Acumen Pharmaceuticals (NASDAQ: ABOS) officer share sales disclosed

Rhea-AI Filing Summary

Acumen Pharmaceuticals Chief Legal Officer and Corporate Secretary Derek Meisner reported several sales of common stock in early January 2026. On January 5 and 6, he sold blocks of shares, including 4,000 shares at $1.9595 and 7,097 shares at $1.9672 per share. Some of these transactions were automatic “sell to cover” sales to pay tax withholding tied to vesting restricted stock units under a Rule 10b5-1 trading plan adopted in May 2024.

Additional sales on January 6 and 7 were made under a separate Rule 10b5-1 trading plan adopted in March 2025, with prices such as $1.9670, $1.9876 and $1.9896 per share. After the reported transactions, Meisner directly beneficially owned 134,459 shares of Acumen Pharmaceuticals common stock.

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^*

Meisner Derek M

(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 Legal Officer & Corp Sec

3. Date of Earliest Transaction (Month/Day/Year)
01/05/2026

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	01/05/2026		S		4,000(1)	D	$1.9595(2)	157,127	D
Common Stock	01/06/2026		S		7,097(1)	D	$1.9672(3)	150,030	D
Common Stock	01/06/2026		S		3,801(4)	D	$1.967(3)	146,229	D
Common Stock	01/07/2026		S		1,700(5)	D	$1.9876(6)	144,529	D
Common Stock	01/07/2026		S		10,070(4)	D	$1.9896(7)	134,459	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 ("RSUs") pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on May 15, 2024.

2. The price reported is a weighted average sales price. The shares were sold in multiple transactions at prices ranging from $1.9200 to $1.9750. 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 $1.9400 to $2.0000. 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.

4. Represents the number of shares sold by the Reporting Person pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on March 29, 2025.

5. 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 RSUs pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on March 29, 2025.

6. The price reported is a weighted average sales price. The shares were sold in multiple transactions at prices ranging from $1.9600 to $2.0200. 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.

7. The price reported is a weighted average sales price. The shares were sold in multiple transactions at prices ranging from $1.9500 to $2.0250. 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	01/07/2026
	** 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 activity did Acumen Pharmaceuticals (ABOS) report in this Form 4?

The Form 4 reports that Derek Meisner, Acumen Pharmaceuticals' Chief Legal Officer and Corporate Secretary, sold multiple blocks of common stock on January 5, 6 and 7, 2026.

How many Acumen Pharmaceuticals shares does Derek Meisner own after these transactions?

Following the reported sales, Derek Meisner beneficially owned 134,459 shares of Acumen Pharmaceuticals common stock directly.

At what prices were the Acumen Pharmaceuticals (ABOS) shares sold in this Form 4?

The reported sales were at weighted average prices including $1.9595, $1.9672, $1.9670, $1.9876 and $1.9896 per share, with detailed ranges described in the footnotes.

Were the Acumen Pharmaceuticals insider sales under a Rule 10b5-1 trading plan?

Yes. The Form 4 states that some sales were made under Rule 10b5-1 trading plans adopted by Derek Meisner on May 15, 2024 and March 29, 2025.

What does 'sell to cover' mean in this Acumen Pharmaceuticals Form 4?

The filing explains that certain sales represent automatic "sell to cover" transactions meant to satisfy tax withholding obligations arising from the vesting of restricted stock units.

Is Derek Meisner a director or major shareholder of Acumen Pharmaceuticals (ABOS)?

According to the filing, Derek Meisner is reported as an officer of Acumen Pharmaceuticals, serving as Chief Legal Officer & Corporate Secretary, and is not listed as a director or 10% owner.