AI Hedge Fund Situational Awareness Loses 67% After Margin Calls Force Asset Sale

Leopold Aschenbrenner's Situational Awareness hedge fund experienced a severe collapse in July 2026, losing 67% of its value after steep declines in AI infrastructure stocks triggered margin calls and forced the liquidation of most of its public equities portfolio. The 25-year-old German-born founder, a former OpenAI researcher with no prior trading experience, had built the fund into a $45 billion operation at its peak by early July before market conditions deteriorated sharply.

The fund's portfolio was heavily concentrated in AI infrastructure plays, including memory chip producers SK Hynix and SanDisk, as well as cloud and energy providers, many of which declined more than 30% during July. Aschenbrenner used significant leverage to amplify his bets on these positions, a strategy common among hedge funds but one that magnified losses when markets moved against him. As positions deteriorated and collateral requirements from lenders increased, the fund faced a liquidity crisis described in internal communications as similar to a bank run, with adverse trading dynamics creating a self-reinforcing downward spiral.

On July 30–31, 2026, Citadel, the hedge fund led by billionaire Ken Griffin, stepped in to purchase the bulk of Situational Awareness' public stock portfolio in a block transaction. This forced asset sale reduced the fund's assets under management from approximately $20 billion to roughly $10 billion. Aschenbrenner acknowledged the failures in a letter to investors, stating "we let you down this month" and taking full responsibility, while noting that the fund ultimately protected investor capital by moving to a fully-paid-for public portfolio with no margin or liquidation risk.

Despite the public equity losses, Situational Awareness retained its private investments, most notably a stake in AI safety company Anthropic valued at approximately $5 billion. The fund remains up roughly 80% on the year despite July's drawdown, and Aschenbrenner indicated the fund would continue operating as a hybrid public-private vehicle while implementing new risk management procedures. The incident has sparked broader market debate about the risks of excessive leverage in AI-focused investments and the market impact of forced liquidations during periods of heightened volatility.

Citadel's acquisition of the portfolio appeared to stabilize AI infrastructure stocks, triggering a relief rally in global AI equities. Market analysts noted that the forced sales were driven by technical leverage dynamics rather than fundamental deterioration in AI infrastructure demand, with long-term growth drivers in semiconductors, compute, memory, and energy infrastructure remaining intact.