Thinking Machines Lab is reportedly close to closing a $5 billion funding round led by venture capital firm Accel at a $40 billion pre-money valuation, Business Insider reported on 6 November, citing people familiar with the matter. If it closes on those terms, the lab would be worth about $45 billion once the new money is counted.

Neither side has confirmed the deal. Thinking Machines Lab declined to comment and Accel did not respond to requests for comment, so the figures remain one outlet's account of a round that has not yet closed. The report says the financing could close within days, and that only Accel has been named as a participant so far, with no stated use of the funds.

The reported valuation is more than three times the $12 billion attached to the company's $2 billion seed round in July 2025, but below the $50 billion figure discussed in talks late last year that were later abandoned. The lab was founded in February 2025 by Mira Murati, the former chief technology officer of OpenAI, and about a third of its founding team has since left for rival labs, according to a Business Insider report in May.

The funding report comes a day after the company released Inkling 2 Small, a second-generation model built for autonomous coding, visual reasoning and knowledge work, which it plans to release as open weights under an Apache 2.0 licence next week once external safety testing is complete. Its first product, Tinker, is a system that helps organisations fine-tune large language models on their own data. TechCrunch reported in September, citing a source, that annual revenue had passed $100 million, modest against the reported price. If the round closes, Thinking Machines Lab will have raised about $7 billion in disclosed funding.