According to CNBC, the years-long legal dispute between the world’s richest man Elon Musk and OpenAI CEO Sam Altman will begin in Northern California on Monday, setting up a dramatic showdown between the two most high-profile figures in the technology world. In Musk’s $134 billion lawsuit, he claims that OpenAI, CEO Altman and company president Greg Brockman reneged on their previous commitments to keep the artificial intelligence laboratory permanently non-profit. OpenAI has since reorganized to allow it to operate a for-profit subsidiary and is now valued at more than $850 billion.

Musk and Altman, who were once good friends, founded OpenAI in 2015 with a group of technologists focused on the potential power of artificial intelligence and the need to advance its development in ways that benefit humanity.

Now, they have become the target of public criticism and their mortal enemies. Musk founded xAI in 2023 to compete with OpenAI and recently merged it with SpaceX. The combined company is valued at US$1.25 trillion. The trial comes as Musk prepares to take SpaceX public, which is expected to set a record IPO.

According to previous reports by CNBC, OpenAI plans to go public in the fourth quarter. In a document sent to potential investors earlier this year, OpenAI described the ongoing litigation with Musk as a possible risk to its business.

The startup has repeatedly dismissed Musk's lawsuit as "baseless," calling it "a harassment campaign driven by ego, jealousy, and a desire to slow down competitors," according to an early April article on the X website.

This war of words has been going on for months.

“Ultraman Liar lies as easily as breathing,” Musk wrote in an August post on X (part of xAI).

“So excited to have Elon testify under oath in a few months, at Christmas in April!” Altman wrote on X in February.

Jury selection in Musk v. Altman is set to begin Monday in federal court in Oakland, just across the Bay Area bridge from San Francisco, where OpenAI is headquartered.

Musk said that if he wins the case, he hopes the court will return all "illegal gains" to OpenAI's non-profit organization rather than to him personally. He also called for Altman and Brockman to be relieved of their duties and for "the undoing of OpenAI's for-profit transition and restructuring."

This is not the only time Musk has sued OpenAI. X (formerly Twitter) and its subsidiary xAI sued OpenAI and Apple in 2025, accusing them of anti-competitive behavior. A hearing in the case is scheduled for May in Texas.

Additionally, in February, a federal judge in California dismissed another lawsuit filed by xAI that accused OpenAI of stealing its trade secrets.

Musk’s conflict with Altman dates back to 2018, when Musk left the OpenAI board over numerous differences with Altman and Brockman over the company’s direction, including a failed attempt to merge the startup with Tesla.

After Musk left, OpenAI formed a for-profit subsidiary to make it easier to obtain outside investment.

OpenAI briefly considered transforming into a for-profit company in 2024, which would have allowed it to lose control of the nonprofit and retain its status as an independent unit. But the company changed its plans after facing pressure from civic leaders and former employees, including Musk. OpenAI completed a recapitalization in October, solidifying its organizational structure as a nonprofit that holds a controlling stake in its for-profit businesses.

In 2024, Musk sued OpenAI, Altman, and Brockman, claiming that they "carefully manipulated" and "deceived" him into promising that the company "would chart a safer and more open path than the for-profit tech giants."

But in recent months, the scope of Musk's claims and his desired outcomes have changed dramatically.

In a January filing, Musk's lawyers said he should receive up to $134 billion in damages from OpenAI and Microsoft. Microsoft is one of OpenAI's long-term supporters and is also named as a defendant in the case. Microsoft is accused of aiding and abetting OpenAI's breach of charitable fiduciary duties.

In November 2024, of the 26 charges filed by Musk against OpenAI, Altman and Brockman, there are currently only four remaining: unjust enrichment, fraud, constructive fraud and breach of charitable fiduciary obligations. Musk's lawyers are seeking to "simplify the case" by dismissing two of the charges - fraud and constructive fraud - before trial, according to a filing.

OpenAI’s lawyers on Wednesday described Musk’s actions as an “evasive maneuver.”

“The trial is set to begin in five days, but the plaintiff continues to refuse to specify what claims he will bring and what remedies he will seek,” they wrote in their filing.

Judge Yvonne Gonzalez Rogers, who was appointed to the U.S. District Court for the Northern District of California by former President Barack Obama in 2011, is the presiding judge in this case. Judge Gonzalez Rogers has heard several high-profile lawsuits involving technology companies, including the antitrust case between Epic Games and Apple. .

According to documents filed in March, nine jurors will be selected and there will be no alternates.

Gonzalez Rogers LLP elected to divide the trial into two phases: a liability phase to determine whether there was any wrongdoing; and a remediation phase to determine the appropriate amount of damages and next steps. The jury only deliberates during the liability finding phase and its verdict is for information purposes only, meaning Gonzalez Rogers LLP will make the final decision during both phases of the trial.

The liability phase of the trial is expected to last until mid-May, with the court meeting Monday through Thursday from 8:30 a.m. to 1:40 p.m. Pacific time.

Opening statements will be held after jury selection. The Gonzalez Rogers law firm gave Musk and OpenAI's lawyers about 20 hours each to present their cases. According to a document, Microsoft will be given five hours to present its case.

All three parties submitted a list of witnesses that could be subpoenaed. The list includes Musk, Altman, Brockman and Microsoft CEO Satya Nadella.

If OpenAI is found liable, Judge Gonzalez Rogers will hear arguments in the remedial phase, which is scheduled to begin on May 18.

"However, if the jury determines that Musk failed to file the lawsuit within the statute of limitations, the court is likely to accept that finding and rule in favor of the defendants," Gonzalez-Rogers wrote.

Related articles:

At Musk’s request, the US judge dismissed his fraud charges in the OpenAI case