Legal AI startup Harvey raised $550M co-led by Lightspeed and Diffusion at a $15.6B valuation, up from an $11B valuation when it raised $200M in March (Rebecca Torrence/Bloomberg)

Harvey, a legal-AI startup, raised $550 million in a financing round co-led by Lightspeed and Diffusion, increasing its valuation to $15.6 billion from $11 billion after a $200 million raise in March. OpenAI reported an internal model, described as far more capable than GPT-6 Astra, solved the Navier-Stokes Millennium Prize problem using 10,000 concurrent agents over 88 hours, while noting possible influence from de-identified data contributed by mathematicians Buckmaster and Alpöge.