SCHEDULE 13G 0002047503 XXXXXXXX LIVE Class A Ordinary Shares, par value $0.0001 per share 09/30/2025 0002047497 Rithm Acquisition Corp. G75751100 799 Broadway 8th Floor New York NY 10003 Rule 13d-1(d) Rithm Acquisition Corp Sponsor LLC DE 6335000.00 0.00 6335000.00 0.00 6335000.00 N 21.5 PN Row 5, 7, 9, and 11: See Item 4 below. Rithm Acquisition Corp Sponsor LLC holds 5,675,000 Class B ordinary shares of the Issuer, which are automatically convertible into the Issuer's Class A ordinary shares, and 660,000 Class A ordinary shares included in the private placement units, in each case as more fully described under the heading "Description of Securities" in the Issuer's registration statement on Form S-1 (File No. 333-284671). Rithm Capital Corp. DE 0.00 6335000.00 0.00 6335000.00 6335000.00 N 21.5 PN Row 6, 8, 9, and 11: See Item 4 below. Rithm Acquisition Corp Sponsor LLC holds 5,675,000 Class B ordinary shares of the Issuer, which are automatically convertible into the Issuer's Class A ordinary shares, and 660,000 Class A ordinary shares included in the private placement units, in each case as more fully described under the heading "Description of Securities" in the Issuer's registration statement on Form S-1 (File No. 333-284671). Michael Nierenberg X1 0.00 6335000.00 0.00 6335000.00 6335000.00 N 21.5 PN Row 6, 8, 9, and 11: See Item 4 below. Rithm Acquisition Corp Sponsor LLC holds 5,675,000 Class B ordinary shares of the Issuer, which are automatically convertible into the Issuer's Class A ordinary shares, and 660,000 Class A ordinary shares included in the private placement units, in each case as more fully described under the heading "Description of Securities" in the Issuer's registration statement on Form S-1 (File No. 333-284671). Rithm Acquisition Corp. 799 Broadway, 8th Floor, New York, NY 10003 Rithm Acquisition Sponsor LLC Rithm Capital Corp. c/o Rithm Acquisition Corp. 799 Broadway, 8th Floor New York, New York 10003 The citizenship of Rithm Acquisition Sponsor LLC is Delaware. The citizenship of Rithm Capital Corp. is Delaware. The citizenship of Michael Nierenberg is the United States. Y The responses to Items 5-11 of the cover pages of this Schedule 13G are incorporated herein by reference. As of September 30, 2025, the Reporting Persons may be deemed to beneficially own 6,335,000 shares of the Issuer's Class A and Class B ordinary shares, representing 21.5% of the total shares of Class A and Class B ordinary shares issued and outstanding. The Class B ordinary shares are automatically convertible into the Issuer's Class A ordinary shares at the time of the Issuer's initial business combination on a one-for-one basis, subject to adjustment, as more fully described under the heading "Description of Securities - Founder Shares" in the Issuer's registration statement on Form S-1 (File No. 333-284671). Rithm Acquisition Sponsor LLC is the record holder of such ordinary shares, and Rithm Acquisition Sponsor LLC is controlled by Rithm Capital Corp., an affiliate of the Issuer, and Michael Nierenberg as a result of his role as chief executive officer, chairman of the board and president of Rithm Capital Corp. As a result, each of Rithm Acquisition Sponsor LLC, Rithm Capital Corp. and Mr. Nierenberg may be deemed to have beneficial ownership of the Class A and Class B ordinary shares held by Rithm Acquisition Sponsor LLC, but each disclaims such beneficial ownership except to the extent of such person's or entity's pecuniary interest therein. See responses to Item 11 on each cover page. See responses to Item 5 on each cover page. See responses to Item 6 on each cover page. See responses to Item 7 on each cover page. See responses to Item 8 on each cover page. Y Y Y Y Y Y Rithm Acquisition Corp Sponsor LLC /s/ Nicola Santoro 11/05/2025 Rithm Capital Corp. /s/ Nicola Santoro 11/05/2025 Michael Nierenberg /s/ Michael Nierenberg 11/05/2025