Blockchain Builders Fund I, LP and related reporting persons filed an amended Schedule 13G with the SEC on November 13, 2026, disclosing beneficial ownership of 225,989 shares of common stock in ZeroStack Corp. as of March 31, 2026.

Key Highlights

  • Aggregate beneficial ownership: Each of the four reporting persons discloses shared beneficial ownership of 225,989 shares of ZeroStack Corp. common stock, representing 9.3% of the class.
  • Warrant exercise: In January 2026, Blockchain Builders Fund I, LP exercised Token Pre-Funded Warrants in full, receiving 225,989 shares of common stock held directly and of record by the Fund.
  • No sole voting or dispositive power: All four reporting persons report 0 shares with sole voting power and 0 shares with sole dispositive power; all 225,989 shares are held under shared voting and shared dispositive power.
  • Reporting persons: The filing covers Blockchain Builders Fund I, LP; Blockchain Builders GP, LLC; Blockchain Builders, LLC; and Gil Rosen, Managing Member of both the General Partner and Investment Manager.
  • Share count basis: The 9.3% figure is calculated against 2,430,808 shares of common stock outstanding as of February 23, 2026, as reported in ZeroStack Corp.'s Annual Report filed February 27, 2026.
  • CUSIP: 98957E106; issuer principal offices listed as 2626 Cole Avenue, Suite 300, Dallas, Texas 75204.

Blockchain Builders Group Accumulates ZeroStack Common Stock via Warrant Exercise

According to the filing, Blockchain Builders Fund I, LP holds the 225,989 shares directly and of record following the full exercise of Token Pre-Funded Warrants in January 2026. The Fund reports it holds no remaining unexercised Token Pre-Funded Warrants and does not beneficially own any other shares of ZeroStack Corp. common stock or any other securities of the issuer convertible into or exercisable for common stock. ZeroStack Corp. is listed on NASDAQ:ZSTK and is headquartered in Dallas, Texas.

The filing states that Blockchain Builders GP, LLC, as general partner of the Fund, Blockchain Builders, LLC, as investment manager of the Fund, and Gil Rosen, as Managing Member of each of those entities, "may each be deemed to share voting power and dispositive power with respect to those securities." The filing also notes that "each of the General Partner, the Investment Manager and Mr. Rosen disclaims beneficial ownership of the securities reported in this statement except to the extent of that person's pecuniary interest therein." All four reporting persons are organized or domiciled in Delaware, with the exception of Gil Rosen, who is a United States citizen. Their shared business address is listed as 51 Essex Street, 6th Floor, New York, New York 10002.

The amended Schedule 13G was triggered by an event dated March 31, 2026. The filing was made jointly by the reporting persons pursuant to Rule 13d-1(k)(1), and the filing expressly states that the joint filing "is not an admission that the Reporting Persons constitute a group for purposes of Section 13(d)(3)."

What Was Disclosed

Blockchain Builders Fund I, LP and three affiliated reporting persons disclosed a combined 9.3% beneficial ownership position in ZeroStack Corp. common stock, consisting of 225,989 shares acquired through the full exercise of Token Pre-Funded Warrants in January 2026, with all voting and dispositive power held on a shared basis.