Leopold Aschenbrenner, a former OpenAI researcher, built a hedge fund around a singular conviction that artificial superintelligence was coming faster than anyone realized.
His fund, Situational Awareness, attracted roughly $225 million in seed funding from high-profile backers including Stripe co-founders Patrick and John Collison, former GitHub CEO Nat Friedman, and trading firm Jane Street.
The fund grew at a stunning pace, ballooning to nearly $45 billion in assets by early July 2026, operated by a team of just eight employees, four of whom were investment professionals.
Aschenbrenner had established his credibility through a 165-page essay that became widely circulated and influential in Silicon Valley, positioning him as one of the few people who clearly understood the trajectory of AI.
The portfolio’s most striking feature was its extraordinary concentration, with approximately 56% of its disclosed U.S. equity holdings split between just two semiconductor stocks, Micron (MU) and SanDisk (SNDK).
Micron holdings surged from 17,362 common shares in the first quarter to 4.83 million shares worth an estimated $5.5 billion, while SanDisk grew from 1.14 million shares to 2.50 million shares worth an estimated $5.6 billion.
Together, those two positions represented approximately $11.25 billion of the fund’s disclosed equity portfolio, a concentration level that left the fund dangerously exposed to any reversal in semiconductor sentiment.
That reversal came swiftly, as a historic momentum shift in AI-related stocks triggered losses on both sides of the portfolio and set off a cascade of margin calls and compulsory asset sales.
The fund suffered a 67% loss in July as Aschenbrenner sold positions to reduce leverage during a severe liquidity squeeze, with assets crashing from nearly $45 billion to around $10 billion.
Situational Awareness was ultimately forced to sell all of its public stock holdings, with Ken Griffin’s Citadel hedge fund reaching a deal to purchase those positions.
The collapse sent shockwaves through the fund’s investor base, with Jane Street losing approximately $15 billion in July partly due to Situational Awareness’s troubles, according to the Wall Street Journal.
Analysts noted that the fund’s underlying directional thesis on AI was not necessarily wrong, but leverage amplified losses when the momentum trade temporarily broke down.
The episode stands as a cautionary example of how concentrated, leveraged bets on a single sector can unravel rapidly, even when the broader investment narrative remains intact.
