Derek M. Meisner - 26 Jan 2026 Form 4 Insider Report for Acumen Pharmaceuticals, Inc. (ABOS)

Role
Chief Legal Officer & Corp Sec
Signature
/s/ Derek Meisner
Issuer symbol
ABOS
Transactions as of
26 Jan 2026
Net transactions value
-$20,431
Form type
4
Filing time
28 Jan 2026, 19:50:04 UTC
Previous filing
23 Jan 2026
Next filing
03 Mar 2026
SEC
View on sec.gov

Reporting Owners (1)

Name Relationship Address Signature Signature date CIK
Meisner Derek M Chief Legal Officer & Corp Sec C/O ACUMEN PHARMACEUTICALS, INC., 1210-1220 WASHINGTON STREET, SUITE 210, NEWTON /s/ Derek Meisner 28 Jan 2026 0001752461

Transactions Table

Type Sym Class Transaction Value $ Shares Change % * Price $ Shares After Date Ownership Footnotes
transaction ABOS Common Stock Options Exercise $27,907 +15,085 +8.7% $1.85 189,084 26 Jan 2026 Direct
transaction ABOS Common Stock Sale $45,263 -15,085 -8% $3.00 173,999 26 Jan 2026 Direct F1, F2
transaction ABOS Common Stock Options Exercise $4,941 +2,671 +1.5% $1.85 176,670 28 Jan 2026 Direct
transaction ABOS Common Stock Sale $8,017 -2,671 -1.5% $3.00 173,999 28 Jan 2026 Direct F1, F2

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) Options Exercise $0 -15,085 -15% $0.000000 85,215 26 Jan 2026 Common Stock 15,085 $1.85 Direct F3
transaction ABOS Employee Stock Option (right to buy) Options Exercise $0 -2,671 -3.1% $0.000000 82,544 28 Jan 2026 Common Stock 2,671 $1.85 Direct F3
* An asterisk sign (*) next to the price indicates that the price is likely invalid.

Buy Plan / Sale Plan: These are also open market purchases/sales of shares, but in this case the transaction is part of a trading plan. Rule 10b5-1 allows insiders to setup a trading plan to buy/sell stocks over a certain period of time. Since the purchases/sales are predetermined, this protects the insiders from violating insider trading law.

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).

Explanation of Responses:

Id Content
F1 The reported sales occurred automatically pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on March 29, 2025.
F2 The price reported is a weighted average sales price. The shares were sold in multiple transactions at prices ranging from $3.0000 to $3.0100. 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.
F3 The shares subject to the employee stock option vest in 48 equal monthly installments starting on the date the option was granted, such that the option will be fully vested on the fourth anniversary of the date of grant, subject to the Reporting Person's continuous service through each such vesting date.