Chai Discovery
Chai Discovery is an AI Protein & Enzyme Design company founded in 2024 and based in San Francisco, United States. It has raised $225M in total funding, most recently a Series B in 2025 at a $1.3B valuation.
Chai Discovery was founded in March 2024 in San Francisco by Joshua Meier (CEO, formerly of Absci, Meta AI, and OpenAI), Jack Dent (President, ex-Stripe), Matt McPartlon (CTO), and Jacques Boitreaud. The company develops large foundation models for molecular interactions, releasing Chai-1 as an open model for biomolecular structure prediction at state-of-the-art accuracy, then Chai-2 for fully de novo antibody design with a reported near-20% experimental hit rate. After a $70 million Series A in 2025 led by Menlo Ventures with OpenAI, Thrive Capital, and Dimension participating, Chai raised a $130 million Series B in December 2025 at a $1.3 billion valuation, bringing total funding past $225 million.
Its Chai models pushed de novo antibody design from sub-1% to near-20% hit rates, signaling a step change in AI-designed biologics.
chaidiscovery.com ↗·AI Protein & Enzyme Design·
United States·private 
