Hedge fund founder piles billions into SanDisk and Micron before collapse

Leopold Aschenbrenner’s hedge fund, Situational Awareness, disclosed a $5.7 billion stake in SanDisk and a $5.6 billion stake in Micron at the close of June, together representing 56% of its roughly $20 billion U.S. stock portfolio. The firm also boosted its TSMC holdings and created a $1.2 billion position in Nebius, while slashing its option book from sixteen contracts to just three. In July, SanDisk and Micron prices dropped 47% and 29% respectively, erasing much of the fund’s gains and causing a 67% portfolio decline that prompted margin calls.

To meet those calls, Aschenbrenner sold most of his public equities to Ken Griffin’s Citadel. The fund, once celebrated for a 1,000% rise since launch, had previously held a $879 million stake in Bloom Energy and reported an investment in Anthropic, though those figures are not captured in the 13F. Aschenbrenner did not respond to a request for comment.