The years-long feud between Elon Musk, the world’s richest man, and OpenAI CEO Sam Altman headed to court in Northern California on Monday in a bitter rivalry between two of the tech industry’s biggest names.
In his $134 billion lawsuit, Musk claimed that OpenAI, Altman and the company’s president, Greg Brockman, had reneged on a pledge they made to keep the intelligence lab permanently non-profit. OpenAI has since restructured to become a for-profit company, and is now valued at over $850 billion.
Musk and Altman were once close friends, and were among a group of techies who founded OpenAI in 2015 out of a shared concern about the potential of AI and the need to advance it in ways that will benefit humanity.
They are now public enemies and bitter rivals, as Musk launched xAI as a competitor to OpenAI in 2023 and recently merged it with SpaceX in a deal that values the combined entity at $1.25 trillion. The lawsuit comes down as Musk prepares to take SpaceX public in what could be a record IPO.
OpenAI is targeting a potential fourth-quarter market, as CNBC previously reported. In a document distributed to potential investors earlier this year, OpenAI stated that the ongoing lawsuit with Musk could be harmful to its business.
The startup also dismissed Musk’s lawsuit as “baseless,” calling it “an abuse campaign driven by ego, jealousy and the 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 scammer Altman lies as easily as he breathes,” Musk wrote in August in a post on X, which is part of xAI.
“So excited to have Elon sworn in in a few months, Christmas in April!,” Altman wrote in X in February.
Jury selection in Musk v. Altman begins Monday in federal court in Oakland, just over the Bay Bridge from San Francisco, where OpenAI is headquartered. If he succeeds, Musk said, he wants the court to return all “ill-gotten gains” to the nonprofit OpenAI, not to him personally. He also wants Altman and Brockman to be removed from their roles and to “free up the transformation and restructuring of OpenAI that makes it profitable.”
It’s not the only lawsuit Musk has brought against OpenAI. UX, formerly of Twitter, and xAI sued OpenAI and Apple in 2025 for alleged anti-competitive behavior. A hearing in that case is scheduled for May in Texas. And in February, a federal judge in California dismissed a separate xAI lawsuit that accused OpenAI of stealing its trade secrets.
The Musk-Altman spat began in 2018, when Musk left OpenAI’s board after disagreements with Altman and Brockman over the company’s direction, including a failed attempt to merge the startup. TeslaMusk’s electric car company. After Musk’s departure, OpenAI established a profitable company that allowed it to raise external investment more easily.
OpenAI briefly considered plans to transition to a for-profit company in 2024, which would have taken control of the nonprofit and kept it as a separate arm. But after facing pressure from community leaders and former employees, including Musk, it changed course. The company completed a recapitalization in October that cemented its structure as a nonprofit with a controlling stake in its for-profit business.
Musk sued OpenAI, Altman and Brockman in 2024, saying he was “duped” and “duped” by their promises that the company would “charge a safer, more open course than the profit-driven tech giants.”
But the scope of Musk’s claims has changed dramatically in recent months, along with the results he desired.
In a January filing, Musk’s lawyers said he should receive $134 billion in damages from OpenAI as well. Microsoftone of OpenAI’s longtime supporters, who is also named as a defendant in the lawsuit. Microsoft is accused of aiding and abetting OpenAI’s alleged misconduct in breaching the charity trust’s claim.
Of the 26 claims that Musk asserted against OpenAI, Altman and Brockman in November 2024, only four remain: unjust enrichment, fraud, constructive fraud, and breach of public trust. Musk’s attorneys are seeking dismissal of two claims, fraud and constructive fraud, before trial in an effort to “streamline the case,” according to the filing.
OpenAI lawyers on Wednesday characterized Musk’s actions as “backhanded tactics.”
“The case starts in five days but the plaintiff refuses to go public about what claims he will pursue and what remedies he will seek,” they wrote in the file.
Judge Yvonne Gonzalez Rogers, who was appointed by former President Barack Obama to the US District Court for the Northern District of California in 2011, is presiding over the case. Gonzalez Rogers has presided over several high-profile cases involving technology companies, including the antitrust case between Epic Games and an apple.
Nine judges will be seated, and there will be no replacements, according to the March filing.
Gonzalez Rogers chose to divide the trial into two parts: a liability phase to determine whether wrongdoing has occurred, and a remedial phase to determine appropriate damages and next steps. The judge will weigh in on the liability phase only, and his decision will be advisory, meaning Gonzalez Rogers will make the final decision on both phases of the case.
The trial phase of the trial is expected to continue in mid-May, and court will operate from 8:30 am to 1:40 pm PT every Monday through Thursday.
Jury selection will be followed by opening arguments. Gonzalez Rogers gave lawyers for Musk and OpenAI a total of 20 hours each to present their case. Microsoft will get five hours, according to the filing.
All three parties submitted a list of witnesses they could call. Musk, Altman, Brockman and Microsoft CEO Satya Nadella were all named.
If OpenAI is found guilty, Gonzalez Rogers will hear arguments in the remedies phase, which is scheduled to begin on May 18.
“However, if a judge finds that Musk failed to bring his action under the statute of limitations, it is highly likely that the Court will accept that finding and direct it against the defendants,” wrote Gonzalez Rogers.
CNBC will be in court starting Monday. Follow the latest coverage here.
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