[SCHEDULE 13G/A] Rithm Acquisition Corp. SEC Filing

Rhea-AI Filing Summary

Healthcare of Ontario Pension Plan Trust Fund (HOOPP) reports beneficial ownership of 480,000 Class A ordinary shares of Rithm Acquisition Corp., representing 2.0% of the Class A shares based on 23,660,000 shares outstanding as reported May 9, 2025. HOOPP identifies itself as a pension plan formed as a trust under Ontario law and registered with the Financial Services Regulatory Authority of Ontario. The filing states the shares were acquired and are held in the ordinary course of business and not for the purpose of influencing control of the issuer; HOOPP also affirms regulatory comparability and offers to furnish additional information to the SEC staff upon request.

Positive

• Disclosure of a clear, quantified holding: 480,000 Class A shares representing 2.0% of the class
• Explicit certification of passive intent: shares held in the ordinary course of business and not to influence control
• Reporting entity identification: HOOPP is a registered Ontario pension trust, providing regulatory context

Negative

• None.

Insights

Pension Fund Analyst

TL;DR: HOOPP holds 480,000 RAC shares (2.0%), a passive pension-fund position; the filing affirms no intent to influence control.

The Schedule 13G/A indicates a 2.0% beneficial stake in Rithm Acquisition Corp., held as a passive position under a pension trust structure. The report specifies the shares were acquired and are held in the ordinary course of business and not for control purposes. The disclosure cites the issuer's outstanding share count (23,660,000) used to calculate the percentage, and the reporting person is identified as a regulated Ontario pension plan.

Corporate Governance Expert

TL;DR: Disclosure shows passive ownership, no group affiliation, and a certification to cooperate with SEC staff if further information is requested.

The filing classifies HOOPP as a pension plan formed as a trust and registered with the Financial Services Regulatory Authority of Ontario. It indicates no group membership and notes that ownership is 5% or less of the class. Itemized certifications state the holdings were not acquired to influence control and that HOOPP will furnish additional information to the SEC staff upon request, which is consistent with passive investor reporting practices.

SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

SCHEDULE 13G

UNDER THE SECURITIES EXCHANGE ACT OF 1934

(Amendment No. 1)

Rithm Acquisition Corp.

(Name of Issuer)

Class A ordinary shares, $0.0001 par value

(Title of Class of Securities)

G75751100

(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. G75751100

1

Names of Reporting Persons

Healthcare of Ontario Pension Plan Trust 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

ONTARIO, CANADA

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 480,000.00
6	Shared Voting Power 0.00
7	Sole Dispositive Power 480,000.00
8	Shared Dispositive Power 0.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

480,000.00

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)

2.0 %

12

Type of Reporting Person (See Instructions)

FI

Comment for Type of Reporting Person: In reference to Rows 5, 7 and 9 above, amount consists of Class A ordinary shares, $0.0001 par value ("Class A Shares"), of Rithm Acquisition Corp., a blank check company formed under the laws of the Cayman Islands (the "Issuer"). In reference to Row 11 above, percentage ownership is based on 23,660,000 Class A Shares issued and outstanding as of May 9, 2025, as reported on the Issuer's quarterly report on Form 10-Q for the quarter ended on March 31, 2025, filed with the Securities and Exchange Commission on May 9, 2025.

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, New York 10003
Item 2.
(a)	Name of person filing: Healthcare of Ontario Pension Plan Trust Fund ("HOOPP")
(b)	Address or principal business office or, if none, residence: 1 York Street, Suite 1900, Toronto, Ontario, Canada, M5J 0B6
(c)	Citizenship: Ontario, Canada
(d)	Title of class of securities: Class A ordinary shares, $0.0001 par value
(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).
	A pension plan formed as a trust under the laws of Ontario, Canada and registered with the Financial Services Regulatory Authority of Ontario.
Item 4.	Ownership
(a)	Amount beneficially owned: See Item 9 on page 2.
(b)	Percent of class: See Item 11 on page 2.
(c)	Number of shares as to which the person has:
	(i) Sole power to vote or to direct the vote: See Item 5 on page 2.
	(ii) Shared power to vote or to direct the vote: See Item 6 on page 2.
	(iii) Sole power to dispose or to direct the disposition of: See Item 7 on page 2.
	(iv) Shared power to dispose or to direct the disposition of: See Item 8 on page 2.
Item 5.	Ownership of 5 Percent or Less of a Class.
	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 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. By signing below I certify that, to the best of my knowledge and belief, the regulatory scheme applicable to a pension plan formed as a trust under the laws of Ontario, Canada and registered with the Financial Services Regulatory Authority of Ontario is substantially comparable to the regulatory scheme applicable to the functionally equivalent U.S. institution(s). I also undertake to furnish to the Securities and Exchange Commission staff, upon request, information that would otherwise be disclosed in a Schedule 13D.

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.

Healthcare of Ontario Pension Plan Trust Fund

Signature:	/s/ Abas Kanu
Name/Title:	VP, HOOPP Compliance Officer
Date:	08/13/2025

FAQ

How many Rithm Acquisition (RAC) shares does HOOPP beneficially own?

HOOPP beneficially owns 480,000 Class A ordinary shares of Rithm Acquisition Corp.

What percentage of RAC does HOOPP's holding represent?

The holding represents 2.0% of the Class A shares based on 23,660,000 shares outstanding as reported May 9, 2025.

Does HOOPP intend to influence control of Rithm Acquisition Corp. (RAC)?

No. HOOPP certifies the securities were acquired and are held in the ordinary course of business and not for the purpose of changing or influencing control.

What type of entity is the reporting person HOOPP?

HOOPP is a pension plan formed as a trust under Ontario law and registered with the Financial Services Regulatory Authority of Ontario.

Is this filing part of a group or does HOOPP own more than 5%?

No. The filing indicates no group affiliation and classifies the ownership as 5% or less.