Perimeter Acquisition Corp. is a SPAC — a blank check company with no operations or revenues — formed to identify, acquire, and take public a private company in the defense and national security sector. Perimeter completed its IPO in mid-2025, raising approximately $241M held in trust, and has 24 months to complete an acquisition or return cash to shareholders at roughly $10.00 per share. Target subsectors include aerospace and defense, space, government services and IT, next-generation and dual-use manufacturing, and national infrastructure security. The sponsor acquired founder shares at a nominal cost and purchased private placement units at $10.00 each; if a deal closes, those founder shares convert to equity in the combined company at a significant economic advantage over public shareholders. If no deal is completed, the trust liquidates and the sponsor loses its founder shares and private placement investment. Perimeter's pitch centers on its management team's defense and investment credentials, including a former U.S. Marine officer with ties to defense-focused venture capital, a former CIO of Canyon Capital, and board members including a retired Vice Admiral and a Thiel Capital managing director. Gamma International Bank, with affiliates managing over $5B in assets, is a strategic investor in the sponsor and is positioned to provide capital markets support.