Leopold Aschenbrenner's meltdown helped AI stocks soar. It likely came too late to save other funds' July returns.

OpenAI researcher turned hedge fund investor Leopold Aschenbrenner was forced to sell the bulk of his publicly traded equity holdings after weeks of steep losses and margin calls from bank partners, according to a person familiar with the fund. Situational Awareness's unloading sent many artificial-intelligence-linked stocks soaring, benefiting Citadel, which beat out Millennium and Jane Street to purchase the stock portfolio. The rebound was a welcome relief, but for many hedge funds that owned the same names, it likely arrived too late to save many funds' months. Whale Rock Capital, run by Alex Sacerdote, was up more than 70% in the first half but added to its stakes in SanDisk and Bloom Energy in the first quarter. Both stocks jumped more than 20% on Thursday, but as of midday Friday, SanDisk remained roughly 45% below where it started July, while Bloom Energy was still down about 30%. Gavin Baker's Atreides Management and Brad Gerstner's Altimeter Capital both added to their CoreWeave positions in the first quarter. The cloud computing company was up more than 20% on Thursday after the portfolio sale, but the rebound erased only a fraction of the stock's losses in July.