A federal courtroom in Oakland, California, will on April 27 begin selecting jurors for one of the most closely watched trials in the American technology industry, a lawsuit pitting Elon Musk against OpenAI, the artificial intelligence company he co-founded and later abandoned.

Judge Yvonne Gonzalez Rogers, who last year described the dispute as "Billionaires versus billionaires," will oversee the proceedings.

Why did Musk sue OpenAI? 

Musk filed the lawsuit in 2024, alleging that OpenAI had abandoned its founding commitment to develop artificial intelligence for the public good, pivoting instead to a profit-driven model through its deep partnership with Microsoft. He later added Microsoft as a defendant.

Musk says he contributed roughly $38 million to OpenAI in its early years on the understanding that the company would remain open-source and non-commercial. He argues that understanding was broken.

"Altman, in concert with other defendants, intentionally courted and deceived Musk, preying on Musk's humanitarian concern about the existential dangers posed by AI," the lawsuit reads. 

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The lawsuit alleges that CEO Sam Altman and President Greg Brockman "convinced him (Musk) to fund and back what they falsely claimed would be a 'nonprofit' devoted to the safe and open development of AI."

Musk is seeking $134 billion in damages, money he says he does not want for himself, but wants directed to OpenAI's non-profit arm. He is also asking the court to remove Altman as CEO.

How did OpenAI respond to Musk?

OpenAI has rejected the allegations and turned the argument around on Musk, accusing him of running a "harassment campaign" driven by competitive self-interest, specifically, a desire to weaken OpenAI and clear the field for his own AI venture, xAI.

The company says the real reason Musk left was a power struggle he lost. In a blog post, OpenAI claimed that Musk "demanded full control of OpenAI and even wanted to merge it into Tesla. When we wouldn't agree to his terms, he walked away and told us we had a '0% chance' of success."

"Elon donated $38 million to the OpenAI nonprofit, which was spent exactly as intended and in service of the mission. Despite claiming and receiving a tax deduction for this donation, he's now asking the court to treat it as an investment that entitles him to significant ownership of OpenAI," OpenAI said in a blog post.

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The company maintains that its mission of "creating AGI that benefits all of humanity" remains intact and that Musk's lawsuit is less about principle and more about rivalry.

Why does it matter?

The trial is expected to run for several weeks and could shape how AI companies navigate the tension between their founding ideals and the commercial realities of scaling frontier technology.  

For Musk, a win would be a significant legal and reputational blow to a company he once backed and now competes against directly. For OpenAI, the stakes are equally high: an adverse verdict could complicate its fundraising, its governance overhaul and its relationship with Microsoft, which has committed billions to the company.