The legal-AI startup is in talks to raise at least $500m at a $15.5bn valuation, including the new money, The Information reported. That is a 40% jump on the $11bn it set only five months ago, when it raised $200m. Lightspeed Venture Partners is keen to lead the round.

The raise follows a revenue surge. Harvey, founded four years ago, now makes more than $350m in annualised revenue, up over 80% from $190m in January. At $15.5bn, that values the company at roughly 44 times its current revenue run rate. It is a price that assumes the growth keeps coming.

Vertical AI is having a moment

Harvey is the poster child for vertical AI, software built for one profession rather than everyone. The bet is that a tool trained on contracts, filings and case law beats a general chatbot for legal work. Its numbers suggest lawyers agree, and rivals such as Legora are chasing the same market.

The momentum runs past the funding line. In recent weeks Harvey took strategic investment from Goldman Sachs and JPMorgan, deepened a partnership with Microsoft, and won firmwide deployments at big law firms. It is trying to become plumbing, not a plug-in.