Accel is reportedly in talks to lead a one-billion-dollar funding round for Thinking Machines Lab at a minimum forty-billion-dollar post-money valuation, with Nvidia separately in talks to co-invest approximately two-point-five billion dollars at the same valuation. Thinking Machines reports over one hundred million dollars in annual recurring revenue, generated primarily from usage-based compute fees on its Tinker platform for the open-weight Inkling model. The forty-billion-dollar target is a significant reduction from the fifty-billion-dollar valuation the company had been seeking in late 2025, when Mira Murati left OpenAI and began building. A prior seed round at a twelve-billion-dollar valuation, led by Andreessen Horowitz with participation from Nvidia, GV, Lightspeed, and Conviction Partners, closed in early 2026. Two of the three co-founders — Lilian Weng and Luke Metz — have since returned to OpenAI. The 400-times revenue multiple at the forty-billion-dollar valuation is justified, by investors, on the founder credibility and platform potential of the Tinker compute marketplace rather than on near-term earnings. The valuation compression from fifty billion to forty billion over six months, in a funding environment where AI valuations have generally sustained or increased, is the detail that warrants attention. Whether it reflects broader market re-rating of foundational AI lab valuations, the co-founder departures, or the competitive pressure from the GPT-6 Astra announcement the same week is not yet clear.