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SilverBox Corp IV is furnishing an investor presentation outlining its proposed business combination with Parataxis Holdings to create PubCo, an institutional digital asset manager. PubCo’s model combines private investment funds, principal balance sheet investments and an actively managed Bitcoin- and Ethereum-focused digital asset treasury, targeting BTC-centric returns rather than passive price exposure.
The materials describe PubCo’s affiliation with Parataxis Capital Management, which manages over $100 million for institutional clients, and highlight early moves in South Korea through Parataxis Korea and Parataxis Ethereum as listed BTC and ETH treasury vehicles. An illustrative transaction summary shows Parataxis equity rollover, SBXD trust cash and preferred equity funding contributing to a pro forma equity value around $393 million at $10 per share with 39.3 million shares outstanding, assuming no redemptions.
The presentation emphasizes accelerating institutional adoption of digital assets, but also details extensive risks, including Bitcoin and ETH price volatility, regulatory changes, security and custody vulnerabilities, potential dilution from warrants, dual-class voting, equity line sales under a standby equity purchase agreement and the possibility that the business combination may not close or may face significant redemptions.
W. R. Berkley Corporation filed an amendment (Schedule 13G/A) reporting beneficial ownership of 1,514,573 Class A Ordinary Shares of SilverBox Corp. The filing lists this holding as 7.4% of the class and shows shared voting and shared dispositive power over 1,514,573 shares. The filing is signed by Richard M. Baio on 05/07/2026.
SilverBox Corp IV and the counterparties to its business combination agreement amended that agreement on May 1, 2026 to extend the agreement's Outside Date from May 6, 2026 to August 6, 2026. The amendment is filed as Exhibit 2.1 to this Current Report on Form 8-K. The filing reiterates that a Registration Statement on Form S-4 (333-289994) including a preliminary proxy statement/prospectus has been filed and that shareholders will receive a definitive proxy statement/prospectus when available. The report also lists securities and tickers for the SPAC units, shares and warrants, and summarizes customary forward-looking risk factors tied to the proposed Business Combination.
SilverBox Corp IV entered into a First Amendment to its Business Combination Agreement with Parataxis entities on May 1, 2026. The amendment extends the agreement’s “Outside Date” for closing the proposed business combination from May 6, 2026 to August 6, 2026, giving the parties more time to satisfy closing conditions and complete the transaction. The company notes that a Registration Statement on Form S-4 containing a proxy statement/prospectus has been filed, and reiterates that shareholders should rely on those SEC materials when evaluating the deal.
SilverBox Corp IV (SBXD) is a Cayman Islands-based special purpose acquisition company formed in April 2024, with no operating revenues to date. It completed a 20,000,000-unit IPO at $10.00 per unit, placing $201,000,000 in a U.S. trust account to fund a future merger.
The sponsor holds 5,000,000 founder shares and 455,000 private placement units. As of March 19, 2026 there were 20,455,000 Class A and 5,000,000 Class B ordinary shares outstanding, and the non‑affiliate Class A float was valued at $216,413,900 as of December 31, 2025.
On August 6, 2025, SBXD entered into a Business Combination Agreement with Parataxis Holdings, using a two‑step merger into a new Delaware holding company, Pubco. Pubco also signed an optional equity facility with Yorkville Advisors for up to $400 million of Pubco Class A stock over 36 months after closing.
Silverbox Corp IV received an Amendment No. 2 to a Schedule 13G from a group of affiliated Sculptor Capital entities regarding its Class A ordinary shares. The filing is dated as of the event on 12/31/2025.
Sculptor Capital LP, Sculptor Capital II LP, Sculptor Capital Holding Corporation, Sculptor Capital Holding II LLC, Sculptor Capital Management, Inc., Sculptor Master Fund, Ltd., and Sculptor Special Funding, LP each report beneficial ownership of 0 Class A ordinary shares, representing 0% of the class. All report 0 shares with sole or shared voting and dispositive power.
The percentage calculations are based on 20,455,000 Class A ordinary shares, as set forth in Silverbox Corp IV’s 10-Q filed on November 12, 2025. The reporting group certifies the securities were not acquired or held to change or influence control of the issuer.
Mizuho Financial Group, Inc., a Japan-based parent holding company, reported beneficial ownership of 1,645,673 SilverBox Corp IV common shares, representing 8.0% of the class as of the event date 12/31/2025. Mizuho has sole power to vote and dispose of these shares, with no shared voting or dispositive power.
The filing notes that Mizuho Financial Group, Mizuho Bank, Ltd. and Mizuho Americas LLC may be deemed indirect beneficial owners of equity securities directly held by their wholly owned subsidiary, Mizuho Securities USA LLC. The securities are stated to be acquired and held in the ordinary course of business and not for changing or influencing control of SilverBox Corp IV.
W. R. Berkley Corporation and its subsidiary Berkley Insurance Company report beneficial ownership of 1,211,674 Class A ordinary shares of SilverBox Corp IV, representing 5.9% of the class.
The shares carry shared voting and dispositive power, with no sole power reported. The securities were acquired and are held in the ordinary course of business and are not intended to change or influence control of SilverBox Corp IV.
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.