Magnetar Financial LLC and affiliated reporting persons filed an amended Schedule 13G with the SEC on November 13, 2026, disclosing beneficial ownership of 900,000 Class A ordinary shares of JAB Acquisition Corp I as of September 30, 2026.

Key Highlights

  • Aggregate beneficial ownership: Each reporting person may be deemed to beneficially own 900,000 Class A ordinary shares, par value $0.0001 per share, of JAB Acquisition Corp I (CUSIP G50004103).
  • Percent of class: The 900,000 shares represent approximately 4.84% of total shares outstanding, based on approximately 18,605,000 shares outstanding as reported by the issuer.
  • No sole voting or dispositive power: All 900,000 shares are held with shared voting power and shared dispositive power; sole voting and sole dispositive power are each reported as 0.
  • Shares distributed across multiple funds: Holdings include 216,000 shares in Constellation Master Fund, 189,000 in Structured Credit Fund, 153,000 each in Alpha Star Fund, Lake Credit Fund, and Xing He Master Fund, 27,000 in Waterfront Series A Fund, and 9,000 in Capital Master Fund.
  • Reporting persons: The filing covers four reporting persons: Magnetar Financial LLC (investment adviser), Magnetar Capital Partners LP (sole member and parent holding company), Supernova Management LLC (general partner), and David J. Snyderman (administrative manager of Supernova Management).
  • Filing date and triggering event: The statement, filed as Amendment No. 1, was dated November 13, 2026, with September 30, 2026 as the date of the event requiring the filing.

Magnetar Entities Disclose Shared Ownership in JAB Acquisition Corp I

According to the filing, Magnetar Financial LLC serves as the investment adviser to the Magnetar Funds and, in that capacity, exercises voting and investment power over the shares held in those funds' accounts. Magnetar Capital Partners LP is identified as the sole member and parent holding company of Magnetar Financial LLC, while Supernova Management LLC acts as the general partner of Magnetar Capital Partners LP. David J. Snyderman, a United States citizen, is the administrative manager of Supernova Management LLC. All four entities share principal business offices at 1603 Orrington Avenue, 13th Floor, Evanston, Illinois 60201.

The filing states that the shares were acquired and are held in the ordinary course of business and "were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities." JAB Acquisition Corp I, the issuer, is a blank-check company whose Class A ordinary shares carry a par value of $0.0001 per share. Its principal executive offices are listed at 270 Sylvan Avenue, Suite 2230, Englewood Cliffs, NJ 07632. The outstanding share count used to calculate the 4.84% ownership percentage was drawn from the issuer's Form 10-Q filed on August 14, 2026, which reported approximately 18,605,000 shares outstanding.

Item 5 of the filing designates this disclosure under the ownership of 5 percent or less of a class, consistent with the reported 4.84% figure. The amendment was signed by Hayley Stein as attorney-in-fact for David J. Snyderman on November 13, 2026. Items 6 through 9 of the filing are each noted as "Not Applicable," indicating no ownership on behalf of another person, no subsidiary acquisition, and no group formation or dissolution relevant to this statement.

What Was Disclosed

Four affiliated reporting persons, led by Magnetar Financial LLC, filed an amended Schedule 13G disclosing combined beneficial ownership of 900,000 Class A ordinary shares, or approximately 4.84%, of JAB Acquisition Corp I as of September 30, 2026, with all voting and dispositive power held on a shared basis across multiple investment funds.