×

Citadel sheds over 80% of aggregate risk from Situational Awareness portfolio

By Thomson Reuters Aug 21, 2026 | 10:33 AM

By Anirban Sen and Arasu Kannagi Basil

Aug 21 (Reuters) – Billionaire investor Ken Griffin’s Citadel has shed more than 80% of the aggregate risk from the original ​portfolio of Leopold Aschenbrenner’s Situational Awareness, which it ‌recently purchased, according to a letter sent to investors that was seen by Reuters on Friday.

Situational, an AI-focused hedge fund run by former OpenAI researcher Aschenbrenner, sold the bulk of its stock bets to Citadel ‌last ​month after heavy losses in its ⁠tech holdings forced it ⁠to unwind most of its public equities portfolio.

Citadel has since completed nearly 100 block trades totaling more than $4 billion in market value as it trimmed the risk from the ​portfolio. The firm declined to comment.

“Our ability to distribute this risk was central to our investment thesis,” Griffin ⁠said in the letter, adding that ⁠the moves included the largest intraday block trades ​of the year in 10 different names.

Citadel, which has about $77 ​billion of assets under management, is one of the ‌world’s most profitable and largest hedge funds. It has built a reputation for seizing opportunities during periods of market dislocation.

Griffin and his top lieutenants had pulled an all-nighter to analyze ⁠the trading book positions of Situational and how liquid the bets were, Reuters reported last month.

“A transaction of this magnitude could ⁠not have been ‌completed without the extraordinary cooperation of the ⁠trading and prime brokerage teams at the banks ​serving ‌both firms. I am grateful for the ​focused effort ⁠they brought to the rapid transfer of the portfolio,” Griffin said.

Citadel Wellington, the firm’s flagship multi-strategy fund, gained 5.94% in July, leaving it up 12% for the year.

(Reporting by Arasu Kannagi Basil in Bengaluru and Anirban Sen in New York; Editing ​by Shilpi Majumdar)