Thinking Machines Lab nears $5 billion funding round at $40 billion valuation

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Business Insider reported on Friday that Thinking Machines Lab is close to raising $5 billion in new funding at a $40 billion pre-money valuation, with venture firm Accel leading the round. People familiar with the talks told the publication the financing could close within days, which would leave the San Francisco artificial intelligence lab with roughly $7 billion in disclosed funding since its founding.

A $40 billion pre-money valuation would put the company at about $45 billion once the new money lands, more than three times the $12 billion valuation attached to its $2 billion seed round in July 2025. The lab had previously tried to raise money at a $50 billion valuation, but those talks were abandoned after several co-founders, including Barret Zoph, Luke Metz and Andrew Tulloch, left for rivals such as Meta and OpenAI.

Mira Murati, OpenAI's former chief technology officer, founded Thinking Machines Lab in February 2025. Its first product, Tinker, lets organisations fine-tune large language models on their own data, and its first open-weight model, Inkling, arrived in July. On November 5 the lab released Inkling 2 Small, a 594-billion-parameter model built for coding, visual reasoning and autonomous work, and said it would publish the model's weights under an Apache 2.0 licence next week, after external safety testing.

The round itself is reported, not announced: Thinking Machines declined to comment and Accel did not respond to requests for comment, so the $5 billion figure, the $40 billion valuation and the closing timetable all rest on Business Insider's account from people familiar with the negotiations. Other outlets have repeated that account rather than confirming the terms independently. The earlier numbers check out against prior reporting, with the $2 billion seed at a $12 billion valuation in July 2025 and the abandoned $50 billion attempt consistent across coverage, but the lab's revenue, described by a single source in September as more than $100 million a year, has not been confirmed by the company.

The money, if it closes on these terms, would arrive as the lab turns from assembling a research team into shipping products and running a platform. Dealroom notes the funds will probably go towards computing power, given the lab's multi-year deal with Nvidia to deploy at least a gigawatt of Vera Rubin systems from early 2027, though the company has not said how it plans to use the money.

A completed round would price the lab at up to 400 times its reported annual revenue, against roughly 25 times for OpenAI, according to Dealroom's comparison, a gap that puts the weight on whether adoption of Tinker and Inkling can grow into the valuation. The closing, expected within days, is the moment that will settle whether the reported terms hold.