AI data center startup Fluidstack is negotiating a $1 billion funding round that would value it at $18 billion, with Jane Street reportedly in discussions to lead, according to Bloomberg. The company was valued at $7.5 billion as recently as December — a 140% step-up in under four months. The primary catalyst is a $50 billion multi-year contract Anthropic signed with Fluidstack to build dedicated AI data centers in Texas and New York. The startup, spun out of Oxford and recently relocated from the UK to New York, also counts Meta, Poolside, and Black Forest Labs as customers.