OpenAI co-founder and CEO Sam Altman took the stand Tuesday in a high-profile civil trial in Oakland, rejecting Elon Musk’s allegation that he abandoned OpenAI’s founding mission to serve the public good.
Altman testified that, contrary to Musk’s portrayal, it was Musk who pushed to seize control of the company. The CEO recalled that Musk initially sought an extremely large equity stake — “An early number that Mr Musk threw out was that he should have 90% of the equity to start,” Altman told the jury — and that even after the figure was reduced, Musk always insisted on a majority stake. Altman said he felt “extremely uncomfortable” ceding majority control and described Musk’s comment that he might pass the company to his children as a “hair-raising moment.” “I didn’t feel comfortable with that,” Altman said.
The lawsuit centers on OpenAI’s organizational history. Founded in 2015 as a nonprofit by several entrepreneurs, including Musk and Altman, OpenAI created a for-profit subsidiary in 2019. Musk sued OpenAI, Altman and president Greg Brockman, accusing them of abandoning the nonprofit mission and turning the organization into a for-profit enterprise. He seeks roughly $150 billion in damages from OpenAI and co-defendant Microsoft, to be paid to an OpenAI nonprofit, and asks the court to force OpenAI to revert to nonprofit status and to remove Altman and Brockman from their roles.
OpenAI denies Musk’s claims and argues the suit was filed after Musk failed to obtain majority control of the commercial entity, calling his actions motivated by revenge. The company says it expects the nonprofit to benefit as the organization succeeds.
During cross-examination, Musk’s lawyer challenged Altman’s honesty, citing testimony from a former board member and several former officials who described a culture of untruthfulness. When asked if he had misled people in business, Altman replied, “I believe I am an honest and trustworthy businessperson,” and later, “I do not think so.”
Separately, OpenAI chair Bret Taylor testified that in February 2025 the nonprofit received a takeover proposal from a group led by Musk’s rival xAI, a move Taylor described as surprising and at odds with the spirit of Musk’s lawsuit.
The trial is in its third week. An advisory jury is expected to consider whether any wrongdoing occurred, with a verdict on those questions anticipated the week of May 18.