[Form 4] Affiliated Managers Group Insider Trading Activity

Rhea-AI Filing Summary

Affiliated Managers Group director Ryan David Christopher reported transactions on Form 4 showing the vesting and receipt of company equity. On 08/15/2025, 1,092 shares of common stock were acquired (transaction code M) at $0, and following the transaction he beneficially owned 3,627 shares. Separately, on 08/14/2025 he acquired 307 deferred stock units (notionally tied to AMG common stock) at $0, which become distributable in common stock upon separation from board service. The filing notes these shares reflect vesting of previously reported awards and prior deferred units.

Positive

• Director equity alignment: Vesting of 1,092 shares and 307 deferred stock units increases the reporting person's stake tied to shareholder outcomes
• Deferred compensation election: Cash fees were deferred into DSUs, showing alignment with long-term shareholder value

Negative

• None.

Insights

Corporate Governance Expert

TL;DR Routine director vesting and fee deferral; not a material corporate event.

The Form 4 documents standard equity vesting and the director's election to defer cash fees into deferred stock units. The reported 1,092 vested shares and 307 DSUs increase the director's alignment with shareholders but do not indicate new compensation terms or extraordinary dilution. This disclosure is supervisory and administrative in nature rather than a strategic change.

Securities Analyst

TL;DR Transaction is operationally neutral; no cash paid and ownership change is modest.

The transactions are coded as vesting (M) and deferral. Both acquisitions show a $0 price, consistent with stock-settled awards and deferred fee units. The post-transaction beneficial ownership of 3,627 shares (including DSUs totaling 4,409 when counted) is disclosed; size is small relative to typical public float, suggesting limited market impact.

SEC Form 4

FORM 4

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940

OMB APPROVAL

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Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

1. Name and Address of Reporting Person^*

Ryan David Christopher

(Last) (First) (Middle)

C/O AFFILIATED MANAGERS GROUP, INC.

777 SOUTH FLAGLER DRIVE

(Street)

WEST PALM BEACH FL 33401

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
AFFILIATED MANAGERS GROUP, INC. [ AMG ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

X	Director		10% Owner
	Officer (give title below)		Other (specify below)

3. Date of Earliest Transaction (Month/Day/Year)
08/14/2025

4. If Amendment, Date of Original Filed (Month/Day/Year)

6. Individual or Joint/Group Filing (Check Applicable Line)

X	Form filed by One Reporting Person
	Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
			Code	V	Amount	(A) or (D)	Price
Common Stock	08/15/2025		M		1,092	A	$0(1)	3,627	D

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares
Deferred Stock Units	(2)	08/14/2025		A		307		(2)	(2)	Common Stock	307	$0	307	D
Stock Units	(1)	08/15/2025		M			1,092	(1)	(1)	Common Stock	1,092	$0	4,409(3)	D

Explanation of Responses:

1. Reflects the vesting of previously reported awards. Awards vest 2022-2027.

2. Reflects cash fees that the director has elected to defer under the Company's deferred compensation plan, which are notionally invested in a measurement fund tracking the Company's common stock during the deferral period. Each deferred stock unit is equal to one share of the Company's common stock, and becomes distributable in common stock upon the reporting person's separation from service as a member of the Board of Directors of the Company.

3. Inclusive of previously reported deferred stock units.

	/s/ Kavita Padiyar, Attorney-in-Fact	08/18/2025
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
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FAQ

What did AMG director Ryan David Christopher report on Form 4?

He reported acquisition of 1,092 common shares on 08/15/2025 and 307 deferred stock units on 08/14/2025, both at $0.

Do the reported transactions involve cash payments?

No. Both the vested shares and the deferred stock units are reported at a $0 price.

What is a deferred stock unit in this filing?

The filing states each DSU equals one share of common stock and becomes distributable in common stock upon the director's separation from board service.

How many shares does the reporting person beneficially own after these transactions?

The filing shows beneficial ownership of 3,627 shares following the 08/15/2025 transaction; inclusive DSUs bring a referenced total of 4,409 units.

Are these transactions considered material for investors?

The filing presents routine vesting and deferral activity; the experts rated the impact as neutral.