Thinking Machines Lab, the AI startup founded by former OpenAI chief technology officer Mira Murati, is set to close a $5 billion funding round at a $40 billion pre-money valuation, Business Insider reported on November 6, citing multiple sources familiar with the matter. Accel is leading the round, which could close as soon as this week.

The Thinking Machines Lab funding round is not final, and neither company has confirmed it. A representative for Thinking Machines Lab declined to comment, and Accel did not respond to Business Insider’s request for comment. The terms, as reported, would more than triple the company’s valuation from its last public financing, a $2 billion seed round in July 2025 at a $12 billion valuation.

What was reported

According to the report, Accel is leading the $5 billion round at a $40 billion pre-money valuation, and the deal could close within days. If it closes, Thinking Machines Lab will have raised about $7 billion in disclosed funding since its founding in February 2025.

The round has been in the works for months. In September, it was reported that Nvidia could supply about half of a $5 billion to $6 billion round. The company had previously sought to raise money at a $50 billion valuation, but those talks were abandoned, and the new round reflects a lower target.

Bar chart of Thinking Machines Lab funding rounds, $2 billion seed in July 2025 and $5 billion round in November 2026
Chart: GPTOnline, based on figures reported by Business Insider via Dealroom.

A valuation that keeps climbing

The reported jump, from $12 billion in July 2025 to $40 billion now, comes with revenue that is still modest against the price. A source told TechCrunch in September that the company’s annual revenue exceeded $100 million, implying a multiple of up to 400 times revenue. For comparison, OpenAI’s $1.25 trillion valuation sits at roughly 25 times its run rate.

The gap is the bet investors are making: that Thinking Machines Lab’s models and its Tinker platform, a system that lets organizations fine-tune large language models on their own data, will turn research strength into a much larger business. The open question, as Dealroom put it, is whether product adoption and revenue can justify the price.

The week Thinking Machines Lab had

The funding report landed a day after the lab launched Inkling 2 Small, its second-generation model, on November 5. The mixture-of-experts system has 594 billion total parameters with 17 billion active per token, and it is available now through Tinker, with its full weights due for release under an Apache 2.0 license next week.

Bar chart of Inkling 2 Small benchmark scores reported by Thinking Machines Lab
Chart: GPTOnline, based on Thinking Machines Lab benchmark figures.

The launch was the lab’s most visible product moment since its first open-weight model, Inkling, arrived in July. It also came after a difficult stretch for the team. Between October 2025 and January 2026, three co-founders, Barret Zoph, Luke Metz and Andrew Tulloch, left for rivals such as Meta and OpenAI.

Nvidia looms large over the round. Beyond the reported September talks, the two companies announced a multi-year deal in March to deploy at least one gigawatt of Nvidia’s Vera Rubin systems from early 2027. With that partnership in place, the new funds will likely go toward computing power, though the company has not disclosed their use.

Why it matters

If the round closes at the reported terms, Thinking Machines Lab becomes one of the best funded independent AI labs in the world, with roughly $7 billion raised in under two years. It would also be a test of whether investors still pay top prices for frontier labs after a bruising week for AI stocks, in which the Nasdaq 100 fell 6.4% on November 5 and Anthropic’s blockbuster IPO ran into doubts over its valuation.

The European comparison is stark. Mistral’s 3 billion euro round in September, the largest equity raise ever by a European tech company, valued it at over 21 billion euros. Thinking Machines Lab, at a reported $40 billion, is priced at nearly twice that, on revenue that is still a fraction of its larger rivals.

For now, the deal is reported, not done. Until Accel or Thinking Machines Lab confirms it, the $40 billion figure is what sources say the round is priced at, not a closed valuation, and a market that has just repriced the whole AI sector could still move the terms.

Sources