X0607 3 2026-08-27 0 0002147219 Rainier Acquisition Corp RNAQ 0001404574 683 Capital Management, LLC false 1700 BROADWAY SUITE 4200 NEW YORK NY 10019 0 0 1 0 0001380126 683 Capital Partners, LP false C/O 683 CAPITAL GP, LLC 1700 BROADWAY, SUITE 4200 NEW YORK NY 10019 0 0 1 0 0001612431 Zweiman Ari false C/O 683 CAPITAL MANAGEMENT 1700 BROADWAY, SUITE 4200 NEW YORK NY 10019 0 0 1 0 Class A Ordinary Shares, $0.0001 Par Value 862500 I By 683 Capital Partners, LP Redeemable warrants 11.50 Class A Ordinary Shares 215625 I By 683 Capital Partners, LP This Form 3 is filed jointly by 683 Capital Management, LLC ("683 Management"), 683 Capital Partners, LP ("683 Partners") and Ari Zweiman (collectively, the "Reporting Persons"). Each of the Reporting Persons may be deemed to be a member of a Section 13(d) group that collectively owns more than 10% of the Class A Ordinary Shares, $0.0001 par value per share, of Rainier Acquisition Corporation (the "Issuer"). Each of the Reporting Persons disclaims beneficial ownership of the securities reported herein except to the extent of his or its pecuniary interest therein. Represents securities held directly by 683 Partners. 683 Management is the investment manager of 683 Partners. Ari Zweiman is the Managing Member of 683 Management. As a result, each of 683 Management and Ari Zweiman may be deemed to beneficially own the securities held by 683 Partners. Each warrant will become exercisable on the later of (i) one year following the Issuer's initial public offering and (ii) the completion by the Issuer of any merger, share exchange, asset acquisition, share purchase, reorganization or similar business combination, involving the Issuer and one or more businesses (a "Business Combination"), and expire five years after the completion of the initial Business Combination, or earlier upon redemption or liquidation. Exercise price is subject to adjustment in accordance with its terms. The reported securities are included within 862,500 Units of the Issuer purchased by the Reporting Persons at $10.00 per Unit. Each Unit consists of one Class A ordinary share, $0.0001 par value per share, and one-quarter of one redeemable warrant, each whole warrant exercisable for one Class A ordinary share at an exercise price of $11.50 per share, subject to adjustment. 683 CAPITAL MANAGEMENT, LLC; By: /s/ Ari Zweiman, Managing Member 2026-09-08 683 CAPITAL PARTNERS, LP; By: 683 Capital GP, LLC General Partner; By: /s/ Ari Zweiman, Managing Member 2026-09-08 /s/ Ari Zweiman 2026-09-08