Director Barbara Trebbi converts 3,286 RSUs at Acadian (AAMI)

Rhea-AI Filing Summary

Acadian Asset Management Inc. director Barbara Trebbi exercised 3,286 restricted stock units, receiving the same number of shares of common stock. These RSUs were granted on May 14, 2025 and vested upon the earlier of May 14, 2026 and the 2026 annual meeting of stockholders. Following this conversion, Trebbi directly holds 39,057 shares of common stock, and no restricted stock units remain from this grant. The transaction reflects a compensation-related derivative exercise rather than an open-market stock purchase or sale.

Insider Trade Summary

3,286 shares exercised/converted

Mixed 2 txns

Insider Trebbi Barbara

Role null

Type	Security	Shares	Price	Value
Exercise	Restricted Stock Units	3,286	$0.00	--
Exercise	Common Stock	3,286	$0.00	--

Holdings After Transaction: Restricted Stock Units — 0 shares (Direct, null); Common Stock — 39,057 shares (Direct, null)

Footnotes (1)

1. Each restricted stock unit represents a right to receive one share of common stock of Acadian Asset Management Inc. On May 14, 2025, the reporting person was granted 3,286 restricted stock units vesting upon the earlier of May 14, 2026 and the date of the 2026 annual meeting of stockholders of Acadian Asset Management Inc.

Key Figures

RSUs exercised: 3,286 units Common shares received: 3,286 shares Post-transaction holdings: 39,057 shares +2 more

5 metrics

RSUs exercised 3,286 units Restricted stock units converted into common stock on May 14, 2026

Common shares received 3,286 shares Shares of Acadian common stock from RSU conversion

Post-transaction holdings 39,057 shares Common stock directly held by Barbara Trebbi after the transaction

RSU grant date May 14, 2025 Grant of 3,286 restricted stock units to the director

Vesting condition date May 14, 2026 Earlier of this date and 2026 annual meeting for RSU vesting

Key Terms

Restricted Stock Units, derivative security, Common Stock, annual meeting of stockholders

4 terms

Restricted Stock Units financial

"Each restricted stock unit represents a right to receive one share of common stock"

Restricted stock units are a type of company reward where employees are promised shares of stock, but they only fully own these shares after meeting certain conditions, like staying with the company for a set time. They matter because they can become valuable assets and are often used to motivate employees to help the company succeed.

derivative security financial

"transaction_code_description: Exercise or conversion of derivative security"

A derivative security is a financial contract whose value comes from the price or performance of something else, such as a stock, bond, commodity, or market index. For investors it acts like an insurance policy or a wager: it can be used to protect against losses, lock in prices, or amplify gains and losses, so it can change a portfolio’s risk and potential return without owning the underlying asset directly.

Common Stock financial

"Each restricted stock unit represents a right to receive one share of common stock of Acadian Asset Management Inc."

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.

annual meeting of stockholders financial

"vesting upon the earlier of May 14, 2026 and the date of the 2026 annual meeting of stockholders"

Form 4 Insider Transactions: What Each Field Means →

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^*

Trebbi Barbara

(Last) (First) (Middle)

C/O ACADIAN ASSET MANAGEMENT INC.

200 STATE STREET, SUITE 601A

(Street)

BOSTON MASSACHUSETTS 02109

(City) (State) (Zip)

UNITED STATES

(Country)

2. Issuer Name and Ticker or Trading Symbol
Acadian Asset Management Inc. [ AAMI ]

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

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

2a. Foreign Trading Symbol

3. Date of Earliest Transaction (Month/Day/Year)
05/14/2026

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

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

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

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	05/14/2026		M		3,286	A	$0	39,057	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
Restricted Stock Units(1)	(1)	05/14/2026		M			3,286	(2)	(2)	Common Stock	3,286	$0	0	D

Explanation of Responses:

1. Each restricted stock unit represents a right to receive one share of common stock of Acadian Asset Management Inc.

2. On May 14, 2025, the reporting person was granted 3,286 restricted stock units vesting upon the earlier of May 14, 2026 and the date of the 2026 annual meeting of stockholders of Acadian Asset Management Inc.

Remarks:

	/s/ Richard J. Hart, By POA for Barbara Trebbi	05/18/2026
	** 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 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.
* Form 4: SEC 1474 (03-26)

FAQ

What insider transaction did Acadian Asset Management (AAMI) report for Barbara Trebbi?

Acadian Asset Management reported that director Barbara Trebbi exercised 3,286 restricted stock units, converting them into an equal number of common shares. This was a compensation-related derivative exercise, not an open-market stock purchase or sale.

How many Acadian Asset Management (AAMI) shares does Barbara Trebbi hold after this filing?

After the RSU conversion, Barbara Trebbi directly holds 39,057 shares of Acadian common stock. This figure reflects her updated ownership position as reported in the Form 4 following the 3,286-share restricted stock unit exercise.

What are restricted stock units in the Acadian Asset Management (AAMI) Form 4?

In this filing, each restricted stock unit (RSU) represents the right to receive one share of Acadian common stock. When the RSUs vested, 3,286 units were converted into 3,286 shares, updating the director’s equity-based compensation holdings.

When were the restricted stock units granted to the Acadian Asset Management (AAMI) director?

The filing states that 3,286 restricted stock units were granted on May 14, 2025. These units were scheduled to vest upon the earlier of May 14, 2026 and the date of Acadian’s 2026 annual meeting of stockholders.

Did the Acadian Asset Management (AAMI) insider transaction involve an open-market trade?

No, the reported activity is an exercise of restricted stock units, classified as a derivative conversion. The transaction price per share is shown as $0.00, indicating a compensation-related vesting rather than an open-market purchase or sale.