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)

Legal AI startup Harvey secured $550 million in a funding round led by Lightspeed and Diffusion, boosting its valuation to $15.6 billion from $11 billion in March. The new capital will support development of proprietary AI models.