Daniel Joseph OConnell - 20 Jan 2026 Form 4 Insider Report for Acumen Pharmaceuticals, Inc. (ABOS)

Role: Chief Executive Officer, Director
Signature: /s/ Derek Meisner, Attorney-in-Fact
Issuer symbol: ABOS
Transactions as of: 20 Jan 2026
Net transactions value: $0
Form type: 4
Filing time: 21 Jan 2026, 18:32:39 UTC
Previous filing: 12 Jan 2026
Next filing: 23 Jan 2026
SEC: View on sec.gov

Reporting Owners (1)

Name	Relationship	Address	Signature	Signature date	CIK
OConnell Daniel Joseph	Chief Executive Officer, Director	C/O ACUMEN PHARMACEUTICALS, INC., 1210-1220 WASHINGTON STREET, SUITE 210, NEWTON	/s/ Derek Meisner, Attorney-in-Fact	21 Jan 2026	0001865136

Transactions Table

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Ownership	Footnotes
transaction	ABOS	Common Stock	Award	$0	+299,800	+51%	$0.000000	893,310	20 Jan 2026	Direct	F1

Derivative Securities (e.g., puts, calls, warrants, options, convertible securities)

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Underlying Class	Amount	Exercise Price	Ownership	Footnotes
transaction	ABOS	Employee Stock Option (right to buy)	Award	$0	+450,000		$0.000000	450,000	20 Jan 2026	Common Stock	450,000	$1.86	Direct	F2

* An asterisk sign (*) next to the price indicates that the price is likely invalid.

Explanation of Responses:

Id	Content
F1	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.
F2	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.