OpenAI Chief Executive Sam Altman is expected to take the witness stand on Tuesday to defend his company against Elon Musk’s lawsuit accusing him of betraying the ChatGPT maker’s founding mission to serve the public good.
The trial may determine the future of OpenAI and its leadership, after the company raised hundreds of billions of dollars from large technology companies and investors to build its computing power ahead of a potential $1 trillion initial public offering.
It also marks a clash among tech giants, with Musk, the world’s richest person, portraying himself as a defender of ordinary people from the perils of AI and Silicon Valley titans who care more about money.
In his lawsuit, Musk accused Altman and OpenAI of persuading him into giving $38 million, only to see the nonprofit abandon its mission to benefit humanity and instead become a for-profit corporation. Musk accused Altman and OpenAI President Greg Brockman, who is also a defendant, of trying to “steal a charity.”
OpenAI has tried to show that Musk knew about the for-profit plan but wanted control of the company, and is suing now because he regrets missing out on potential riches.
Musk is seeking about $150 billion in damages
Musk is seeking about $150 billion in damages from OpenAI and Microsoft MSFT.O, a major investor, to be paid to an OpenAI nonprofit. He also wants the removal of Altman and Brockman from their roles.
Bret Taylor, chairman of OpenAI, testified on Tuesday that OpenAI received a formal takeover offer from a consortium led by Musk’s rival company xAI in February 2025, six months after Musk sued.
“I was surprised,” Taylor said. “This proposal was to acquire this non-profit by a group of for-profit investors, which felt contradictory to the spirit of the lawsuit.”
Testimony in the trial before US District Judge Yvonne Gonzalez Rogers in the Oakland, California, federal court may conclude this week. Jurors could begin deliberating whether the defendants are liable by May 18. Rogers would determine any remedies.
The faceoff has transfixed many in Silicon Valley and beyond, with testimony at times focusing on the clashing personalities and leadership styles of Musk and Altman.
Former OpenAI chief scientist Ilya Sutskever testified on Monday that he spent about a year gathering evidence for OpenAI directors that Altman had displayed a “consistent pattern of lying.”
Microsoft Chief Executive Satya Nadella, whose company is a major OpenAI investor, testified on Monday that the investment was a “calculated risk.”
Others who have testified include Brockman, former OpenAI technology chief Mira Murati, and Shivon Zilis, a former OpenAI board member who is also the mother of four of Musk’s children.
Musk testified early, saying: “If you have someone who is not trustworthy in charge of AI, I think that’s a very big danger for the whole world.”
He also said OpenAI was his idea before executives looted it, and that while he knew there were discussions about making OpenAI a for-profit enterprise, Altman assured him it would remain a nonprofit.
