Magnetar Financial LLC and affiliated reporting persons filed an amended Schedule 13G on November 13, 2026, disclosing beneficial ownership of 250,000 Class A ordinary shares of Launch One Acquisition Corp. as of September 30, 2026.

Key Highlights

  • Aggregate beneficial ownership: Each of the four reporting persons may be deemed to beneficially own 250,000 Class A ordinary shares of Launch One Acquisition Corp.
  • Ownership percentage: The 250,000 shares represent approximately 3.32% of the total shares outstanding, based on approximately 7,523,610 shares outstanding.
  • Shares distributed across eight funds: Holdings span Constellation Master Fund (58,082 shares), Lake Credit Fund (42,929), Structured Credit Fund (40,404), Xing He Master Fund (37,879), Alpha Star Fund (25,252), Purpose Alternative Credit Fund (22,727), SC Fund (17,677), and Purpose Alternative Credit Fund - T (5,050).
  • Voting and dispositive power: All 250,000 shares are held with shared voting and shared dispositive power; sole power is reported as zero for all reporting persons.
  • Reporting persons: The filing names Magnetar Financial LLC (investment adviser), Magnetar Capital Partners LP (sole member and parent holding company of Magnetar Financial), Supernova Management LLC (general partner of Magnetar Capital Partners), and David J. Snyderman (administrative manager of Supernova Management).
  • Filing event date: The event requiring this statement occurred on September 30, 2026.

Magnetar Financial's Ownership Structure Across Eight Funds in Launch One Acquisition

According to the filing, Magnetar Financial LLC serves as the investment adviser to the group of funds collectively referred to as the Magnetar Funds, and in that capacity exercises voting and investment power over the Class A ordinary shares held in those funds' accounts. Launch One Acquisition Corp., a special purpose acquisition company incorporated in the Cayman Islands with principal offices at 180 Grand Avenue, Suite 1530, Oakland, CA 94612, issued the Class A ordinary shares at a par value of $0.0001 per share carrying the CUSIP number G5S86M100.

The filing discloses that the 250,000 shares are distributed across eight separate funds, ranging from 58,082 shares at Constellation Master Fund to 5,050 shares at Purpose Alternative Credit Fund - T. The percentage of class, 3.32%, was calculated based on approximately 7,523,610 shares outstanding, a figure the filing attributes to information provided by the issuer in a Form 10-Q filed on August 12, 2026. The reporting persons certified, as required, that the securities "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."

The filing is designated Amendment No. 1 to a previously filed Schedule 13G. All four reporting persons share their principal business address at 1603 Orrington Avenue, 13th Floor, Evanston, Illinois 60201. The statement was signed on November 13, 2026 by Hayley Stein, identified as attorney-in-fact for David J. Snyderman, Administrative Manager of Supernova Management LLC.

What Was Disclosed

Magnetar Financial LLC and three affiliated entities filed an amended Schedule 13G disclosing collective beneficial ownership of 250,000 Class A ordinary shares of Launch One Acquisition Corp., equal to approximately 3.32% of shares outstanding, as of September 30, 2026.