The $5B bets that went spectacularly wrong for tech bro before he lost $30B overnight

By New York Post (U.S.) | Created at 2026-08-17 22:51:25 | Updated at 2026-08-18 03:37:44 4 hours ago

The “Nostradamus of AI” made a pair of $5 billion bets — only to watch his $45 billion hedge fund implode days before his lavish California wedding.

Leopold Aschenbrenner’s Situational Awareness fund held a $5.7 billion stake in SanDisk and $5.6 billion in Micron Technology at the end of June, according to quarterly filings.

The two bets made up more than half of his US stock portfolio, which had ballooned from less than $4 billion to more than $20 billion during the second quarter.

Then the wheels came off.

Leopold Aschenbrenner. Aschenbrenner recently founded an investment firm focused on AGI, with anchor investments from Patrick Collison, John Collison, Nat Friedman, and Daniel Gross. For Our Posterity
Leopold Aschenbrenner, 24, is seen in an undated LinkedIn photograph. Aschenbrenner is a German artificial intelligence researcher, investor and the chief investment officer of Situational Awareness. Linkedin/Leopold Aschenbrenner

SanDisk shares plunged 47% in July, while Micron tumbled 29%, helping wipe out roughly 67% of the fund’s portfolio value in a single month. The losses triggered margin calls and forced Situational Awareness to sell billions of dollars of holdings in a fire sale to billionaire Ken Griffin’s Citadel.

Bloom Energy, the fund’s next-largest holding, accounted for nearly 10% of the portfolio and also plunged 31% during the month.

A sign is posted in front of the SanDisk headquarters on Wednesday, October 21, 2015, in Milpitas, California. Computer data storage company Western Digital announced plans to acquire flash memory storage maker SanDisk for $19 billion. (Getty Images North America) Getty Images
The Micron Technology Inc. headquarters is pictured on Thursday, April 18, 2024, in Boise, Idaho. Micron Technology Inc., the largest US maker of computer-memory chips, is poised to get $6.1 billion in grants from the Commerce Department to help pay for domestic factory projects. (Bloomberg) Bloomberg via Getty Images

Aschenbrenner had also sharply increased his positions in TSMC and opened a $1.2 billion position in Nebius before those stocks fell alongside the broader AI trade.

The carnage shrank Situational Awareness from roughly $45 billion to about $10 billion — though the fund remained up sharply for the year after reportedly returning 439% during the first half of 2026.

The disastrous bets also reportedly cost Wall Street trading giant Jane Street nearly $15 billion.

Aschenbrenner, 24, has become one of Silicon Valley’s most closely watched AI thinkers. He graduated from Columbia University at 19 and later worked at Sam Bankman-Fried’s now-defunct FTX before joining OpenAI in 2023.

He was fired the following year after allegedly leaking sensitive information to an Anthropic executive’s husband.

Leopold Aschenbrenner speaks with Dwarkesh Patel on his podcast in a video posted to YouTube on June 4, 2024. Aschenbrenner, a former OpenAI researcher with no professional investing experience, launched Situational Awareness in 2024 with a few hundred million dollars. YouTube/Dwarkesh Patel

Aschenbrenner quickly rebuilt his reputation with his 165-page essay, “Situational Awareness: The Decade Ahead,” which predicted artificial general intelligence could arrive by 2027 and warned of the geopolitical threat posed by superintelligent AI.

His hedge fund launched in 2024.

The spectacular collapse came just days before Aschenbrenner’s lavish California wedding.

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