Chai Discovery Raises $400M Series C, Tripling Valuation to $3.8B in Seven Months

SiliconANGLE·high signal

AI molecular-design startup Chai Discovery closed a $400M Series C led by Index Ventures (with Kleiner Perkins, Sequoia, Dimension, and existing backers Thrive, OpenAI, Menlo, General Catalyst), lifting its valuation to $3.8B from $1.3B in December — total funding now ~$630M. Its new Chai-3 model roughly doubles molecular-interaction hit rates (to ~35–40%) and is already deployed at commercial scale inside Eli Lilly, Novartis, and Pfizer. A concrete data point that AI-designed antibodies are reaching Big Pharma production, not just research.