SilverBox Corp IV (SBXD) files a range of documents with the U.S. Securities and Exchange Commission (SEC) that detail its activities as a New York Stock Exchange-listed special purpose acquisition company (SPAC). On this page, investors can review SBXD’s SEC filings, including current reports on Form 8-K that describe material events connected to its proposed business combination with Parataxis Holdings LLC and Parataxis Holdings Inc. (Pubco).
The company’s Form 8-K filings outline key steps in the transaction process, such as the execution and amendment of the Business Combination Agreement, the filing of the Registration Statement on Form S-4 that includes a preliminary proxy statement and prospectus, and changes to preferred equity subscription agreements related to Bitcoin purchases by Parataxis Holdings. Other 8-K reports address governance matters, including director resignations and appointments and committee assignments.
For a SPAC like SilverBox Corp IV, investors often focus on filings that explain the structure and consideration of the business combination, the treatment of public shares and warrants, and the conditions that must be satisfied before closing. The Registration Statement on Form S-4, referenced repeatedly in SBXD’s 8-Ks, is central to understanding the proposed mergers that will result in SilverBox Corp IV and Parataxis Holdings LLC becoming wholly owned subsidiaries of Pubco.
Stock Titan’s platform provides access to these SEC filings with AI-powered summaries that help explain complex transaction terms and risk disclosures in clearer language. Users can quickly see the main points of lengthy documents such as Form 8-Ks and the S-4 Registration Statement, while still being able to open the full text for detailed review. Real-time updates from EDGAR ensure that new filings, including any future proxy materials or additional current reports, are available as soon as they are posted, supporting investors who monitor SBXD’s progress toward its initial business combination.
SilverBox Corp IV and Parataxis Holdings are pursuing a business combination to form PubCo, an institutional digital asset management and Bitcoin-focused treasury platform. The strategy combines fee-based asset management, principal capital deployment and BTC yield and accumulation, aiming to reinvest returns into a BTC-centric balance sheet.
Parataxis has built listed Bitcoin and Ethereum treasury vehicles in South Korea, raising about KRW 25 billion (~US$17 million) for Parataxis Korea since August 2025 and launching Parataxis Ethereum in January 2026. An illustrative framework shows fee-based EBITDA scaling with assets under management and highlights potential equity value both from recurring fees and balance sheet returns, alongside extensive risk disclosures tied to Bitcoin volatility, regulation, and SPAC-related dilution.
SilverBox Corp IV reports that Parataxis Holdings LLC has entered into a definitive agreement with Sinsiway Co. Ltd. in a transaction valued at up to KRW 35 billion. The deal is structured to give Parataxis Holdings a controlling interest in Sinsiway, subject to closing conditions. After closing, Sinsiway plans to change its name to Parataxis ETH, Inc. while remaining listed on the KOSDAQ. The parties describe the planned combination as creating South Korea’s first Ethereum-based treasury platform listed on the country’s public markets, anchored by U.S.-based institutional digital-asset investors. The 8-K also reminds SilverBox shareholders that a Registration Statement on Form S-4 for the broader business combination among SilverBox, Parataxis Holdings and a new holding company is on file with the SEC and will form the basis of the proxy and prospectus materials.
Highbridge Capital Management filed Amendment No. 1 to Schedule 13G reporting beneficial ownership of 280,000 Class A Ordinary Shares of SilverBox Corp IV (SBXD), representing 1.4% of the class.
The percentage is based on 20,455,000 Class A shares outstanding as of August 12, 2025 and assumes conversion of Class B shares held by Highbridge-advised funds. Highbridge reports sole voting power: 280,000 and sole dispositive power: 280,000. The filing certifies the securities were acquired and are held in the ordinary course and not for the purpose of changing or influencing control. Highbridge notes the funds have rights to dividends or sale proceeds on the reported shares.
SilverBox Corp IV reported third‑quarter results as a SPAC focused on completing a business combination. Total assets were $211.4 million, primarily U.S. Treasury investments in the Trust Account. Class A ordinary shares subject to possible redemption were recorded at $211,208,265, or $10.56 per share as of September 30, 2025.
Net income was $637,702 for the quarter and $4,031,086 for the nine months, driven by $2,255,300 and $6,553,627 of interest earned on the Trust Account, respectively, offset by general and administrative expenses. Cash outside the Trust Account was $55,669.
On August 6, 2025, the company entered into a Business Combination Agreement with Parataxis entities; Santander US Capital Markets was engaged for equity capital markets advisory with fees of up to $10.3 million payable upon closing. The filing notes substantial doubt about the company’s ability to continue as a going concern absent completing a business combination by the current deadline of August 19, 2026. As of November 12, 2025, there were 20,455,000 Class A and 5,000,000 Class B shares outstanding.
Goldman Sachs Group, Inc. and Goldman Sachs & Co. LLC filed a Schedule 13G/A (Amendment No. 2) reporting beneficial ownership of 654,022 Class A shares of SilverBox Corp IV (SBXD), representing 3.2% of the class as of 09/30/2025.
The filers report shared voting and dispositive power over 654,022 shares and no sole power. The certification states the securities were acquired and are held in the ordinary course and not for the purpose of changing or influencing control.
SilverBox Corp IV reported that Parataxis Holdings Inc. (Pubco), Parataxis Holdings LLC, and certain accredited investors amended previously signed Preferred Equity Subscription Agreements. The original agreements, dated August 6, 2025, covered an aggregate of 3,100,000 preferred equity units of the Company at $10.00 per unit for an aggregate purchase price of $31,000,000.
Effective October 31, 2025, the amendment removes restrictions that had prohibited the Company from pledging or otherwise encumbering the Bitcoin purchased with the Preferred Equity proceeds, and expressly permits using such Bitcoin as collateral or other credit support to secure indebtedness or obligations under lending or other financing arrangements. The update is made in the context of the proposed business combination among SBXD, Parataxis Holdings LLC, and Pubco, for which a Form S-4 (333-289994) has been filed, and includes standard cautions that this communication is not an offer or solicitation.
SilverBox Corp IV reported an amendment to previously disclosed Preferred Equity Subscription Agreements tied to its proposed business combination with Parataxis. Earlier, Parataxis agreed to sell an aggregate of 3,100,000 preferred equity units at $10.00 per unit for a total of $31,000,000 in a private placement.
Effective October 31, 2025, the parties removed restrictions that had barred pledging the Bitcoin purchased with those proceeds and now permit that Bitcoin to be used as collateral or other credit support to secure indebtedness or obligations under lending or other financing arrangements. The filing also notes that a Registration Statement on Form S-4 (No. 333-289994) including a preliminary proxy statement/prospectus has been filed for the proposed business combination.
SilverBox Corp IV reports that Parataxis Holdings Inc. and Parataxis Holdings LLC have filed a Form S-4 registration statement for their previously announced business combination with SilverBox. The S-4 includes a preliminary proxy statement for SilverBox shareholders and a prospectus for Pubco, which will be mailed in definitive form to shareholders as of a future record date to vote on the transaction. The communication stresses that it is not an offer or solicitation and that any securities offering will be made only by a prospectus meeting Securities Act requirements.
The filing outlines extensive forward-looking risk factors, including the possibility the deal may not close, high redemption levels, listing uncertainties for Pubco, costs of becoming public, and Pubco’s planned Bitcoin-focused strategy. It notes that Pubco’s results and stock price may be highly sensitive to Bitcoin prices, regulatory treatment of crypto assets, potential dilution from warrants and equity financing, and legal, regulatory and geopolitical risks, including those related to South Korea and a KOSDAQ-listed investment.
Highbridge Capital Management, LLC filed a Schedule 13G reporting ownership of 1,228,800 Class A Ordinary Shares of SilverBox Corp IV (CUSIP G81354105), representing 5.9% of the Class A shares outstanding based on 20,455,000 shares as of May 13, 2025. The reported amount includes 280,000 Class A shares issuable upon conversion of Class B ordinary shares held by Highbridge Funds. The filing states the securities are held in the ordinary course of business and not for the purpose of changing or influencing control of the issuer.
The report cites Highbridge's address in New York and identifies it as a Delaware investment adviser filing on behalf of the Highbridge Funds.
Polar Asset Management Partners Inc. reports beneficial ownership of 1,480,000 Class A ordinary shares of Silverbox Corp IV, representing 7.2% of the class. The filing is a Schedule 13G/A amendment and shows Polar holds sole voting and sole dispositive power over the shares.
The filing states Polar serves as investment adviser to Polar Multi-Strategy Master Fund and that the securities are held in the ordinary course of business and not for the purpose of changing or influencing control of the issuer. The disclosure provides clarity on a material passive stake above 5% in Silverbox Corp IV.