[SCHEDULE 13G/A] Acumen Pharmaceuticals, Inc. SEC Filing

Rhea-AI Filing Summary

Acumen Pharmaceuticals (ABOS) is reported to have a combined 3,417,075 shares beneficially owned by Sands-linked reporting persons, representing 5.6% of the outstanding common stock based on 60,573,425 shares. The position is held across three Sands funds—Sands Capital Ventures Discovery Fund III (1,124,729 shares, 1.9%), Sands Capital Global Venture Fund II (1,146,173 shares, 1.9%) and Sands Capital Life Sciences Pulse Fund (1,146,173 shares, 1.9%)—with Sands Capital Alternatives acting as investment manager and Frank M. Sands retaining ultimate voting and investment power. The filing reports shared voting and dispositive power rather than sole control and includes a certification that the securities were not acquired to influence control.

Insights

Financial Analyst

TL;DR: Sands-linked entities hold a material, coordinated 5.6% position in ABOS, reported as passive with shared voting power.

The filing discloses an aggregate beneficial position of 3,417,075 shares, equal to 5.6% of the company's common stock based on the stated share count. Ownership is allocated across three Sands-managed funds, each holding roughly 1.9%. The reporting structure shows shared voting and dispositive power rather than sole control, and the filers certify the position is not intended to influence control. For market participants, this is a material institutional stake but characterized as passive in this filing.

Corporate Governance Expert

TL;DR: A >5% institutional stake by Sands is material to ownership composition but recorded as passive with no sole voting control.

The Schedule 13G/A attributes ultimate voting and investment power to Frank M. Sands and names Sands Capital Alternatives as the investment manager for the Sands Funds. The filing documents shared voting and dispositive power over 3,417,075 shares and contains a certification that the securities were not acquired to change or influence issuer control. From a governance perspective, the disclosure signals coordinated ownership without an asserted intent to pursue control or activist action.

SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

SCHEDULE 13G

UNDER THE SECURITIES EXCHANGE ACT OF 1934

(Amendment No. 2)

Acumen Pharmaceuticals, Inc.

(Name of Issuer)

Common Stock, par value $0.0001 per share

(Title of Class of Securities)

00509G209

(CUSIP Number)

06/30/2025

(Date of Event Which Requires Filing of this Statement)

Check the appropriate box to designate the rule pursuant to which this Schedule is filed:

Rule 13d-1(b)

Rule 13d-1(c)

Rule 13d-1(d)

SCHEDULE 13G

CUSIP No. 00509G209

1

Names of Reporting Persons

Sands Capital Alternatives, LLC

2

Check the appropriate box if a member of a Group (see instructions)

(a)
(b)

3

Sec Use Only

4

Citizenship or Place of Organization

DELAWARE

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 0.00
6	Shared Voting Power 3,417,075.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 3,417,075.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

3,417,075.00

10

Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)

11

Percent of class represented by amount in row (9)

5.6 %

12

Type of Reporting Person (See Instructions)

OO

Comment for Type of Reporting Person: The percentages reported in this Schedule 13G are based upon 60,573,425 Shares outstanding as of August 8, 2025 (according to the Issuer's Form 10-Q as filed with the Securities and Exchange Commission on August 12, 2025).

SCHEDULE 13G

CUSIP No. 00509G209

1

Names of Reporting Persons

Sands Capital Ventures Discovery Fund III, L.P.

2

Check the appropriate box if a member of a Group (see instructions)

(a)
(b)

3

Sec Use Only

4

Citizenship or Place of Organization

DELAWARE

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 0.00
6	Shared Voting Power 1,124,729.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 1,124,729.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

1,124,729.00

10

Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)

11

Percent of class represented by amount in row (9)

1.9 %

12

Type of Reporting Person (See Instructions)

PN

Comment for Type of Reporting Person: The percentages reported in this Schedule 13G are based upon 60,573,425 Shares outstanding as of August 8, 2025 (according to the Issuer's Form 10-Q as filed with the Securities and Exchange Commission on August 12, 2025).

SCHEDULE 13G

CUSIP No. 00509G209

1

Names of Reporting Persons

Sands Capital Global Venture Fund II, L.P.

2

Check the appropriate box if a member of a Group (see instructions)

(a)
(b)

3

Sec Use Only

4

Citizenship or Place of Organization

DELAWARE

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 0.00
6	Shared Voting Power 1,146,173.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 1,146,173.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

1,146,173.00

10

Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)

11

Percent of class represented by amount in row (9)

1.9 %

12

Type of Reporting Person (See Instructions)

PN

Comment for Type of Reporting Person: The percentages reported in this Schedule 13G are based upon 60,573,425 Shares outstanding as of August 8, 2025 (according to the Issuer's Form 10-Q as filed with the Securities and Exchange Commission on August 12, 2025).

SCHEDULE 13G

CUSIP No. 00509G209

1

Names of Reporting Persons

Sands Capital Life Sciences Pulse Fund, LLC

2

Check the appropriate box if a member of a Group (see instructions)

(a)
(b)

3

Sec Use Only

4

Citizenship or Place of Organization

DELAWARE

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 0.00
6	Shared Voting Power 1,146,173.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 1,146,173.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

1,146,173.00

10

Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)

11

Percent of class represented by amount in row (9)

1.9 %

12

Type of Reporting Person (See Instructions)

PN

Comment for Type of Reporting Person: The percentages reported in this Schedule 13G are based upon 60,573,425 Shares outstanding as of August 8, 2025 (according to the Issuer's Form 10-Q as filed with the Securities and Exchange Commission on August 12, 2025).

SCHEDULE 13G

CUSIP No. 00509G209

1

Names of Reporting Persons

SANDS FRANK M.

2

Check the appropriate box if a member of a Group (see instructions)

(a)
(b)

3

Sec Use Only

4

Citizenship or Place of Organization

UNITED STATES

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 0.00
6	Shared Voting Power 3,417,075.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 3,417,075.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

3,417,075.00

10

Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)

11

Percent of class represented by amount in row (9)

5.6 %

12

Type of Reporting Person (See Instructions)

IN, HC

Comment for Type of Reporting Person: The percentages reported in this Schedule 13G are based upon 60,573,425 Shares outstanding as of August 8, 2025 (according to the Issuer's Form 10-Q as filed with the Securities and Exchange Commission on August 12, 2025).

SCHEDULE 13G

Item 1.
(a)	Name of issuer: Acumen Pharmaceuticals, Inc.
(b)	Address of issuer's principal executive offices: 1210-1220 WASHINGTON STREET, SUITE 210, NEWTON, MASSACHUSETTS, 02465.
Item 2.
(a)	Name of person filing: This Schedule 13G is being filed jointly by: (i) Sands Capital Ventures Discovery Fund III, L.P. ("Sands Discovery Fund"), with respect to the shares of Common Stock held by it; (ii) Sands Capital Global Venture Fund II, L.P. ("Sands Venture Fund"), with respect to the shares of Common Stock held by it; (iii) Sands Capital Life Sciences Pulse Fund, LLC ("Sands Pulse Fund" and together with Sands Discovery Fund and Sands Venture Fund, the "Sands Funds"), with respect to the shares of Common Stock held by it; (iv) Sands Capital Alternatives, LLC ("Sands Capital Alternatives"), the investment manager of the Sands Funds, with respect to the shares of Common Stock held by the Sands Funds; and (v) Frank M. Sands ("Sands"), with respect to the shares of Common Stock held by the Sands Funds. The Sands Funds, Sands Capital Alternatives and Sands are together referred to herein as the "Reporting Persons". Sands Capital Ventures Discovery Fund III-GP, LLC ("Sands Discovery GP") is the general partner of Sands Discovery Fund. Sands Capital Global Venture Fund II-GP, L.P. ("Sands Venture GP LP") is the general partner of Sands Venture Fund. Sands Capital Global Venture Fund II-GP, LLC ("Sands Venture GP LLC" and, together with Sands Discovery GP and Sands Venture GP LP, the "Sands General Partners") is the general partner of Sands Venture GP LP. Sands Capital Alternatives is the investment manager of each of the Sands Funds and thus may be deemed to beneficially own the shares of Common Stock held by the Sands Funds. Sands holds ultimate voting and investment power over securities held by the Sands Funds and thus may be deemed to beneficially own the shares of Common Stock held by the Sands Funds. Each Reporting Person and the Sands General Partners disclaim beneficial ownership of any securities beyond its pecuniary interest therein.
(b)	Address or principal business office or, if none, residence: The principal business address of each of the Reporting Persons and the Sands General Partners is 1000 Wilson Blvd., Suite 3000, Arlington, VA 22209.
(c)	Citizenship: Each of Sands Capital Alternatives, the Sands Funds and the Sands General Partners is organized under the laws of the State of Delaware. Sands is a citizen of the United States.
(d)	Title of class of securities: Common Stock, par value $0.0001 per share
(e)	CUSIP No.: 00509G209
Item 3.	If this statement is filed pursuant to §§ 240.13d-1(b) or 240.13d-2(b) or (c), check whether the person filing is a:
(a)	Broker or dealer registered under section 15 of the Act (15 U.S.C. 78o);
(b)	Bank as defined in section 3(a)(6) of the Act (15 U.S.C. 78c);
(c)	Insurance company as defined in section 3(a)(19) of the Act (15 U.S.C. 78c);
(d)	Investment company registered under section 8 of the Investment Company Act of 1940 (15 U.S.C. 80a-8);
(e)	An investment adviser in accordance with § 240.13d-1(b)(1)(ii)(E);
(f)	An employee benefit plan or endowment fund in accordance with § 240.13d-1(b)(1)(ii)(F);
(g)	A parent holding company or control person in accordance with § 240.13d-1(b)(1)(ii)(G);
(h)	A savings associations as defined in Section 3(b) of the Federal Deposit Insurance Act (12 U.S.C. 1813);
(i)	A church plan that is excluded from the definition of an investment company under section 3(c)(14) of the Investment Company Act of 1940 (15 U.S.C. 80a-3);
(j)	A non-U.S. institution in accordance with § 240.13d-1(b)(1)(ii)(J). If filing as a non-U.S. institution in accordance with § 240.13d-1(b)(1)(ii)(J), please specify the type of institution:
(k)	Group, in accordance with Rule 240.13d-1(b)(1)(ii)(K).
Item 4.	Ownership
(a)	Amount beneficially owned: See rows 5 through 11 of cover pages.
(b)	Percent of class: See rows 5 through 11 of cover pages.
(c)	Number of shares as to which the person has:
	(i) Sole power to vote or to direct the vote: See rows 5 through 11 of cover pages.
	(ii) Shared power to vote or to direct the vote: See rows 5 through 11 of cover pages.
	(iii) Sole power to dispose or to direct the disposition of: See rows 5 through 11 of cover pages.
	(iv) Shared power to dispose or to direct the disposition of: See rows 5 through 11 of cover pages.
Item 5.	Ownership of 5 Percent or Less of a Class.
Item 6.	Ownership of more than 5 Percent on Behalf of Another Person.
	Not Applicable
Item 7.	Identification and Classification of the Subsidiary Which Acquired the Security Being Reported on by the Parent Holding Company or Control Person.
	Not Applicable
Item 8.	Identification and Classification of Members of the Group.
	Not Applicable
Item 9.	Notice of Dissolution of Group.
	Not Applicable

Item 10.

Certifications:

By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having that purpose or effect, other than activities solely in connection with a nomination under § 240.14a-11.

SIGNATURE

After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

Sands Capital Alternatives, LLC

Signature:	/s/ Jonathan Goodman
Name/Title:	Jonathan Goodman, General Counsel
Date:	08/13/2025

Sands Capital Ventures Discovery Fund III, L.P.

Signature:	/s/ Jonathan Goodman
Name/Title:	Jonathan Goodman, General Counsel of the General Partner of Sands Capital Ventures Discovery Fund III, L.P.
Date:	08/13/2025

Sands Capital Global Venture Fund II, L.P.

Signature:	/s/ Jonathan Goodman
Name/Title:	Jonathan Goodman, General Counsel of the GP of the GP of Sands Capital Global Venture Fund II, L.P.
Date:	08/13/2025

Sands Capital Life Sciences Pulse Fund, LLC

Signature:	/s/ Jonathan Goodman
Name/Title:	Jonathan Goodman, General Counsel
Date:	08/13/2025

SANDS FRANK M.

Signature:	/s/ Frank M. Sands
Name/Title:	Frank M. Sands
Date:	08/13/2025

Comments accompanying signature: Sands Capital Ventures Discovery Fund III, L.P. signed by Sands Capital Ventures Discovery Fund III-GP, LLC, its general partner, by Jonathan Goodman, General Counsel. Sands Capital Global Venture Fund II, L.P. signed by Sands Capital Global Venture Fund II-GP, L.P., its general partner, by Sands Capital Global Venture Fund II-GP, LLC, its general partner, by Jonathan Goodman, General Counsel.