A years-long legal battle between the world’s richest man, Elon Musk, and OpenAI CEO Sam Altman heads to a Northern California courtroom on Monday, marking a dramatic showdown between two of the tech industry’s most high-profile figures.
Musk alleges in his $134 billion lawsuit that OpenAI, Altman and the company’s president, Greg Brockman, have broken a vow to keep the artificial intelligence lab permanently nonprofit. OpenAI has since reorganized itself to operate commercial subsidiaries and is now valued at more than $850 billion.
Musk and Altman were once close friends and were among a group of engineers who founded OpenAI in 2015 out of a shared concern for the potential power of AI and the need to advance it in ways that benefit humanity.
The two companies are now public enemies and bitter rivals, with Musk launching xAI as a competitor to OpenAI in 2023 and recently merging xAI with SpaceX in a deal that values the combined company at $1.25 trillion. The trial comes as Musk prepares to take SpaceX public in what will likely be a record-setting initial public offering.
As CNBC previously reported, OpenAI is aiming for a potential market debut in the fourth quarter. In a document distributed to prospective investors earlier this year, OpenAI characterized the ongoing litigation with Musk as a potential risk to its business.
The company has repeatedly dismissed Musk’s lawsuit as “baseless,” calling it a “harassment campaign driven by ego, jealousy, and a desire to slow down a competitor,” according to a post on X in early April.
The war of words has been going on for months.
“The deceiver Altman lies as easily as he breathes,” Musk wrote in August in a post about X, part of xAI.
“I’m so excited to have Elon sworn in in a few months and have Christmas in April,” Altman wrote in X magazine in February.
Jury selection in Musk v. Altman begins Monday in federal court in Oakland, just across the Bay Bridge from San Francisco, where OpenAI is headquartered. If successful, Musk said he would like the court to return all “ill-gotten gains” to the OpenAI nonprofit rather than to him personally. He also calls for removing Altman and Brockman from their roles and “unwinding the commercialization and restructuring of OpenAI.”
This is not the only lawsuit Musk has filed against OpenAI. Along with xAI, X (formerly Twitter) sued OpenAI and Apple in 2025 for alleged anti-competitive conduct. A hearing in the case is scheduled for May in Texas. And in February, a federal judge in California dismissed another lawsuit from xAI that accused OpenAI of stealing trade secrets.
The spat between Musk and Altman dates back to 2018. At the time, Musk resigned from the board after a number of disagreements with Altman and Brockman about the company’s direction, including a failed merger plan with OpenAI. teslaMusk’s electric car company. After Musk left office, OpenAI created a for-profit subsidiary to make it easier to raise outside investment.
OpenAI briefly considered plans to become a for-profit company in 2024, which would take control away from the nonprofit organization and keep it as an independent arm. But after facing pressure from civic leaders, including Musk, and former employees, the company reversed course. The company completed a recapitalization in October, strengthening its structure as a nonprofit organization with control of its for-profit businesses.
Musk sued OpenAI, Altman and Brockman in 2024, claiming the companies were “relentlessly manipulated” and “deceived” into their promises to “chart a safer and more open path than the profit-driven tech giants.”
But the scope of Mr. Musk’s claims and his desired outcomes have changed dramatically in recent months.
In a January filing, Musk’s lawyers said Musk was working with OpenAI. microsoftone of OpenAI’s longtime supporters, is also named as a defendant in the lawsuit. Microsoft is accused of aiding and abetting OpenAI’s misconduct regarding charitable trust violations.
Of the 26 claims Musk filed against OpenAI, Altman, and Brockman in November 2024, only four remain: unjust enrichment, fraud, constructive fraud, and breach of charitable trust. Musk’s lawyers are asking for two claims, fraud and constructive fraud, to be dismissed ahead of trial in order to “streamline litigation,” according to the filing.
OpenAI’s lawyers on Wednesday characterized Musk’s actions as “evasive tactics.”
“The trial begins in five days, and the plaintiffs still refuse to state what claims they will pursue or what relief they seek,” they wrote in their filing.
The case is being handled by Judge Yvonne Gonzalez Rogers, who was appointed by former President Barack Obama in 2011 to the U.S. District Court for the Northern District of California. Gonzalez Rogers is working with Epic Games. apple.
Nine jurors are seated, with no alternates, according to the March filing.
Gonzalez-Rogers chose to divide the trial into two parts. One is the liability stage, which determines whether wrongdoing occurred, and the other is the remedy stage, which determines appropriate damages and next steps. Because the jury only deliberates during the liability phase and its verdict is advisory, Gonzalez-Rogers will have the final say on both sections of the trial.
The liability phase of the trial is scheduled to last until mid-May, with court hours from 8:30 a.m. to 1:40 p.m. Pacific Time every Monday through Thursday.
Following jury selection, opening arguments will be held. Gonzalez-Rogers gave Musk and OpenAI’s lawyers a total of about 20 hours of arguments each. Microsoft will have five hours to do so, according to the filing.
All three parties submitted lists of witnesses that could be called. Musk, Altman, Brockman and Microsoft CEO Satya Nadella are among the names mentioned.
If OpenAI is found liable, Gonzalez-Rogers will hear arguments in the relief phase, scheduled to begin May 18.
“However, if the jury determines that Mr. Musk has failed to file a lawsuit within the statute of limitations, the court will likely accept that finding and award a verdict directly against the defendant,” Gonzalez-Rogers wrote.
CNBC will be in court starting Monday. Click here for the latest coverage.
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