Leopold Aschenbrenner launched his AI-focused hedge fund less than two years ago with no professional investing experience.

The fund is now larger than Bill Ackman’s flagship Pershing Square Holdings and has Wall Street’s most profitable trading firm as a backer.

Quant giant Jane Street has become a limited partner in Situational Awareness, according to a Wall Street Journal report. Jane Street rarely allocates capital to outside money managers, making the check notable.

Situational Awareness now manages more than $20 billion in assets, surpassing the roughly $16 billion in Ackman’s London-listed Pershing Square Holdings.

The fund is up about 270% after fees this year and over 1,000% since launching in late 2024, though it dipped in early 2025 during the China DeepSeek-driven chipmaker selloff.

The Anthropic Bet That Powered The Run

A single position in AI lab Anthropic accounts for roughly a fifth of the fund’s assets, the Journal reported.

Situational Awareness first invested in Anthropic at a $61.5 billion valuation in February 2025.

Anthropic confidentially filed for an IPO on June 1, targeting a $965 billion valuation.

On Polymarket, traders are pricing an 83% probability that Anthropic lists before OpenAI, with similar volumes seen on Kalshi.

Retail Traders Mirror The Disclosures

The trading app Autopilot, attached to the viral Nancy Pelosi stock tracker, rolled out a feature in March that lets users copy Aschenbrenner’s disclosed trades.

His recently revealed stake in solar manufacturer T1 Energy (NASDAQ:TE) sent the stock up 23% in a single day on its second-highest trading volume ever.

A May filing then showed Situational Awareness held $8.5 billion in put options, which some observers misread as a bearish bet on Nvidia Corp. (NASDAQ:NVDA) and sparked an online panic.

The puts are more consistent with portfolio hedging, as 13F filings only show a partial picture of a fund’s positioning.

Jane Street’s Broader AI Infrastructure Push

The LP check is not Jane Street’s only tie to Aschenbrenner. The two firms co-led a recent venture round in AI chip startup MatX and are backing a new round for AI cloud provider Fluidstack, the Journal reported.

Jane Street has been building broader AI infrastructure exposure, including a $6 billion cloud computing deal with CoreWeave Inc. (NASDAQ:CRWV) in April.

Situational Awareness has also profited from international plays, including an early stake in Korean memory-chip maker SK Hynix from November 2024.

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