GigCapital9(GIXXU) - Prospectus

As filed with the U.S. Securities and Exchange Commission on December 1, 2025. Registration No. 333-[ ] UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM S-1 REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933 GigCapital9 Corp. Table of Contents (Exact name of registrant as specified in its charter) (State or other jurisdiction of incorporation or organization) Cayman Islands 6770 98-1894186 (Primary Standard Industrial Classification Code Number) (I.R.S. Employer Identificati ...