Acumen Pharmaceuticals (ABOS) CEO O'Connell sells shares in tax-related trades

Rhea-AI Filing Summary

Acumen Pharmaceuticals, Inc. Chief Executive Officer Daniel Joseph O'Connell reported automatic stock sales related to tax withholding. On January 21, 2026, he sold 9,346 shares of common stock at a weighted average price of $1.8112 per share. On January 22, 2026, he sold an additional 2,689 shares at a weighted average price of $1.8838 per share.

According to the footnotes, these transactions were automatic "sell to cover" trades to satisfy tax withholding obligations arising from the vesting of restricted stock units under a Rule 10b5-1 trading plan adopted on June 24, 2024. After these sales, O'Connell beneficially owned 881,275 shares of Acumen common stock directly.

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
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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^*

OConnell Daniel Joseph

(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)

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

3. Date of Earliest Transaction (Month/Day/Year)
01/21/2026

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	01/21/2026		S		9,346(1)	D	$1.8112(2)	883,964	D
Common Stock	01/22/2026		S		2,689(1)	D	$1.8838(3)	881,275	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

Explanation of Responses:

1. Represents the number of shares sold by the Reporting Person through an automatic "sell to cover" transaction to satisfy tax withholding obligations in connection with the vesting of restricted stock units pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on June 24, 2024.

2. The price reported is a weighted average sales price. The shares were sold in multiple transactions at prices ranging from $1.7600 to $1.8800. Upon request, the Reporting Person will provide to the staff of the Securities and Exchange Commission, the Issuer, or any security holder of the Issuer, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.

3. The price reported is a weighted average sales price. The shares were sold in multiple transactions at prices ranging from $1.8700 to $1.9000. Upon request, the Reporting Person will provide to the staff of the Securities and Exchange Commission, the Issuer, or any security holder of the Issuer, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.

Remarks:

	/s/ Derek Meisner, Attorney-in-Fact	01/23/2026
	** 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 insider transaction did Acumen Pharmaceuticals (ABOS) disclose in this Form 4?

Acumen Pharmaceuticals disclosed that its Chief Executive Officer, Daniel Joseph O'Connell, sold shares of common stock in two transactions on January 21 and 22, 2026, as reported on Form 4.

How many Acumen Pharmaceuticals (ABOS) shares did the CEO sell and at what prices?

On January 21, 2026, the CEO sold 9,346 shares at a weighted average price of $1.8112 per share. On January 22, 2026, he sold 2,689 shares at a weighted average price of $1.8838 per share.

Why were the Acumen Pharmaceuticals (ABOS) CEO’s shares sold in these transactions?

The footnotes state that the reported shares were sold through automatic "sell to cover" transactions to satisfy tax withholding obligations related to the vesting of restricted stock units, under a Rule 10b5-1 trading plan adopted on June 24, 2024.

How many Acumen Pharmaceuticals (ABOS) shares does the CEO own after these sales?

Following the reported transactions, Chief Executive Officer Daniel Joseph O'Connell beneficially owned 881,275 shares of Acumen Pharmaceuticals common stock directly.

Were the Acumen Pharmaceuticals (ABOS) CEO’s share sales made under a trading plan?

Yes. The filing explains that the sales were executed pursuant to a Rule 10b5-1 trading plan adopted by the CEO on June 24, 2024, in connection with tax withholding for vested restricted stock units.

What does the weighted average price mean in this Acumen Pharmaceuticals (ABOS) Form 4?

The filing notes that the reported prices are weighted average sales prices. The shares were sold in multiple transactions within price ranges of $1.76 to $1.88 and $1.87 to $1.90, and detailed trade-level prices are available upon request.