Thinking Machines, the AI startup founded by former OpenAI chief technology officer Mira Murati, is nearing a $5 billion funding round led by Accel that would value the company at roughly $40 billion pre-money, according to reporting that has not yet been confirmed by the company itself.
The figure would mark a three-to-four-fold jump from the roughly $10-12 billion valuation Thinking Machines carried after a $2 billion seed round in 2025, one of the largest seed rounds in Silicon Valley history at the time. Nvidia is separately said to be in talks to invest around $2.5 billion in the new round, though neither company has commented publicly.
A rocky run since launch
The fundraising comes after a turbulent stretch for the company. Three co-founders departed between October 2025 and January 2026, with some moving to Meta and OpenAI — the very company Murati left to start Thinking Machines. An earlier attempt to raise capital at a $50 billion valuation reportedly fell through before the current, lower figure took shape.
On the product side, Thinking Machines shipped its second-generation model, called Inkling 2 Small, on November 6, part of an effort to show investors the company is translating its star-studded founding team and enormous capital base into shipped technology rather than just research promise.
A bet against the week's own market signal
The timing is notable: investors are pushing Thinking Machines' valuation sharply higher in the same week that public AI stocks, including Nvidia and Micron, suffered their steepest selloff since April on fears that regulatory and political headwinds could slow AI infrastructure spending. The contrast underscores how differently private and public AI investors are currently pricing risk — venture capital continuing to chase foundation-model startups at ever-higher valuations even as public markets flinch at the first sign of political friction.
If the round closes as reported, Thinking Machines would become one of the most richly valued AI startups to not yet have a widely used consumer product, intensifying scrutiny of whether its valuation can be justified by revenue rather than promise alone.
