Citadel Bought $16 Billion in AI Stocks From Situational Awareness After Leverage Turned a 439% Gain Into a Margin Crisis
Leopold Aschenbrenner's AI-focused hedge fund delivered 439% net returns in H1 2026 by going long AI infrastructure and short disrupted software. Then July's selloff hit his leveraged positions. Within 24 hours, Ken Griffin's Citadel assembled a deal to buy the bulk of a $16 billion stock portfolio. The fund survives with a smaller book and its Anthropic stake intact, but the episode exposes a structural problem: even the most conviction-heavy AI thesis cannot survive 4x leverage when semiconductor stocks correct 15-20% in a month.