OpenAI co-founder and CEO Sam Altman has taken the witness stand in a high-stakes trial pitting some of the world’s richest technology giants against each other.
Testifying Tuesday, Altman rejected Elon Musk’s claims that he betrayed the company’s founding mission of serving the public good.
Altman said it was Musk, the richest man in the world, who was interested in gaining control of the artificial intelligence startup.
Why is Musk suing Altman and OpenAI?
OpenAI, the creators of ChatGPT, was founded as a nonprofit in 2015 by several entrepreneurs, including Musk and Altman. It established a for-profit subsidiary in 2019.
In the ongoing civil lawsuit in a federal court in Oakland, California, Musk accuses Altman, OpenAI president Greg Brockman and the company of abandoning their core mission of benefiting humanity and instead becoming a profit-driven corporation.
OpenAI countered that Musk, now also an AI player with XAI and its Grok chatbot, is motivated by petty vendettas.
They claim that Musk filed the lawsuit only after failing to seize majority control of OpenAI’s commercial unit.
Altman says Musk wanted majority control of OpenAI
Asked by his lawyer Tuesday whether Musk opposed the for-profit plan, Altman said: “Quite the contrary.”
He alleged that Musk demanded a larger controlling stake.
“The initial number that Mr. Musk came up with was that he should have 90% equity to start,” Altman told the jury. “Then it softened, but it was always the majority.”
He said he was “extremely uncomfortable” with giving up majority control, even though Musk had reduced his demands.
Musk even said he might pass the company on to his children, Altman said, when asked what would happen to OpenAI after his death.
Altman said Musk’s response was a “hair-raising moment” in the early days of OpenAI.
“I didn’t feel comfortable in it.”
Under questions from his attorney, Altman denied Musk’s claim that he and Brockman had tried to “steal a charity.”
“It seems hard to even wrap your head around that frame,” Altman said.
He hopes that “as OpenAI continues to perform well, the nonprofit will perform even better,” he said.
Musk OpenAI and co-defendants are seeking approximately $150 billion in damages from Microsoft, a major OpenAI investor, to be paid to the OpenAI nonprofit.
Musk’s legal case demands that OpenAI be returned to non-profit status. The move will impact Anthropic’s position in the global artificial intelligence race against Google and China’s DeepSeek.
He also wants Altman and Brockman removed from their roles.
Altman faces questions about lying
Musk’s lawyers have tried to prove Altman was a liar about his plans for OpenAI.
During cross-examination Tuesday, Musk’s attorney Steven Molloy challenged Altman’s integrity.
He cited testimony from a former OpenAI board member that Altman fostered a “toxic culture of lying” and seven former OpenAI executives who said Altman was not trustworthy.
“Have you misled people while doing business?” Mollo asked Altman.
Altman responded, “I believe that I am an honest and trustworthy businessman.”
“That’s not my question. Have you misled people while doing business?”
“I don’t think so.”
OpenAI chairperson Brett Taylor separately testified on Tuesday that OpenAI had received a formal acquisition offer from a consortium led by Musk’s rival company xAI in February 2025, six months after Musk filed the lawsuit.
“I was surprised,” Taylor said. “The proposal was for a group of profit-seeking investors to acquire this nonprofit, which seemed contrary to the spirit of the lawsuit.”
The trial is now in its third week. An advisory jury is expected to reach a verdict on any actual wrongdoing by the week of May 18.
Edited by: Zack Crellin