Hydrazine Capital

The firm primarily makes direct investments in private companies. Public portfolio disclosures do not show a pattern of fund-of-funds commitments common at institutional family offices. The few known positions are all direct equity stakes in startups where Altman has personal or professional proximity to the founders.

Hydrazine Capital is Sam Altman's personal investment firm and is operationally distinct from OpenAI, where he serves as CEO. Altman has publicly stated he holds no direct equity in OpenAI. The portfolio companies are independent entities, though some, like Worldcoin, share a founder in Altman.

There is no public investment policy identifying excluded sectors. However, based on the observable portfolio concentration in deep tech, enterprise software, and AI-adjacent businesses, the firm does not appear active in consumer packaged goods, traditional retail, or hydrocarbon-based energy. No positions in tobacco, defense contracting, or extractive industries have been identified.

Hydrazine Capital does not publicly disclose assets under management. Given the known sizes of individual bets — including a reported $180 million commitment to Retro Biosciences — the implied capitalization is substantial for a single-principal vehicle. Any precise figure remains an external estimate.

Sourcing is predominantly network-driven through Altman's roles at Y Combinator and OpenAI. As a former Y Combinator president and a central node in the San Francisco AI ecosystem, Altman sees deal flow that is unavailable to most institutional investors. The firm does not advertise a formal origination team or open application process for founders.