Table of Contents As filed with the Securities and Exchange Commission on April 12, 2024. Registration No. 333-278192 UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Cayman Islands 6770 86-1885237 (Primary Standard Industrial Classification Code Number) 640 Fifth Avenue, 14th Floor New York, NY 10019 Telephone: (212) 380-7500 Amendment No. 1 to FORM S-1 REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933 Churchill Capital Corp IX (Exact Name of Registrant as Specified in its Char ...