Ken Griffin's Citadel purchased a heavily discounted portion of Situational Awareness's public equities portfolio on July 30, 2026.
The AI-focused hedge fund suffered catastrophic losses from tumbling semiconductor stocks and mounting margin calls.
The California-based fund, managed by 24-year-old former OpenAI researcher Leopold Aschenbrenner, saw its assets collapse from a peak of $45 billion to approximately $10 billion, according to Reuters and CNBC.
With leverage reported up to 400 percent, the portfolio lost 67 percent of its value in July.
This forced the liquidation of hard-hit holdings like SK Hynix and CoreWeave.
Citadel executives worked through the night to analyze the troubled fund's $16 billion public equities book before completing the transaction.
The intervention adds to Griffin's history of rescue operations, having previously absorbed positions from failing entities like Enron, Sowood Capital, Amaranth Advisors, and Melvin Capital.
The downturn marks a sharp reversal for Aschenbrenner, who gained Silicon Valley prominence after publishing a 165-page AI manifesto in June 2024.
He subsequently raised $100 million for the fund that November.
Despite racking up gains exceeding 1,000 percent since its inception, the fund drew criticism from Wall Street figures regarding Aschenbrenner's lack of prior money management experience and his past employment at the collapsed cryptocurrency firm FTX.
Market participants noted that the high leverage made the sudden unwinding predictable during a short-term market correction.
"A lot of people saw this blow-up as a matter of not if, but when," said Jerry Diao, who runs a Wall Street coaching firm.
Diao noted that while long-term tech projections might hold merit, public market participants must remain insulated against sudden volatility.
"Maybe his views on AI are correct in the long run, but in the public markets, you have to be prepared for the short-term," said Diao.
Following the forced liquidations, Aschenbrenner issued a direct acknowledgment of the portfolio's severe downturn to his financial backers.
"We let you down," wrote Aschenbrenner, Founder and CEO of Situational Awareness, in a letter to investors.
The remaining assets of Situational Awareness are comprised of private company stakes, including a multibillion-dollar investment in Anthropic, alongside approximately $10 billion in residual holdings.
Citadel leaders emphasized that their operational framework allows the firm to absorb significant risks during broader market disruptions when traditional risk management models fail.
"During market stress, the collective judgment of our business leaders, risk managers and portfolio managers enables us to capitalize on market opportunities when others, who depend on simplistic stop-loss approaches, cannot," wrote Ken Griffin in a 2023 investor letter.
Griffin elaborated on his risk management philosophy during a podcast appearance, noting the necessity of bounding potential losses.
"You'll never manage a portfolio for every possible tail event but you should stay very focused on what is the worst-case scenario.
Can I tolerate that loss? And monitor and maintain your exposures such that that loss is a tolerable loss," said Griffin.
Prior to the fund's collapse, Aschenbrenner worked on OpenAI's Superalignment team before being terminated in 2024 over allegations of sharing confidential information, which he disputed as a security whistleblowing effort.
Academic colleagues recalled his specialized focus on technological threats during his undergraduate years at Columbia University.
"I liked Leopold while at OpenAI," said Scott Aaronson, a computer scientist now at the University of Texas at Austin who previously worked on AI safety at OpenAI.
Former peers noted that while Aschenbrenner possessed distinct intellectual traits, his social presentation during college was relatively ordinary.
"It was not like he was some prince, emerging out of the school," said Sofia Montrone, a Columbia classmate.
Montrone stated that she was unfamiliar with him until shortly before their 2021 graduation ceremony. "He was just some guy," said Montrone.
The asset sale concluded just before Aschenbrenner's scheduled weekend wedding to Avital Balwit, the chief of staff for Anthropic CEO Dario Amodei.
