Clarkston group discloses 3.21% Affiliated Managers stake (NYSE: AMG)

Rhea-AI Filing Summary

Affiliated Managers Group, Inc. received an updated ownership report showing that Clarkston Capital Partners, LLC and related entities collectively report beneficial ownership of 904,119 shares of Common Stock. This represents 3.21% of the company’s outstanding shares, based on 28,128,908 shares outstanding as of November 4, 2025.

The shares are held in accounts of Clarkston Capital’s discretionary clients or an account over which a control person has beneficial ownership. Clarkston Capital and the individual reporting persons certify that the securities were acquired and are held in the ordinary course of business and not for the purpose of changing or influencing control of Affiliated Managers Group.

SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

SCHEDULE 13G

UNDER THE SECURITIES EXCHANGE ACT OF 1934

(Amendment No. 3)

Affiliated Managers Group, Inc.

(Name of Issuer)

Common Stock

(Title of Class of Securities)

008252108

(CUSIP Number)

12/31/2025

(Date of Event Which Requires Filing of this Statement)

Check the appropriate box to designate the rule pursuant to which this Schedule is filed:

Rule 13d-1(b)

Rule 13d-1(c)

Rule 13d-1(d)

SCHEDULE 13G

CUSIP No. 008252108

1

Names of Reporting Persons

Clarkston Capital Partners, LLC

2

Check the appropriate box if a member of a Group (see instructions)

(a)
(b)

3

Sec Use Only

4

Citizenship or Place of Organization

MICHIGAN

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 452,500.00
6	Shared Voting Power 394,049.00
7	Sole Dispositive Power 452,500.00
8	Shared Dispositive Power 451,619.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

904,119.00

10

Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)

11

Percent of class represented by amount in row (9)

3.21 %

12

Type of Reporting Person (See Instructions)

IA

SCHEDULE 13G

CUSIP No. 008252108

1

Names of Reporting Persons

Clarkston Companies, Inc.

2

Check the appropriate box if a member of a Group (see instructions)

(a)
(b)

3

Sec Use Only

4

Citizenship or Place of Organization

MICHIGAN

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 452,500.00
6	Shared Voting Power 394,049.00
7	Sole Dispositive Power 452,500.00
8	Shared Dispositive Power 451,619.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

904,119.00

10

Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)

11

Percent of class represented by amount in row (9)

3.21 %

12

Type of Reporting Person (See Instructions)

HC, CO

SCHEDULE 13G

CUSIP No. 008252108

1

Names of Reporting Persons

Modell Capital LLC

2

Check the appropriate box if a member of a Group (see instructions)

(a)
(b)

3

Sec Use Only

4

Citizenship or Place of Organization

MICHIGAN

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 452,500.00
6	Shared Voting Power 394,049.00
7	Sole Dispositive Power 452,500.00
8	Shared Dispositive Power 451,619.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

904,119.00

10

Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)

11

Percent of class represented by amount in row (9)

3.21 %

12

Type of Reporting Person (See Instructions)

HC, OO

SCHEDULE 13G

CUSIP No. 008252108

1

Names of Reporting Persons

Jeffrey A. Hakala

2

Check the appropriate box if a member of a Group (see instructions)

(a)
(b)

3

Sec Use Only

4

Citizenship or Place of Organization

UNITED STATES

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 452,500.00
6	Shared Voting Power 394,049.00
7	Sole Dispositive Power 452,500.00
8	Shared Dispositive Power 451,619.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

904,119.00

10

Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)

11

Percent of class represented by amount in row (9)

3.21 %

12

Type of Reporting Person (See Instructions)

HC, IN

SCHEDULE 13G

CUSIP No. 008252108

1

Names of Reporting Persons

Gerald W. Hakala

2

Check the appropriate box if a member of a Group (see instructions)

(a)
(b)

3

Sec Use Only

4

Citizenship or Place of Organization

UNITED STATES

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 452,500.00
6	Shared Voting Power 394,049.00
7	Sole Dispositive Power 452,500.00
8	Shared Dispositive Power 451,619.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

904,119.00

10

Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)

11

Percent of class represented by amount in row (9)

3.21 %

12

Type of Reporting Person (See Instructions)

HC, IN

SCHEDULE 13G

CUSIP No. 008252108

1

Names of Reporting Persons

Jeremy J. Modell

2

Check the appropriate box if a member of a Group (see instructions)

(a)
(b)

3

Sec Use Only

4

Citizenship or Place of Organization

UNITED STATES

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 452,500.00
6	Shared Voting Power 394,049.00
7	Sole Dispositive Power 452,500.00
8	Shared Dispositive Power 451,619.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

904,119.00

10

Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)

11

Percent of class represented by amount in row (9)

3.21 %

12

Type of Reporting Person (See Instructions)

HC, IN

SCHEDULE 13G

Item 1.
(a)	Name of issuer: Affiliated Managers Group, Inc.
(b)	Address of issuer's principal executive offices: 777 South Flagler Drive, West Palm Beach, FL 33401
Item 2.
(a)	Name of person filing: This Schedule 13G/A is filed jointly pursuant to that certain Joint Filing Agreement filed herewith as Exhibit 99.1 by: (1) Clarkston Capital Partners, LLC ("CCP") (2) Clarkston Companies, Inc. ("CC") (3) Modell Capital LLC ("MC") (4) Jeffrey A. Hakala (5) Gerald W. Hakala (6) Jeremy J. Modell
(b)	Address or principal business office or, if none, residence: 303 E Third St., Suite 110, Rochester, MI 48307
(c)	Citizenship: CCP and MC are Michigan limited liability companies. CC is a Michigan corporation. Jeffrey A. Hakala, Gerald W. Hakala, and Jeremy J. Modell (the "Individual Reporting Persons") are citizens of the United States of America.
(d)	Title of class of securities: Common Stock
(e)	CUSIP No.: 008252108
Item 3.	If this statement is filed pursuant to §§ 240.13d-1(b) or 240.13d-2(b) or (c), check whether the person filing is a:
(a)	Broker or dealer registered under section 15 of the Act (15 U.S.C. 78o);
(b)	Bank as defined in section 3(a)(6) of the Act (15 U.S.C. 78c);
(c)	Insurance company as defined in section 3(a)(19) of the Act (15 U.S.C. 78c);
(d)	Investment company registered under section 8 of the Investment Company Act of 1940 (15 U.S.C. 80a-8);
(e)	An investment adviser in accordance with § 240.13d-1(b)(1)(ii)(E);
(f)	An employee benefit plan or endowment fund in accordance with § 240.13d-1(b)(1)(ii)(F);
(g)	A parent holding company or control person in accordance with § 240.13d-1(b)(1)(ii)(G);
(h)	A savings associations as defined in Section 3(b) of the Federal Deposit Insurance Act (12 U.S.C. 1813);
(i)	A church plan that is excluded from the definition of an investment company under section 3(c)(14) of the Investment Company Act of 1940 (15 U.S.C. 80a-3);
(j)	A non-U.S. institution in accordance with § 240.13d-1(b)(1)(ii)(J). If filing as a non-U.S. institution in accordance with § 240.13d-1(b)(1)(ii)(J), please specify the type of institution:
(k)	Group, in accordance with Rule 240.13d-1(b)(1)(ii)(K).
Item 4.	Ownership
(a)	Amount beneficially owned: CCP is an investment adviser. Collectively, the securities reported in this Schedule 13G/A are held in the accounts of CCP's discretionary clients or in an account over which a control person of CCP has beneficial ownership. The sole members of CCP are CC and MC. The sole owners of CC are Jeffrey A. Hakala and Gerald W. Hakala. The sole member of MC is the Jeremy J. Modell Revocable Living Trust. The information required by Item 4(a) is set forth in Row 9 of the cover page for each of the Reporting Persons and is incorporated herein by reference. Based upon 28,128,908 shares of Common Stock, par value $0.01 per share ("Common Stock"), of Affiliated Managers Group, Inc. (the "Issuer") outstanding as of November 4, 2025, as reported in the Issuer's quarterly report on Form 10-Q filed with the Securities and Exchange Commission on November 6, 2025.
(b)	Percent of class: 3.21%
(c)	Number of shares as to which the person has:
	(i) Sole power to vote or to direct the vote: 452,500
	(ii) Shared power to vote or to direct the vote: 394,049
	(iii) Sole power to dispose or to direct the disposition of: 452,500
	(iv) Shared power to dispose or to direct the disposition of: 451,619
Item 5.	Ownership of 5 Percent or Less of a Class.
	Ownership of 5 percent or less of a class
Item 6.	Ownership of more than 5 Percent on Behalf of Another Person.
	If any other person is known to have the right to receive or the power to direct the receipt of dividends from, or the proceeds from the sale of, such securities, a statement to that effect should be included in response to this item and, if such interest relates to more than 5 percent of the class, such person should be identified. A listing of the shareholders of an investment company registered under the Investment Company Act of 1940 or the beneficiaries of employee benefit plan, pension fund or endowment fund is not required. The shares reported in this statement have been purchased by CCP on behalf of CCP's discretionary clients or by a control person of CCP in an account over which such control person has beneficial ownership. CCP's clients have the right to receive or the power to direct the receipt of dividends from, or the proceeds from the sale of such securities held in their accounts, subject to CCP's general authority to invest and reinvest the assets in each account under its management.
Item 7.	Identification and Classification of the Subsidiary Which Acquired the Security Being Reported on by the Parent Holding Company or Control Person.
	If a parent holding company has filed this schedule, pursuant to Rule 13d-1(b)(ii)(G), so indicate under Item 3(g) and attach an exhibit stating the identity and the Item 3 classification of the relevant subsidiary. If a parent holding company has filed this schedule pursuant to Rule 13d-1(c) or Rule 13d-1(d), attach an exhibit stating the identification of the relevant subsidiary. With respect to CC, MC and the Individual Reporting Persons, see Item 4.
Item 8.	Identification and Classification of Members of the Group.
	Not Applicable
Item 9.	Notice of Dissolution of Group.
	Not Applicable

Item 10.

Certifications:

By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were acquired and are held in the ordinary course of business and were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having that purpose or effect, other than activities solely in connection with a nomination under ?? 240.14a-11.

SIGNATURE

After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

Clarkston Capital Partners, LLC

Signature:	/s/ Jeffrey A. Hakala
Name/Title:	Chief Executive Officer
Date:	02/13/2026

Clarkston Companies, Inc.

Signature:	/s/ Jeffrey A. Hakala
Name/Title:	Chief Executive Officer and President
Date:	02/13/2026

Modell Capital LLC

Signature:	/s/ Jeremy J. Modell
Name/Title:	Member
Date:	02/13/2026

Jeffrey A. Hakala

Signature:	/s/ Jeffrey A. Hakala
Name/Title:	Jeffrey A. Hakala
Date:	02/13/2026

Gerald W. Hakala

Signature:	/s/ Gerald W. Hakala
Name/Title:	Gerald W. Hakala
Date:	02/13/2026

Jeremy J. Modell

Signature:	/s/ Jeremy J. Modell
Name/Title:	Jeremy J. Modell
Date:	02/13/2026

Exhibit Information

Joint Filing Agreement

FAQ

What ownership stake in Affiliated Managers Group (AMG) does Clarkston report?

Clarkston-affiliated reporting persons disclose beneficial ownership of 904,119 shares of Affiliated Managers Group common stock, representing 3.21% of the class. This percentage is based on 28,128,908 shares outstanding as of November 4, 2025, per the company’s Form 10-Q.

Who are the reporting persons in this Schedule 13G/A for AMG?

The filing is made jointly by Clarkston Capital Partners, LLC, Clarkston Companies, Inc., Modell Capital LLC, and individuals Jeffrey A. Hakala, Gerald W. Hakala, and Jeremy J. Modell. They act together under a joint filing agreement as reporting persons for this ownership disclosure.

How are the AMG shares held according to Clarkston’s filing?

The shares reported are held in discretionary client accounts managed by Clarkston Capital Partners or in an account over which a control person has beneficial ownership. Clients retain the right to receive dividends or sale proceeds from securities in their respective accounts.

What voting and dispositive powers are reported over AMG shares?

The reporting persons disclose 452,500 shares with sole voting and sole dispositive power. They also report 394,049 shares with shared voting power and 451,619 shares with shared dispositive power, reflecting how authority over the holdings is allocated among the reporting persons.

Does Clarkston intend to influence control of Affiliated Managers Group (AMG)?

The reporting persons certify that the securities were acquired and are held in the ordinary course of business, and not for the purpose of changing or influencing control of Affiliated Managers Group, nor in connection with any transaction having that control-related purpose or effect.

Why is this AMG Schedule 13G/A amendment being filed?

This Amendment No. 3 updates the ownership information of Clarkston-related reporting persons as of December 31, 2025. It reflects their current beneficial holdings and percentage of Affiliated Managers Group common stock, as required under the Schedule 13G reporting rules.