		Commercial Lines Insurance/Reinsurance
				135,369,109
		> Diversified Financial Companies 0.8%
	3,510,346	Leucadia National		71,119,610
		Holding Company
		> Credit Cards 0.7%
	703,142	WEX (a)		61,060,851
		Card Processor
		> Finance Companies 0.4%
	1,018,222	McGrath Rentcorp		27,176,345
		Mini-rental Conglomerate
	284,817	World Acceptance (a)(b)		7,644,489
		Personal Loans
	46,177	CAI International (a)		465,464
		International Container Leasing
				35,286,298
Finance: Total				1,007,957,657
Health Care 10.6%
		> Medical Supplies 3.7%
	3,544,076	Cepheid (a)		160,192,235
		Molecular Diagnostics
	940,171	Bio-Techne		86,928,211
		Maker of Consumables & Systems for the Life Science Market
	349,334	Henry Schein (a)		46,363,608
		Distributor of Dental, Vet & Medical Products
	1,742,943	VWR (a)		44,776,206
		Distributor of Lab Supplies
				338,260,260
		> Biotechnology & Drug Delivery 2.8%
	881,105	Ultragenyx Pharmaceutical (a)		84,859,222
		Biotech Focused on "Ultra-Orphan" Drugs
	1,406,314	Seattle Genetics (a)		54,227,468
		Antibody-based Therapies for Cancer
	1,465,091	Sarepta Therapeutics (a)(b)		47,044,072
		Biotech Focused on Rare Diseases
	167,157	Intercept Pharmaceuticals (a)		27,724,660
		Biotech Developing Drugs for Several Diseases
	2,162,687	Celldex Therapeutics (a)		22,794,721
		Biotech Developing Drugs for Cancer
	278,315	Agios Pharmaceuticals (a)(b)		19,646,256
		Biotech Focused on Cancer & Orphan Diseases

Number of Shares			Value
	359,944	MicroDose Therapeutx Contingent Value Rights (a)(d)(e)	$	327,549
		Drug Inhaler Development
				256,623,948
		> Health Care Services 1.7%
	1,430,434	Medidata Solutions (a)		60,235,576
		Cloud-based Software for Drug Studies
	1,564,880	HealthSouth		60,044,445
		Inpatient Rehabilitation Facilities & Home Health Care
	953,559	Envision Healthcare Holdings (a)		35,081,436
		Provider of Health Care Outsourcing Services
				155,361,457
		> Medical Equipment & Devices 1.7%
	914,276	Align Technology (a)		51,894,306
		Invisalign System to Correct Malocclusion (Crooked Teeth)
	410,018	Sirona Dental Systems (a)		38,271,080
		Manufacturer of Dental Equipment
	1,764,061	Wright Medical Group (a)		37,080,562
		Foot & Ankle Replacement
	631,624	Abaxis (b)		27,785,140
		Instruments & Tests for Vet & Medical Markets
				155,031,088
		> Pharmaceuticals 0.7%
	2,343,909	Akorn (a)		66,813,126
		Developer, Manufacturer & Distributor of Specialty Generic Drugs
Health Care: Total				972,089,879
Other Industries 6.9%
		> Real Estate 4.8%
	599,049	Federal Realty		81,740,236
		Shopping Centers & Mixed Use Projects
	2,277,125	EdR		75,031,269
		Student Housing
	182,278	Amerco		71,720,924
		North American Moving & Storage King
	915,342	Extra Space Storage		70,627,789
		Self Storage Facilities
	1,040,362	Post Properties		60,642,701
		Multifamily Properties
	2,148,681	Terreno Realty		42,200,095
		Industrial Properties
	276,235	Jones Lang LaSalle		39,714,306
		Real Estate Services
				441,677,320
		> Transportation 1.5%
	2,816,684	Heartland Express		56,164,679
		Regional Trucker
	1,998,351	Rush Enterprises, Class A (a)(c)		48,360,094
		Truck Sales & Service
	545,660	JB Hunt Transport Services		38,960,124
		Truck & Intermodal Carrier
				143,484,897

COLUMBIA ACORN® FUND

STATEMENT OF INVESTMENTS (UNAUDITED), CONTINUED

Number of Shares			Value
		> Regulated Utilities 0.6%
	1,036,839	Eversource Energy	$	52,484,790
		Regulated Electric Utility
Other Industries: Total				637,647,007
Energy & Minerals 3.0%
		> Oil & Gas Producers 1.7%
	528,771	Cimarex Energy		54,188,452
		Oil & Gas Producer in Texas, New Mexico & Oklahoma
	1,216,733	Carrizo Oil & Gas (a)		37,159,026
		Oil & Gas Producer
	681,333	PDC Energy (a)		36,117,462
		Oil & Gas Producer in the United States
	685,658	SM Energy		21,968,482
		Oil & Gas Producer
	107,561,000	ShaMaran Petroleum (Iraq) (a)(c)		5,843,516
		Oil Exploration & Production in Kurdistan
	64,294,000	Petromanas (Canada) (a)(c)		2,047,580
		Exploring for Oil in Albania
	24,115,500	Canadian Overseas Petroleum (Canada) (a)(c)		722,833
	8,400,000	Canadian Overseas Petroleum (Canada) (a)(c)(d)		239,191
		Oil & Gas Exploration Offshore West Africa
				158,286,542
		> Mining 0.8%
	385,377	Core Labs (Netherlands) (b)		38,460,625
		Oil & Gas Reservoir Consulting
	6,115,764	Kirkland Lake Gold (Canada) (a)(c)		25,434,612
		Gold Mining
	3,412,300	Silvercrest Mines (a)		3,017,245
		Gold & Silver Mining
	3,000,000	Kaminak Gold (a)		1,798,426
		Exploration Stage Canadian Gold Miner
	1,001,900	Argonaut Gold (Canada) (a)		1,021,045
		Gold & Silver Mining
				69,731,953
		> Oil Services 0.4%
	1,740,523	ShawCor (Canada)		36,492,944
		Oil & Gas Pipeline Products
		> Agricultural Commodities 0.1%
	1,306,818	Union Agriculture Group (Uruguay) (a)(d)(e)		8,598,862
		Farmland Operator in Uruguay

Number of Shares			Value
		> Non-Ferrous Metals —%
	1,504,355	AuRico Metals (Canada) (a)	$	744,005
		Gold Mining Royalty Company
Energy & Minerals: Total				273,854,306
Total Equities: 95.5% (Cost: $5,345,603,743)				8,767,169,248	(f)
Short-Term Investments 5.0%
	280,000,000	JPMorgan U.S. Government Money Market Fund, IM Shares (7 day yield of 0.01%)		280,000,000
	176,408,128	JPMorgan U.S. Government Money Market Fund, Agency Shares (7 day yield of 0.01%)		176,408,128
Total Short-Term Investments: 5.0% (Cost: $456,408,128)				456,408,128
Securities Lending Collateral 2.2%
	201,734,609	Dreyfus Government Cash Management Fund, Institutional Shares (7 day yield of 0.01%) (g)		201,734,609
Total Securities Lending Collateral: 2.2% (Cost: $201,734,609)				201,734,609
Total Investments: 102.7% (Cost: $6,003,746,480)(h)				9,425,311,985	(i)
Obligation to Return Collateral for Securities Loaned: (2.2)%				(201,734,609	)
Cash and Other Assets Less Liabilities: (0.5)%				(45,111,515	)
Net Assets: 100.0%			$	9,178,465,861

ADR - American Depositary Receipts

> Notes to Statement of Investments

(a) Non-income producing security.

(b) All or a portion of this security was on loan at September 30, 2015. The total market value of securities on loan at September 30, 2015 was $201,168,923.

(c) An affiliated person of the Fund, as defined in the Investment Company Act of 1940, as amended, may include any company in which the Fund owns five percent or more of its outstanding voting shares. Holdings and transactions in these affiliated companies during the period ended September 30, 2015, are as follows:

Security	Balance of Shares Held 12/31/14		Purchases/ Additions		Sales/ Reductions		Balance of Shares Held 9/30/15		Value		Dividend
Donaldson		7,952,000		-		193,068		7,758,932	$	217,870,810	$	4,014,779
Cepheid (1)		5,350,800		-		1,806,724		3,544,076		160,192,235		-
Nordson (1)		3,130,000		-		1,033,481		2,096,519		131,954,906		1,700,313
HEICO		3,626,750		-		763,102		2,863,648		130,038,256		207,352
Associated Banc-Corp (1)		9,000,000		414,000		2,393,376		7,020,624		126,160,613		2,544,665
Vonage		14,044,775		455,225		24,777		14,475,223		85,114,311		-
Bankrate		6,300,300		1,199,700		-		7,500,000		77,625,000		-
Generac (1)		3,632,000		-		1,068,402		2,563,598		77,138,664		-
EdR (1)		2,450,000		-		172,875		2,277,125		75,031,269		2,563,898
Drew Industries		1,610,000		-		268,714		1,341,286		73,247,629		3,220,000
Moog (1)		2,456,000		-		1,159,974		1,296,026		70,076,126		-
The Fresh Market		1,492,000		1,069,000		-		2,561,000		57,852,990		-
Virtusa (1)		1,658,000		-		579,672		1,078,328		55,329,010		-
ESCO Technologies		1,948,000		-		509,244		1,438,756		51,651,340		353,340
Knoll (1)		3,366,000		-		1,080,183		2,285,817		50,242,258		954,022
SPS Commerce (1)		1,330,000		-		591,833		738,167		50,114,158		-
Navigant Consulting		4,128,523		-		1,087,061		3,041,462		48,389,660		-
Rush Enterprises, Class A		3,200,000		-		1,201,649		1,998,351		48,360,094		-
Sarepta Therapeutics (1)		2,523,900		-		1,058,809		1,465,091		47,044,072		-
GTT Communications		1,950,000		651,000		762,156		1,838,844		42,771,511		-
Terreno Realty (1)		2,150,000		-		1,319		2,148,681		42,200,095		687,789
Hackett Group		2,903,719		-		315,074		2,588,645		35,593,869		264,305
PGT		3,592,200		-		727,000		2,865,200		35,184,656		-
Thermon		1,940,094		43,735		344,194		1,639,635		33,694,499		-
Cavco Industries		500,000		-		44,975		455,025		30,982,653		-
McGrath Rentcorp (1)		1,580,000		-		561,778		1,018,222		27,176,345		996,023
Kirkland Lake Gold		6,347,100		350,100		581,436		6,115,764		25,434,612		-
RetailMeNot		1,112,930		1,679,000		23,930		2,768,000		22,808,320		-
Boingo Wireless		2,800,000		100,000		172,681		2,727,319		22,582,201		-
inContact (1)		3,741,000		-		1,550,279		2,190,721		16,452,315		-
Gaiam		2,100,000		-		-		2,100,000		12,915,000		-
World Acceptance (1)		808,343		-		523,526		284,817		7,644,489		-
ShaMaran Petroleum		28,962,000		78,599,000		-		107,561,000		5,843,516		-
Towerstream		4,000,000		-		224,320		3,775,680		4,039,978		-
Rubicon Technology		2,500,000		-		475,114		2,024,886		2,085,633		-
Petromanas		67,500,000		-		3,206,000		64,294,000		2,047,580		-
Argonaut Gold (1)		9,014,700		1,001,900		9,014,700		1,001,900		1,021,045		-
Canadian Overseas Petroleum		32,515,500		-		-		32,515,500		962,024		-
CAI International (1)		1,500,000		-		1,453,823		46,177		465,464		-
Allied Nevada Gold (1)		7,103,513		-		7,103,513		-		-		-
Amber Road (1)		2,000,000		-		2,000,000		-		-		-
Audience (1)		2,150,000		-		2,150,000		-		-		-
Boulder Brands (1)		3,484,000		-		3,484,000		-		-		-
E2Open (1)		2,575,000		-		2,575,000		-		-		-
Liquidity Services (1)		1,600,000		-		1,600,000		-		-		-
Marlin Business Services (1)		902,210		-		902,210		-		-		-
Petrodorado Energy (1)		2,600,000		-		2,600,000		-		-		-
RGS Energy (1)		5,000,000		-		5,000,000		-		-		-
Synageva BioPharma (1)		2,419,209		-		2,419,209		-		-		-
Total of Affiliated Transactions		286,550,566		85,562,660		64,809,181		307,304,045	$	2,005,339,206	$	17,506,486

(1) At September 30, 2015, the Fund owned less than five percent of the company's outstanding voting shares.

The aggregate cost and value of these companies at September 30, 2015, was $778,247,105 and $1,067,096,142, respectively. Investments in affiliated companies represented 11.63% of the Fund's total net assets at September 30, 2015.

COLUMBIA ACORN® FUND

STATEMENT OF INVESTMENTS (UNAUDITED), CONTINUED

> Notes to Statement of Investments

(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 Fund's Board of Trustees. At September 30, 2015, the market value of these securities amounted to $9,165,602, which represented 0.10% of total net assets. Additional information on these securities is as follows:

Security	Acquisition Dates	Shares		Cost		Value
Union Agriculture Group	12/8/10-6/27/12		1,306,818	$	15,000,000	$	8,598,862
MicroDose Therapeutx Contingent Value Rights	8/14/13		359,944		-		327,549
Canadian Overseas Petroleum	11/24/10		8,400,000		3,591,152		239,191
				$	18,591,152	$	9,165,602

(e) Illiquid security.

(f) On September 30, 2015, the market value of foreign securities represented 1.83% of total net assets. The Fund's foreign portfolio was diversified as follows:

Country	Value		Percentage of Net Assets
Canada	$	115,302,390		1.26
Netherlands		38,460,625		0.42
Uruguay		8,598,862		0.09
Iraq		5,843,516		0.06
Total Foreign Portfolio	$	168,205,393		1.83

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

(h) At September 30, 2015, for federal income tax purposes, the cost of investments was approximately $6,003,746,480 and net unrealized appreciation was $3,421,565,505 consisting of gross unrealized appreciation of $3,858,935,414 and gross unrealized depreciation of $437,369,909.

(i) Securities are valued using policies described in the Notes to Financial Statements in the shareholder report dated June 30, 2015.

Fair Value Measurements

Various inputs are used in determining the value of the Fund's investments, following the input prioritization hierarchy established by accounting principles generally accepted in the United States of America (GAAP). These inputs are summarized in the three broad levels listed below:

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

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

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

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

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

The Committee is responsible for applying the Trust's Portfolio Pricing Policy and the CWAM pricing procedures (the Policies), which are approved by and subject to the oversight of the Board.

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

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

> Notes to Statement of Investments

The following table summarizes the inputs used, as of September 30, 2015, 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	$	2,585,405,134	$	-	$	-	$	2,585,405,134
Industrial Goods & Services		2,078,580,944		-		-		2,078,580,944
Consumer Goods & Services		1,211,634,321		-		-		1,211,634,321
Finance		1,007,957,657		-		-		1,007,957,657
Health Care		971,762,330		-		327,549		972,089,879
Other Industries		637,647,007		-		-		637,647,007
Energy & Minerals		265,016,253		239,191		8,598,862		273,854,306
Total Equities		8,758,003,646		239,191		8,926,411		8,767,169,248
Total Short-Term Investments		456,408,128		-		-		456,408,128
Total Securities Lending Collateral		201,734,609		-		-		201,734,609
Total Investments	$	9,416,146,383	$	239,191	$	8,926,411	$	9,425,311,985

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

The Fund does not hold any significant investments (greater than one percent of net assets) categorized as Level 3.

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

COLUMBIA ACORN INTERNATIONAL®

MAJOR PORTFOLIO CHANGES IN THE THIRD QUARTER (UNAUDITED)

	Number of Shares
	6/30/15		9/30/15
Purchases
Asia
> Japan
Asahi Intecc		210,800		832,000
Bandai Namco		0		1,058,000
Capcom Co., Ltd.		0		942,150
Ebara		0		7,590,000
FamilyMart		1,050,000		1,447,000
IHI		7,100,000		15,000,000
Kansai Paint		1,692,600		1,838,600
NGK Insulators		2,400,000		2,700,000
Sega Sammy Holdings, Inc.		0		2,083,000
Sony Financial Holdings		0		1,550,000
Suruga Bank		1,270,000		1,870,000
Yamaguchi Financial Group, Inc.		0		1,750,000
> China
CAR Inc		27,000,000		30,700,000
TravelSky Technology		14,556,000		21,755,000
> Korea
Cheil Worldwide		1,187,900		1,300,093
CJ Hellovision		2,908,469		3,149,876
KCC		65,494		113,183
Koh Young Technology		43,923		197,100
Korea Investment Holdings		0		397,002
> Taiwan
Far EasTone Telecom		17,600,000		23,150,000
Silergy		820,000		2,234,000
> India
Container Corporation of India		1,382,783		1,505,000
> Hong Kong
Value Partners		0		29,042,000
Vitasoy International		9,675,000		14,595,000
> Singapore
China Everbright Water		28,242,100		31,700,000
SIIC Environment		33,146,240		33,724,000
Europe
> United Kingdom
Domino's Pizza UK & Ireland		2,660,000		3,050,000
DS Smith		0		1,178,371
Halfords		4,712,000		6,222,700
Halma		2,725,000		4,399,000
Next		0		173,000
Regus		8,840,000		12,365,000
Shaftesbury		1,480,000		2,100,000
Smith & Nephew		1,280,000		3,000,000

	Number of Shares
	6/30/15		9/30/15
> Sweden
Hexagon		1,666,208		2,055,208
Modern Times Group		1,137,000		1,286,000
Trelleborg		0		1,317,000
> Germany
NORMA Group		795,000		1,067,000
Wirecard		1,350,000		1,750,000
> Denmark
Novozymes		1,315,800		1,647,800
> Netherlands
Arcadis		849,025		1,573,025
Core Labs		114,395		255,510
Gemalto		324,700		650,000
> Switzerland
Geberit		116,500		228,300
Panalpina Welttransport Holding		0		190,000
> Spain
Distribuidora Internacional de Alimentación		10,110,000		13,425,000
Prosegur		6,564,000		8,555,000
> France
Neopost		1,350,000		1,660,000
> Finland
Konecranes		1,103,420		1,387,000
> Norway
Atea		2,613,864		3,050,864
> Italy
Hera		4,213,201		7,800,200
Other Countries
> Australia
Domino's Pizza Enterprises		2,123,737		2,200,000
IAG		5,260,000		7,680,000
Spotless		47,446,000		58,000,000
> United States
Bladex		912,000		1,092,000
Latin America
> Mexico
Grupo Aeroportuario del Sureste - ADR		283,000		300,000
> Brazil
Odontoprev		7,000,000		7,885,300

	Number of Shares
	6/30/15		9/30/15
Sales
Asia
> Japan
Aeon Financial Service		1,400,000		1,260,000
Asahi Diamond Industrial		1,914,500		0
Benesse		987,200		0
Cocokara Fine		68,100		0
Daiseki		1,270,000		961,000
Disco		343,400		291,400
Doshisha		1,600,000		1,447,000
Icom		771,000		614,200
Japan Airport Terminal		550,000		450,000
Kaken Pharmaceutical		341,400		184,900
Milbon		698,480		578,680
Misumi Group		1,950,000		624,000
MonotaRO		705,200		536,000
Nabtesco		1,020,000		0
Nakanishi		580,000		414,600
Nihon Parkerizing		1,822,292		497,592
Nippon Kayaku		3,111,000		1,910,000
Nippon Paint Holdings		915,000		0
NOF		4,938,000		4,319,000
OBIC		665,000		621,000
OSG		1,440,000		1,230,000
Otsuka		641,900		430,900
Park24		1,678,000		1,463,000
Santen Pharmaceutical		2,911,000		2,792,000
> China
AMVIG Holdings		24,511,227		19,554,463
China Everbright International		53,103,100		36,307,582
Chongqing Rural Commercial Bank		32,128,392		0
Jiangnan Group		29,387,362		20,818,090
Shanghai Industrial		29,365,135		0
Sino Biopharmaceutical		22,874,405		0
WuXi PharmaTech - ADR		32,117,600		21,691,420
> Korea
CJ Corp		215,971		141,971
Grand Korea Leisure		475,576		0
Hyundai Marine & Fire Insurance		444,715		0
LF Corp		1,119,428		788,428
LS Industrial Systems		494,303		412,977
Nongshim		145,900		88,583

	Number of Shares
	6/30/15		9/30/15
> Taiwan
Chroma Ate		3,061,000		0
Delta Electronics		6,351,000		5,557,000
Ginko International		1,925,000		369,000
Largan Precision		399,000		253,000
Lite-On Technology		16,513,035		0
Novatek Microelectronics		8,126,000		5,704,000
PChome Online		2,272,094		0
President Chain Store		9,100,000		3,400,000
St. Shine Optical		2,081,000		1,780,000
Vanguard International Semiconductor		27,141,000		19,984,000
Voltronic Power		1,594,982		1,173,686
> Hong Kong
Lifestyle International		8,099,500		2,655,500
Melco Crown Entertainment - ADR		1,130,000		0
Melco International		15,000,000		13,016,000
> Singapore
CDL Hospitality Trust		7,795,600		0
Mapletree Commercial Trust		50,000,000		41,009,700
Mapletree Industrial Trust		10,502,000		0
Mapletree Logistics Trust		13,847,750		0
Petra Foods		8,500,000		8,200,000
> Indonesia
Ace Indonesia		312,000,000		59,667,800
Arwana Citramulia		220,150,800		150,349,000
Link Net		50,000,000		45,000,000
Matahari Department Store		24,195,600		19,540,600
Mayora Indah		3,993,900		0
Surya Citra Media		61,947,300		0
Tower Bersama Infrastructure		31,000,000		18,442,800
> Thailand
Home Product Center		114,913,600		100,000,000
Robinson Department Store		14,485,000		1,621,900
> Philippines
Puregold Price Club		35,000,000		33,345,000
Robinsons Retail Holdings		13,500,000		12,200,000
Universal Robina		5,900,000		0
> Cambodia
Nagacorp		55,000,000		47,028,000
> Malaysia
7-Eleven Malaysia Holdings		41,700,000		37,835,900

COLUMBIA ACORN INTERNATIONAL®

MAJOR PORTFOLIO CHANGES IN THE THIRD QUARTER (UNAUDITED), CONTINUED

	Number of Shares
	6/30/15		9/30/15
Sales (continued)
Europe
> United Kingdom
Aggreko		1,980,000		0
AVEVA		908,500		0
Babcock International		1,568,000		1,398,000
Jardine Lloyd Thompson Group		2,540,000		1,944,000
> Sweden
Mekonomen		1,044,000		916,000
Recipharm		1,205,000		849,000
> Kazakhstan
Halyk Savings Bank of Kazakhstan - GDR		5,143,000		4,356,790
> Belgium
EVS Broadcast Equipment		450,656		258,681
Other Countries
> Canada
Baytex		1,358,857		0
Boulder Energy		2,245,052		1,301,152
CCL Industries		651,772		633,741
Granite Oil		376,629		0
> Australia
Amcor		4,270,000		3,692,000
Austbrokers		1,070,000		0
Challenger Financial		6,170,000		2,800,000
> South Africa
Coronation Fund Managers		13,683,594		12,895,812
Naspers		142,892		0
Northam Platinum		8,665,223		2,476,175
Rand Merchant Insurance		16,575,943		14,139,634
> United States
Hornbeck Offshore		634,500		0
Textainer Group Holdings		440,152		0
> New Zealand
Ryman Healthcare		4,011,000		2,759,000
Sky City Entertainment		8,000,000		5,435,000
> Israel
Caesarstone		791,000		0

	Number of Shares
	6/30/15		9/30/15
Latin America
> Mexico
Qualitas		13,215,000		12,647,809
> Brazil
Linx		1,400,000		0
> Chile
Sociedad Quimica y Minera de Chile - ADR		921,000		0

COLUMBIA ACORN INTERNATIONAL®

STATEMENT OF INVESTMENTS (UNAUDITED), SEPTEMBER 30, 2015

Number of Shares			Value
			Equities: 94.1%
Asia 43.9%
		> Japan 22.2%
	1,447,000	FamilyMart	$	65,972,817
		Convenience Store Operator
	2,700,000	NGK Insulators		51,665,596
		Ceramic Products for Auto, Power & Electronics
	3,000,000	Aeon Mall		46,083,997
		Suburban Shopping Mall Developer, Owner & Operator
	930,000	JIN		43,672,574
		Eyeglasses Retailer
	1,840,000	Glory		43,488,443
		Currency Handling Systems & Related Equipment
	3,600,000	Ushio		43,248,354
		Industrial Light Sources
	15,000,000	IHI		38,544,541
		Industrial Conglomerates
	28,000	Orix JREIT		37,879,826
		Diversified REIT
	2,792,000	Santen Pharmaceutical		37,484,296
		Specialty Pharma (Ophthalmic Medicine)
	1,225,000	Recruit Holdings		36,730,775
		Recruitment & Media Services
	10,440,000	Aozora Bank		36,209,177
		Commercial Bank
	1,870,000	Suruga Bank		34,795,902
		Regional Bank
	1,440,000	NGK Spark Plug		33,056,388
		Automobile Parts
	833,800	Ariake Japan		32,679,286
		Commercial Soup & Sauce Extracts
	655,500	Ezaki Glico		30,293,809
		Confectionary, Ice Cream & Dairy Products
	276,620	Hirose Electric		30,113,922
		Electrical Connectors
	832,000	Asahi Intecc		29,987,516
		Medical Guidewires for Surgery
	4,319,000	NOF		29,625,226
		Specialty Chemicals, Life Science & Rocket Fuels
	6,149	Kenedix Office Investment		29,227,495
		Tokyo Mid-size Office REIT
	621,000	OBIC		28,407,197
		Computer Software
	2,736,000	Moshi Moshi Hotline		28,268,044
		Call Center Operator
	7,590,000	Ebara		28,038,693
		Pumps, Compressors, Turbines & Related Products & Services
	1,463,000	Park24		27,457,264
		Parking Lot Operator
	390,000	Hoshizaki Electric		27,337,640
		Commercial Kitchen Equipment
	1,548,800	Kintetsu World Express		27,315,795
		Airfreight Logistics

Number of Shares			Value
	1,447,000	Doshisha	$	26,552,405
		Consumer Goods Wholesaler
	1,402,000	Tamron (a)		25,611,056
		Camera Lenses
	1,550,000	Sony Financial Holdings		25,440,046
		Life Insurance, Assurance & Internet Banking
	1,838,600	Kansai Paint		25,005,737
		Paint Producer in Japan, India, China & Southeast Asia
	1,260,000	Aeon Financial Service		24,930,378
		Diversified Consumer-related Finance Company in Japan
	1,237,000	Aica Kogyo		24,748,705
		Laminated Sheets, Building Materials & Chemical Adhesives
	1,058,000	Bandai Namco		24,554,824
		Branded Toys & Related Content
	775,000	Toto		24,151,830
		Toilets & Bathroom Fittings
	309,000	Rinnai		23,575,446
		Gas Appliances for Home & Commercial Use
	12,050	Japan Retail Fund		23,315,060
		Retail REIT in Japan
	1,230,000	OSG		23,288,191
		Consumable Cutting Tools
	1,107,000	Stanley Electric		22,086,423
		Automobile Lighting & LED Equipment
	313,200	Hikari Tsushin		21,921,648
		Office IT/Mobiles/Insurance Distribution
	1,750,000	Yamaguchi Financial Group, Inc.		21,451,463
		Regional Bank in Yamaguchi, Fukuoka & Hiroshima
	430,900	Otsuka		20,995,020
		One-stop IT Services & Office Supplies Provider
	291,400	Disco		20,494,676
		Semiconductor Dicing & Grinding Equipment
	300,400	Nippon Shokubai		20,428,423
		Producer of Acrylic Acid & Super Absorbent Polymers Used in Disposable Diapers
	2,083,000	Sega Sammy Holdings, Inc.		20,327,412
		Gaming Software/Hardware & Leisure Facilities
	1,910,000	Nippon Kayaku		19,886,223
		Functional Chemicals, Pharmaceuticals & Auto Safety Systems
	2,600,000	Dowa Holdings		19,702,401
		Environmental/Recycling, Nonferrous Metals, Electric Material & Metal Processing
	450,000	Japan Airport Terminal (b)		19,449,276
		Airport Terminal Operator at Haneda
	578,680	Milbon		19,179,973
		Hair Products for Salons
	822,700	Hamamatsu Photonics		18,618,680
		Optical Sensors for Medical & Industrial Applications

COLUMBIA ACORN INTERNATIONAL®

STATEMENT OF INVESTMENTS (UNAUDITED), CONTINUED

Number of Shares			Value
		> Japan—continued
	942,150	Capcom Co., Ltd.	$	18,577,800
		Packaged, Online & Mobile Games
	4,170	Industrial & Infrastructure Fund		18,146,375
		Industrial REIT in Japan
	184,900	Kaken Pharmaceutical		17,161,970
		Pharmaceutical & Agrochemical Producer
	961,000	Daiseki		16,399,574
		Waste Disposal & Recycling
	414,600	Nakanishi		15,423,723
		Dental Tools & Machinery
	614,200	Icom		12,761,452
		Two Way Radio Communication Equipment
	536,000	MonotaRO		12,279,066
		Online Maintenance, Repair & Operations Goods Distributor in Japan
	624,000	Misumi Group		6,439,644
		Industrial Components Distributor
	497,592	Nihon Parkerizing		4,068,576
		Metal Surface Treatment Chemicals & Processing Service
				1,534,558,049
		> China 3.9%
	30,700,000	CAR Inc (b)(c)		44,437,967
		Consolidator of Chinese Auto Rental Sector
	25,845,000	China Everbright International		36,307,582
		Municipal Waste Operator
	90,360,000	Sihuan Pharmaceutical Holdings Group (d)		34,013,605
		Chinese Generic Drug Manufacturer
	21,755,000	TravelSky Technology		27,514,988
		Chinese Air Travel Transaction Processor
	13,424,000	Phoenix Healthcare Group		21,912,356
		Private Hospital Management Group
	502,000	WuXi PharmaTech - ADR (c)		21,691,420
		Contract Research Organization in China
	101,000,000	Jiangnan Group		20,818,090
		Cable & Wire Manufacturer
	46,942,000	AMVIG Holdings (a)		19,554,463
		Chinese Tobacco Packaging Material Supplier
	48,234,000	NewOcean Energy		18,224,381
		Southern China Liquefied Petroleum Gas Distributor
	560,388	BitAuto - ADR (b)(c)		16,682,751
		Automotive Information Website for Buyers & Dealers
	375,000	51job - ADR (b)(c)		10,275,000
		Integrated Human Resource Services
				271,432,603
		> Korea 3.7%
	478,317	KT&G		44,994,808
		Tobacco & Ginseng Products
	113,183	KCC		39,541,998
		Paint & Housing Material Manufacturer

Number of Shares			Value
	141,971	CJ Corp	$	31,701,721
		Holding Company of Korean Consumer Conglomerate
	3,149,876	CJ Hellovision		29,860,667
		Cable TV, Broadband & Mobile Virtual Network Operator
	88,583	Nongshim		27,417,085
		Instant Noodles, Snacks & Bottled Water
	788,428	LF Corp		21,806,590
		Apparel Design & Retail
	397,002	Korea Investment Holdings		20,533,346
		Brokerage & Asset Management
	1,300,093	Cheil Worldwide (c)		20,087,392
		Advertising
	412,977	LS Industrial Systems		15,870,630
		Electrical & Automation Equipment
	197,100	Koh Young Technology		5,716,605
		Inspection Systems for Printed Circuit Boards
				257,530,842
		> Taiwan 3.5%
	23,150,000	Far EasTone Telecom		49,927,326
		Mobile Operator in Taiwan
	5,557,000	Delta Electronics		26,211,032
		Industrial Automation, Switching Power Supplies & Passive Components
	19,984,000	Vanguard International Semiconductor		22,760,296
		Semiconductor Foundry
	3,192,686	Advantech		21,924,659
		Industrial PC & Components
	1,780,000	St. Shine Optical		21,839,389
		Disposable Contact Lens Original Equipment Manufacturer
	2,234,000	Silergy		21,830,505
		Chinese Provider of Analog & Mixed Digital Integrated Circuits
	3,400,000	President Chain Store		21,204,718
		Convenience Chain Store Operator in Taiwan
	253,000	Largan Precision		19,745,372
		Mobile Device Camera Lenses & Modules
	5,704,000	Novatek Microelectronics		17,908,229
		Display Related Integrated Circuit Designer
	1,173,686	Voltronic Power		15,273,330
		Uninterruptible Power Supply Products
	369,000	Ginko International		3,715,871
		Contact Lens Maker in China
				242,340,727
		> India 3.4%
	13,478,000	Zee Entertainment Enterprises		80,955,057
		Indian Programmer of Pay Television Content
	1,505,000	Container Corporation of India		34,071,142
		Railway Cargo Services
	6,229,667	Bharti Infratel		33,755,358
		Communications Towers

Number of Shares			Value
		> India—continued
	6,095,000	Adani Ports & Special Economic Zone	$	27,843,514
		Indian West Coast Shipping Port
	1,840,000	Colgate Palmolive India		26,985,935
		Consumer Products in Oral Care
	1,850,000	United Breweries		24,911,941
		Indian Brewer
	519,553	Amara Raja		8,183,126
		Indian Maker of Auto & Industrial Batteries, Mostly for the Replacement Market
				236,706,073
		> Hong Kong 2.1%
	63,364,000	Mapletree Greater China Commercial Trust		41,479,787
		Retail & Office Property Landlord
	12,000,000	Samsonite International		39,214,531
		Mass Market Luggage & Travel Accessories
	29,042,000	Value Partners		27,322,193
		Mutual Fund Management
	14,595,000	Vitasoy International		21,581,628
		Hong Kong Soy Food Brand
	13,016,000	Melco International		16,001,247
		Macau Casino Operator
	2,655,500	Lifestyle International		3,804,769
		Mid- to High-end Department Store Operator in Hong Kong & China
				149,404,155
		> Singapore 2.0%
	11,000,000	Singapore Exchange		54,416,162
		Singapore Equity & Derivatives Market Operator
	41,009,700	Mapletree Commercial Trust		36,185,740
		Retail & Office Property Landlord
	33,724,000	SIIC Environment (c)		19,927,624
		Waste Water Treatment Operator
	8,200,000	Petra Foods		14,475,695
		Chocolate Manufacturer in Southeast Asia
	31,700,000	China Everbright Water (c)		13,513,661
		Waste Water Treatment Operator
				138,518,882
		> Indonesia 0.8%
	19,540,600	Matahari Department Store		21,582,816
		Department Store Chain in Indonesia
	45,000,000	Link Net (c)		13,824,771
		Fixed Broadband & Cable TV Service Provider
	18,442,800	Tower Bersama Infrastructure (c)		8,247,421
		Communications Towers
	54,631,700	MNC Sky Vision (c)		5,542,730
		Satellite Pay TV Operator in Indonesia
	150,349,000	Arwana Citramulia		4,586,038
		Ceramic Tiles for Home Decoration
	59,667,800	Ace Indonesia		2,059,974
		Home Improvement Retailer
				55,843,750

Number of Shares			Value
		> Thailand 0.8%
	4,360,000	Airports of Thailand	$	33,841,512
		Airport Operator of Thailand
	100,000,000	Home Product Center		18,900,692
		Home Improvement Retailer
	1,621,900	Robinson Department Store		1,703,573
		Department Store Operator in Thailand
				54,445,777
		> Philippines 0.7%
	33,345,000	Puregold Price Club		22,115,854
		Supermarket Operator in the Philippines
	12,200,000	Robinsons Retail Holdings		19,083,048
		Multi-format Retailer in the Philippines
	90,000,000	Melco Crown (Philippines) Resorts (c)		7,194,951
		Integrated Resort Operator in Manila
				48,393,853
		> Cambodia 0.4%
	47,028,000	Nagacorp		28,280,030
		Casino & Entertainment Complex in Cambodia
		> Malaysia 0.4%
	37,835,900	7-Eleven Malaysia Holdings		12,735,689
		Exclusive 7-Eleven Franchisor for Malaysia
	19,000,000	Astro Malaysia Holdings		12,181,292
		Pay TV Operator in Malaysia
				24,916,981
Asia: Total				3,042,371,722
Europe 36.5%
		> United Kingdom 11.3%
	2,638,000	WH Smith		62,413,501
		Newsprint, Books & General Stationery Retailer
	12,365,000	Regus		57,349,981
		Rental of Office Space in Full Service Business Centers
	1,004,000	Rightmove		55,405,840
		Internet Real Estate Listings
	1,253,571	Spirax Sarco		53,116,451
		Steam Systems for Manufacturing & Process Industries
	3,000,000	Smith & Nephew		52,326,004
		Medical Equipment & Supplies
	4,399,000	Halma		48,012,830
		Health & Safety Sensor Technology
	6,222,700	Halfords		43,471,017
		UK Retailer of Leisure Goods & Auto Parts
	3,050,000	Domino's Pizza UK & Ireland		40,971,306
		Pizza Delivery in the UK, Ireland & Germany
	45,000,000	Cable and Wireless		37,712,844
		Telecommunications Service Provider in the Caribbean

COLUMBIA ACORN INTERNATIONAL®

STATEMENT OF INVESTMENTS (UNAUDITED), CONTINUED

Number of Shares			Value
		> United Kingdom—continued
	7,430,000	Polypipe	$	37,063,005
		Manufacturer of Plastic Piping & Fittings
	4,033,732	Abcam		35,452,770
		Online Sales of Antibodies
	14,379,428	Connect Group (a)		34,151,381
		Newspaper & Magazine Distributor
	39,805,000	Assura		32,967,708
	7,961,000	Assura Rights (c)(d)		572,042
		UK Primary Health Care Property Developer
	1,944,000	Jardine Lloyd Thompson Group		29,966,599
		International Business Insurance Broker
	2,100,000	Shaftesbury		29,131,016
		London Prime Retail REIT
	958,646	Fidessa Group		26,016,430
		Software for Financial Trading Systems
	4,712,000	Ocado (c)		22,809,841
		Online Grocery Retailer
	173,000	Next		19,915,800
		Clothes & Home Retailer in the UK
	3,075,000	PureCircle (c)		19,769,744
		Natural Sweeteners
	1,398,000	Babcock International		19,297,767
		Public Sector Outsourcer
	5,650,001	Elementis		19,076,984
		Specialty Chemicals
	1,178,371	DS Smith		7,021,583
		Packaging
				783,992,444
		> Sweden 4.4%
	948,422	Unibet		79,318,921
		European Online Gaming Operator
	2,055,208	Hexagon		62,687,902
		Design, Measurement & Visualization Software & Equipment
	2,925,024	Sweco (b)		40,538,209
		Engineering Consultants
	1,286,000	Modern Times Group (b)		33,049,015
		Nordic TV Broadcaster
	967,247	Swedish Match		29,202,482
		Swedish Snus
	916,000	Mekonomen		21,231,190
		Nordic Integrated Wholesaler/Retailer of Automotive Parts & Service
	1,317,000	Trelleborg		20,832,956
		Manufacturer of Sealing, Dampening & Protective Solutions for Industry
	849,000	Recipharm		15,519,447
		Contract Development Manufacturing Organization
				302,380,122

Number of Shares			Value
		> Germany 4.2%
	1,750,000	Wirecard (b)	$	83,507,461
		Online Payment Processing & Risk Management
	691,000	MTU Aero Engines		57,747,088
		Airplane Engine Components & Services
	1,067,000	NORMA Group		52,370,256
		Clamps for Automotive & Industrial Applications
	117,000	Rational		46,731,494
		Commercial Ovens
	795,000	Aurelius		36,923,548
		European Turnaround Investor
	885,000	Elringklinger		17,009,057
		Automobile Components
				294,288,904
		> Denmark 3.3%
	1,932,063	SimCorp		97,220,180
		Software for Investment Managers
	1,647,800	Novozymes		71,786,715
		Industrial Enzymes
	700,000	William Demant Holding (c)		58,181,763
		Manufacture & Distribution of Hearing Aids & Diagnostic Equipment
				227,188,658
		> Netherlands 3.1%
	2,103,770	Aalberts Industries		62,200,891
		Flow Control & Heat Treatment
	650,000	Gemalto (b)		42,133,227
		Digital Security Solutions
	1,573,025	Arcadis		36,920,436
		Engineering Consultants
	718,124	Vopak		28,634,767
		Operator of Petroleum & Chemical Storage Terminals
	255,510	Core Labs (b)		25,499,898
		Oil & Gas Reservoir Consulting
	1,201,000	Brunel		20,337,963
		Temporary Specialist & Energy Staffing
				215,727,182
		> Switzerland 2.6%
	213,500	Partners Group		72,345,962
		Private Markets Asset Management
	228,300	Geberit		69,736,210
		Plumbing Systems
	190,000	Panalpina Welttransport Holding		20,762,364
		Air & Sea Freight Forwarding
	72,500	INFICON		20,233,942
		Gas Detection Instruments
				183,078,478
		> Spain 2.4%
	13,425,000	Distribuidora Internacional de Alimentación		81,050,886
		Discount Retailer in Spain & Latin America

Number of Shares			Value
		> Spain—continued
	8,555,000	Prosegur	$	41,105,220
		Security Guards
	379,000	Viscofan		22,817,881
		Sausage Casings Maker
	535,000	Bolsas y Mercados Españoles		18,059,803
		Spanish Stock Markets
				163,033,790
		> France 2.0%
	1,445,000	Eutelsat		44,241,202
		Fixed Satellite Services
	1,660,000	Neopost (b)		43,181,683
		Postage Meter Machines
	90,000	Eurofins Scientific		27,625,470
		Food, Pharmaceuticals & Materials Screening & Testing
	745,310	Saft		24,351,338
		Niche Battery Manufacturer
				139,399,693
		> Finland 1.3%
	1,387,000	Konecranes (b)		34,654,271
		Manufacture & Service of Industrial Cranes & Port Handling Equipment
	7,766,000	Sponda		30,302,616
		Office, Retail & Logistics Properties
	1,669,000	Tikkurila		27,694,358
		Decorative & Industrial Paint in Scandinavia, Central & Eastern Europe
				92,651,245
		> Norway 0.8%
	3,050,864	Atea		28,042,347
		Nordic IT Hardware/Software Reseller & Integrator
	3,529,000	Orkla		26,157,015
		Food & Brands, Aluminum, Chemicals Conglomerate
				54,199,362
		> Italy 0.6%
	459,000	Industria Macchine Automatiche		20,515,457
		Food & Drugs Packaging & Machinery
	7,800,200	Hera		20,238,413
		Northern Italian Utility
				40,753,870
		> Kazakhstan 0.4%
	4,356,790	Halyk Savings Bank of Kazakhstan - GDR		25,748,629
		Retail Bank & Insurer in Kazakhstan
		> Belgium 0.1%
	258,681	EVS Broadcast Equipment		6,682,837
		Digital Live Mobile Production Software & Systems
Europe: Total				2,529,125,214

Number of Shares			Value
Other Countries 11.6%
		> Canada 4.1%
	633,741	CCL Industries	$	88,961,185
		Global Label Converter
	3,188,000	CAE		33,779,183
		Flight Simulator Equipment & Training Centers
	898,000	Vermilion Energy (b)		28,914,994
		Canadian Exploration & Production Company
	490,200	Onex Capital		28,295,321
		Private Equity
	1,067,730	ShawCor		22,386,726
		Oil & Gas Pipeline Products
	2,115,898	Rona		21,579,147
		Canadian Home Improvement Retailer
	726,000	Keyera		19,992,881
		Integrated Supply of Hydrocarbon Processing, Transport & Storage
	1,010,000	PrairieSky Royalty (b)		19,193,406
		Canadian Owner of Oil & Gas Mineral Interests
	545,909	Ag Growth (b)		14,673,478
		Manufacturer of Augers & Grain Handling Equipment
	1,301,152	Boulder Energy (c)		4,845,804
		Canadian Exploration & Production
				282,622,125
		> Australia 3.6%
	58,000,000	Spotless (a)		87,887,279
		Facility Management & Catering Company
	2,200,000	Domino's Pizza Enterprises		62,574,580
		Domino's Pizza Operator in Australia & New Zealand
	3,692,000	Amcor		34,335,068
		Global Leader in Flexible & Rigid Packaging
	7,680,000	IAG		26,258,885
		General Insurance Provider
	4,900,000	Estia Health		23,426,282
		Residential Aged Care Operator
	2,800,000	Challenger Financial		14,130,566
		Annuity Provider in Australia
				248,612,660
		> South Africa 1.5%
	12,895,812	Coronation Fund Managers		60,754,596
		South African Fund Manager
	14,139,634	Rand Merchant Insurance		42,260,248
		Directly Sold Property & Casualty Insurance; Holdings in other Insurers
	2,476,175	Northam Platinum (c)		4,811,732
		Platinum Mining in South Africa
				107,826,576
		> United States 0.9%
	350,000	Cimarex Energy		35,868,000
		Oil & Gas Producer in Texas, New Mexico & Oklahoma

COLUMBIA ACORN INTERNATIONAL®

STATEMENT OF INVESTMENTS (UNAUDITED), CONTINUED

Number of Shares			Value
		> United States—continued
	1,092,000	Bladex	$	25,279,800
		Latin American Trade Financing House
				61,147,800
		> New Zealand 0.9%
	10,800,000	Auckland International Airport		33,809,341
		Auckland Airport Operator
	5,435,000	Sky City Entertainment		13,018,433
		Casino & Entertainment Complex
	2,759,000	Ryman Healthcare		12,923,155
		Retirement Village Operator
				59,750,929
		> Egypt 0.6%
	5,963,570	Commercial International Bank of Egypt		40,516,545
		Private Universal Bank in Egypt
Other Countries: Total				800,476,635
Latin America 2.1%
		> Mexico 0.9%
	300,000	Grupo Aeroportuario del Sureste - ADR		45,681,000
		Mexican Airport Operator
	12,647,809	Qualitas (c)		17,387,567
		Auto Insurer in Mexico & Central America
				63,068,567
		> Brazil 0.6%
	3,500,000	Localiza Rent a Car		21,558,835
		Car Rental
	7,885,300	Odontoprev		19,472,086
		Dental Insurance
				41,030,921
		> Colombia 0.3%
	23,377,000	Isagen		21,803,760
		Colombian Electricity Provider
		> Guatemala 0.2%
	1,626,600	Tahoe Resources		12,566,689
		Silver & Gold Projects in Guatemala & Peru

Number of Shares			Value
		> Uruguay 0.1%
	1,306,818	Union Agriculture Group (c)(d)(e)	$	8,598,862
		Farmland Operator in Uruguay
Latin America: Total				147,068,799
Total Equities: 94.1% (Cost: $5,799,123,091)				6,519,042,370	(f)
Short-Term Investments 5.4%
	220,000,000	JPMorgan U.S. Government Money Market Fund, IM Shares (7 day yield of 0.01%)		220,000,000
	154,315,334	JPMorgan U.S. Government Money Market Fund, Agency Shares (7 day yield of 0.01%)		154,315,334
Total Short-Term Investments: 5.4% (Cost: $374,315,334)				374,315,334
Securities Lending Collateral 2.4%
	162,686,410	Dreyfus Government Cash Management Fund, Institutional Shares (7 day yield of 0.01%) (g)		162,686,410
Total Securities Lending Collateral: 2.4% (Cost: $162,686,410)				162,686,410
Total Investments: 101.9% (Cost: $6,336,124,835)(h)				7,056,044,114	(i)
Obligation to Return Collateral for Securities Loaned: (2.4)%				(162,686,410	)
Cash and Other Assets Less Liabilities: 0.5%				28,484,127
Net Assets: 100.0%			$	6,921,841,831

ADR - American Depositary Receipts

GDR - Global Depositary Receipts

REIT - Real Estate Investment Trust

> Notes to Statement of Investments

(a) An affiliated person of the Fund, as defined in the Investment Company Act of 1940, may include any company in which the Fund owns five percent or more of its outstanding voting shares. Holdings and transactions in these affiliated companies during the period ended September 30, 2015, are as follows:

Security	Balance of Shares Held 12/31/14		Purchases/ Additions		Sales/ Reductions		Balance of Shares Held 9/30/15		Value		Dividend
Spotless		42,700,000		15,300,000		-		58,000,000	$	87,887,279	$	3,711,991
Connect Group		14,379,428		-		-		14,379,428		34,151,381		2,165,535
Tamron		1,402,000		-		-		1,402,000		25,611,056		283,129
AMVIG Holdings		35,119,000		12,381,000		558,000		46,942,000		19,554,463		2,457,546
Icom (1)		835,000		-		220,800		614,200		12,761,452		233,389
Total of Affiliated Transactions		94,435,428		27,681,000		778,800		121,337,628	$	179,965,631	$	8,851,590

(1) At September 30, 2015, the Fund owned less than five percent of the company's outstanding voting shares.

The aggregate cost and value of these companies at September 30, 2015, was $185,078,946 and $167,204,179, respectively. Investments in affiliated companies represented 2.42% of the Fund's total net assets at September 30, 2015.

(b) All or a portion of this security was on loan at September 30, 2015. The total market value of securities on loan at September 30, 2015 was $155,982,904.

(d) Illiquid security.

(e) Denotes a restricted security, which is subject to restrictions on resale under federal securities laws. This security is valued at fair value determined in good faith under consistently applied procedures established by the Fund's Board of Trustees. At September 30, 2015, the market value of this security amounted to $8,598,862, which represented 0.12% of total net assets. Additional information on this security is as follows:

Security				Acquisition Dates				Shares				Cost				Value
Union Agriculture Group				12/8/10-6/27/12					1,306,818			$	15,000,000			$	8,598,862

(f) On September 30, 2015, the Fund's total equity investments were denominated in currencies as follows:

Currency	Value		Percentage of Net Assets
Japanese Yen	$	1,534,558,049		22.1
Euro		927,037,622		13.4
British Pound		783,992,444		11.3
Hong Kong Dollar		358,987,830		5.2
Other currencies less than 5% of total net assets		2,914,466,425		42.1
Total Equities	$	6,519,042,370		94.1

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

(h) At September 30, 2015, for federal income tax purposes, the cost of investments was approximately $6,336,124,835 and net unrealized appreciation was $719,919,279 consisting of gross unrealized appreciation of $1,315,851,645 and gross unrealized depreciation of $595,932,366.

(i) Securities are valued using policies described in the Notes to Financial Statements in the shareholder report dated June 30, 2015.

Fair Value Measurements

• 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.

COLUMBIA ACORN INTERNATIONAL®

STATEMENT OF INVESTMENTS (UNAUDITED), CONTINUED

> Notes to Statement of Investments

The Committee is responsible for applying the Trust's Portfolio Pricing Policy and the CWAM pricing procedures (the Policies), which are approved by and subject to the oversight of the Board.

The following table summarizes the inputs used, as of September 30, 2015, 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	$	48,649,171	$	2,959,708,946	$	34,013,605	$	3,042,371,722
Europe		25,499,898		2,503,625,316		-		2,529,125,214
Other Countries		343,769,925		456,706,710		-		800,476,635
Latin America		138,469,937		-		8,598,862		147,068,799
Total Equities		556,388,931		5,920,040,972		42,612,467		6,519,042,370
Total Short-Term Investments		374,315,334		-		-		374,315,334
Total Securities Lending Collateral		162,686,410		-		-		162,686,410
Total Investments	$	1,093,390,675	$	5,920,040,972	$	42,612,467	$	7,056,044,114

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

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

The Fund does not hold any significant investments (greater than one percent of net assets) categorized as Level 3.

Financial assets were transferred from Level 2 to Level 3 as trading halted during the period. As a result, as of period end, the Committee determined to value the security(s) under consistently applied procedures established by and under the general supervision of the Board.

The following table shows transfers between Level 2 and Level 3 of the fair value hierarchy:

Transfers In				Transfers Out
Level 2		Level 3		Level 2		Level 3
$	-	$	55,274,689	$	55,274,689	$	-

Transfers in and/or out of Level 3 are determined based on the fair value at the beginning of the period for security positions held throughout the period.

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

COLUMBIA ACORN INTERNATIONAL®

PORTFOLIO DIVERSIFICATION (UNAUDITED)

At September 30, 2015, the Fund's portfolio investments as a percentage of net assets were diversified as follows:

	Value		Percentage of Net Assets
> Industrial Goods & Services
Machinery	$	446,174,540		6.4
Industrial Materials & Specialty Chemicals		378,180,527		5.4
Other Industrial Services		346,980,371		5.0
Outsourcing Services		225,978,209		3.3
Electrical Components		186,067,929		2.7
Conglomerates		156,983,174		2.3
Construction		106,799,214		1.5
Waste Management		36,307,582		0.5
Water		33,441,285		0.5
Industrial Distribution		12,279,066		0.2
		1,929,191,897		27.8
> Consumer Goods & Services
Retail		501,503,138		7.2
Food & Beverage		223,149,553		3.2
Casinos & Gaming		164,140,992		2.4
Nondurables		153,135,966		2.2
Consumer Goods Distribution		109,611,368		1.6
Restaurants		103,545,886		1.5
Other Durable Goods		86,901,384		1.2
Travel		65,996,802		1.0
Leisure Products		63,769,356		0.9
Consumer Electronics		25,611,056		0.4
Apparel		21,806,590		0.3
Other Consumer Services		3,804,769		0.1
		1,522,976,860		22.0
> Information
Business Software		241,846,697		3.5
Financial Processors		137,923,624		2.0
Computer Hardware & Related Equipment		112,225,086		1.6
Mobile Communications		104,691,556		1.5
Semiconductors & Related Equipment		82,993,706		1.2
Internet Related		82,363,591		1.2
Entertainment Programming		80,955,057		1.2
Instrumentation		72,348,115		1.1
Satellite Broadcasting & Services		61,965,224		0.9
Advertising		56,818,167		0.8
Computer Services		49,037,367		0.7
Cable TV		43,685,438		0.6
Telephone & Data Services		37,712,844		0.5
TV Broadcasting		33,049,015		0.5
Business Information & Marketing Services		28,268,044		0.4
Telecommunications Equipment		19,745,372		0.3
Consumer Software		18,577,800		0.3
		1,264,206,703		18.3

	Value			Percentage of Net Assets
> Finance
Banks	$	208,931,894			3.0
Insurance		174,915,997			2.5
Brokerage & Money Management		160,422,751			2.3
Finance Companies		28,295,321			0.4
Diversified Financial Companies		20,533,346			0.3
Financial Processors		18,059,803			0.3
		611,159,112			8.8
> Other Industries
Real Estate		325,291,663			4.7
Transportation		166,852,270			2.4
Regulated Utilities		42,042,174			0.6
Industrial Distribution		7,021,583			0.1
		541,207,690			7.8
> Health Care
Medical Equipment & Devices		155,919,007			2.3
Pharmaceuticals		125,870,738			1.8
Medical Supplies		61,008,030			0.9
Health Care Services		36,349,437			0.5
Hospital Management		21,912,356			0.3
		401,059,568			5.8
> Energy & Minerals
Oil & Gas Producers		88,822,204			1.3
Oil Refining, Marketing & Distribution		66,852,028			1.0
Mining		42,878,319			0.6
Oil Services		22,386,726			0.3
Non-Ferrous Metals		19,702,401			0.3
Agricultural Commodities		8,598,862			0.1
		249,240,540			3.6
Total Equities:		6,519,042,370			94.1
Short-Term Investments:		374,315,334			5.4
Securities Lending Collateral:		162,686,410			2.4
Total Investments:		7,056,044,114			101.9
Obligation to Return Collateral for Securities Loaned:		(162,686,410	)		(2.4	)
Cash and Other Assets Less Liabilities:		28,484,127			0.5
Net Assets:	$	6,921,841,831			100.0

COLUMBIA ACORN USA®

MAJOR PORTFOLIO CHANGES IN THE THIRD QUARTER (UNAUDITED)

	Number of Shares
	6/30/15		9/30/15
Purchases
Information
CalAmp		0		147,000
CoreLogic		0		187,951
Cvent		30,092		260,473
Globalstar		0		1,939,407
Littelfuse		0		51,365
Lumos Networks		304,372		548,849
Industrial Goods & Services
Donaldson		948,000		962,092
HEICO		725,500		736,284
Consumer Goods & Services
Arctic Cat		111,261		263,238
Blue Nile		87,000		214,366
Cato		0		138,361
Coupons.com		0		507,432
Fiesta Restaurant Group		130,773		243,683
Fossil		33,310		82,518
HRG Group		0		259,637
Mattress Firm		0		44,654
Vail Resorts		28,314		81,734
Finance
Associated Banc-Corp		881,038		894,134
Health Care
Celldex Therapeutics		260,148		342,159
VWR		229,638		329,051

	Number of Shares
	6/30/15		9/30/15
Sales
Information
Belden		73,282		0
Global Payments		77,000		56,832
IPG Photonics		383,000		261,583
Liquidity Services		294,000		0
Mettler-Toledo International		117,400		80,145
NetSuite		111,053		99,510
Solera Holdings		196,527		0
Industrial Goods & Services
Ametek		793,000		730,787
Graham		76,612		0
Kennametal		143,520		0
Lumber Liquidators		96,000		0
Moog		238,000		202,973
Consumer Goods & Services
Avis Budget Group		425,950		313,542
Caesarstone (Israel)		150,828		0
Pool		249,822		205,535
United Natural Foods		101,595		0
Zulily		252,955		0
Finance
CAI International		490,177		12,405
First Commonwealth		311,445		0
Hancock Holding		268,466		198,804
Marlin Business Services		334,361		0
McGrath Rentcorp		214,681		120,681
World Acceptance		108,257		61,834
Heath Care
Allscripts Healthcare Solutions		506,139		0
HealthSouth		144,897		91,233
Sarepta Therapeutics		429,694		241,227
Seattle Genetics		183,203		149,391
Ultragenyx Pharmaceutical		193,081		119,836
Other Industries
Extra Space Storage		587,914		539,820
Rush Enterprises, Class A		468,091		426,335
Energy & Minerals
Clayton Williams		66,620		41,603
Gulfport Energy		93,267		0
Hornbeck Offshore		133,239		0

COLUMBIA ACORN USA®

STATEMENT OF INVESTMENTS (UNAUDITED), SEPTEMBER 30, 2015

Number of Shares			Value
			Equities: 93.3%
Information 24.2%
		> Business Software 7.5%
	233,418	Ansys (a)	$	20,573,463
		Simulation Software for Engineers & Designers
	249,334	SPS Commerce (a)		16,927,285
		Supply Chain Management Software Delivered via the Web
	489,644	Textura (a)(b)		12,652,401
		Construction Vendor Management Software
	200,293	DemandWare (a)		10,351,142
		E-Commerce Website Platform for Retailers & Apparel Manufacturers
	260,473	Cvent (a)		8,767,521
		Software for Corporate Event Planners & Marketing Platform for Hotels
	99,510	NetSuite (a)		8,348,889
		Enterprise Software Delivered via the Web
	816,767	Amber Road (a)(b)		3,446,761
		Global Trade Management Software Delivered via the Web
	316,000	inContact (a)		2,373,160
		Call Center Systems Delivered via the Web & Telco Services
				83,440,622
		> Computer Services 4.3%
	562,849	ExlService Holdings (a)		20,786,014
		Business Process Outsourcing
	234,943	Virtusa (a)		12,054,925
		Offshore IT Outsourcing
	295,791	WNS - ADR (a)		8,267,358
		Offshore Business Process Outsourcing Services
	432,000	Hackett Group		5,940,000
		IT Integration & Best Practice Research
	219,420	RCM Technologies		1,081,741
		Technology & Engineering Services
				48,130,038
		> Instrumentation 3.8%
	80,145	Mettler-Toledo International (a)		22,820,487
		Laboratory Equipment
	261,583	IPG Photonics (a)		19,872,461
		Fiber Lasers
				42,692,948
		> Semiconductors & Related Equipment 1.5%
	140,289	Monolithic Power Systems		7,182,797
		High Performance Analog & Mixed Signal Integrated Circuits
	51,365	Littelfuse		4,681,920
		Little Fuses
	253,535	Atmel		2,046,027
		Microcontrollers, Radio Frequency & Memory Semiconductors
	96,813	Knowles (a)(b)		1,784,264
		Microphones & Speakers for Mobile Devices & other Electronics

Number of Shares			Value
	499,644	Rubicon Technology (a)(b)	$	514,633
		Producer of Sapphire for the Lighting, Electronics & Automotive Industries
				16,209,641
		> Financial Processors 1.2%
	187,951	CoreLogic (a)		6,997,416
		Data Processing Services for Real Estate, Insurance, & Mortgages
	56,832	Global Payments		6,520,335
		Credit Card Processor
				13,517,751
		> Business Information & Marketing Services 1.2%
	730,182	Bankrate (a)		7,557,384
		Internet Advertising for the Insurance, Credit Card & Banking Markets
	372,190	Navigant Consulting (a)		5,921,543
		Financial Consulting Firm
				13,478,927
		> Telephone & Data Services 1.1%
	548,849	Lumos Networks		6,674,004
		Telephone & Fiber Optic Data Services
	630,231	Boingo Wireless (a)		5,218,313
		Wi-Fi & Cellular Communications Networks
				11,892,317
		> Telecommunications Equipment 1.0%
	451,293	Infinera (a)		8,827,291
		Optical Networking Equipment
	147,000	CalAmp (a)		2,365,230
		Machine-to-machine Communications
				11,192,521
		> Mobile Communications 0.8%
	407,454	Gogo (a)(b)		6,225,897
		Provider of Wi-Fi on Airplanes
	1,939,407	Globalstar (a)		3,044,869
		Satellite Mobile Voice & Data Carrier
				9,270,766
		> Contract Manufacturing 0.7%
	356,018	Sanmina (a)		7,608,105
		Electronic Manufacturing Services
		> Internet Related 0.6%
	838,357	Vonage (a)		4,929,539
		Business & Consumer Internet Telephony
	253,276	RetailMeNot (a)		2,086,994
		Digital Coupon Marketplace
				7,016,533
		> Computer Hardware & Related Equipment 0.5%
	114,936	Rogers (a)		6,112,296
		Printed Circuit Materials & High Performance Foams
Information: Total				270,562,465
Industrial Goods & Services 21.2%
		> Machinery 18.1%
	730,787	Ametek		38,234,776
		Aerospace/Industrial Instruments

COLUMBIA ACORN USA^SM

STATEMENT OF INVESTMENTS (UNAUDITED), CONTINUED

Number of Shares			Value
		> Machinery—continued
	736,284	HEICO	$	33,434,656
		FAA-approved Aircraft Replacement Parts
	522,655	Nordson		32,895,906
		Dispensing Systems for Adhesives & Coatings
	962,092	Donaldson		27,015,543
		Industrial Air Filtration
	225,300	Toro		15,892,662
		Turf Maintenance Equipment
	202,973	Moog (a)		10,974,750
		Motion Control Products for Aerospace, Defense & Industrial Markets
	282,269	ESCO Technologies		10,133,457
		Industrial Filtration & Advanced Measurement Equipment
	184,785	Dorman Products (a)(b)		9,403,709
		Aftermarket Auto Parts Distributor
	303,618	Generac (a)(b)		9,135,866
		Standby Power Generators
	81,131	Middleby (a)		8,534,170
		Manufacturer of Cooking Equipment
	169,023	Oshkosh Corporation		6,140,605
		Specialty Truck Manufacturer
				201,796,100
		> Industrial Materials & Specialty Chemicals 1.9%
	395,515	Drew Industries		21,599,074
		RV & Manufactured Home Components
		> Electrical Components 0.4%
	238,597	Thermon (a)		4,903,168
		Global Engineered Thermal Solutions
		> Construction 0.4%
	395,515	PGT (a)		4,856,924
		Wind Resistant Windows & Doors
		> Industrial Distribution 0.4%
	91,337	WESCO International (a)		4,244,431
		Industrial Distributor
Industrial Goods & Services: Total				237,399,697
Consumer Goods & Services 16.6%
		> Travel 3.7%
	313,542	Avis Budget Group (a)		13,695,515
		Car Rental Company
	513,832	Hertz (a)		8,596,409
		U.S. Rental Car Operator
	81,734	Vail Resorts		8,555,915
		Ski Resort Operator & Developer
	250,155	HomeAway (a)		6,639,114
		Vacation Rental Online Marketplace
	72,365	Choice Hotels		3,448,192
		Franchisor of Budget Hotel Brands
				40,935,145
		> Retail 3.4%
	502,188	The Fresh Market (a)(b)		11,344,427
		Specialty Food Retailer

Number of Shares			Value
	87,523	Casey's General Stores	$	9,007,867
		Owner/Operator of Convenience Stores
	214,366	Blue Nile (a)		7,189,836
		Online Jewelry Retailer
	138,361	Cato		4,708,425
		Women's Apparel Retailing, Focusing on Private Labels & Low Prices
	82,518	Fossil (a)		4,611,106
		Watch Designer & Retailer
	193,577	Gaiam (a)		1,190,498
		Promoter of Healthy Living through Catalogs, E-Commerce & Gaiam TV
				38,052,159
		> Other Durable Goods 2.5%
	190,794	Cavco Industries (a)		12,991,163
		Manufactured Homes
	383,048	Select Comfort (a)		8,381,090
		Specialty Mattresses
	405,415	Gentex		6,283,933
		Manufacturer of Auto Parts
				27,656,186
		> Restaurants 1.8%
	243,683	Fiesta Restaurant Group (a)		11,055,897
		Owner/Operator of Two Restaurant Chains: Pollo Tropical & Taco Cabana
	140,289	Papa John's International		9,606,991
		Franchisor of Pizza Restaurants
				20,662,888
		> Other Consumer Services 1.5%
	303,397	Blackhawk Network (a)		12,860,999
		Third-party Distributor of Prepaid Content, Mostly Gift Cards
	507,432	Coupons.com (a)(b)		4,566,888
		Allows CPGs to Digitally Distribute Coupons, Advertising, & Trade Promotion
				17,427,887
		> Consumer Goods Distribution 1.5%
	205,535	Pool		14,860,181
		Swimming Pool Supplies & Equipment Distributor
	131,839	The Chefs' Warehouse (a)		1,866,840
		Distributor of Specialty Foods to Fine Dining Restaurants
				16,727,021
		> Leisure Products 1.0%
	263,238	Arctic Cat		5,838,619
		Manufacturer of ATVs & Snowmobiles
	369,171	Performance Sports Group (a)		4,954,275
		Sporting Goods Manufacturer
				10,792,894
		> Furniture & Textiles 0.9%
	388,754	Knoll		8,544,813
		Office Furniture
	44,654	Mattress Firm (a)(b)		1,864,751
		Mattress Retailer
				10,409,564

Number of Shares			Value
		> Nondurables 0.3%
	259,637	HRG Group (a)	$	3,045,542
		Holding Company
Consumer Goods & Services: Total				185,709,286
Finance 13.0%
		> Banks 8.3%
	427,629	Lakeland Financial		19,307,449
		Indiana Bank
	537,495	MB Financial		17,543,837
		Chicago Bank
	894,134	Associated Banc-Corp		16,067,588
		Midwest Bank
	133,528	SVB Financial Group (a)		15,427,825
		Bank to Venture Capitalists
	375,345	First Busey		7,458,105
		Illinois Bank
	198,804	Hancock Holding		5,377,648
		Gulf Coast Bank
	165,403	Sandy Spring Bancorp		4,330,251
		Baltimore & Washington, D.C. Bank
	695,000	TrustCo Bank		4,058,800
		New York State Bank
	168,031	Guaranty Bancorp		2,767,471
		Colorado Bank
				92,338,974
		> Brokerage & Money Management 1.5%
	348,189	SEI Investments		16,793,155
		Mutual Fund Administration & Investment Management
		> Insurance 1.2%
	504,566	Patriot National (a)		7,987,280
		Underwriting, Claims Administration & Case Management Outsourcing for Workers Comp Insurers
	136,909	Allied World Assurance Company Holdings		5,225,816
		Commercial Lines Insurance/Reinsurance
				13,213,096
		> Savings & Loans 1.2%
	428,644	LegacyTexas		13,065,069
		Texas Thrift
		> Diversified Financial Companies 0.4%
	247,619	Leucadia National		5,016,761
		Holding Company
		> Finance Companies 0.4%
	120,681	McGrath Rentcorp		3,220,976
		Mini-rental Conglomerate
	61,834	World Acceptance (a)(b)		1,659,625
		Personal Loans
	12,405	CAI International (a)		125,042
		International Container Leasing
				5,005,643
Finance: Total				145,432,698

Number of Shares			Value
Health Care 10.2%
		> Medical Supplies 3.6%
	456,364	Cepheid (a)	$	20,627,653
		Molecular Diagnostics
	115,781	Bio-Techne		10,705,111
		Maker of Consumables & Systems for the Life Science Market
	329,051	VWR (a)		8,453,320
		Distributor of Lab Supplies
				39,786,084
		> Biotechnology & Drug Delivery 3.0%
	119,836	Ultragenyx Pharmaceutical (a)		11,541,405
		Biotech Focused on "Ultra-Orphan" Drugs
	241,227	Sarepta Therapeutics (a)(b)		7,745,799
		Biotech Focused on Rare Diseases
	149,391	Seattle Genetics (a)		5,760,517
		Antibody-based Therapies for Cancer
	342,159	Celldex Therapeutics (a)(b)		3,606,356
		Biotech Developing Drugs for Cancer
	40,566	Agios Pharmaceuticals (a)(b)		2,863,554
		Biotech Focused on Cancer & Orphan Diseases
	12,843	Intercept Pharmaceuticals (a)		2,130,140
		Biotech Developing Drugs for Several Diseases
				33,647,771
		> Health Care Services 1.4%
	186,619	Medidata Solutions (a)		7,858,526
		Cloud-based Software for Drug Studies
	118,317	Envision Healthcare Holdings (a)		4,352,883
		Provider of Health Care Outsourcing Services
	91,233	HealthSouth		3,500,610
		Inpatient Rehabilitation Facilities & Home Health Care
				15,712,019
		> Medical Equipment & Devices 1.3%
	64,229	Sirona Dental Systems (a)		5,995,135
		Manufacturer of Dental Equipment
	262,701	Wright Medical Group (a)		5,521,975
		Foot & Ankle Replacement
	79,119	Abaxis (b)		3,480,445
		Instruments & Tests for Vet & Medical Markets
				14,997,555
		> Pharmaceuticals 0.9%
	363,878	Akorn (a)		10,372,342
		Developer, Manufacturer & Distributor of Specialty Generic Drugs
Health Care: Total				114,515,771
Other Industries 6.3%
		> Real Estate 4.4%
	539,820	Extra Space Storage		41,652,511
		Self Storage Facilities
	232,070	EdR		7,646,707
		Student Housing
				49,299,218

COLUMBIA ACORN USA^SM

STATEMENT OF INVESTMENTS (UNAUDITED), CONTINUED

Number of Shares			Value
		> Transportation 1.9%
	426,335	Rush Enterprises, Class A (a)	$	10,317,307
	106,560	Rush Enterprises, Class B (a)		2,483,914
		Truck Sales & Service
	422,559	Heartland Express		8,425,826
		Regional Trucker
				21,227,047
Other Industries: Total				70,526,265
Energy & Minerals 1.8%
		> Oil & Gas Producers 1.3%
	99,398	PDC Energy (a)		5,269,088
		Oil & Gas Producer in the United States
	140,289	Carrizo Oil & Gas (a)		4,284,426
		Oil & Gas Producer
	103,105	SM Energy		3,303,484
		Oil & Gas Producer
	41,603	Clayton Williams (a)		1,614,613
		Oil & Gas Producer
				14,471,611
		> Mining 0.5%
	50,707	Core Labs (Netherlands) (b)		5,060,558
		Oil & Gas Reservoir Consulting
Energy & Minerals: Total				19,532,169
Total Equities: 93.3% (Cost: $669,727,578)				1,043,678,351	(c)

Number of Shares			Value
Short-Term Investments 8.5%
	94,766,116	JPMorgan U.S. Government Money Market Fund, Agency Shares (7 day yield of 0.01%)	$	94,766,116
Total Short-Term Investments: 8.5% (Cost: $94,766,116)				94,766,116
Securities Lending Collateral 3.2%
	35,653,438	Dreyfus Government Cash Management Fund, Institutional Shares (7 day yield of 0.01%) (d)		35,653,438
Total Securities Lending Collateral: 3.2% (Cost: $35,653,438)				35,653,438
Total Investments: 105.0% (Cost: $800,147,132)(e)				1,174,097,905	(f)
Obligation to Return Collateral for Securities Loaned: (3.2)%				(35,653,438	)
Cash and Other Assets Less Liabilities: (1.8)%				(20,159,484	)
Net Assets: 100.0%			$	1,118,284,983

ADR - American Depositary Receipts

> Notes to Statement of Investments

(a) Non-income producing security.

(b) All or a portion of this security was on loan at September 30, 2015. The total market value of securities on loan at September 30, 2015 was $35,262,900.

(c) On September 30, 2015, the market value of foreign securities represented 0.45% of total net assets. The Fund's foreign portfolio was diversified as follows:

Country				Value				Percentage of Net Assets
Netherlands				$	5,060,558				0.45

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

(e) At September 30, 2015, for federal income tax purposes, the cost of investments was approximately $800,147,132 and net unrealized appreciation was $373,950,773 consisting of gross unrealized appreciation of $429,389,779 and gross unrealized depreciation of $55,439,006.

(f) Securities are valued using policies described in the Notes to Financial Statements in the shareholder report dated June 30, 2015.

Fair Value Measurements

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

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

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

> Notes to Statement of Investments

The Committee is responsible for applying the Trust's Portfolio Pricing Policy and the CWAM pricing procedures (the Policies), which are approved by and subject to the oversight of the Board.

The following table summarizes the inputs used, as of September 30, 2015, 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	$	270,562,465	$	-	$	-	$	270,562,465
Industrial Goods & Services		237,399,697		-		-		237,399,697
Consumer Goods & Services		185,709,286		-		-		185,709,286
Finance		145,432,698		-		-		145,432,698
Health Care		114,515,771		-		-		114,515,771
Other Industries		70,526,265		-		-		70,526,265
Energy & Minerals		19,532,169		-		-		19,532,169
Total Equities		1,043,678,351		-		-		1,043,678,351
Total Short-Term Investments		94,766,116		-		-		94,766,116
Total Securities Lending Collateral		35,653,438		-		-		35,653,438
Total Investments	$	1,174,097,905	$	-	$	-	$	1,174,097,905

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

COLUMBIA ACORN INTERNATIONAL SELECT^SM

MAJOR PORTFOLIO CHANGES IN THE THIRD QUARTER (UNAUDITED)

	Number of Shares
	6/30/15		9/30/15
Purchases
Europe
> United Kingdom
Compass Group PLC		0		122,000
Next		0		18,000
Smith & Nephew		130,000		200,000
> France
Essilor International		0		16,000
> Spain
Distribuidora Internacional de Alimentación		655,000		919,000
> Sweden
Hennes & Mauritz		0		50,000
> Denmark
Novozymes		71,500		109,500
Asia
> Japan
Sony Financial Holdings		0		208,000
> Korea
Samsung Fire & Marine Preferred		0		7,354
> China
China Everbright International		0		1,327,000
NetEase.com - ADR		0		17,000
Other Countries
> Australia
IAG		514,000		525,000

	Number of Shares
	6/30/15		9/30/15
Sales
Europe
> United Kingdom
Aggreko		100,000		0
Babcock International		162,000		129,000
Jardine Lloyd Thompson Group		147,000		132,000
Asia
> Japan
Park24		128,000		0
Recruit Holdings		262,000		234,000
Rinnai		30,700		0
> Singapore
CapitaLand Mall Trust		5,824,000		4,264,000
Singapore Exchange		1,564,000		897,000
> Korea
CJ Corp		26,294		11,994
KT&G		66,800		31,200
Samsung Fire and Marine		23,200		8,500
Other Countries
> South Africa
Coronation Fund Managers		663,000		618,552
> Canada
Goldcorp		258,000		0
> Australia
Amcor		320,000		204,000
Challenger Financial		670,000		0
Latin America
> Brazil
Beadell Resources		12,057,582		0
> Guatemala
Tahoe Resources		588,000		0

COLUMBIA ACORN INTERNATIONAL SELECT^SM

STATEMENT OF INVESTMENTS (UNAUDITED), SEPTEMBER 30, 2015

Number of Shares			Value
			Equities: 97.7%
Europe 43.5%
		> United Kingdom 10.5%
	232,000	WH Smith	$	5,488,981
		Newsprint, Books & General Stationery Retailer
	200,000	Smith & Nephew		3,488,400
		Medical Equipment & Supplies
	32,000	Whitbread		2,259,685
		UK Hotelier & Coffee Shop
	18,000	Next		2,072,164
		Clothes & Home Retailer in the UK
	132,000	Jardine Lloyd Thompson Group		2,034,769
		International Business Insurance Broker
	122,000	Compass Group PLC		1,943,369
		Catering & Support Services
	129,000	Babcock International		1,780,695
		Public Sector Outsourcer
				19,068,063
		> Germany 9.0%
	976,500	Telefonica Deutschland		5,958,719
		Mobile & Fixed-line Communications in Germany
	62,300	MTU Aero Engines		5,206,431
		Airplane Engine Components & Services
	107,400	Wirecard (a)		5,124,972
		Online Payment Processing & Risk Management
				16,290,122
		> Switzerland 5.1%
	21,040	Partners Group		7,129,551
		Private Markets Asset Management
	6,600	Geberit		2,016,027
		Plumbing Systems
				9,145,578
		> France 5.0%
	146,000	Eutelsat		4,470,045
		Fixed Satellite Services
	111,000	Vivendi		2,620,783
		Global Media Conglomerate
	16,000	Essilor International		1,946,957
		Eyeglass Lenses
				9,037,785
		> Spain 4.4%
	919,000	Distribuidora Internacional de Alimentación		5,548,288
		Discount Retailer in Spain & Latin America
	39,000	Viscofan		2,348,014
		Sausage Casings Maker
				7,896,302
		> Sweden 4.1%
	120,000	Swedish Match		3,622,961
		Swedish Snus
	62,900	Hexagon		1,918,574
		Design, Measurement & Visualization Software & Equipment
	50,000	Hennes & Mauritz		1,826,176
		Discount Fashion Retailer
				7,367,711

Number of Shares			Value
		> Denmark 2.6%
	109,500	Novozymes	$	4,770,388
		Industrial Enzymes
		> Norway 1.8%
	453,000	Orkla		3,357,644
		Food & Brands, Aluminum, Chemicals Conglomerate
		> Netherlands 1.0%
	44,000	Vopak		1,754,474
		Operator of Petroleum & Chemical Storage Terminals
Europe: Total				78,688,067
Asia 39.4%
		> Japan 23.9%
	395,000	KDDI		8,841,326
		Mobile & Fixed Line Communication Service Provider in Japan
	120,000	Secom		7,216,867
		Security Services
	234,000	Recruit Holdings		7,016,328
		Recruitment & Media Services
	160,000	Japan Tobacco		4,963,231
		Cigarettes
	190,600	NGK Spark Plug		4,375,380
		Automobile Parts
	208,000	Sony Financial Holdings		3,413,890
		Life Insurance, Assurance & Internet Banking
	1,530	Nippon Prologis REIT		2,776,165
		Logistics REIT in Japan
	1,300	Japan Retail Fund		2,515,318
		Retail REIT in Japan
	133,000	Aeon Mall		2,043,057
		Suburban Shopping Mall Developer, Owner & Operator
				43,161,562
		> Singapore 5.6%
	4,264,000	CapitaLand Mall Trust		5,701,693
		Singapore Commercial Property Real Estate Investment Trust
	897,000	Singapore Exchange		4,437,391
		Singapore Equity & Derivatives Market Operator
				10,139,084
		> Korea 4.8%
	31,200	KT&G		2,934,953
		Tobacco & Ginseng Products
	11,994	CJ Corp		2,678,226
		Holding Company of Korean Consumer Conglomerate
	8,500	Samsung Fire and Marine		2,007,208
	7,354	Samsung Fire & Marine Preferred		1,036,063
		Non-life Insurance
				8,656,450

COLUMBIA ACORN INTERNATIONAL SELECT^SM

STATEMENT OF INVESTMENTS (UNAUDITED), CONTINUED

Number of Shares			Value
		> China 2.1%
	17,000	NetEase.com - ADR	$	2,042,040
		Chinese Online Gaming Services
	1,327,000	China Everbright International		1,864,197
		Municipal Waste Operator
				3,906,237
		> Hong Kong 1.6%
	123,726	Hong Kong Exchanges and Clearing		2,838,398
		Hong Kong Equity & Derivatives Market Operator
		> Taiwan 1.4%
	32,000	Largan Precision		2,497,438
		Mobile Device Camera Lenses & Modules
Asia: Total				71,199,169
Other Countries 14.1%
		> South Africa 5.8%
	61,000	Naspers		7,617,726
		Media in Africa, China, Russia & other Emerging Markets
	618,552	Coronation Fund Managers		2,914,115
		South African Fund Manager
				10,531,841
		> Canada 5.3%
	49,271	CCL Industries		6,916,400
		Global Label Converter
	85,000	Vermilion Energy (a)		2,736,943
		Canadian Exploration & Production Company
				9,653,343
		> Australia 2.1%
	204,000	Amcor		1,897,171
		Global Leader in Flexible & Rigid Packaging
	525,000	IAG		1,795,041
		General Insurance Provider
				3,692,212
		> United States 0.9%
	27,000	Anadarko Petroleum		1,630,530
		Worldwide Production of Oil & Gas
Other Countries: Total				25,507,926

Number of Shares			Value
Latin America 0.7%
		> Uruguay 0.7%
	191,666	Union Agriculture Group (b)(c)(d)	$	1,261,162
		Farmland Operator in Uruguay
Latin America: Total				1,261,162
Total Equities: 97.7% (Cost: $160,786,851)				176,656,324	(e)
Short-Term Investments 2.3%
	4,096,481	JPMorgan U.S. Government Money Market Fund, IM Shares (7 day yield of 0.01%)		4,096,481
Total Short-Term Investments: 2.3% (Cost: $4,096,481)				4,096,481
Securities Lending Collateral 3.3%
	6,046,604	Dreyfus Government Cash Management Fund, Institutional Shares (7 day yield of 0.01%) (f)		6,046,604
Total Securities Lending Collateral: 3.3% (Cost: $6,046,604)				6,046,604
Total Investments: 103.3% (Cost: $170,929,936)(g)				186,799,409	(h)
Obligation to Return Collateral for Securities Loaned: (3.3)%				(6,046,604	)
Cash and Other Assets Less Liabilities: —%				39,100
Net Assets: 100.0%			$	180,791,905

ADR - American Depositary Receipts

REIT - Real Estate Investment Trust

> Notes to Statement of Investments

(a) All or a portion of this security was on loan at September 30, 2015. The total market value of securities on loan at September 30, 2015 was $5,882,988.

(b) Denotes a restricted security, which is subject to restrictions on resale under federal securities laws. This security is valued at fair value determined in good faith under consistently applied procedures established by the Fund's Board of Trustees. At September 30, 2015, the market value of this security amounted to $1,261,162, which represented 0.70% of total net assets. Additional information on this security is as follows:

Security				Acquisition Dates				Shares				Cost				Value
Union Agriculture Group				12/8/10-6/27/12					191,666			$	2,200,000			$	1,261,162

> Notes to Statement of Investments

(d) Illiquid security.

(e) On September 30, 2015, the Fund's total equity investments were denominated in currencies as follows:

Currency	Value		Percentage of Net Assets
Japanese Yen	$	43,161,562		23.9
Euro		34,978,683		19.4
British Pound		19,068,063		10.5
South African Rand		10,531,841		5.8
Singapore Dollar		10,139,084		5.6
Canadian Dollar		9,653,343		5.3
Swiss Franc		9,145,578		5.1
Other currencies less than 5% of total net assets		39,978,170		22.1
Total Equities	$	176,656,324		97.7

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

(g) At September 30, 2015, for federal income tax purposes, the cost of investments was approximately $170,929,936 and net unrealized appreciation was $15,869,473 consisting of gross unrealized appreciation of $28,062,280 and gross unrealized depreciation of $12,192,807.

(h) Securities are valued using policies described in the Notes to Financial Statements in the shareholder report dated June 30, 2015.

At September 30, 2015, the Fund had entered into the following forward foreign currency exchange contracts:

Forward Foreign
Currency Exchange
Contracts to Buy

Forward Foreign
Currency Exchange
Contracts to Sell

Principal Amount
in Foreign Currency

Principal Amount
in U.S. Dollar

Settlement
Date

Unrealized
Appreciation
(Depreciation)

USD

ZAR

95,175,500

7,000,000

10/15/15

148,080

The counterparty for all forward foreign currency exchange contracts is Morgan Stanley.

USD - U.S. Dollar

ZAR - South African Rand

Fair Value Measurements

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

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

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

The Committee is responsible for applying the Trust's Portfolio Pricing Policy and the CWAM pricing procedures (the Policies), which are approved by and subject to the oversight of the Board.

COLUMBIA ACORN INTERNATIONAL SELECT^SM

STATEMENT OF INVESTMENTS (UNAUDITED), CONTINUED

> Notes to Statement of Investments

The following table summarizes the inputs used, as of September 30, 2015, 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	$	-	$	78,688,067	$	-	$	78,688,067
Asia		2,042,040		69,157,129		-		71,199,169
Other Countries		11,283,873		14,224,053		-		25,507,926
Latin America		-		-		1,261,162		1,261,162
Total Equities		13,325,913		162,069,249		1,261,162		176,656,324
Total Short-Term Investments		4,096,481		-		-		4,096,481
Total Securities Lending Collateral		6,046,604		-		-		6,046,604
Total Investments	$	23,468,998	$	162,069,249	$	1,261,162	$	186,799,409
Derivatives
Assets
Forward Foreign Currency Exchange Contracts		-		148,080		-		148,080
Total	$	23,468,998	$	162,217,329	$	1,261,162	$	186,947,489

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

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

The Fund does not hold any significant investments (greater than one percent of net assets) categorized as Level 3.

COLUMBIA ACORN INTERNATIONAL SELECT^SM

PORTFOLIO DIVERSIFICATION (UNAUDITED)

At September 30, 2015, the Fund's portfolio investments as a percentage of net assets were diversified as follows:

	Value		Percentage of Net Assets
> Information
Financial Processors	$	12,400,761		6.8
Internet Related		9,659,766		5.3
Mobile Communications		8,841,326		4.9
Advertising		7,016,328		3.9
Telephone & Data Services		5,958,719		3.3
Satellite Broadcasting & Services		4,470,045		2.5
Telecommunications Equipment		2,497,438		1.4
Business Software		1,918,574		1.1
		52,762,957		29.2
> Consumer Goods & Services
Retail		14,935,609		8.3
Nondurables		14,814,584		8.2
Food & Beverage		5,970,975		3.3
Other Durable Goods		4,375,380		2.4
Restaurants		4,203,054		2.3
Other Consumer Services		2,620,783		1.5
		46,920,385		26.0
> Industrial Goods & Services
Other Industrial Services		12,423,298		6.9
Industrial Materials & Specialty Chemicals		6,667,559		3.7
Conglomerates		6,035,870		3.3
Construction		2,016,027		1.1
Waste Management		1,864,197		1.0
Outsourcing Services		1,780,695		1.0
		30,787,646		17.0
> Finance
Insurance		10,286,971		5.7
Brokerage & Money Management		10,043,666		5.5
		20,330,637		11.2
> Other Industries
Real Estate		13,036,233		7.2
		13,036,233		7.2
> Energy & Minerals
Oil & Gas Producers		4,367,473		2.4
Oil Refining, Marketing & Distribution		1,754,474		1.0
Agricultural Commodities		1,261,162		0.7
		7,383,109		4.1

	Value			Percentage of Net Assets
> Health Care
Medical Equipment & Devices	$	5,435,357			3.0
		5,435,357			3.0
Total Equities:		176,656,324			97.7
Short-Term Investments:		4,096,481			2.3
Securities Lending Collateral:		6,046,604			3.3
Total Investments:		186,799,409			103.3
Obligation to Return Collateral for Securities Loaned:		(6,046,604	)		(3.3	)
Cash and Other Assets Less Liabilities:		39,100			0.0
Net Assets:	$	180,791,905			100.0

COLUMBIA ACORN SELECT^SM

MAJOR PORTFOLIO CHANGES IN THE THIRD QUARTER (UNAUDITED)

	Number of Shares
	6/30/15		9/30/15
Purchases
Industrial Goods & Services
Expeditors International of Washington		269,000		291,687
Nordson		230,000		267,230
Information
Bankrate		871,000		1,080,494
Consumer Goods & Services
Fossil		174,000		185,236
Polaris Industries		0		75,650
Health Care
Align Technology		0		186,643
Other Industries
EdR		256,000		328,749
Energy & Minerals
Core Labs (Netherlands)		60,000		79,999

	Number of Shares
	6/30/15		9/30/15
Sales
Industrial Goods & Services
Airgas		165,000		151,705
Ametek		703,000		578,711
Donaldson		850,000		776,657
LKQ		996,000		794,620
Quanta Services		374,000		312,342
Information
Vonage		1,635,000		1,548,771
Amphenol		287,000		266,095
Ansys		149,000		130,558
F5 Networks		125,000		108,347
Solera Holdings		350,000		0
Trimble Navigation		459,000		0
WNS - ADR		455,000		319,876
Consumer Goods & Services
Gentex		1,035,000		899,664
The Fresh Market		669,000		630,647
United Natural Foods		134,000		0
Vail Resorts		175,000		158,306
Finance
Associated Banc-Corp		915,000		689,605
Eaton Vance		348,000		317,937
SEI Investments		562,000		350,151
Heath Care
Cepheid		243,000		209,466
Henry Schein		31,000		0
Ultragenyx Pharmaceutical		80,000		28,686
VWR		376,300		283,603
Other Industries
Post Properties		176,000		104,814
Energy & Minerals
Gulfport Energy		134,000		0

COLUMBIA ACORN SELECT^SM

STATEMENT OF INVESTMENTS (UNAUDITED), SEPTEMBER 30, 2015

Number of Shares			Value
			Equities: 98.5%
Industrial Goods & Services 31.2%
		> Machinery 16.8%
	578,711	Ametek	$	30,278,159
		Aerospace/Industrial Instruments
	776,657	Donaldson		21,808,529
		Industrial Air Filtration
	267,230	Nordson		16,819,456
		Dispensing Systems for Adhesives & Coatings
	328,030	Generac (a)(b)		9,870,423
		Standby Power Generators
				78,776,567
		> Other Industrial Services 9.9%
	794,620	LKQ (a)		22,535,423
		Alternative Auto Parts Distribution
	291,687	Expeditors International of Washington		13,723,874
		International Freight Forwarder
	193,695	Robert Half International		9,909,436
		Temporary & Permanent Staffing in Finance, Accounting & other Professions
				46,168,733
		> Industrial Distribution 2.9%
	151,705	Airgas		13,551,807
		Industrial Gas Distributor
		> Outsourcing Services 1.6%
	312,342	Quanta Services (a)		7,561,800
		Electrical Transmission & Pipeline Contracting Services
Industrial Goods & Services: Total				146,058,907
Information 22.8%
		> Business Software 5.1%
	70,657	Ultimate Software (a)		12,648,310
		Human Capital Management Systems
	130,558	Ansys (a)		11,507,382
		Simulation Software for Engineers & Designers
				24,155,692
		> Computer Hardware & Related Equipment 2.9%
	266,095	Amphenol		13,560,201
		Electronic Connectors
		> Mobile Communications 2.7%
	161,161	Crown Castle International		12,710,768
		Communications Towers
		> Telecommunications Equipment 2.7%
	108,347	F5 Networks (a)		12,546,583
		Internet Traffic Management Equipment
		> Business Information & Marketing Services 2.4%
	1,080,494	Bankrate (a)		11,183,113
		Internet Advertising for the Insurance, Credit Card & Banking Markets

Number of Shares			Value
		> Instrumentation 2.4%
	38,799	Mettler-Toledo International (a)	$	11,047,627
		Laboratory Equipment
		> Internet Related 1.9%
	1,548,771	Vonage (a)		9,106,773
		Business & Consumer Internet Telephony
		> Computer Services 1.9%
	319,876	WNS - ADR (a)		8,940,534
		Offshore Business Process Outsourcing Services
		> Semiconductors & Related Equipment 0.8%
	467,000	Atmel		3,768,690
		Microcontrollers, Radio Frequency & Memory Semiconductors
Information: Total				107,019,981
Consumer Goods & Services 16.1%
		> Retail 5.3%
	630,647	The Fresh Market (a)(b)		14,246,316
		Specialty Food Retailer
	185,236	Fossil (a)		10,350,987
		Watch Designer & Retailer
				24,597,303
		> Travel 3.5%
	158,306	Vail Resorts		16,571,472
		Ski Resort Operator & Developer
		> Other Durable Goods 3.0%
	899,664	Gentex		13,944,792
		Manufacturer of Auto Parts
		> Other Consumer Services 2.3%
	252,795	Blackhawk Network (a)		10,715,980
		Third-party Distributor of Prepaid Content, Mostly Gift Cards
		> Leisure Products 1.9%
	75,650	Polaris Industries		9,068,166
		Leisure Vehicles & Related Products
		> Food & Beverage 0.1%
	2,539,770	GLG Life Tech (Canada) (a)(b)(c)		551,917
		Producer of an All-natural Sweetener Extracted from the Stevia Plant
Consumer Goods & Services: Total				75,449,630
Finance 11.5%
		> Brokerage & Money Management 5.9%
	350,151	SEI Investments		16,887,783
		Mutual Fund Administration & Investment Management
	317,937	Eaton Vance		10,625,454
		Specialty Mutual Funds
				27,513,237
		> Insurance 3.0%
	737,866	CNO Financial Group		13,879,260
		Life, Long-term Care & Medical Supplement Insurance

COLUMBIA ACORN SELECT^SM

STATEMENT OF INVESTMENTS (UNAUDITED), CONTINUED

Number of Shares			Value
		> Banks 2.6%
	689,605	Associated Banc-Corp	$	12,392,202
		Midwest Bank
Finance: Total				53,784,699
Health Care 6.4%
		> Medical Supplies 3.6%
	209,466	Cepheid (a)		9,467,863
		Molecular Diagnostics
	283,603	VWR (a)		7,285,761
		Distributor of Lab Supplies
				16,753,624
		> Medical Equipment & Devices 2.2%
	186,643	Align Technology (a)		10,593,857
		Invisalign System to Correct Malocclusion (Crooked Teeth)
		> Biotechnology & Drug Delivery 0.6%
	28,686	Ultragenyx Pharmaceutical (a)		2,762,749
		Biotech Focused on "Ultra-Orphan" Drugs
Health Care: Total				30,110,230
Other Industries 5.5%
		> Real Estate 5.5%
	328,749	EdR		10,832,280
		Student Housing
	115,626	Extra Space Storage		8,921,702
		Self Storage Facilities
	104,814	Post Properties		6,109,608
		Multifamily Properties
				25,863,590
Other Industries: Total				25,863,590
Energy & Minerals 5.0%
		> Agricultural Commodities 2.5%
	1,742,424	Union Agriculture Group (Uruguay) (a)(d)(e)		11,465,150
		Farmland Operator in Uruguay
		> Mining 1.7%
	79,999	Core Labs (Netherlands) (b)		7,983,900
		Oil & Gas Reservoir Consulting

Number of Shares			Value
		> Oil & Gas Producers 0.8%
	108,492	Carrizo Oil & Gas (a)	$	3,313,346
		Oil & Gas Producer
	22,500,000	Canadian Overseas Petroleum (Canada) (a)(e)		640,689
		Oil & Gas Exploration Offshore West Africa
				3,954,035
Energy & Minerals: Total				23,403,085
Total Equities: 98.5% (Cost: $392,586,822)				461,690,122	(f)
Short-Term Investments 2.4%
	11,047,991	JPMorgan U.S. Government Money Market Fund, Agency Shares (7 day yield of 0.01%)		11,047,991
Total Short-Term Investments: 2.4% (Cost: $11,047,991)				11,047,991
Securities Lending Collateral 4.8%
	22,305,179	Dreyfus Government Cash Management Fund, Institutional Shares (7 day yield of 0.01%) (g)		22,305,179
Total Securities Lending Collateral: 4.8% (Cost: $22,305,179)				22,305,179
Total Investments: 105.7% (Cost: $425,939,992)(h)				495,043,292	(i)
Obligation to Return Collateral for Securities Loaned: (4.8)%				(22,305,179	)
Cash and Other Assets Less Liabilities: (0.9)%				(4,223,713	)
Net Assets: 100.0%			$	468,514,400

ADR - American Depositary Receipts

> Notes to Statement of Investments

(a) Non-income producing security.

(b) All or a portion of this security was on loan at September 30, 2015. The total market value of securities on loan at September 30, 2015 was $22,308,347.

(c) An affiliated person of the Fund, as defined in the Investment Company Act of 1940, may include any company in which the Fund owns five percent or more of its outstanding voting shares. Holdings and transactions in these affiliated companies during the period ended September 30, 2015, are as follows:

Security	Balance of Shares Held 12/31/14		Purchases/ Additions		Sales/ Reductions		Balance of Shares Held 9/30/15		Value		Dividend
Canadian Overseas Petroleum (1)		22,500,000		-		-		22,500,000	$	640,689	$	-
GLG Life Tech		1,500,000		1,224,770		185,000		2,539,770		551,917		-
Petrodorado Energy (1)		3,370,000		-		3,370,000		-		-		-
Total of Affiliated Transactions		27,370,000		1,224,770		3,555,000		25,039,770	$	1,192,606	$	-

(1) At September 30, 2015, the Fund owned less than five percent of the company's outstanding voting shares.

> Notes to Statement of Investments

The aggregate cost and value of these companies at September 30, 2015, was $8,092,624 and $551,917, respectively. Investments in affiliated companies represented 0.12% of the Fund's total net assets at September 30, 2015.

(d) Illiquid security.

(e) Denotes a restricted security, which is subject to restrictions on resale under federal securities laws. These securities are valued at fair value determined in good faith under consistently applied procedures established by the Fund's Board of Trustees. At September 30, 2015, the market value of these securities amounted to $12,105,839, which represented 2.58% of total net assets. Additional information on these securities is as follows:

Security	Acquisition Dates	Shares		Cost		Value
Union Agriculture Group	12/8/10-6/27/12		1,742,424	$	20,000,000	$	11,465,150
Canadian Overseas Petroleum	11/24/10		22,500,000		9,596,330		640,689
				$	29,596,330	$	12,105,839

(f) On September 30, 2015, the market value of foreign securities represented 4.41% of total net assets. The Fund's foreign portfolio was diversified as follows:

Country	Value		Percentage of Net Assets
Uruguay	$	11,465,150		2.45
Netherlands		7,983,900		1.70
Canada		1,192,606		0.26
Total Foreign Portfolio	$	20,641,656		4.41

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

(h) At September 30, 2015, for federal income tax purposes, the cost of investments was approximately $425,939,992 and net unrealized appreciation was $69,103,300 consisting of gross unrealized appreciation of $118,722,070 and gross unrealized depreciation of $49,618,770.

(i) Securities are valued using policies described in the Notes to Financial Statements in the shareholder report dated June 30, 2015.

Fair Value Measurements

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

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

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

The Committee is responsible for applying the Trust's Portfolio Pricing Policy and the CWAM pricing procedures (the Policies), which are approved by and subject to the oversight of the Board.

COLUMBIA ACORN SELECT^SM

STATEMENT OF INVESTMENTS (UNAUDITED), CONTINUED

> Notes to Statement of Investments

The following table summarizes the inputs used, as of September 30, 2015, in valuing the Fund's assets:

Investment Type	Quoted Prices (Level 1)		Other Significant Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)		Total
Equities
Industrial Goods & Services	$	146,058,907	$	-	$	-	$	146,058,907
Information		107,019,981		-		-		107,019,981
Consumer Goods & Services		75,449,630		-		-		75,449,630
Finance		53,784,699		-		-		53,784,699
Health Care		30,110,230		-		-		30,110,230
Other Industries		25,863,590		-		-		25,863,590
Energy & Minerals		11,297,246		640,689		11,465,150		23,403,085
Total Equities		449,584,283		640,689		11,465,150		461,690,122
Total Short-Term Investments		11,047,991		-		-		11,047,991
Total Securities Lending Collateral		22,305,179		-		-		22,305,179
Total Investments	$	482,937,453	$	640,689	$	11,465,150	$	495,043,292

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

The following table reconciles asset balances for the period ended September 30, 2015, in which significant observable and/or unobservable inputs (Level 3) were used in determining value:

Investments in Securities	Balance as of December 31, 2014		Realized Gain (Loss)		Change in Unrealized Appreciation (Depreciation)			Purchases		Sales		Transfers into Level 3		Transfers out of Level 3		Balance as of September 30, 2015
Equities
Energy & Minerals	$	15,908,331	$	-	$	(4,443,181	)	$	-	$	-	$	-	$	-	$	11,465,150

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

The change in unrealized depreciation attributed to securities owned at September 30, 2015, which were valued using significant unobservable inputs (Level 3), amounted to $4,443,181.

Quantitative information pertaining to Level 3 unobservable fair value measurements

Fair Value at
September 30, 2015

Valuation Technique(s)

Unobservable Input(s)

Range (Weighted
Average)

Equities
Energy & Minerals

11,465,150

Market Comparable
Companies

Discount for Lack
of Marketability

%—23%

COLUMBIA THERMOSTAT FUND^SM

STATEMENT OF INVESTMENTS (UNAUDITED), SEPTEMBER 30, 2015

Number of Shares			Value
		> Affiliated Bond Funds 65.1%
	29,230,037	Columbia Short Term Bond Fund, Class I Shares (a)	$	290,546,564
	15,942,467	Columbia Intermediate Bond Fund, Class I Shares (a)		146,032,995
	26,433,185	Columbia U.S. Government Mortgage Fund, Class I Shares (a)		145,118,188
	14,953,512	Columbia Income Opportunities Fund, Class I Shares (a)		141,609,757
Total Affiliated Bond Funds: (Cost: $724,707,807)				723,307,504
		> Affiliated Stock Funds 34.5%
	1,970,586	Columbia Acorn International, Class I Shares (a)		77,266,688
	4,405,453	Columbia Dividend Income Fund, Class I Shares (a)		76,742,995
	3,691,070	Columbia Contrarian Core Fund, Class I Shares (a)		76,405,144
	2,296,396	Columbia Select Large Cap Growth Fund, Class I Shares (a)(b)		38,464,627
	1,905,751	Columbia Acorn Select, Class I Shares (a)(b)		38,153,146

Number of Shares			Value
	1,918,512	Columbia Large Cap Enhanced Core Fund, Class I Shares (a)	$	38,120,840
	1,295,195	Columbia Acorn Fund, Class I Shares (a)(b)		38,013,960
Total Affiliated Stock Funds: (Cost: $374,647,050)				383,167,400
		> Short-Term Investments 0.4%
	4,370,209	JPMorgan U.S. Government Money Market Fund, Agency Shares (7 day yield of 0.01%)		4,370,209
Total Short-Term Investments: (Cost: $4,370,209)				4,370,209
Total Investments: 100.0% (Cost: $1,103,725,066)(c)				1,110,845,113	(d)
Cash and Other Assets Less Liabilities: —%				457,595
Net Assets: 100.0%			$	1,111,302,708

> Notes to Statement of Investments

Security	Balance of Shares Held 12/31/14		Purchases/ Additions		Sales/ Reductions		Balance of Shares Held 9/30/15		Value		Dividend
Columbia Short Term Bond Fund, Class I Shares		42,849,246		5,207,106		18,826,315		29,230,037	$	290,546,564	$	3,054,592
Columbia Intermediate Bond Fund, Class I Shares		28,994,280		3,263,471		16,315,284		15,942,467		146,032,995		4,044,445
Columbia U.S. Government Mortgage Fund, Class I Shares		28,883,507		9,759,570		12,209,892		26,433,185		145,118,188		3,883,346
Columbia Income Opportunities Fund, Class I Shares		21,780,174		2,989,721		9,816,383		14,953,512		141,609,757		7,098,020
Columbia Acorn International, Class I Shares		898,450		1,734,602		662,466		1,970,586		77,266,688		-
Columbia Dividend Income Fund, Class I Shares		1,962,468		4,083,835		1,640,850		4,405,453		76,742,995		1,054,854
Columbia Contrarian Core Fund, Class I Shares		1,291,662		3,692,054		1,292,646		3,691,070		76,405,144		-
Columbia Select Large Cap Growth Fund, Class I Shares		1,023,561		2,226,817		953,982		2,296,396		38,464,627		-
Columbia Acorn Select, Class I Shares		836,113		1,807,777		738,139		1,905,751		38,153,146		-
Columbia Large Cap Enhanced Core Fund, Class I Shares		870,296		1,775,846		727,630		1,918,512		38,120,840		207,636
Columbia Acorn Fund, Class I Shares		879,308		1,039,936		624,049		1,295,195		38,013,960		-
Total of Affiliated Transactions		130,269,065		37,580,735		63,807,636		104,042,164	$	1,106,474,904	$	19,342,893

The aggregate cost and value of these companies at September 30, 2015, was $1,099,354,857 and $1,106,474,904, respectively. Investments in affiliated companies represented 99.6% of the Fund's total net assets at September 30, 2015.

(b) Non-income producing security.

(c) At September 30, 2015, for federal income tax purposes, the cost of investments was approximately $1,103,725,066 and net unrealized appreciation was $7,120,047 consisting of gross unrealized appreciation of $13,708,862 and gross unrealized depreciation of $6,588,815.

(d) Securities are valued using policies described in the Notes to Financial Statements in the shareholder report dated June 30, 2015.

COLUMBIA THERMOSTAT FUND^SM

STATEMENT OF INVESTMENTS (UNAUDITED), CONTINUED

> Notes to Statement of Investments

Fair Value Measurements

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

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

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

Examples of the types of securities in which the Fund would typically invest and how they are classified within this hierarchy are as follows. Typical Level 1 securities include mutual funds whose NAVs are published each day.

The Committee is responsible for applying the Trust's Portfolio Pricing Policy and the CWAM pricing procedures (the Policies), which are approved by and subject to the oversight of the Board.

The following table summarizes the inputs used, as of September 30, 2015, 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 Affiliated Bond Funds	$	723,307,504	$	-	$	-	$	723,307,504
Total Affiliated Stock Funds		383,167,400		-		-		383,167,400
Total Short-Term Investments		4,370,209		-		-		4,370,209
Total Investments	$	1,110,845,113	$	-	$	-	$	1,110,845,113

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

COLUMBIA ACORN EMERGING MARKETS FUND^SM

MAJOR PORTFOLIO CHANGES IN THE THIRD QUARTER (UNAUDITED)

	Number of Shares
	6/30/15		9/30/15
Purchases
Asia
> China
51job - ADR		66,000		134,000
BitAuto - ADR		126,613		183,613
CAR Inc		3,668,000		3,947,000
China Everbright International		2,340,000		2,488,000
TravelSky Technology		2,459,000		3,580,000
Xinhua Winshare Publishing		3,303,000		4,140,000
> India
Container Corporation of India		160,788		175,000
> Taiwan
Far EasTone Telecom		1,900,000		3,050,000
Silergy		160,000		431,000
> Indonesia
Surya Citra Media		18,149,000		22,620,000
> Philippines
Puregold Price Club		5,087,200		6,742,200
> Thailand
Mega Lifesciences		6,899,100		8,700,000
> Korea
CJ Hellovision		0		27,983
KCC		0		4,038
Latin America
> Brazil
Odontoprev		1,430,100		1,471,400
Other Countries
> United States
Bladex		140,000		158,000

	Number of Shares
	6/30/15		9/30/15
Sales
Asia
> China
AMVIG Holdings		25,200,000		8,032,000
Canvest Environment Protection		9,263,000		0
Chongqing Rural Commercial Bank		5,600,000		0
NewOcean Energy		13,784,000		8,230,000
Phoenix Healthcare Group		2,265,000		2,200,000
Phoenix New Media - ADR		464,000		0
Shanghai Industrial		1,207,000		1,086,300
WuXi PharmaTech - ADR		117,000		0
> Taiwan
Chroma Ate		775,990		0
Largan Precision		59,000		40,000
PChome Online		470,602		0
President Chain Store		940,000		500,000
Vanguard International Semiconductor		4,177,000		3,243,000
Voltronic Power		424,000		277,156
> Indonesia
Arwana Citramulia		66,827,701		45,639,400
Link Net		10,600,000		10,000,000
Matahari Department Store		4,068,700		2,761,700
MNC Sky Vision		59,276,600		59,081,400
Tower Bersama Infrastructure		6,406,300		4,074,200
> Philippines
Robinsons Retail Holdings		2,451,090		2,150,090
> Thailand
Home Product Center		22,534,651		13,870,500
Robinson Department Store		3,271,700		1,167,300
> Hong Kong
Melco International		2,616,000		2,114,000
Vitasoy International		3,698,000		3,594,000
> Malaysia
Astro Malaysia Holdings		5,300,000		4,800,000
> Singapore
China Everbright Water		5,345,200		0
Petra Foods		1,397,400		1,386,000
SIIC Environment		8,493,560		5,400,000
> Cambodia
Nagacorp		6,300,000		4,715,000

COLUMBIA ACORN EMERGING MARKETS FUND^SM

MAJOR PORTFOLIO CHANGES IN THE THIRD QUARTER (UNAUDITED), CONTINUED

	Number of Shares
	6/30/15		9/30/15
Sales (continued)
Latin America
> Mexico
Grupo Aeroportuario del Sureste - ADR		48,525		30,525
> Colombia
Isagen		6,047,782		5,494,871
> Chile
Forus		1,586,000		913,508
Other Countries
> South Africa
Coronation Fund Managers		1,795,460		1,665,833
Rand Merchant Insurance		2,262,148		1,929,663
Europe
> Finland
Tikkurila		290,000		180,000

COLUMBIA ACORN EMERGING MARKETS FUND^SM

STATEMENT OF INVESTMENTS (UNAUDITED), SEPTEMBER 30, 2015

Number of Shares			Value
			Equities: 94.0%
Asia 69.1%
		> China 16.3%
	3,947,000	CAR Inc (a)(b)	$	5,713,246
		Consolidator of Chinese Auto Rental Sector
	183,613	BitAuto - ADR (a)		5,466,159
		Automotive Information Website for Buyers & Dealers
	3,580,000	TravelSky Technology		4,527,863
		Chinese Air Travel Transaction Processor
	11,951,000	Sihuan Pharmaceutical Holdings Group (c)		4,498,634
		Chinese Generic Drug Manufacturer
	134,000	51job - ADR (a)(b)		3,671,600
		Integrated Human Resource Services
	3,757,000	CapitaLand Retail China Trust		3,610,635
		China Commercial Property Real Estate Investment Trust
	2,200,000	Phoenix Healthcare Group		3,591,119
		Private Hospital Management Group
	2,488,000	China Everbright International		3,495,193
		Municipal Waste Operator
	8,032,000	AMVIG Holdings		3,345,862
		Chinese Tobacco Packaging Material Supplier
	4,140,000	Xinhua Winshare Publishing		3,273,161
		Sichuan Publisher, Distributor & Retailer
	15,338,000	Jiangnan Group		3,161,464
		Cable & Wire Manufacturer
	8,230,000	NewOcean Energy		3,109,563
		Southern China Liquefied Petroleum Gas Distributor
	1,086,300	Shanghai Industrial		2,409,961
		Shanghai State Owned Enterprise
				49,874,460
		> India 13.8%
	2,422,982	Zee Entertainment Enterprises		14,553,542
		Indian Programmer of Pay Television Content
	1,737,269	Adani Ports & Special Economic Zone		7,936,288
		Indian West Coast Shipping Port
	380,700	Colgate Palmolive India		5,583,449
		Consumer Products in Oral Care
	318,483	United Breweries		4,288,665
		Indian Brewer
	175,000	Container Corporation of India		3,961,761
		Railway Cargo Services
	730,342	Bharti Infratel		3,957,347
		Communications Towers
	110,352	Amara Raja		1,738,079
		Indian Maker of Auto & Industrial Batteries, Mostly for the Replacement Market
				42,019,131
		> Taiwan 13.0%
	3,050,000	Far EasTone Telecom		6,577,898
		Mobile Operator in Taiwan

Number of Shares			Value
	420,000	St. Shine Optical	$	5,153,114
		Disposable Contact Lens Original Equipment Manufacturer
	431,000	Silergy		4,211,704
		Chinese Provider of Analog & Mixed Digital Integrated Circuits
	575,988	Advantech		3,955,397
		Industrial PC & Components
	3,243,000	Vanguard International Semiconductor		3,693,537
		Semiconductor Foundry
	277,156	Voltronic Power		3,606,668
		Uninterruptible Power Supply Products
	340,000	Ginko International		3,423,838
		Contact Lens Maker in China
	40,000	Largan Precision		3,121,798
		Mobile Device Camera Lenses & Modules
	500,000	President Chain Store		3,118,341
		Convenience Chain Store Operator in Taiwan
	881,000	Novatek Microelectronics		2,765,980
		Display Related Integrated Circuit Designer
				39,628,275
		> Indonesia 6.4%
	59,081,400	MNC Sky Vision (a)		5,994,180
		Satellite Pay TV Operator in Indonesia
	22,620,000	Surya Citra Media		4,253,449
		Free to Air TV Station in Indonesia
	10,000,000	Link Net (a)		3,072,172
		Fixed Broadband & Cable TV Service Provider
	2,761,700	Matahari Department Store		3,050,329
		Department Store Chain in Indonesia
	4,074,200	Tower Bersama Infrastructure (a)		1,821,938
		Communications Towers
	45,639,400	Arwana Citramulia		1,392,121
		Ceramic Tiles for Home Decoration
				19,584,189
		> Philippines 5.1%
	56,400,000	RFM Corporation		4,827,471
		Flour, Bread, Pasta & Ice Cream Manufacturer/Distributor in the Philippines
	6,742,200	Puregold Price Club		4,471,720
		Supermarket Operator in the Philippines
	2,150,090	Robinsons Retail Holdings		3,363,137
		Multi-format Retailer in the Philippines
	34,926,300	Melco Crown (Philippines) Resorts (a)		2,792,145
		Integrated Resort Operator in Manila
				15,454,473
		> Thailand 4.2%
	8,732,800	Samui Airport Property Fund		4,667,759
		Thai Airport Operator
	8,700,000	Mega Lifesciences		4,395,612
		Manufacturer of Health Supplements & Pharmaceutical Products

COLUMBIA ACORN EMERGING MARKETS FUND^SM

STATEMENT OF INVESTMENTS (UNAUDITED), CONTINUED

Number of Shares			Value
		> Thailand—continued
	13,870,500	Home Product Center	$	2,621,620
		Home Improvement Retailer
	1,167,300	Robinson Department Store		1,226,081
		Department Store Operator in Thailand
				12,911,072
		> Korea 2.9%
	241,088	Koh Young Technology		6,992,414
		Inspection Systems for Printed Circuit Boards
	4,038	KCC		1,410,729
		Paint & Housing Material Manufacturer
	27,983	CJ Hellovision		265,278
		Cable TV, Broadband & Mobile Virtual Network Operator
	343	Nongshim Holdings		42,249
		Holding Company of Food Conglomerate
				8,710,670
		> Hong Kong 2.6%
	3,594,000	Vitasoy International		5,314,449
		Hong Kong Soy Food Brand
	2,114,000	Melco International		2,598,850
		Macau Casino Operator
				7,913,299
		> Malaysia 2.1%
	10,000,000	7-Eleven Malaysia Holdings		3,366,033
		Exclusive 7-Eleven Franchisor for Malaysia
	4,800,000	Astro Malaysia Holdings		3,077,379
		Pay TV Operator in Malaysia
				6,443,412
		> Singapore 1.8%
	5,400,000	SIIC Environment (a)		3,190,878
		Waste Water Treatment Operator
	1,386,000	Petra Foods		2,446,746
		Chocolate Manufacturer in Southeast Asia
				5,637,624
		> Cambodia 0.9%
	4,715,000	Nagacorp		2,835,339
		Casino & Entertainment Complex in Cambodia
Asia: Total				211,011,944
Latin America 10.1%
		> Mexico 4.3%
	3,748,000	Qualitas (a)		5,152,561
		Auto Insurer in Mexico & Central America
	30,525	Grupo Aeroportuario del Sureste - ADR		4,648,042
		Mexican Airport Operator
	2,747,000	Hoteles City Express (a)		3,542,440
		Budget Hotel Operator in Mexico
				13,343,043

Number of Shares			Value
		> Brazil 3.4%
	595,970	Localiza Rent a Car	$	3,670,976
		Car Rental
	1,471,400	Odontoprev		3,633,499
		Dental Insurance
	280,000	Linx		3,041,897
		Retail Management Software in Brazil
				10,346,372
		> Colombia 1.7%
	5,494,871	Isagen		5,125,074
		Colombian Electricity Provider
		> Chile 0.7%
	913,508	Forus		2,055,027
		Multi-brand Latin American Wholesaler & Retailer
Latin America: Total				30,869,516
Other Countries 7.8%
		> South Africa 4.4%
	1,665,833	Coronation Fund Managers		7,848,053
		South African Fund Manager
	1,929,663	Rand Merchant Insurance		5,767,337
		Directly Sold Property & Casualty Insurance; Holdings in other Insurers
				13,615,390
		> Egypt 2.2%
	975,991	Commercial International Bank of Egypt		6,630,891
		Private Universal Bank in Egypt
		> United States 1.2%
	158,000	Bladex		3,657,700
		Latin American Trade Financing House
Other Countries: Total				23,903,981
Europe 7.0%
		> United Kingdom 3.5%
	7,207,000	Cable and Wireless		6,039,922
		Telecommunications Service Provider in the Caribbean
	736,860	PureCircle (a)		4,737,409
		Natural Sweeteners
				10,777,331
		> Kazakhstan 2.5%
	1,268,483	Halyk Savings Bank of Kazakhstan - GDR (b)		7,496,734
		Retail Bank & Insurer in Kazakhstan
		> Finland 1.0%
	180,000	Tikkurila		2,986,809
		Decorative & Industrial Paint in Scandinavia, Central & Eastern Europe
Europe: Total				21,260,874
Total Equities: 94.0% (Cost: $349,288,967)			287,046,315(d)

Number of Shares			Value
Short-Term Investments 5.3%
	16,245,671	JPMorgan U.S. Government Money Market Fund, IM Shares (7 day yield of 0.01%)	$	16,245,671
Total Short-Term Investments: 5.3% (Cost: $16,245,671)				16,245,671
Securities Lending Collateral 1.3%
	3,979,700	Dreyfus Government Cash Management Fund, Institutional Shares (7 day yield of 0.01%) (e)		3,979,700
Total Securities Lending Collateral: 1.3% (Cost: $3,979,700)				3,979,700
Total Investments: 100.6% (Cost: $369,514,338)(f)				307,271,686	(g)
Obligation to Return Collateral for Securities Loaned: (1.3)%				(3,979,700	)
Cash and Other Assets Less Liabilities: 0.7%				2,170,734
Net Assets: 100.0%			$	305,462,720

ADR - American Depositary Receipts

GDR - Global Depositary Receipts

> Notes to Statement of Investments

(a) Non-income producing security.

(b) All or a portion of this security was on loan at September 30, 2015. The total market value of securities on loan at September 30, 2015 was $3,768,609.

(d) On September 30, 2015, the Fund's total equity investments were denominated in currencies as follows:

Currency	Value		Percentage of Net Assets
Hong Kong Dollar	$	47,874,704		15.7
Indian Rupee		42,019,131		13.8
Taiwan Dollar		39,628,275		13.0
U.S. Dollar		24,940,235		8.2
Indonesian Rupiah		19,584,189		6.4
Philippine Peso		15,454,472		5.0
Other currencies less than 5% of total net assets		97,545,309		31.9
Total Equities	$	287,046,315		94.0

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

(f) At September 30, 2015, for federal income tax purposes, the cost of investments was approximately $369,514,338 and net unrealized depreciation was $62,242,652 consisting of gross unrealized appreciation of $20,417,260 and gross unrealized depreciation of $82,659,912.

(g) Securities are valued using policies described in the Notes to Financial Statements in the shareholder report dated June 30, 2015.

COLUMBIA ACORN EMERGING MARKETS FUND^SM

STATEMENT OF INVESTMENTS (UNAUDITED), CONTINUED

> Notes to Statement of Investments

Fair Value Measurements

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

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

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

The Committee is responsible for applying the Trust's Portfolio Pricing Policy and the CWAM pricing procedures (the Policies), which are approved by and subject to the oversight of the Board.

The following table summarizes the inputs used, as of September 30, 2015, 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	$	9,137,759	$	197,375,551	$	4,498,634	$	211,011,944
Latin America		30,869,516		-		-		30,869,516
Other Countries		3,657,700		20,246,281		-		23,903,981
Europe		-		21,260,874		-		21,260,874
Total Equities		43,664,975		238,882,706		4,498,634		287,046,315
Total Short-Term Investments		16,245,671		-		-		16,245,671
Total Securities Lending Collateral		3,979,700		-		-		3,979,700
Total Investments	$	63,890,346	$	238,882,706	$	4,498,634	$	307,271,686

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

> Notes to Statement of Investments

The following table reconciles asset balances for the period ended September 30, 2015, in which significant observable and/or unobservable inputs (Level 3) were used in determining value:

Investments in Securities	Balance as of December 31, 2014		Realized Gain (Loss)		Change in Unrealized Appreciation (Depreciation)			Purchases		Sales		Transfers Into Level 3		Transfers out of Level 3		Balance as of September 30, 2015
Equities
Asia	$	-	$	-	$	(3,450,678	)	$	-	$	-	$	7,949,312	$	-	$	4,498,634

The change in unrealized depreciation attributed to securities owned at September 30, 2015, which were valued using significant unobservable inputs (Level 3), amounted to $3,450,678.

Quantitative information pertaining to Level 3 unobservable fair value measurements

Fair Value at
September 30, 2015

Valuation Technique(s)

Unobservable Input(s)

Range (Weighted
Average)

Equities
Asia

4,498,634

Float price
with market index

Discount for lack
of liquidity

%-16%

The following table shows transfers between Level 2 and Level 3 of the fair value hierarchy:

Transfers In				Transfers Out
Level 2		Level 3		Level 2		Level 3
$	-	$	7,949,312	$	7,949,312	$	-

Transfers in and/or out of Level 3 are determined based on the fair value at the beginning of the period for security positions held throughout the period.

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

COLUMBIA ACORN EMERGING MARKETS FUND^SM

PORTFOLIO DIVERSIFICATION (UNAUDITED)

At September 30, 2015, the Fund's portfolio investments as a percentage of net assets were diversified as follows:

	Value		Percentage of Net Assets
> Information
Entertainment Programming	$	14,553,542		4.7
Mobile Communications		12,357,183		4.0
Semiconductors & Related Equipment		10,671,221		3.5
Internet Related		9,137,759		3.0
Satellite Broadcasting & Services		9,071,559		3.0
Business Software		7,569,760		2.5
Computer Hardware & Related Equipment		7,562,065		2.5
Instrumentation		6,992,414		2.3
Telephone & Data Services		6,039,922		2.0
TV Broadcasting		4,253,449		1.4
Cable TV		3,337,450		1.1
Telecommunications Equipment		3,121,798		1.0
		94,668,122		31.0
> Consumer Goods & Services
Retail		26,545,449		8.7
Food & Beverage		21,614,740		7.1
Travel		12,926,662		4.2
Consumer Goods Distribution		9,979,061		3.2
Casinos & Gaming		8,226,334		2.7
Other Durable Goods		1,738,079		0.6
		81,030,325		26.5
> Finance
Banks		17,785,325		5.8
Insurance		14,553,397		4.8
Brokerage & Money Management		7,848,053		2.6
		40,186,775		13.2
> Industrial Goods & Services
Industrial Materials & Specialty Chemicals		9,135,521		3.0
Other Industrial Services		7,936,288		2.6
Waste Management		3,495,193		1.2
Water		3,190,878		1.0
Electrical Components		3,161,464		1.0
Conglomerates		2,452,210		0.8
		29,371,554		9.6

	Value			Percentage of Net Assets
> Other Industries
Transportation	$	13,277,562			4.3
Regulated Utilities		5,125,074			1.7
Real Estate		3,610,635			1.2
		22,013,271			7.2
> Health Care
Medical Supplies		8,576,952			2.8
Pharmaceuticals		4,498,634			1.5
Hospital Management		3,591,119			1.2
		16,666,705			5.5
> Energy & Minerals
Oil Refining, Marketing & Distribution		3,109,563			1.0
		3,109,563			1.0
Total Equities:		287,046,315			94.0
Short-Term Investments:		16,245,671			5.3
Securities Lending Collateral:		3,979,700			1.3
Total Investments:		307,271,686			100.6
Obligation to Return Collateral for Securities Loaned:		(3,979,700	)		(1.3	)
Cash and Other Assets Less Liabilities:		2,170,734			0.7
Net Assets:	$	305,462,720			100.0

COLUMBIA ACORN EUROPEAN FUND^SM

MAJOR PORTFOLIO CHANGES IN THE THIRD QUARTER (UNAUDITED)

	Number of Shares
	6/30/15		9/30/15
Purchases
Europe
> United Kingdom
Assura		1,811,485		1,990,765
Cable and Wireless		1,043,540		1,091,240
Cambian		204,460		213,850
Connect Group		225,231		239,871
Domino's Pizza UK & Ireland		44,010		51,500
Elementis		114,720		141,140
Halfords		81,000		99,490
Halma		46,890		48,730
Jardine Lloyd Thompson Group		35,000		36,320
Ocado		95,010		99,190
Regus		137,120		145,000
Spirax Sarco		24,357		27,267
WH Smith		35,360		36,670
> Sweden
Hexagon		24,633		26,343
Mekonomen		25,800		46,940
Modern Times Group		21,470		31,850
Recipharm		44,030		64,280
Sweco		63,050		65,250
Trelleborg		0		36,320
Unibet		14,591		15,131
> Germany
Aurelius		27,900		31,360
Elringklinger		18,950		22,890
MTU Aero Engines		9,730		13,200
NORMA Group		19,770		24,150
Wirecard		18,900		27,390
> France
AKKA Technologies		17,288		18,048
Bonduelle		19,310		20,830
Eutelsat		32,020		34,750
Neopost		27,860		33,020
Saft		13,821		14,431
> Netherlands
Aalberts Industries		32,560		33,820
Arcadis		20,005		36,405
Brunel		35,741		35,971
Gemalto		6,060		10,780
Vopak		11,490		12,010
> Finland
Konecranes		25,836		30,850
Munksjo		185,880		189,960
Sponda		160,990		167,120
Tikkurila		33,751		37,441

	Number of Shares
	6/30/15		9/30/15
> Switzerland
Geberit		2,530		3,230
INFICON		1,530		2,040
Panalpina Welttransport Holding		0		5,380
> Spain
Bolsas y Mercados Españoles		12,520		13,530
Distribuidora Internacional de Alimentación		202,320		263,590
Prosegur		142,750		182,250
Viscofan		8,720		9,070
> Denmark
William Demant Holding		14,000		14,330
> Norway
Atea		62,050		113,560
> Italy
Hera		105,433		195,200
Industria Macchine Automatiche		10,540		11,280
> Belgium
EVS Broadcast Equipment		19,420		20,210

COLUMBIA ACORN EUROPEAN FUND^SM

MAJOR PORTFOLIO CHANGES IN THE THIRD QUARTER (UNAUDITED), CONTINUED

	Number of Shares
	6/30/15		9/30/15
Sales
Europe
> United Kingdom
Abcam		66,010		64,937
Aggreko		33,220		0
AVEVA		20,150		0
Babcock International		49,910		39,480
> France
HiPay		23,940		6,856

COLUMBIA ACORN EUROPEAN FUND^SM

STATEMENT OF INVESTMENTS (UNAUDITED), SEPTEMBER 30, 2015

Number of Shares			Value
			Equities: 95.3%
Europe 95.3%
		> United Kingdom 27.5%
	1,990,765	Assura	$	1,648,812
	383,513	Assura Rights (b)(c)		27,557
		UK Primary Health Care Property Developer
	384,788	Charles Taylor		1,429,026
		Insurance Services
	27,267	Spirax Sarco		1,155,360
		Steam Systems for Manufacturing & Process Industries
	1,091,240	Cable and Wireless		914,528
		Telecommunications Service Provider in the Caribbean
	213,850	Cambian		910,657
		Mental Health Facilities & Programs
	36,670	WH Smith		867,590
		Newsprint, Books & General Stationery Retailer
	99,490	Halfords		695,025
		UK Retailer of Leisure Goods & Auto Parts
	51,500	Domino's Pizza UK & Ireland		691,811
		Pizza Delivery in the UK, Ireland & Germany
	70,640	Dialight (a)		679,099
		LED Products for Hazardous & Industrial Environments
	145,000	Regus		672,523
		Rental of Office Space in Full Service Business Centers
	23,460	Fidessa Group		636,674
		Software for Financial Trading Systems
	97,930	PureCircle (b)		629,610
		Natural Sweeteners
	125,110	Polypipe		624,085
		Manufacturer of Plastic Piping & Fittings
	10,760	Rightmove		593,792
		Internet Real Estate Listings
	64,937	Abcam		570,736
		Online Sales of Antibodies
	239,871	Connect Group		569,698
		Newspaper & Magazine Distributor
	36,320	Jardine Lloyd Thompson Group		559,870
		International Business Insurance Broker
	39,480	Babcock International		544,975
		Public Sector Outsourcer
	48,730	Halma		531,863
		Health & Safety Sensor Technology
	99,190	Ocado (b)		480,159
		Online Grocery Retailer
	141,140	Elementis		476,553
		Specialty Chemicals
				15,910,003

Number of Shares			Value
		> Sweden 12.8%
	15,131	Unibet	$	1,265,444
		European Online Gaming Operator
	64,280	Recipharm		1,175,018
		Contract Development Manufacturing Organization
	46,940	Mekonomen		1,087,982
		Nordic Integrated Wholesaler/Retailer of Automotive Parts & Service
	65,250	Sweco (a)		904,306
		Engineering Consultants
	31,850	Modern Times Group		818,516
		Nordic TV Broadcaster
	26,343	Hexagon		803,513
		Design, Measurement & Visualization Software & Equipment
	25,662	Swedish Match		774,770
		Swedish Snus
	36,320	Trelleborg		574,528
		Manufacturer of Sealing, Dampening & Protective Solutions for Industry
				7,404,077
		> Germany 11.5%
	31,360	Aurelius		1,456,506
		European Turnaround Investor
	27,390	Wirecard (a)		1,307,011
		Online Payment Processing & Risk Management
	24,150	NORMA Group		1,185,325
		Clamps for Automotive & Industrial Applications
	13,200	MTU Aero Engines		1,103,128
		Airplane Engine Components & Services
	1,480	Rational		591,134
		Commercial Ovens
	94,780	Telefonica Deutschland		578,359
		Mobile & Fixed-line Communications in Germany
	22,890	Elringklinger		439,929
		Automobile Components
				6,661,392
		> France 8.0%
	34,750	Eutelsat		1,063,932
		Fixed Satellite Services
	33,020	Neopost		858,951
		Postage Meter Machines
	15,360	Cegedim (b)		617,877
		Medical Market Research/IT Services
	1,900	Eurofins Scientific		583,204
		Food, Pharmaceuticals & Materials Screening & Testing
	20,830	Bonduelle		535,335
		Producer of Canned, Deep-frozen & Fresh Vegetables
	14,431	Saft		471,501
		Niche Battery Manufacturer
	18,048	AKKA Technologies		466,056
		Engineering Consultancy
	6,856	HiPay (a)(b)		53,856
		Micropayment & Payment Processing
				4,650,712

COLUMBIA ACORN EUROPEAN FUND^SM

STATEMENT OF INVESTMENTS (UNAUDITED), CONTINUED

Number of Shares			Value
		> Netherlands 7.1%
	33,820	Aalberts Industries	$	999,935
		Flow Control & Heat Treatment
	36,405	Arcadis		854,461
		Engineering Consultants
	10,780	Gemalto		698,763
		Digital Security Solutions
	35,971	Brunel		609,140
		Temporary Specialist & Energy Staffing
	12,010	Vopak		478,892
		Operator of Petroleum & Chemical Storage Terminals
	4,400	Core Labs (a)		439,120
		Oil & Gas Reservoir Consulting
				4,080,311
		> Finland 6.3%
	92,850	Munksjo (d)		815,354
	97,110	Munksjo		813,830
		Specialty Paper Maker
	30,850	Konecranes (a)		770,789
		Manufacture & Service of Industrial Cranes & Port Handling Equipment
	167,120	Sponda		652,096
		Office, Retail & Logistics Properties
	37,441	Tikkurila		621,273
		Decorative & Industrial Paint in Scandinavia, Central & Eastern Europe
				3,673,342
		> Switzerland 6.3%
	4,480	Partners Group		1,518,079
		Private Markets Asset Management
	3,230	Geberit		986,632
		Plumbing Systems
	5,380	Panalpina Welttransport Holding		587,903
		Air & Sea Freight Forwarding
	2,040	INFICON		569,341
		Gas Detection Instruments
				3,661,955
		> Spain 6.0%
	263,590	Distribuidora Internacional de Alimentación		1,591,375
		Discount Retailer in Spain & Latin America
	182,250	Prosegur		875,678
		Security Guards
	9,070	Viscofan		546,064
		Sausage Casings Maker
	13,530	Bolsas y Mercados Españoles		456,727
		Spanish Stock Markets
				3,469,844
		> Denmark 4.3%
	25,640	SimCorp		1,290,188
		Software for Investment Managers
	14,330	William Demant Holding (b)		1,191,064
		Manufacture & Distribution of Hearing Aids & Diagnostic Equipment
				2,481,252

Number of Shares			Value
		> Norway 2.9%
	113,560	Atea	$	1,043,799
		Nordic IT Hardware/Software Reseller & Integrator
	87,370	Orkla		647,588
		Food & Brands, Aluminum, Chemicals Conglomerate
				1,691,387
		> Italy 1.7%
	195,200	Hera		506,466
		Northern Italian Utility
	11,280	Industria Macchine Automatiche		504,171
		Food & Drugs Packaging & Machinery
				1,010,637
		> Belgium 0.9%
	20,210	EVS Broadcast Equipment		522,111
		Digital Live Mobile Production Software & Systems
Europe: Total				55,217,023
Total Equities: 95.3% (Cost: $56,042,373)			55,217,023(e)
Short-Term Investments 7.5%
	4,342,051	JPMorgan U.S. Government Money Market Fund, IM Shares (7 day yield of 0.01%)		4,342,051
Total Short-Term Investments: 7.5% (Cost: $4,342,051)				4,342,051
Securities Lending Collateral 3.9%
	2,252,502	Dreyfus Government Cash Management Fund, Institutional Shares (7 day yield of 0.01%) (f)		2,252,502
Total Securities Lending Collateral: 3.9% (Cost: $2,252,502)				2,252,502
Total Investments: 106.7% (Cost: $62,636,926)(g)				61,811,576	(h)
Obligation to Return Collateral for Securities Loaned: (3.9)%				(2,252,502	)
Cash and Other Assets Less Liabilities: (2.8)%				(1,652,615	)
Net Assets: 100.0%			$	57,906,459

> Notes to Statement of Investments

(a) All or a portion of this security was on loan at September 30, 2015. The total market value of securities on loan at September 30, 2015 was $2,185,268.

(b) Non-income producing security.

(d) Security is traded on a Swedish exchange.

(e) On September 30, 2015, the Fund's total equity investments were denominated in currencies as follows:

Currency	Value		Percentage of Net Assets
Euro	$	22,813,874		39.4
British Pound		15,910,003		27.5
Swedish Krona		8,219,432		14.2
Swiss Franc		3,661,955		6.3
Other currencies less than 5% of total net assets		4,611,759		7.9
Total Equities	$	55,217,023		95.3

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

(g) At September 30, 2015, for federal income tax purposes, the cost of investments was approximately $62,636,926 and net unrealized depreciation was $825,350 consisting of gross unrealized appreciation of $4,904,772 and gross unrealized depreciation of $5,730,122.

(h) Securities are valued using policies described in the Notes to Financial Statements in the shareholder report dated June 30, 2015.

Fair Value Measurements

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

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

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

The Committee is responsible for applying the Trust's Portfolio Pricing Policy and the CWAM pricing procedures (the Policies), which are approved by and subject to the oversight of the Board.

COLUMBIA ACORN EUROPEAN FUND^SM

STATEMENT OF INVESTMENTS (UNAUDITED), CONTINUED

> Notes to Statement of Investments

The following table summarizes the inputs used, as of September 30, 2015, 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	$	439,120	$	54,777,903	$	-	$	55,217,023
Total Equities		439,120		54,777,903		-		55,217,023
Total Short-Term Investments		4,342,051		-		-		4,342,051
Total Securities Lending Collateral		2,252,502		-		-		2,252,502
Total Investments	$	7,033,673	$	54,777,903	$	-	$	61,811,576

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

COLUMBIA ACORN EUROPEAN FUND^SM

PORTFOLIO DIVERSIFICATION (UNAUDITED)

At September 30, 2015, the Fund's portfolio investments as a percentage of net assets were diversified as follows:

	Value		Percentage of Net Assets
> Industrial Goods & Services
Machinery	$	5,635,071		9.7
Other Industrial Services		4,033,002		7.0
Industrial Materials & Specialty Chemicals		3,741,467		6.5
Outsourcing Services		3,168,372		5.5
Conglomerates		3,104,029		5.3
Construction		1,610,717		2.8
Electrical Components		1,150,600		2.0
		22,443,258		38.8
> Information
Business Software		2,730,375		4.7
Computer Services		1,661,676		2.9
Telephone & Data Services		1,492,887		2.6
Financial Processors		1,307,011		2.3
Computer Hardware & Related Equipment		1,220,874		2.1
Satellite Broadcasting & Services		1,063,932		1.8
TV Broadcasting		818,516		1.4
Internet Related		647,648		1.1
Instrumentation		531,863		0.9
		11,474,782		19.8
> Consumer Goods & Services
Retail		4,722,131		8.1
Food & Beverage		2,485,779		4.3
Casinos & Gaming		1,265,444		2.2
Restaurants		691,811		1.2
Consumer Goods Distribution		569,698		1.0
		9,734,863		16.8
> Finance
Insurance		1,988,896		3.4
Brokerage & Money Management		1,518,079		2.6
Financial Processors		456,727		0.8
		3,963,702		6.8
> Health Care
Medical Equipment & Devices		1,191,064		2.0
Pharmaceuticals		1,175,018		2.0
Health Care Services		910,657		1.6
Medical Supplies		570,736		1.0
		3,847,475		6.6
> Other Industries
Real Estate		2,328,465		4.0
Regulated Utilities		506,466		0.9
		2,834,931		4.9

	Value			Percentage of Net Assets
> Energy & Minerals
Oil Refining, Marketing & Distribution	$	478,892			0.8
Mining		439,120			0.8
		918,012			1.6
Total Equities:		55,217,023			95.3
Short-Term Investments:		4,342,051			7.5
Securities Lending Collateral:		2,252,502			3.9
Total Investments:		61,811,576			106.7
Obligation to Return Collateral for Securities Loaned:		(2,252,502	)		(3.9	)
Cash and Other Assets Less Liabilities:		(1,652,615	)		(2.8	)
Net Assets:	$	57,906,459			100.0

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COLUMBIA ACORN FAMILY OF FUNDS EXPENSE INFORMATION

as of 9/30/15

Columbia Acorn® Fund	Class A			Class B^(a)			Class C			Class I			Class R			Class R4			Class R5			Class Y			Class Z
Management Fees		0.65	%		0.65	%		0.65	%		0.65	%					0.65	%		0.65	%		0.65	%		0.65	%
Distribution and Service (12b-1) Fees		0.25	%		0.75	%		1.00	%		0.00	%					0.00	%		0.00	%		0.00	%		0.00	%
Other Expenses		0.19	%		0.53	%		0.15	%		0.08	%					0.22	%		0.12	%		0.07	%		0.15	%
Net Expense Ratio		1.09	%		1.93	%		1.80	%		0.73	%					0.87	%		0.77	%		0.72	%		0.80	%
Columbia Acorn International®
Management Fees		0.76	%		0.76	%		0.76	%		0.76	%		0.76	%		0.76	%		0.76	%		0.76	%		0.76	%
Distribution and Service (12b-1) Fees		0.25	%		0.75	%		1.00	%		0.00	%		0.50	%		0.00	%		0.00	%		0.00	%		0.00	%
Other Expenses		0.23	%		0.59	%		0.22	%		0.12	%		0.35	%		0.29	%		0.16	%		0.11	%		0.20	%
Net Expense Ratio		1.24	%		2.10	%		1.98	%		0.88	%		1.61	%		1.05	%		0.92	%		0.87	%		0.96	%
Columbia Acorn USA®
Management Fees		0.87	%		0.87	%		0.87	%		0.87	%					0.87	%		0.87	%		0.87	%		0.87	%
Distribution and Service (12b-1) Fees		0.25	%		0.75	%		1.00	%		0.00	%					0.00	%		0.00	%		0.00	%		0.00	%
Other Expenses		0.22	%		0.97	%		0.15	%		0.06	%					0.23	%		0.14	%		0.09	%		0.22	%
Net Expense Ratio		1.34	%		2.59	%		2.02	%		0.93	%					1.10	%		1.01	%		0.96	%		1.09	%
Columbia Acorn International Select^SM
Management Fees		0.94	%		0.94	%		0.94	%		0.94	%					0.94	%		0.94	%		0.94	%		0.94	%
Distribution and Service (12b-1) Fees		0.25	%		0.75	%		1.00	%		0.00	%					0.00	%		0.00	%		0.00	%		0.00	%
Other Expenses		0.35	%		0.51	%		0.37	%		0.25	%					0.33	%		0.27	%		0.21	%		0.30	%
Net Expense Ratio		1.54	%		2.20	%		2.31	%		1.19	%					1.27	%		1.21	%		1.15	%		1.24	%
Columbia Acorn Select^SM
Management Fees		0.74	%		0.74	%		0.74	%		0.74	%					0.74	%		0.74	%		0.74	%		0.74	%
Distribution and Service (12b-1) Fees		0.25	%		0.75	%		1.00	%		0.00	%					0.00	%		0.00	%		0.00	%		0.00	%
Other Expenses		0.25	%		0.61	%		0.23	%		0.10	%					0.26	%		0.21	%		0.12	%		0.22	%
Net Expense Ratio		1.24	%		2.10	%		1.97	%		0.84	%					1.00	%		0.95	%		0.86	%		0.96	%
Columbia Thermostat Fund^SM
Management Fees		0.10	%		0.10	%		0.10	%								0.10	%		0.10	%		0.10	%		0.10	%
Distribution and Service (12b-1) Fees		0.25	%		0.75	%		1.00	%								0.00	%		0.00	%		0.00	%		0.00	%
Other Expenses		0.15	%		0.15	%		0.15	%								0.15	%		0.14	%		0.09	%		0.15	%
Net Expense Ratio^(b)		0.50	%		1.00	%		1.25	%								0.25	%		0.24	%		0.19	%		0.25	%
Columbia Acorn Emerging Markets Fund^SM(c)
Management Fees		1.06	%					1.06	%		1.06	%					1.06%			1.06	%		1.06	%		1.06	%
Distribution and Service (12b-1) Fees		0.25	%					1.00	%		0.00	%					0.00%			0.00	%		0.00	%		0.00	%
Other Expenses		0.33	%					0.34	%		0.22	%					0.28%			0.26	%		0.19	%		0.33	%
Net Expense Ratio		1.64	%					2.40	%		1.28	%					1.34%			1.32	%		1.25	%		1.39	%
Columbia Acorn European Fund^SM
Management Fees		1.19	%					1.19	%		1.19	%					1.19%			1.19	%					1.19%
Distribution and Service (12b-1) Fees		0.25	%					1.00	%		0.00	%					0.00%			0.00	%					0.00%
Other Expenses		0.31	%					0.31	%		0.25	%					0.31%			0.29	%					0.31%
Net Expense Ratio		1.75	%					2.50	%		1.44	%					1.50%			1.48	%					1.50%

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 nine months ended September 30, 2015. The fees and expenses of Columbia Acorn International Select and Columbia Acorn Select include the effect of the voluntary undertaking by Columbia Wanger Asset Management, LLC (CWAM) to reimburse each Fund so that the ordinary operating expenses (excluding transaction costs and certain other investment-related expenses, interest and fees on borrowings and expenses associated with the Fund's investment in other investment companies, if any), after giving effect to any balance credits or overdraft charges from the Fund's custodian, do not exceed the following annual rates as a percentage of each class' average daily net assets:

Fund	Class A			Class B			Class C			Class I			Class R4			Class R5			Class Y			Class Z
Columbia Acorn International Select		1.70	%		2.20	%		2.45	%		1.37	%		1.45	%		1.42	%		1.37	%		1.45	%
Columbia Acorn Select		1.60	%		2.10	%		2.35	%		1.25	%		1.35	%		1.30	%		1.25	%		1.35	%

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

Effective May 1, 2015, CWAM has contractually agreed to waive 0.20% of the advisory fee otherwise payable to it by Columbia Acorn Select through April 30, 2016. When determining whether the Fund's total expenses exceed the voluntary expense cap described above, the Fund's net advisory fee, reflecting application of the 0.20% waiver, will be used to calculate the Fund's total expenses. This arrangement may only be modified or amended with approval from all parties to the arrangement, including the Fund and CWAM.

The fees and expenses of Columbia Thermostat Fund include the effect of CWAM's contractual undertaking to waive fees and/or reimburse expenses of the Fund so that the ordinary operating expenses (excluding transaction costs and certain other investment-related expenses, interest and fees on borrowings and expenses associated with the Fund's investment in underlying portfolio funds), do not exceed annually the rates of 0.50%, 1.00%, 1.25%, 0.25%, 0.24%, 0.19% and 0.25% of the Fund's average daily net assets attributable to Class A, Class B, Class C, Class R4, Class R5, Class Y and Class Z shares, respectively, through April 30, 2016. There is no guarantee that this agreement will continue thereafter.

The fees and expenses of Columbia Acorn Emerging Markets Fund and Columbia Acorn European Fund include the effect of CWAM's contractual undertaking to waive fees and/or reimburse expenses of each Fund so that the ordinary operating expenses (excluding transaction costs and certain other investment-related expenses, interest and fees on borrowings and expenses associated with the Fund's investment in other investment companies, if any), of each Fund's Class A, Class C, Class I, Class R4, Class R5, Class Y (if offered) and Class Z shares through April 30, 2016, do not exceed the following annual rates as a percentage of each class' average daily net assets:

Fund	Class A			Class C			Class I			Class R4			Class R5			Class Y			Class Z
Columbia Acorn Emerging Markets Fund		1.85	%		2.60	%		1.48	%		1.60	%		1.53	%		1.48	%		1.60	%
Columbia Acorn European Fund		1.75	%		2.50	%		1.41	%		1.50	%		1.46	%		—			1.50	%

There is no guarantee that these arrangements will continue thereafter.

The fees and expenses of Columbia Acorn International include the effect of the voluntary undertaking by Columbia Management Investment Services Corp., the Funds' transfer agent, to waive a portion of total annual Fund operating expenses attributable to transfer agency 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.

(a) 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 Acorn Family of Funds.

(b) Does not include estimated fees and expenses of 0.52% incurred by the Fund from the underlying portfolio funds in which it invests.

(c) Effective July 11, 2014, Columbia Acorn Emerging Markets Fund is closed to most new investors and new accounts, except as described in the Fund's prospectus, dated May 1, 2015.

COLUMBIA ACORN FAMILY OF FUNDS

Trustees

Laura M. Born

Chair of the Board

David J. Rudis

Vice Chair of the Board

Maureen M. Culhane

P. Zachary Egan

Margaret M. Eisen

Thomas M. Goldstein

John C. Heaton

Steven N. Kaplan

Charles R. Phillips

Ralph Wanger (Trustee Emeritus)

Officers

P. Zachary Egan

President

Alan G. Berkshire

Vice President

Robert A. Chalupnik

Vice President

Michael G. Clarke

Assistant Treasurer

Joseph F. DiMaria

Assistant Treasurer

William J. Doyle

Vice President

David L. Frank

Vice President

Paul B. Goucher

Assistant Secretary

Fritz Kaegi

Vice President

John M. Kunka

Treasurer and Principal Accounting and Financial Officer

Stephen Kusmierczak

Vice President

Joseph C. LaPalm

Vice President

Ryan C. Larrenaga

Assistant Secretary

Satoshi Matsunaga

Vice President

Charles P. McQuaid

Vice President

Louis J. Mendes

Vice President

Robert A. Mohn*

Vice President

Christopher J. Olson

Vice President

Robert P. Scales

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

Matthew S. Szafranski

Vice President

Andreas Waldburg-Wolfegg

Vice President

Linda K. Roth-Wiszowaty

Secretary

*Robert Mohn retired effective October 1, 2015.

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 columbiathreadneedle.com/us under "About Us." From there, click on "Disclosures."

The Funds file a complete schedule of portfolio holdings with the SEC for the first and third quarters of each fiscal year on Form N-Q. The Funds' Form N-Q is available on the SEC's website at www.sec.gov and may be reviewed and copied at the SEC's Public Reference Room in Washington, D.C. Information on the operation of the Public Reference Room may be obtained by calling 1-800-SEC-0330. The Funds' complete portfolio holdings are disclosed at columbiathreadneedle.com/us approximately 30 to 40 days after each month-end.

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

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

Find out what's new – visit our website at:

columbiathreadneedle.com/us

Our e-mail address is:

serviceinquiries@columbiathreadneedle.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 Acorn Family of Funds
Class A, B, C, I, R, R4, R5, Y and Z Shares

Third Quarter Report, September 30, 2015
225 Franklin Street, Boston, MA 02110

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: columbiathreadneedle.com/us

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.

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.

800.345.6611 columbiathreadneedle.com/us

QTR110_12_E01_(11/15) 1351092