Ex-OpenAI Researcher’s $20B Fund Up 270% on Anthropic Bet

Situational Awareness, the hedge fund run by former OpenAI researcher Leopold Aschenbrenner, rose about 270% through May and now manages roughly $20 billion. The gains were driven by a large private stake in Anthropic and concentrated investments in power generation and AI computing infrastructure.

Aschenbrenner, 24, set out his investment thesis in a 165-page essay published in 2024. In the essay he argued that the physical inputs for large AI models — mainly electricity and computing hardware — will determine which companies capture most of the economic value from the technology.

The fund’s single largest holding is a private share of Anthropic, the maker of the Claude chatbot. The position was bought in February 2025 when Anthropic’s private valuation was about $60 billion; a funding round in May 2026 pushed the company’s valuation to roughly $965 billion. That Anthropic stake represents about one-fifth of the fund’s assets.

Situational Awareness has also invested in firms that supply power and AI compute. Public holdings include Bloom Energy, a maker of on-site fuel cells, and CoreWeave, a provider of GPU-based cloud compute for AI workloads. The fund holds several former Bitcoin mining data centers that have been converted to host AI servers.

In addition to those long positions, the fund has placed large short bets against chipmakers. Reported short positions include more than $1.5 billion against Nvidia shares and over $2 billion against a basket of other chip companies. The fund’s strategy is based on the view that chip prices currently reflect optimistic growth, while constraints on power and physical compute capacity will be the tighter limits.

Institutional investors have taken part in the fund; one well-known trading firm has backed Situational Awareness alongside other parties.

The fund’s concentrated holdings mean its performance depends on a small set of outcomes: continued strong demand for large-scale AI compute and sustained private valuations for companies like Anthropic. If corporate AI spending slows, Anthropic’s private valuation weakens, or pressure on power supplies eases, the fund’s value could decline.

The coming months will show whether demand for electricity and data-center capacity keeps pace with model growth and whether Anthropic’s private valuation remains at current levels.