Thinking Machines Lab Nears $5 Billion Funding Round at $40 Billion Valuation
Mira Murati’s artificial intelligence startup is reportedly preparing to raise $5 billion in a funding round led by Accel, potentially more than tripling its previous valuation.
Thinking Machines Lab, the artificial intelligence startup founded by former OpenAI Chief Technology Officer Mira Murati, is reportedly close to securing $5 billion in new funding at a $40 billion pre-money valuation. According to a report published by Business Insider on November 6, 2026, venture capital firm Accel is leading the proposed investment round, which could close within days. The development highlights continued investor interest in advanced AI companies despite growing competition across the technology industry.
The proposed investment would represent a significant increase from the company’s previous funding round in July 2025, when it raised $2 billion at a valuation of approximately $12 billion. If completed at the reported terms, the latest investment would bring its valuation to around $45 billion after the new funding is added. The company had previously explored raising money at a $50 billion valuation, but those discussions were abandoned. Neither Thinking Machines Lab nor Accel has officially confirmed the latest funding arrangement.
Founded in February 2025, Thinking Machines Lab focuses on developing advanced AI systems and tools that allow businesses to customise large language models using their own data. Its first major product, Tinker, enables developers and organisations to fine-tune AI models for specialised applications. The company recently released an updated version of the platform, reporting improvements in AI coding capabilities. Its products and research ambitions have attracted investors interested in the next generation of artificial intelligence technology.
However, the company is also facing challenges in retaining experienced researchers and executives as competition for AI talent intensifies. Several founding members, including Barret Zoph, Luke Metz and Andrew Tulloch, have reportedly left for rival technology companies such as OpenAI and Meta. Reports indicate that approximately one-third of its original founding team has departed. If the proposed funding round is completed, the capital could help Thinking Machines strengthen its research capabilities, expand its workforce and secure the computing resources needed to compete with established AI companies.
