Rithm Acquisition Corp. Schedule 13G/A reports beneficial ownership positions held by First Trust entities as of 03/31/2026. The filing lists First Trust Merger Arbitrage Fund (VARBX) owning 293,004 shares (1.24%) and First Trust Capital Management L.P., First Trust Capital Solutions L.P. and FTCS Sub GP LLC collectively owning 363,144 shares (1.53%).
The filing clarifies that FTCM, as investment adviser, has authority to vote and dispose of shares held in client accounts and that FTCS and Sub GP may be deemed control persons of FTCM. Signatures are dated 05/15/2026.
Positive
None.
Negative
None.
Insights
Retail view: two First Trust-related holders report modest stakes in RAC.
The filing lists concrete holdings: 293,004 shares (1.24%) for VARBX and 363,144 shares (1.53%) held via FTCM/FTCS/Sub GP as of 03/31/2026. These percentages indicate passive institutional positions below typical activist thresholds.
Control language states FTCM ‘‘has the authority to purchase, vote and dispose’’ of client account shares and that FTCS/Sub GP may be deemed control persons of FTCM. Subsequent trading or amendments would appear in later filings.
Filing emphasizes advisory control, not direct managerial change.
The statement clarifies that FTCS and Sub GP are control persons of FTCM and that FTCS/Sub GP do not own shares in their own accounts. This describes attribution of beneficial ownership under securities rules rather than operational control of the issuer.
Investors should note the filing is informational: it documents holdings and voting/dispositive authority as of 03/31/2026; any material change requires an amended report.
Key Figures
VARBX shares:293,004 sharesVARBX percent:1.24%FTCM/FTCS/Sub GP shares:363,144 shares+3 more
6 metrics
VARBX shares293,004 sharesAs of 03/31/2026
VARBX percent1.24%Percent of class as of 03/31/2026
FTCM/FTCS/Sub GP shares363,144 sharesAs of 03/31/2026
FTCM group percent1.53%Percent of class as of 03/31/2026
Reporting date03/31/2026Amount beneficially owned reported as of this date
Filing signature date05/15/2026Signatures dated on amendment
"As investment adviser to the Client Accounts, FTCM has the authority to invest the funds"
A beneficial owner is the person who ultimately owns or controls a financial asset or property, even if their name isn't directly on official documents. Think of it like someone who secretly holds the keys to a safe deposit box—others may appear to have access, but the true owner is the one who benefits from what's inside. Identifying beneficial owners helps ensure transparency and prevent illegal activities like money laundering or fraud.
investment adviserfinancial
"FTCM, an investment adviser registered with the SEC that provides investment advisory services"
An investment adviser is a person or firm that professionally manages money and gives recommendations about buying, selling, or holding investments. Like a financial coach or guide, they have a legal duty to act in a client's best financial interest, so their advice, fees and potential conflicts can directly affect returns and risk — making their role important for investors who want informed, accountable help with portfolios.
Joint Filing Statementregulatory
"This /A is being filed jointly by First Trust Merger Arbitrage Fund"
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549
SCHEDULE 13G
UNDER THE SECURITIES EXCHANGE ACT OF 1934
(Amendment No. 2)
Rithm Acquisition Corp.
(Name of Issuer)
Class A Ordinary Shares, par value $0.0001 per share
(Title of Class of Securities)
G75751100
(CUSIP Number)
03/31/2026
(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):
G75751100
1
Names of Reporting Persons
First Trust Merger Arbitrage Fund
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
293,004.00
6
Shared Voting Power
0.00
7
Sole Dispositive Power
293,004.00
8
Shared Dispositive Power
0.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
293,004.00
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)
1.24 %
12
Type of Reporting Person (See Instructions)
IV
SCHEDULE 13G
CUSIP Number(s):
G75751100
1
Names of Reporting Persons
First Trust Capital Management 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
363,144.00
6
Shared Voting Power
0.00
7
Sole Dispositive Power
363,144.00
8
Shared Dispositive Power
0.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
363,144.00
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)
1.53 %
12
Type of Reporting Person (See Instructions)
IA
SCHEDULE 13G
CUSIP Number(s):
G75751100
1
Names of Reporting Persons
First Trust Capital Solutions 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
363,144.00
6
Shared Voting Power
0.00
7
Sole Dispositive Power
363,144.00
8
Shared Dispositive Power
0.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
363,144.00
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)
1.53 %
12
Type of Reporting Person (See Instructions)
HC
SCHEDULE 13G
CUSIP Number(s):
G75751100
1
Names of Reporting Persons
FTCS Sub 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
363,144.00
6
Shared Voting Power
0.00
7
Sole Dispositive Power
363,144.00
8
Shared Dispositive Power
0.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
363,144.00
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)
1.53 %
12
Type of Reporting Person (See Instructions)
HC
SCHEDULE 13G
Item 1.
(a)
Name of issuer:
Rithm Acquisition Corp.
(b)
Address of issuer's principal executive offices:
799 BROADWAY, 8TH FLOOR, NEW YORK, NY, 10003
Item 2.
(a)
Name of person filing:
This Schedule 13G/A is being filed jointly by First Trust Merger Arbitrage Fund ("VARBX"), First Trust Capital Management L.P. ("FTCM"), First Trust Capital Solutions L.P. ("FTCS") and FTCS Sub GP LLC ("Sub GP").
(1) VARBX, a series of Investment Managers Series Trust II, an investment company registered under the Investment Company Act of 1940.
(2) FTCM, an investment adviser registered with the SEC that provides investment advisory services to, among others, (i) series of Investment Managers Series Trust II, an investment company registered under the Investment Company Act of 1940, specifically First Trust Multi-Strategy Fund and VARBX, (ii) First Trust Alternative Opportunities Fund, an investment company registered under the Investment Company Act of 1940, and (iii) Highland Capital Management Institutional Fund II, LLC, a Delaware limited liability company (collectively, the "Client Accounts").
(3) FTCS, a Delaware limited partnership and control person of FTCM.
(4) Sub GP, a Delaware limited liability company and control person of FTCM.
Each of the persons identified herein is referred to as a "Reporting Person" and, collectively, as the "Reporting Persons." Each of the Reporting Persons is a party to that certain Joint Filing Statement attached hereto.
(b)
Address or principal business office or, if none, residence:
The principal business address of FTCM, FTCS and Sub GP is 225 W. Wacker Drive, 21st Floor, Chicago, IL 60606. The principal business address of VARBX is 235 West Galena Street, Milwaukee, WI 53212.
(c)
Citizenship:
United States
(d)
Title of class of securities:
Class A Ordinary Shares, par value $0.0001 per share
(e)
CUSIP No.:
G75751100
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:
As investment adviser to the Client Accounts, FTCM has the authority to invest the funds of the Client Accounts in securities (including Ordinary Shares of Rithm Acquisition Corp (the "Issuer")) as well as the authority to purchase, vote and dispose of securities, and may thus be deemed the beneficial owner of any shares of the Issuer's Ordinary Shares held in the Client Accounts. As of March 31, 2026 VARBX owned 293,004 shares of the outstanding Ordinary Shares of the Issuer, while FTCM, FTCS and Sub GP collectively owned 363,144 shares of the outstanding Ordinary Shares of the Issuer.
FTCS and Sub GP may be deemed to control FTCM and therefore may be deemed to be beneficial owners of the Ordinary Shares reported in this Schedule 13G/A. No one individual controls FTCS or Sub GP. FTCS and Sub GP do not own any Ordinary Shares of the Issuer for their own accounts.
(b)
Percent of class:
VARBX: 1.24%
FTCM, FTCS and Sub GP: 1.53%
(c)
Number of shares as to which the person has:
(i) Sole power to vote or to direct the vote:
VARBX: 293004
FTCM, FTCS and Sub GP: 363144
(ii) Shared power to vote or to direct the vote:
VARBX: 0
FTCM, FTCS and Sub GP: 0
(iii) Sole power to dispose or to direct the disposition of:
VARBX: 293004
FTCM, FTCS and Sub GP: 363144
(iv) Shared power to dispose or to direct the disposition of:
VARBX: 0
FTCM, FTCS and Sub GP: 0
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.
If any other person is known to have the right to receive or the power to direct the receipt of dividends from, or the proceeds from the sale of, such securities, a statement to that effect should be included in response to this item and, if such interest relates to more than 5 percent of the class, such person should be identified. A listing of the shareholders of an investment company registered under the Investment Company Act of 1940 or the beneficiaries of employee benefit plan, pension fund or endowment fund is not required.
See Item 4.
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.
See Item 2.
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 acquired and are held in the ordinary course of business and 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.
What stake does First Trust Merger Arbitrage Fund hold in Rithm Acquisition Corp (RAC)?
VARBX beneficially owns 293,004 shares, representing 1.24% of the class as of 03/31/2026. The filing attributes sole voting and dispositive power over those shares to VARBX as reported.
How many shares do First Trust Capital Management and affiliated entities report for RAC?
FTCM, FTCS and FTCS Sub GP collectively report beneficial ownership of 363,144 shares, or 1.53% of the class as of 03/31/2026. The filing states sole voting and dispositive power for those shares.
Does the Schedule 13G/A indicate First Trust controls Rithm Acquisition Corp?
No. The filing attributes beneficial ownership and advisory authority to FTCM and notes FTCS/Sub GP may control FTCM; it does not claim control of the issuer or managerial changes to Rithm Acquisition Corp.
What authority does FTCM assert over the reported RAC shares?
FTCM states it has the authority to purchase, vote and dispose of securities held in the client accounts and thus may be deemed the beneficial owner of the reported shares as of 03/31/2026.
When was this Schedule 13G/A signed and filed?
The filing bears signatures dated 05/15/2026 and reports holdings as of 03/31/2026, per the amendment cover and signature block.
