Thinking Machines, the AI lab founded by former OpenAI CTO Mira Murati, is in talks to raise $1 billion at a valuation of at least $40 billion, with existing investor Accel leading the round. The fundraising would mark a sharp increase from the company’s previous $12 billion valuation in its earlier $2 billion financing led by a16z, with participation from Nvidia, GV, and others. The company was founded early last year and launched its open-weight model Inkling in July. It charges for compute usage through its Tinker platform and has annualized revenue of more than $100 million. Several co-founders, including Lilian Weng and Luke Metz, have since returned to OpenAI. If completed, the new round would still come in below the $50 billion valuation target rumored late last year.