one year on
Ex-OpenAI CTO Mira Murati raises $2 billion for AI startup Thinking Machines Lab
The seed round, led by Andreessen Horowitz and joined by Nvidia, AMD, Cisco, Accel, ServiceNow, and Jane Street, values the company that has yet to reveal a product at $12 billion — making it one of the largest first rounds in Silicon Valley history.
Mira Murati, the former chief technology officer of OpenAI, announced Tuesday that her artificial intelligence startup Thinking Machines Lab has raised $2 billion in a seed round at a $12 billion valuation. The round, one of the largest first rounds in Silicon Valley history, is led by Andreessen Horowitz with participation from Nvidia, AMD, Accel, ServiceNow, Cisco and Jane Street.
Murati, who served as interim CEO of OpenAI during Sam Altman’s brief ouster in November 2023, left the company in September and launched Thinking Machines Lab in February. The startup has yet to reveal a product, but Murati said in a post on X that the company will announce its first product in the next couple months and that it will include a significant open-source component for researchers and startups. “We believe AI should serve as an extension of individual agency and, in the spirit of freedom, be distributed as widely and equitably as possible,” she wrote.
The company has attracted former OpenAI researchers John Schulman, Barret Zoph and Luke Metz. A spokesperson for Thinking Machines Lab declined to comment further on the product or valuation. Several outlets reported in June that the company was close to closing a $2 billion round at a $10 billion valuation, suggesting the final price tag rose in recent weeks.
On Hacker News, the news sparked vigorous debate. Some commenters called the round a sign of a frothy bubble, noting the company has no revenue or public product. Others argued Murati’s and her team’s track record at OpenAI justifies the bet. One commenter pointed to her role in the November 2023 board drama as evidence of astute political instincts — or a red flag, depending on risk tolerance.
The record
Compared the round to a Shark Tank pitch where a founder with no revenue or business model would be laughed off the set, calling the situation a bubble.
view the original post →Argued that Murati is not a random person off the street and that her track record at OpenAI justifies the investment.
view the original post →Questioned the valuation, saying LLMs are now a commodity and that capital alone does not guarantee a breakthrough; also criticized Murati's role in the November 2023 OpenAI board drama.
view the original post →One year later — open only if you can handle spoilers
The "first product in a couple months" took until October — Tinker, an API for fine-tuning open-weight models rather than the frontier system many expected. The $12 billion seed proved a floor, not a ceiling: by November the lab was reportedly raising again at a $50-billion-plus valuation — roughly quadruple in under five months — before those talks collapsed by January 2026, leaving it back at $12 billion, with co-founders Barret Zoph and Luke Metz gone back to OpenAI. The largest seed in history bought a year of vertiginous expectations; whether the products can carry them is still unsettled.
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