Acumen Pharmaceuticals (ABOS) COO receives RSUs and 126,900 options grant

Rhea-AI Filing Summary

Acumen Pharmaceuticals Chief Operating Officer Barton Russell reported new equity awards in the company. On 01/16/2026, he received 84,600 shares of Common Stock in the form of restricted stock units, granted at a price of $0. These RSUs vest in three equal annual installments starting one year after the grant date, as long as he continues in service.

On the same date, he was also granted an employee stock option for 126,900 shares of Common Stock with an exercise price of $1.89 per share. The option vests in 48 equal monthly installments and is fully vested on the fourth anniversary of the grant date, subject to continued service. After these transactions, Russell directly beneficially owned 207,869 shares of Common Stock and 126,900 stock options.

Insider Trade Summary

2 transactions reported

Mixed 2 txns

Insider Barton Russell

Role Chief Operating Officer

Type	Security	Shares	Price	Value
Grant/Award	Employee Stock Option (right to buy)	126,900	$0.00	--
Grant/Award	Common Stock	84,600	$0.00	--

Holdings After Transaction: Employee Stock Option (right to buy) — 126,900 shares (Direct); Common Stock — 207,869 shares (Direct)

Footnotes (1)

1. Represents a restricted stock unit ("RSU") award. Each RSU represents a contingent right to receive one share of the Issuer's Common Stock. The RSUs will vest in three equal annual installments commencing one year after the grant date, subject to the Reporting Person's continuous service through each such vesting date. The shares subject to the option will vest in 48 equal monthly installments such that the option is fully vested on the fourth anniversary of the date of grant, subject to the Reporting Person's continuous service through each such vesting date.

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^*

Barton Russell

(Last) (First) (Middle)

C/O ACUMEN PHARMACEUTICALS, INC.

1210-1220 WASHINGTON STREET, SUITE 210

(Street)

NEWTON MA 02465

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
Acumen Pharmaceuticals, Inc. [ ABOS ]

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

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

3. Date of Earliest Transaction (Month/Day/Year)
01/16/2026

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	01/16/2026		A		84,600(1)	A	$0	207,869	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
Employee Stock Option (right to buy)	$1.89	01/16/2026		A		126,900		(2)	01/16/2036	Common Stock	126,900	$0	126,900	D

Explanation of Responses:

1. Represents a restricted stock unit ("RSU") award. Each RSU represents a contingent right to receive one share of the Issuer's Common Stock. The RSUs will vest in three equal annual installments commencing one year after the grant date, subject to the Reporting Person's continuous service through each such vesting date.

2. The shares subject to the option will vest in 48 equal monthly installments such that the option is fully vested on the fourth anniversary of the date of grant, subject to the Reporting Person's continuous service through each such vesting date.

Remarks:

	/s/ Derek Meisner, Attorney-in-Fact	01/21/2026
	** 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.

FAQ

What did Acumen Pharmaceuticals (ABOS) COO Barton Russell report on this Form 4?

Barton Russell reported receiving 84,600 restricted stock units of Common Stock and an option to purchase 126,900 shares of Acumen Pharmaceuticals Common Stock, both granted on 01/16/2026.

How many Acumen Pharmaceuticals (ABOS) shares and options does Barton Russell hold after the reported transactions?

Following the grants, Barton Russell directly beneficially owned 207,869 shares of Common Stock and 126,900 employee stock options of Acumen Pharmaceuticals.

What are the vesting terms of Barton Russell’s restricted stock units in Acumen Pharmaceuticals (ABOS)?

The 84,600 RSUs vest in three equal annual installments, starting one year after the grant date of 01/16/2026, subject to his continuous service through each vesting date.

What are the vesting terms of Barton Russell’s stock options at Acumen Pharmaceuticals (ABOS)?

The option for 126,900 shares vests in 48 equal monthly installments and will be fully vested on the fourth anniversary of the 01/16/2026 grant date, if he remains in continuous service.

What is the exercise price of Barton Russell’s Acumen Pharmaceuticals (ABOS) stock options?

The employee stock option granted to Barton Russell has an exercise price of $1.89 per share for 126,900 shares of Acumen Pharmaceuticals Common Stock.

Were Barton Russell’s equity awards on this Acumen Pharmaceuticals (ABOS) Form 4 purchases or grants?

Both the 84,600 RSUs and the 126,900 stock options were reported with transaction code A, indicating they were awards or grants with a transaction price of $0 at grant.