Ex-OpenAI researcher's $45 billion AI hedge fund got wiped out, but a $5 billion Anthropic stake may save him

Ex-OpenAI Researcher's $45 Billion AI Hedge Fund Got Wiped Out, but a $5 Billion Anthropic Stake May Save Him

Leopold Aschenbrenner built a $45 billion hedge fund on a single conviction: that scaling AI would require massive spending on semiconductors, compute, memory, and energy infrastructure 1. Situational Awareness returned 439 percent through June, according to the Financial Times, and its assets under management peaked near $45 billion, CNBC reported 1. Then, within weeks, the infrastructure trade fell apart. Situational Awareness has sold the majority of its public stock portfolio to Ken Griffin's Citadel following steep losses over the past month, The Wall Street Journal reported 1. The sale drew coverage from CNBC, Reuters, Bloomberg, and the Financial Times 2. Assets dropped to roughly $10 billion, Bloomberg reported, down from around $20 billion in recent months per the WSJ 1.

What the fund kept tells a different story than what it sold. Situational Awareness held onto its private-market investments, including a stake in Anthropic currently valued at $5 billion, according to Bloomberg 1. Anthropic was last valued at $965 billion in a Series H round in May and is expected to go public as soon as October, potentially at a higher valuation 1. That unsellable stake may be the single asset that keeps the fund afloat.

What cracked

Over the past month, public investors turned against AI capital expenditure, questioning whether the billions pouring into data centers, chips, and power generation were producing near-term revenue 1. The fund's holdings absorbed the full force of that reversal. Memory chip producers SK Hynix and Sandisk, clean energy developer Bloom Energy, and neocloud provider Nebius Group each fell more than 30 percent 1. Borrowed money magnified the losses 1.

With losses compounding, Aschenbrenner made a direct appeal to his investors. A July 24 letter reported by the Financial Times called the sell-off "one of the best buying opportunities since early last year" and offered a window for new commitments starting August 1 1. Bloomberg reported that the response fell short of what he was seeking 1. Citadel, which already held overlapping AI infrastructure stocks in its own portfolio, has a track record of acquiring assets from leveraged sellers, the WSJ reported 1.

The split

A fund that returned 439 percent betting on AI infrastructure got dismantled in weeks. The one asset that held its value was equity in the lab building the AI itself, locked in private markets where no one could sell it or price it while the public portfolio burned.

This is the real structure of the AI economy in mid-2026. Public markets have drawn a line: infrastructure spending that does not produce near-term revenue gets punished. Memory chips, fuel cells, cloud capacity. Those are commodity bets now, and commodity bets carry commodity volatility. The scarcity premium has migrated upstream to the model layer, to the labs developing frontier AI. But that equity is trapped in private hands, priced only when a funding round or an IPO forces a number onto it.

Anthropic's potential October IPO is not just a liquidity event for one hedge fund. It is the first time the public market will set a price on a standalone frontier AI lab. Every fund, every limited partner, every secondary-market buyer who has been marking private AI holdings at paper valuations will face a test. If Anthropic prices above its $965 billion May valuation, the private AI equity complex gets validated. If it prices below, the paper wealth sustaining funds like Aschenbrenner's comes under pressure alongside the losses already booked.

Background

Aschenbrenner, who is 25, had no prior trading experience when he launched Situational Awareness in 2024 1. He had joined OpenAI's superalignment team in 2023 and was dismissed a year later over what the company described as "an improper disclosure of internal information" 1. Early backers of the fund included quant-trading firm Jane Street, Stripe co-founders Patrick and John Collison, and Meta executives Daniel Gross and Nat Friedman 1. The fund also retains positions in chipmaker MatX and AI data center startup Fluidstack, which was in talks in April to raise a round at an $18 billion valuation 1. Those investors are now counting on an Anthropic IPO to do what the public market would not: reward the thesis.