Leopold Aschenbrenner's AI Hedge Fund Collapses, Sold to Citadel

Leopold Aschenbrenner Situational Awareness Citadel margin call AI hedge fund

Leopold Aschenbrenner, a former OpenAI researcher, founded the hedge fund Situational Awareness in 2024. The fund, which focused on AI infrastructure and semiconductor stocks, grew to about $45 billion in assets and posted a 439 % return for the year through June 2026, a 1,551 % gain since its inception. It operated with leverage of roughly 400 % (about four times its capital).

In July 2026 a sharp decline in AI‑related chip stocks triggered margin calls. To meet the calls, the fund sold the majority of its publicly listed holdings to Ken Griffin’s Citadel at a discount. The sale reduced the fund’s assets to roughly $10 billion. Aschenbrenner sent a letter to investors taking responsibility, confirming the fund was not liquidated and that it retained private‑equity positions such as Anthropic.

The episode, reported by Reuters, the Wall Street Journal, CNBC, the Financial Times and other outlets, highlights the risks of high‑leverage, sector‑concentrated strategies even amid earlier spectacular returns.

Entities

AI hedge fund sector · Anthropic · Citadel · Ken Griffin · Leopold Aschenbrenner · SK Hynix · Situational Awareness

Claims

What the coverage asserts, and how many sources carry each claim.

[● 5 SOURCES] The fund sold the majority of its public‑equity holdings to Citadel. www.merca2.es · www.cash.ch · www.finanznachrichten.de · t3n.de · dnyuz.com
[● 2 SOURCES] Situational Awareness invested heavily in AI infrastructure and semiconductor companies such as Broadcom, Intel, CoreWeave, SK Hynix and Anthropic. actualidad.rt.com · www.diebewertung.de
[● 7 SOURCES] The fund posted a 439 % return for the year through June 2026 and a 1,551 % gain since its founding. www.cash.ch · www.finanznachrichten.de · www.merca2.es · t3n.de · www.diebewertung.de · +2 more
[● 2 SOURCES] The fund posted a 439 % return from early 2026 to June 2026. www.merca2.es · actualidad.rt.com
[● 5 SOURCES] In July 2026 a slump in AI‑related semiconductor stocks triggered margin calls on the fund. www.diebewertung.de · www.cash.ch · www.merca2.es · www.blockmedia.co.kr · dnyuz.com
[● 10 SOURCES] After the sale, the fund's assets fell to about $10 billion. actualidad.rt.com · www.merca2.es · www.diebewertung.de · www.novinky.cz · www.cash.ch · +5 more
[● 10 SOURCES] The fund’s assets peaked at about $45 billion in mid‑2026. actualidad.rt.com · www.cash.ch · www.finanznachrichten.de · www.merca2.es · www.diebewertung.de · +5 more
[● 10 SOURCES] The fund returned 439 % from early 2026 to June 2026. www.merca2.es · www.diebewertung.de · actualidad.rt.com · www.cash.ch · www.finanznachrichten.de · +5 more
[● 9 SOURCES] Aschenbrenner wrote to investors confirming the sale and stating the fund was not liquidated. www.merca2.es · www.diebewertung.de · www.novinky.cz · actualidad.rt.com · www.cash.ch · +4 more
[● 11 SOURCES] Citadel is owned by billionaire Ken Griffin. www.merca2.es · www.diebewertung.de · www.novinky.cz · actualidad.rt.com · www.cash.ch · +6 more
[● 9 SOURCES] In July 2026 the fund sold the majority of its public equity holdings to Citadel. www.merca2.es · www.diebewertung.de · www.novinky.cz · actualidad.rt.com · www.cash.ch · +4 more
[● 11 SOURCES] The fund was leveraged up to roughly 400 % (about four times its capital). www.merca2.es · www.diebewertung.de · www.novinky.cz · actualidad.rt.com · www.cash.ch · +6 more