Artificial intelligence developer Thinking Machines Lab, led by former OpenAI Chief Technology Officer Mira Murati, is in discussions to raise at least $1 billion in a new funding round at a pre-money valuation of no less than $40 billion, according to a person familiar with the matter.
Existing investor Accel is in talks to lead the round, according to that person and another source. The company, which launched its first model, Inkling, in July, is also in discussions with chip giant NVIDIA about participating in the funding round, separate sources said.
The proposed valuation is lower than the startup's target from late last year, when it planned to raise $4-$5 billion from investors at a valuation above $50 billion. Even so, the figure remains impressive given that Thinking Machines Lab was founded less than two years ago.
This round comes six months after NVIDIA announced a significant but undisclosed investment in the startup, along with plans for a "gigawatt-scale long-term strategic partnership," widely believed to be aimed at helping Thinking Machines Lab secure access to NVIDIA's scarce AI server chips. The company's open-weight Inkling model is free to use, with its business model centered on selling access to tools that allow enterprises to customize AI models—including but not limited to Inkling—using their own data. According to a person with knowledge of the figures, the startup's annualized revenue is at least several hundred million dollars, calculated by multiplying the latest monthly revenue by 12. Compared with most startups in the sector, a $40 billion valuation is quite high when measured against projected revenue multiples.
In July, Thinking Machines Lab stated its mission is to build AI that "expands human will and judgment," focusing on releasing proprietary models, providing tools for building personalized models, and publishing research findings. The new funding will provide additional capital for model training, server leasing, and hiring as the company, founded in early 2025, looks to scale operations.
This valuation marks a significant jump from the company's first funding round in July 2025. That round raised $2 billion at a $10 billion pre-money valuation, led by Andreessen Horowitz, with participation from NVIDIA, GV, Lightspeed Venture Partners, Jane Street Capital, and Factorial Funds.
Thinking Machines Lab is among the most closely watched members of a group of emerging AI startups known as "neolabs" that are challenging major model providers. These companies have raised billions of dollars to fund the costly training of foundation models while attracting top talent. In the race for market share among AI application developers using open-weight models, Thinking Machines Lab competes with other open-weight model providers. Closed-source firms like OpenAI and Anthropic produce stronger models, and Thinking Machines Lab does not plan to compete with them directly. Its primary rivals are cloud service providers and so-called inference computing services, all vying for enterprise customers seeking to customize AI models based on their own data. The company has also launched specialized AI models for voice interaction scenarios.
Like its competitors, Thinking Machines Lab has seen executive turnover. Earlier this summer, co-founder Lilian Weng announced her return to OpenAI, making her the fourth co-founder to depart the company over the past year. Mira Murati and John Schulman, who also co-founded OpenAI, are now Thinking Machines Lab's only two co-founders. Murati holds an unusual degree of control over the company, which may give some investors pause. In the previous funding round, she secured special board voting rights: her single vote carries the same weight as the combined votes of all other directors plus one additional vote. This provision ensures that on major matters such as accepting acquisition offers, dismissing executives, and approving executive compensation, Murati can control board decisions regardless of how many other directors vote in opposition.