Advantage Solutions Inc. Schedule 13G reports that CastleKnight-related filers beneficially own 18,138,473 shares of Class A common stock, equal to 5.5% of the class. The filing lists CastleKnight Master Fund LP, its GP/management entities, Weitman Capital LLC and Aaron Weitman as reporting persons.
The filing shows shared voting and dispositive power of 18,138,473 shares for each reporting person and disclaims individual beneficial ownership beyond pecuniary interest. Signatures are dated 03/26/2026.
Positive
None.
Negative
None.
Insights
CastleKnight group reports a 5.5% passive stake in Advantage Solutions.
The filing documents 18,138,473 shares and 5.5% ownership by CastleKnight Master Fund LP and affiliated entities, with identical shared voting and dispositive power figures. The report includes a standard disclaimer that reporting persons disclaim beneficial ownership except for pecuniary interest.
Cash‑flow treatment and any plans to trade or dispose are not stated in the excerpt; subsequent disclosures would be needed to show any change in holdings or voting alignment.
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549
SCHEDULE 13G
UNDER THE SECURITIES EXCHANGE ACT OF 1934
Advantage Solutions Inc.
(Name of Issuer)
Class A common stock, $0.0001 par value per share
(Title of Class of Securities)
00791N102
(CUSIP Number)
03/19/2026
(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):
00791N102
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
18,138,473.00
7
Sole Dispositive Power
0.00
8
Shared Dispositive Power
18,138,473.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
18,138,473.00
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)
5.5 %
12
Type of Reporting Person (See Instructions)
PN
SCHEDULE 13G
CUSIP Number(s):
00791N102
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
18,138,473.00
7
Sole Dispositive Power
0.00
8
Shared Dispositive Power
18,138,473.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
18,138,473.00
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)
5.5 %
12
Type of Reporting Person (See Instructions)
OO
SCHEDULE 13G
CUSIP Number(s):
00791N102
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
18,138,473.00
7
Sole Dispositive Power
0.00
8
Shared Dispositive Power
18,138,473.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
18,138,473.00
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)
5.5 %
12
Type of Reporting Person (See Instructions)
IA, PN
SCHEDULE 13G
CUSIP Number(s):
00791N102
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
18,138,473.00
7
Sole Dispositive Power
0.00
8
Shared Dispositive Power
18,138,473.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
18,138,473.00
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)
5.5 %
12
Type of Reporting Person (See Instructions)
OO
SCHEDULE 13G
CUSIP Number(s):
00791N102
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
18,138,473.00
7
Sole Dispositive Power
0.00
8
Shared Dispositive Power
18,138,473.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
18,138,473.00
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)
5.5 %
12
Type of Reporting Person (See Instructions)
OO
SCHEDULE 13G
CUSIP Number(s):
00791N102
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
18,138,473.00
7
Sole Dispositive Power
0.00
8
Shared Dispositive Power
18,138,473.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
18,138,473.00
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)
5.5 %
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
(d)
Title of class of securities:
Class A common stock, $0.0001 par value per share
(e)
CUSIP Number(s):
00791N102
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 - 18,138,473
CastleKnight Fund GP LLC - 18,138,473
CastleKnight Management LP - 18,138,473
CastleKnight Management GP LLC - 18,138,473
Weitman Capital LLC - 18,138,473
Aaron Weitman - 18,138,473
(b)
Percent of class:
CastleKnight Master Fund LP - 5.5%
CastleKnight Fund GP LLC - 5.5%
CastleKnight Management LP - 5.5%
CastleKnight Management GP LLC - 5.5%
Weitman Capital LLC - 5.5%
Aaron Weitman - 5.5%
(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 - 18,138,473
CastleKnight Fund GP LLC - 18,138,473
CastleKnight Management LP - 18,138,473
CastleKnight Management GP LLC - 18,138,473
Weitman Capital LLC - 18,138,473
Aaron Weitman - 18,138,473
(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 - 18,138,473
CastleKnight Fund GP LLC - 18,138,473
CastleKnight Management LP - 18,138,473
CastleKnight Management GP LLC - 18,138,473
Weitman Capital LLC - 18,138,473
Aaron Weitman - 18,138,473
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, By: /s/ Aaron Weitman
Name/Title:
Aaron Weitman/Manager
Date:
03/26/2026
CastleKnight Fund GP LLC
Signature:
By: Weitman Capital LLC, its managing member, By: /s/ Aaron Weitman
Name/Title:
Aaron Weitman/Manager
Date:
03/26/2026
CastleKnight Management LP
Signature:
By: CastleKnight Management GP LLC, its general partner By: Weitman Capital LLC, its managing member, By: /s/ Aaron Weitman
Name/Title:
Aaron Weitman/Manager
Date:
03/26/2026
CastleKnight Management GP LLC
Signature:
By: Weitman Capital LLC, its managing member, By: /s/ Aaron Weitman
Name/Title:
Aaron Weitman/Manager
Date:
03/26/2026
Weitman Capital LLC
Signature:
/s/ Aaron Weitman
Name/Title:
Aaron Weitman/Manager
Date:
03/26/2026
Aaron Weitman
Signature:
/s/ Aaron Weitman
Name/Title:
Aaron Weitman
Date:
03/26/2026
Comments accompanying signature: * Each Reporting Person disclaims beneficial ownership of the reported securities except to the extent of his or its pecuniary interest therein, and this report shall not be deemed an admission that such Reporting Person is the beneficial owner of the securities for purposes of Section 16 of the Securities Exchange Act of 1934, as amended, or for any other purpose.
Exhibit Information
[Exhibit A - Joint Filing Agreement]
[Exhibit B - Control Person Identification]
What stake does CastleKnight report in Advantage Solutions (ADV)?
CastleKnight reports beneficial ownership of 18,138,473 shares. The filing states this equals 5.5% of Advantage Solutions' Class A common stock and is held with shared voting and dispositive power as disclosed.
Which entities are listed as reporting persons on the ADV Schedule 13G?
Reporting persons include CastleKnight Master Fund LP, CastleKnight Fund GP LLC, CastleKnight Management LP, CastleKnight Management GP LLC, Weitman Capital LLC, and Aaron Weitman. Addresses and citizenships are provided in the filing.
Does the Schedule 13G indicate CastleKnight has sole voting control over the shares?
No; the filing lists zero sole voting power and 18,138,473 shares of shared voting power. Each reporting person shows shared voting and shared dispositive power for the same share count.
When was the Schedule 13G for ADV signed?
Signatures are dated 03/26/2026. The filing includes multiple signatures by Aaron Weitman on behalf of the reporting entities with that date.
Does the filing state whether CastleKnight intends to sell or acquire more ADV shares?
The excerpt does not state any intent to buy or sell additional shares. The report provides ownership and power figures but does not describe plans or transactions.
