Elon Musk takes the stand against Sam Altman in a trial that could blow up the world's most powerful AI company

Elon Musk came up with the name. He recruited the key people. He provided the early funding. And now he is asking a federal jury to hand him $134 billion and fire Sam Altman.

The trial of Musk v. Altman opened April 28 at the Ronald V. Dellums Federal Building in Oakland, California, with Musk taking the witness stand as the first witness in his own case. Altman, the chief executive of OpenAI, was in the courtroom watching. Nine jurors will deliver an advisory verdict to guide US District Judge Yvonne Gonzalez Rogers, who will ultimately decide the remedies if OpenAI is found liable.

The stakes could not be higher for the AI industry. Musk is asking the court to reverse OpenAI's conversion from a nonprofit to a for-profit public benefit corporation, remove Altman and co-founder Greg Brockman from their roles, and disgorge what his lawyers describe as up to $134 billion in wrongful gains. An adverse ruling would threaten OpenAI's blockbuster IPO, expected as early as this year, and reshape the development of the most consequential technology of the current era.

On the stand, Musk was direct about why he helped found OpenAI in 2015 alongside Altman and Brockman. "I came up with the idea, the name, recruited the key people, provided all the initial funding," he said. "I could have started it as a for-profit, and I chose not to." He testified that he would never have put in his resources if he had known OpenAI's founders intended to run it for private gain, and that a verdict siding with OpenAI would effectively greenlight the looting of American charities.

Musk testified that OpenAI was founded specifically as a counterweight to Google's AI ambitions. He described a falling out with Google co-founder Larry Page after recruiting AI researcher Ilya Sutskever away from the company, a process he said took four to five days of back-and-forth while Page tried to convince Sutskever to stay. Page, Musk testified, called him a speciest for being pro-humanity over AI, and stopped speaking to him after Sutskever left. Musk also said he spent an hour in a private meeting with then-President Barack Obama in 2015 warning him about the dangers of the technology, choosing to sound the alarm rather than seek favors for his companies.

The broader context of Musk's testimony was his stated fear about AI itself. "I have extreme concerns over AI," he told the jury. He described it as a technology that could also kill us all, making his argument that the public benefit nature of OpenAI's original mission was not a legal nicety but an existential safeguard.

OpenAI's lawyers offered a very different version of events. Lead attorney William Savitt told the jury that Musk launched the lawsuit because he had fallen behind in the AI race. "The evidence will show that Musk never cared about OpenAI being a nonprofit, he never cared about open source, he never cared about AI safety," Savitt said. "The only thing Musk cared about is being on top." OpenAI's counterclaim alleges Musk never delivered the full $1 billion he promised, quit when Altman and the co-founders refused to hand him control of the organization or absorb it into Tesla, and then went on to found xAI, his own competing AI company.

Microsoft, named as a co-defendant for its partnership with and investment in OpenAI's for-profit arm, also pushed back. Microsoft's attorney Russell P. Cohen pointed out that Musk has a direct line to Microsoft chief executive Satya Nadella and never called to raise his concerns before filing suit.

Musk was expected back on the stand April 29. Former OpenAI chief scientist Sutskever, former chief technology officer Mira Murati and Nadella are also scheduled to testify as the trial unfolds.

The courtroom was packed from the first hour. The line stretched through the front doors of the federal courthouse before opening arguments began.