Artificial intelligence startup Thinking Machines Lab, founded by former OpenAI Chief Technology Officer Mira Murati, is reportedly nearing a $5 billion funding round that would value the company at $40 billion before the new investment.
According to a report by Business Insider published on 6 November 2026, the funding round is being led by venture capital firm Accel and could close as early as this week. The publication cited multiple sources familiar with the discussions.
If completed on the reported terms, the financing would represent a significant increase from the company’s previous publicly reported valuation of more than $10 billion, following its $2 billion seed funding round in 2025.
Murati, who previously served as OpenAI’s Chief Technology Officer, founded Thinking Machines Lab in 2025 with the ambition of developing artificial intelligence systems that are more adaptable and useful across different applications. Her leadership and experience in the development of advanced AI products have helped attract significant investor attention to the startup.
The company has already introduced Tinker, a platform that enables developers to fine-tune large AI models for specific requirements. It released an updated version of the product on 5 November, highlighting improvements in its coding capabilities.
Thinking Machines Lab has also established a major infrastructure partnership with Nvidia, reflecting the substantial computing resources required to develop and operate advanced AI systems.
The reported fundraising comes amid intensifying competition for experienced researchers and engineers across the artificial intelligence industry. The startup has attracted prominent talent, but has also experienced departures among members of its founding team, with some joining competitors including Meta and OpenAI.
The company previously explored raising capital at a valuation of approximately $50 billion, but those discussions were abandoned. The latest reported valuation of $40 billion represents a revised fundraising target, although it would still place the relatively young company among the most highly valued private AI businesses.
Neither Thinking Machines Lab nor Accel has publicly confirmed the latest funding details. A company representative declined to comment to Business Insider, while Accel did not respond to the publication’s request for comment.
If finalised, the investment would provide Thinking Machines Lab with substantial additional capital to develop its AI technology, expand its operations and compete in an increasingly crowded global market.
Murati’s journey from leading AI development at OpenAI to building an independent technology company has placed her among the prominent entrepreneurs shaping the next phase of the artificial intelligence industry.
