As filed with the U.S. Securities and Exchange Commission on April 18, 2025. No. 333-285974 UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 AMENDMENT NO. 1 TO FORM S-1 REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933 Perimeter Acquisition Corp. I (Exact name of registrant as specified in its charter) Cayman Islands 6770 98-1843886 (State or other jurisdiction of incorporation or organization) (Primary Standard Industrial (I.R.S. Employer Identification No.) 6060 N. Central Exp ...