SilverBox Corp IV (SBXD) is a SPAC — a blank check company with no operations whose sole purpose is to identify and complete a merger or acquisition with a private company, thereby taking that company public. SBXD raised $200M in its August 2024 IPO, with total proceeds held in a trust account invested in U.S. government securities or money market funds until a deal closes or the company liquidates. SBXD has 24 months from its IPO to complete an acquisition. In August 2025, SBXD announced a business combination with Parataxis Holdings, a Delaware LLC, under which both SBXD and Parataxis would become subsidiaries of a new public holding company; the transaction has not yet closed. The SPAC earns no revenue during its search phase — economics are entirely event-driven. The sponsor received 5M founder shares for a nominal $25,000 investment, which become valuable upon deal completion, while public shareholders can redeem shares for approximately $10.05 per share from the trust if they choose not to participate. SBXD also arranged a Standby Equity Purchase Agreement with Yorkville Advisors, giving the combined company the option to sell up to $400M of stock to Yorkville over 36 months post-closing as a potential capital source. SilverBox's management team previously sponsored three other SPACs, including combinations with Atlas Technical Consultants and Black Rifle Coffee Company.