AI Infrastructure Firm Fluidstack Raises $1.5B at $18B Valuation

Fluidstack, an AI infrastructure company, has raised $1.5 billion in a funding round led by quantitative trading giant Jane Street, bringing its post-money valuation to $18 billion. In July 2026, the company raised $750 million at a $7.5 billion valuation, meaning its valuation rose about 2.4 times within 60 days.

Fluidstack's key asset is a multi-year contract backed by Anthropic. The company was selected to build and operate custom data centers for Anthropic and has been involved in the plan to deploy up to 1 million Google TPUs. Unlike heavy-asset data center operators, Fluidstack uses its self-developed bare-metal orchestration system, Atlas OS, to integrate power, facilities and GPU resources, delivering large-scale clusters quickly. It can deploy thousands of GPUs in 48 hours and bring modular data centers online in about six months.

Founded in 2017 and now headquartered in New York, Fluidstack has raised about $2.6 billion in total equity funding to date, along with billions in debt financing for data center construction. Its customers include Mistral AI, Character.ai, Poolside and Black Forest Labs. According to an investment memo, the company expects to operate 1.3 GW of compute capacity across more than 10 sites in 2026, with revenue of $660 million, more than double the $200 million expected for 2025. The new round has also pushed its three founders into the ranks of Europe's youngest self-made billionaires. Jane Street has been active in AI infrastructure in 2026, previously signing a roughly $6 billion cloud contract with CoreWeave and leading a $700 million round in chip startup Etched.