AMG (AMG) director Cates G. Staley discloses 4,905-share Form 3 holding

Rhea-AI Filing Summary

AFFILIATED MANAGERS GROUP, INC. director Cates G. Staley filed an initial Form 3 showing ownership of 4,905 shares of Common Stock held directly. This filing does not report a new purchase or sale; it simply discloses Staley’s existing beneficial holdings upon becoming a reporting insider.

Insider Trade Summary

1 transaction reported

Mixed 1 txn

Insider Cates G. Staley

Role Director

Type	Security	Shares	Price	Value
holding	Common Stock	--	--	--

Holdings After Transaction: Common Stock — 4,905 shares (Direct)

Footnotes (1)

Key Figures

Common Stock owned: 4,905 shares

1 metrics

Common Stock owned 4,905 shares Direct beneficial ownership reported on Form 3

Key Terms

Form 3, Common Stock, beneficial ownership

3 terms

Form 3 regulatory

"director Cates G. Staley filed an initial Form 3 showing ownership"

Form 3 is the initial public filing that officers, directors and large shareholders must submit to report their ownership of a company’s securities when they become insiders. It acts like an opening inventory sheet that gives investors a starting point to see who holds significant stakes and to spot later trades or potential conflicts of interest, helping assess insider confidence and transparency.

Common Stock financial

"ownership of 4,905 shares of Common Stock held directly"

Common stock represents ownership shares in a company, giving investors a stake in its success and a say in important decisions through voting rights. It is the most common type of stock traded on markets and can provide income through dividends, as well as potential for value growth. For investors, holding common stock means sharing in the company’s profits and risks.

beneficial ownership financial

"simply discloses Staley’s existing beneficial holdings upon becoming a reporting insider"

Beneficial ownership means the person or entity that actually enjoys the benefits of owning shares or other assets — such as receiving dividends, voting rights, or price gains — even if the legal title is held in another name. For investors it matters because knowing who truly controls and profits from a company reveals who can influence decisions, exposes potential conflicts of interest or hidden concentration of power, and affects transparency and risk in the stock.

Understanding Insider Trading Forms →

SEC Form 3

FORM 3

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

INITIAL STATEMENT OF BENEFICIAL OWNERSHIP OF SECURITIES

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:			3235-0104
Estimated average burden
hours per response:			0.5

1. Name and Address of Reporting Person^*

Cates G. Staley

(Last) (First) (Middle)

C/O AFFILIATED MANAGERS GROUP, INC.

1001 U.S. HIGHWAY ONE NORTH

(Street)

JUPITER FLORIDA 33477

(City) (State) (Zip)

UNITED STATES

(Country)

2. Date of Event Requiring Statement (Month/Day/Year)
04/01/2026

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

3a. Foreign Trading Symbol

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

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

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

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 Beneficially Owned
1. Title of Security (Instr. 4)	2. Amount of Securities Beneficially Owned (Instr. 4)	3. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	4. Nature of Indirect Beneficial Ownership (Instr. 5)
Common Stock	4,905	D

Table II - Derivative Securities Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 4)	2. Date Exercisable and Expiration Date (Month/Day/Year)		3. Title and Amount of Securities Underlying Derivative Security (Instr. 4)		4. Conversion or Exercise Price of Derivative Security	5. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	6. Nature of Indirect Beneficial Ownership (Instr. 5)
	Date Exercisable	Expiration Date	Title	Amount or Number of Shares

Explanation of Responses:

Remarks:

Exhibit 24 - Power of Attorney

	/s/ Kavita Padiyar, Attorney-in-Fact	04/06/2026
	** 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 5 (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.
* Form 3: SEC 1473 (03-26)

FAQ

What does the AMG Form 3 filing by Cates G. Staley show?

The Form 3 shows that director Cates G. Staley beneficially owns 4,905 shares of Common Stock in Affiliated Managers Group, Inc. It is an initial ownership report, not a disclosure of a new transaction.

Is the AMG Form 3 for Cates G. Staley a stock purchase or sale?

No, the Form 3 does not report a purchase or sale. It records existing ownership of 4,905 Common Stock shares, fulfilling disclosure requirements when an individual becomes a reporting insider at Affiliated Managers Group, Inc.

How many AMG shares does Cates G. Staley report owning on Form 3?

Cates G. Staley reports owning 4,905 shares of Affiliated Managers Group Common Stock. These shares are listed as held directly, providing a baseline of Staley’s beneficial ownership as a company director.

Are any derivative securities reported in the AMG Form 3 for Cates G. Staley?

No derivative securities are listed. The Form 3 only shows 4,905 shares of Common Stock with no options, warrants, or other derivatives reported, giving a straightforward view of equity ownership.

Does the AMG Form 3 indicate indirect ownership for Cates G. Staley?

No, the filing classifies the 4,905 shares as direct ownership. The direct ownership code "D" is used, and there is no separate indirect holding or entity listed in the nature of ownership for this position.