[Form 4] Affiliated Managers Group Insider Trading Activity

Rhea-AI Filing Summary

Jay C. Horgen, CEO and Director of Affiliated Managers Group (AMG), reported transactions on 09/02/2025. He acquired 75,000 common shares via exercise of options at $74.49 and purchased those shares for $0 upon exercise, increasing his direct holdings to 559,322 shares. He also sold 44,935 shares at $229.97, leaving 514,387 shares directly owned. An additional 34,058 shares are held indirectly by family trusts.

Positive

• Insider exercise increased direct holdings to 559,322 shares before the sale, demonstrating continued ownership in AMG
• Substantial remaining direct stake of 514,387 shares after transactions, indicating ongoing alignment with shareholders

Negative

• Partial sale of 44,935 shares could reflect executive liquidity needs or profit-taking
• Transaction includes disposal at a high price ($229.97), reducing direct holdings compared with pre-sale level

Insights

Corporate Governance Expert

TL;DR: Insider exercised options and sold a portion of stock, modest net decrease in direct ownership; routine executive liquidity action.

The filing shows a common pattern where an executive exercises employee stock options and concurrently disposes of a tranche of shares. The post-transaction direct ownership remains substantial at 514,387 shares, with 34,058 held indirectly by family trusts. This is consistent with typical compensation realization and partial monetization rather than a change in control or governance concerns.

Securities Analyst

TL;DR: Option exercise at $74.49 and share sale at $229.97 indicate profit-taking; net position remains large but slightly reduced.

The option exercise for 75,000 shares at a strike of $74.49 followed by a sale of 44,935 shares at $229.97 suggests liquidity management by the reporting person. Net direct shares after reported transactions are 514,387, preserving meaningful insider alignment with shareholders while realizing gains on earlier equity compensation.

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

OMB Number:			3235-0287
Estimated average burden
hours per response:			0.5

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^*

Horgen Jay C.

(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
X	Officer (give title below)		Other (specify below)
	Chief Executive Officer

3. Date of Earliest Transaction (Month/Day/Year)
09/02/2025

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	09/02/2025		M		75,000	A	$74.49	559,322	D
Common Stock	09/02/2025		F		44,935	D	$229.97	514,387	D
Common Stock								34,058	I	By Family Trusts

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
Employee Stock Option (Right to Buy)	$74.49	09/02/2025		M			75,000	08/15/2024	08/15/2026	Common Stock	75,000	$0	75,000	D

Explanation of Responses:

	/s/ Kavita Padiyar, Attorney-in-Fact	09/04/2025
	** 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.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.

FAQ

What insider transactions did AMG (AMG) report on 09/02/2025?

Jay C. Horgen exercised 75,000 options at a strike of $74.49 and sold 44,935 common shares at $229.97 on 09/02/2025.

How many AMG shares does Jay C. Horgen own after the reported transactions?

Following the transactions, he directly owns 514,387 shares and indirectly holds 34,058 shares through family trusts.

What type of transactions were reported on the Form 4 for AMG?

The Form 4 reports a non-derivative acquisition via option exercise (code M) for 75,000 shares and a disposition (code F) of 44,935 shares.

Who filed the Form 4 for AMG and what is the reporter's role?

The reporting person is Jay C. Horgen, identified as both Chief Executive Officer and a Director of Affiliated Managers Group.

What prices were involved in AMG insider transactions?

Options were exercised at $74.49 and shares were sold at $229.97 as reported on the Form 4.