Situational Awareness, the AI-focused hedge fund founded by former OpenAI researcher Leopold Aschenbrenner, sold the majority of its public stock portfolio to Ken Griffin's Citadel, as first reported by The Wall Street Journal on July 30, 2026 and subsequently detailed by TechCrunch. The fund retained its shares in Anthropic, the AI lab that remains privately held.

The sale caps a sharp reversal for a fund that, per the Financial Times, returned 439% for the year through June. CNBC had reported Situational Awareness's assets under management peaked at $45 billion before declining. After Citadel absorbed the bulk of the public holdings, Bloomberg pegged the fund's overall assets at roughly $10 billion, down from around $20 billion in recent months according to an earlier WSJ report.

Losses in the public portfolio were amplified by leverage. The hardest-hit names included SK Hynix, SanDisk, Bloom Energy, and Nebius Group, each dropping more than 30% over the prior month. These positions align with the fund's reported thesis: a March 2026 Forbes piece noted that Situational Awareness was betting on power plants and data centers rather than AI model developers directly.

Six days before the Citadel sale surfaced, Aschenbrenner was already rallying investors. On July 24, 2026, he wrote a letter to investors, seen by the Financial Times, calling the selloff one of the best buying opportunities since early last year and inviting clients to commit fresh capital starting August 1. Bloomberg reported that the appeal did not generate the hoped-for response.

Aschenbrenner is 25, German-born, and had no prior trading experience before launching Situational Awareness in 2024. He joined OpenAI's superalignment team in 2023 and was dismissed roughly a year later, with OpenAI citing improper disclosure of internal information. The fund's early backers included quant-trading firm Jane Street, Stripe co-founders Patrick and John Collison, and Meta executives Daniel Gross and Nat Friedman — a roster that reads as a who's-who of AI-adjacent capital.

SEC filings paint a picture of aggressive positioning beyond public equities. Situational Awareness LP, a Delaware limited partnership (CIK 0002045724, EIN 992901544, fiscal year ending December 31), filed a Form 13F-HR on May 15, 2026 for the quarterly period ending March 31, 2026, listing its address at 512 2nd Street, Suite 400. A Schedule 13G filed May 20, 2026 identifies the firm as an adviser in connection with an entity called "SAF AI." A separate Schedule 13G filed June 17, 2026 lists "Situational Awareness Partners LP" as a reporting person. And as of April 14, 2026, TechCrunch reported that AI data center startup Fluidstack was in talks for a $1 billion funding round led by Situational Awareness at an $18 billion valuation.

The retention of Anthropic shares is the detail that stands out. The public portfolio, built around the infrastructure layer of the AI buildout — memory chips, energy, and data center operators — bore the brunt of the recent selloff and the leverage layered on top. The Anthropic stake, still private and illiquid, was not part of what Citadel acquired. Whether that holding appreciates or decays will likely determine whether Aschenbrenner's fund stages a recovery or continues to shrink.

There is a broader pattern worth noting. Funds built around a single individual's conviction, especially one with no prior trading record, tend to experience velocity in both directions. The 439% return through June attracted capital at scale; the drawdown that followed has now triggered forced deleveraging via a block sale to one of the largest market-making firms in the world. The fact that Aschenbrenner's investor letter framed the selloff as a buying opportunity, and that the response reportedly fell short, suggests that at least some of his limited partners are reassessing their exposure rather than doubling down.

The private holdings — Anthropic, the potential Fluidstack lead, the "SAF AI" vehicle — represent the portion of the strategy that cannot be unwound in a single block trade. They are also the portion whose value is hardest to mark. For a fund that has now demonstrated it can move from $45 billion in AUM to $10 billion in a compressed timeframe, the gap between the liquid and illiquid sides of the book is where the next chapter of this story will be written.