CastleKnight group discloses 5.9% ADV stake in Schedule 13G/A filing

Rhea-AI Filing Summary

CastleKnight Master Fund LP and related entities filed an amended beneficial ownership report for Advantage Solutions Inc. They report beneficial ownership of 757,354 shares of Class A common stock, representing 5.9% of the class, with shared voting and dispositive power over all reported shares and no sole voting or dispositive power.

A note states that as of June 30, 2026, these reporting persons beneficially owned 581,347 shares, and as of August 14, 2026, they beneficially owned 757,354 shares. Multiple related entities and Aaron Weitman are each reported as beneficial owners of the same 5.9% stake.

Key Figures

Beneficially owned shares: 757,354 shares Percent of class: 5.9% Prior beneficial ownership: 581,347 shares +2 more

5 metrics

Beneficially owned shares 757,354 shares Class A common stock beneficially owned as of August 14, 2026

Percent of class 5.9% Percentage of Advantage Solutions Inc. Class A common stock

Prior beneficial ownership 581,347 shares Class A common stock beneficially owned as of June 30, 2026

Shared voting power 757,354 shares Shares over which each reporting person has shared voting power

Sole voting power 0 shares Shares over which each reporting person has sole voting power

Key Terms

beneficially owned, shared voting power, shared dispositive power, parent holding company, +1 more

5 terms

beneficially owned financial

"This figure represents the amount of Class A common stock ... beneficially owned by the Reporting Persons"

Beneficially owned describes securities or assets where a person has the economic rights and control—such as the right to receive dividends and to direct voting—even if legal title is held in another name. Think of it like having the keys and using a car that’s registered to someone else: you get the benefits and make decisions. Investors care because beneficial ownership reveals who truly controls value and voting power, affecting corporate decisions and takeover dynamics.

shared voting power financial

"6 | Shared Voting Power 757,354.00"

Shared voting power occurs when two or more parties jointly have the right to vote or decide how a block of company shares is cast, like co-owners who must agree before moving a piece of furniture. Investors care because who controls voting rights affects board elections, major corporate decisions and takeover outcomes, and shared control can alter regulatory disclosures and the practical influence any holder has over a company’s direction and value.

shared dispositive power financial

"8 | Shared Dispositive Power 757,354.00"

parent holding company financial

"Identification and Classification of the Subsidiary Which Acquired the Security Being Reported on by the Parent Holding Company"

Schedule 13G regulatory

"Identification and Classification of the Subsidiary Which Acquired the Security Being Reported on by the Parent Holding Company"

A Schedule 13G is a formal document that investors file with the government when they acquire a large ownership stake in a company, usually for investment purposes rather than control. It helps keep the public informed about who owns significant parts of a company's shares, which can influence how the company is managed and how investors make decisions. Filing this schedule is important for transparency and understanding the ownership landscape of publicly traded companies.

FAQ

What stake in Advantage Solutions Inc. (ADV) does CastleKnight report in this Schedule 13G/A?

CastleKnight and related entities report beneficial ownership of 757,354 shares of Advantage Solutions Inc. Class A common stock, representing 5.9% of the class, with shared voting and dispositive power and no sole voting or dispositive power reported.

How has CastleKnight’s beneficial ownership in Advantage Solutions Inc. (ADV) changed over time?

The filing notes that as of June 30, 2026, the reporting persons beneficially owned 581,347 shares of ADV, while as of August 14, 2026, they beneficially owned 757,354 shares, indicating an increase in their reported share position.

Who are the reporting persons in the Advantage Solutions Inc. (ADV) Schedule 13G/A?

The reporting group comprises CastleKnight Master Fund LP, CastleKnight Fund GP LLC, CastleKnight Management LP, CastleKnight Management GP LLC, Weitman Capital LLC, and Aaron Weitman, each listed with the same 757,354 shares and 5.9% beneficial ownership of ADV Class A stock.

What voting and dispositive powers do the CastleKnight entities report over ADV shares?

Each reporting person discloses 0 shares with sole voting or dispositive power and 757,354 shares with shared voting and shared dispositive power, indicating decisions regarding these ADV shares are made on a shared basis among the reporting persons.

Is this Advantage Solutions Inc. (ADV) filing a joint Schedule 13G/A?

Yes. The entities and individual file jointly, supported by Exhibit A – Joint Filing Agreement. The filing also references Exhibit B – Control Person Identification, which further outlines the control relationships among the reporting persons.

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Available on EDGAR 08/14/2026 - 06:36 PM Accepted by SEC EDGAR 08/14/2026 - 06:35 PM Learn about SEC filing dates

SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

SCHEDULE 13G

UNDER THE SECURITIES EXCHANGE ACT OF 1934

(Amendment No. 1)

Advantage Solutions Inc.

(Name of Issuer)

Class A common stock, $0.0001 par value per share

(Title of Class of Securities)

00791N201

(CUSIP Number)

06/30/2026

(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)

schemaVersion:

SCHEDULE 13G

CUSIP Number(s): 00791N201

1

Names of Reporting Persons

CastleKnight Master Fund LP

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

CAYMAN ISLANDS

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 0.00
6	Shared Voting Power 757,354.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 757,354.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

757,354.00

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)

5.9 %

12

Type of Reporting Person (See Instructions)

PN

Comment for Type of Reporting Person: This figure represents the amount of Class A common stock, $0.0001 par value per share beneficially owned by the Reporting Persons as of August 14, 2026. As of June 30, 2026 the Reporting Persons beneficially owned 581,347 shares of Class A common stock, $0.0001 par value per share.

SCHEDULE 13G

CUSIP Number(s): 00791N201

1

Names of Reporting Persons

CastleKnight Fund GP 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 757,354.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 757,354.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

757,354.00

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)

5.9 %

12

Type of Reporting Person (See Instructions)

OO

SCHEDULE 13G

CUSIP Number(s): 00791N201

1

Names of Reporting Persons

CastleKnight Management LP

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 757,354.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 757,354.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

757,354.00

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)

5.9 %

12

Type of Reporting Person (See Instructions)

IA, PN

SCHEDULE 13G

CUSIP Number(s): 00791N201

1

Names of Reporting Persons

CastleKnight Management GP 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 757,354.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 757,354.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

757,354.00

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)

5.9 %

12

Type of Reporting Person (See Instructions)

OO

SCHEDULE 13G

CUSIP Number(s): 00791N201

1

Names of Reporting Persons

Weitman Capital 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

NEW JERSEY

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 0.00
6	Shared Voting Power 757,354.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 757,354.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

757,354.00

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)

5.9 %

12

Type of Reporting Person (See Instructions)

OO

SCHEDULE 13G

CUSIP Number(s): 00791N201

1

Names of Reporting Persons

Aaron Weitman

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 757,354.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 757,354.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

757,354.00

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)

5.9 %

12

Type of Reporting Person (See Instructions)

HC, IN

SCHEDULE 13G

Item 1.
(a)	Name of issuer: Advantage Solutions Inc.
(b)	Address of issuer's principal executive offices: 7676 Forsyth Boulevard, Fifth Floor, St. Louis, Missouri 63105
Item 2.
(a)	Name of person filing: CastleKnight Master Fund LP CastleKnight Fund GP LLC CastleKnight Management LP CastleKnight Management GP LLC Weitman Capital LLC Aaron Weitman
(b)	Address or principal business office or, if none, residence: CastleKnight Master Fund LP Maples Corporate Services Limited P.O. Box 309 Ugland House Grand Cayman KY1-1104 Cayman Islands CastleKnight Fund GP LLC 888 Seventh Avenue, 24th Floor New York, New York 10019 United States of America CastleKnight Management LP 888 Seventh Avenue, 24th Floor New York, New York 10019 United States of America CastleKnight Management GP LLC 888 Seventh Avenue, 24th Floor New York, New York 10019 United States of America Weitman Capital LLC c/o Aaron Weitman c/o CastleKnight Management LP 888 Seventh Avenue, 24th Floor New York, New York 10019 United States of America Aaron Weitman c/o CastleKnight Management LP 888 Seventh Avenue, 24th Floor New York, New York 10019 United States of America
(c)	Citizenship: CastleKnight Master Fund LP - Cayman Islands CastleKnight Fund GP LLC - Delaware CastleKnight Management LP - Delaware CastleKnight Management GP LLC - Delaware Weitman Capital LLC - New Jersey Aaron Weitman - United States of America
(d)	Title of class of securities: Class A common stock, $0.0001 par value per share
(e)	CUSIP No.: 00791N201
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: CastleKnight Master Fund LP - 757,354 CastleKnight Fund GP LLC - 757,354 CastleKnight Management LP - 757,354 CastleKnight Management GP LLC - 757,354 Weitman Capital LLC - 757,354 Aaron Weitman - 757,354
(b)	Percent of class: CastleKnight Master Fund LP - 5.9% CastleKnight Fund GP LLC - 5.9% CastleKnight Management LP - 5.9% CastleKnight Management GP LLC - 5.9% Weitman Capital LLC - 5.9% Aaron Weitman - 5.9%
(c)	Number of shares as to which the person has:
	(i) Sole power to vote or to direct the vote: CastleKnight Master Fund LP - 0 CastleKnight Fund GP LLC - 0 CastleKnight Management LP - 0 CastleKnight Management GP LLC - 0 Weitman Capital LLC - 0 Aaron Weitman - 0
	(ii) Shared power to vote or to direct the vote: CastleKnight Master Fund LP - 757,354 CastleKnight Fund GP LLC - 757,354 CastleKnight Management LP - 757,354 CastleKnight Management GP LLC - 757,354 Weitman Capital LLC - 757,354 Aaron Weitman - 757,354
	(iii) Sole power to dispose or to direct the disposition of: CastleKnight Master Fund LP - 0 CastleKnight Fund GP LLC - 0 CastleKnight Management LP - 0 CastleKnight Management GP LLC - 0 Weitman Capital LLC - 0 Aaron Weitman - 0
	(iv) Shared power to dispose or to direct the disposition of: CastleKnight Master Fund LP - 757,354 CastleKnight Fund GP LLC - 757,354 CastleKnight Management LP - 757,354 CastleKnight Management GP LLC - 757,354 Weitman Capital LLC - 757,354 Aaron Weitman - 757,354
Item 5.	Ownership of 5 Percent or Less of a Class.
	Not Applicable
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.
	If a parent holding company has filed this schedule, pursuant to Rule 13d-1(b)(ii)(G), so indicate under Item 3(g) and attach an exhibit stating the identity and the Item 3 classification of the relevant subsidiary. If a parent holding company has filed this schedule pursuant to Rule 13d-1(c) or Rule 13d-1(d), attach an exhibit stating the identification of the relevant subsidiary. Please see Exhibit B attached hereto.
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.

CastleKnight Master Fund LP

Signature:	By: CastleKnight Fund GP LLC, its general partner By: Weitman Capital LLC, its managing member, /s/ Aaron Weitman
Name/Title:	Aaron Weitman, Manager
Date:	08/14/2026

CastleKnight Fund GP LLC

Signature:	By: Weitman Capital LLC, its managing member, /s/ Aaron Weitman
Name/Title:	Aaron Weitman, Manager
Date:	08/14/2026

CastleKnight Management LP

Signature:	By: CastleKnight Management GP LLC, its general partner, By: Weitman Capital LLC, its managing member, /s/ Aaron Weitman
Name/Title:	Aaron Weitman, Manager
Date:	08/14/2026

CastleKnight Management GP LLC

Signature:	By: Weitman Capital LLC, its managing member, /s/ Aaron Weitman
Name/Title:	Aaron Weitman, Manager
Date:	08/14/2026

Weitman Capital LLC

Signature:	/s/ Aaron Weitman
Name/Title:	Aaron Weitman, Manager
Date:	08/14/2026

Aaron Weitman

Signature:	/s/ Aaron Weitman
Name/Title:	Aaron Weitman
Date:	08/14/2026

Exhibit Information

Exhibit A - Joint Filing Agreement Exhibit B - Control Person Identification