Sec Form 4 Filing - Hardie Robert D. @ Acumen Pharmaceuticals, Inc. - 2021-07-06

FORM 4 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

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, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940

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1. Name and Address of Reporting Person Hardie Robert D. 2. Issuer Name and Ticker or Trading Symbol Acumen Pharmaceuticals, Inc. [ ABOS] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director X __ 10% Owner _____ Officer (give title below) _____ Other (specify below) (Last) (First) (Middle) 210 RIDGE MCINTIRE ROAD, SUITE 350 3. Date of Earliest Transaction (MM/DD/YY) 07/06/2021 (Street) CHARLOTTESVILLE, VA22903 4. If Amendment, Date Original Filed (MM/DD/YY) 6. Individual or Joint/Group Filing (Check Applicable Line) __ X __ Form filed by One Reporting Person _____ Form filed by More than One Reporting Person (City) (State) (Zip)

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned 1.Title of Security (Instr. 3) 2. Transaction Date (MM/DD/YY) 2A. Deemed Execution Date, if any (MM/DD/YY) 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 07/06/2021 C 1,124,830 A 1,124,830 I See footnote ( 2 ) Common Stock 07/06/2021 C 2,076,326 A 3,201,156 I See footnotes ( 3 ) Common Stock 07/06/2021 P 750,000 A $ 16 3,951,156 I See footnote ( 4 )

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 (MM/DD/YY) 3A. Deemed Execution Date, if any (MM/DD/YY) 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 (MM/DD/YY) 7. Title and Amount of Underlying Securities (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 of Derivative Security: 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 Series A-1 Preferred Stock ( 1 ) 07/06/2021 C 1,124,830 ( 1 ) ( 1 ) Common Stock 1,124,830 $ 0 0 I See footnote ( 2 ) Series B Preferred Stock ( 1 ) 07/06/2021 C 2,076,326 ( 1 ) ( 1 ) Common Stock 2,076,326 $ 0 0 I See footnote ( 3 )

Reporting Owners Reporting Owner Name / Address Relationships Director 10% Owner Officer Other Hardie Robert D. 210 RIDGE MCINTIRE ROAD, SUITE 350 CHARLOTTESVILLE, VA22903 X Signatures /s/ Katherine Denby, Attorney-in-Fact 07/08/2021 Signature of Reporting Person Date

Explanation of Responses:

( 1 )On July 6, 2021, each share of Series A-1 Convertible Preferred Stock and Series B Convertible Preferred Stock (collectively, the "Preferred Stock") converted into Common Stock on a one-for-one basis without payment of further consideration upon closing of the initial public offering of the Issuer's common stock. The shares had no expiration date. ( 2 )Consists of 562,415 shares of common stock issuable upon conversion of Series A-1 preferred stock held by H7 Holdings LLC, and 562,415shares of common stock issuable upon conversion of Series A-1 preferred stock held by Level One Partners, LLC. Robert D. Hardie is theManager of both H7 Holdings, LLC and Level One Partners, LLC and has the power to vote or dispose of the shares held by each entity. TheReporting Person disclaims beneficial ownership of the shares held by H7 Holdings, LLC and Level One Partners, LLC, except to the extent ofhis pecuniary interest therein. ( 3 )Consists of 1,038,163 shares of common stock issuable upon conversion of Series B convertible preferred stock held by H7 Holdings LLC, and1,038,163 shares of common stock issuable upon conversion of Series B convertible preferred stock held by Level One Partners, LLC. Robert D.Hardie is the Manager of both H7 Holdings, LLC and Level One Partners, LLC and has the power to vote or dispose of the shares held by eachentity. The Reporting Person disclaims beneficial ownership of the shares held by H7 Holdings, LLC and Level One Partners, LLC, except to theextent of his pecuniary interest therein. ( 4 )Consists of 375,000 shares of common stock held by H7 Holdings LLC, and 375,000 shares of common stock held by Level One Partners, LLC. Robert D. Hardie is the Manager of both H7 Holdings, LLC and Level One Partners, LLC and has the power to vote or dispose of the shares held by each entity. The Reporting Person disclaims beneficial ownership of the shares held by H7 Holdings, LLC and Level One Partners, LLC, except to the extent of his pecuniary interest therein.

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).

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