Thinking Machines Lab to Raise $5 Billion at $40 Billion Valuation

AI startup Thinking Machines Lab is set to close a $5 billion funding round as soon as this week at a $40 billion pre-money valuation, more than tripling the company’s worth from its last public round, Business Insider reported, citing multiple sources familiar with the matter. Accel is leading the round. The jump from the more than $10 billion valuation attached to last year’s $2 billion seed round shows investors remain willing to place enormous bets on frontier AI labs even as the industry’s talent war intensifies.

The new figure also lands below the $50 billion valuation the company was seeking last year, talks for which were abandoned. A representative for Thinking Machines Lab declined to comment, and Accel did not respond to a request for comment.

Mira Murati’s Startup Emerged From Stealth With OpenAI Ties

Thinking Machines Lab emerged from stealth last year as one of the highest-profile AI labs in the industry, thanks to leadership with deep ties to OpenAI. CEO Mira Murati previously served as OpenAI’s chief technology officer, and other key figures helped train early versions of ChatGPT. The company’s first product, Tinker, lets users more easily fine-tune large language models, and a new version released Thursday added gains in AI coding, the company said.

Talent War Hits the Founding Team

The funding push comes as Thinking Machines Lab has lost roughly a third of its founding team to rivals, Business Insider reported in May. Departures include Barret Zoph, Luke Metz, and Andrew Tulloch, who left for competing companies amid huge pay packages offered by labs such as Meta and OpenAI. At the same time, the startup has attracted top talent including competitive coder Neal Wu.

What the $40 Billion Figure Signals for AI Labs

The round places Thinking Machines Lab among the most richly valued private AI companies, reflecting investor appetite for labs building tools to customize frontier models rather than the models themselves. The Information reported in September that the company was in talks to raise a new round.

Questions Readers Still Ask About the Round

Who is leading the funding round? Accel is leading the $5 billion round, according to sources familiar with the matter. Accel did not respond to a request for comment.

Thinking Machines Lab was valued at more than $10 billion when it raised a $2 billion seed round last year; the new $40 billion pre-money valuation more than triples that figure.

Yes.

The round, if closed at the reported terms, would stand as one of the largest private funding rounds in the AI sector, a bet that fine-tuning infrastructure will remain central even as rivals spend heavily to poach the researchers who built it.