The bitter rivalry between two of the tech world’s most powerful men arrives in court this week, as Elon Musk’s lawsuit against Sam Altman and OpenAI heads to trial in Oakland, California. The case is set to feature some of the biggest names in Silicon Valley, and its outcome could affect the course of the AI boom.

Musk’s suit, filed in 2024, focuses on the formative years of OpenAI when he, Altman and others co-founded the artificial intelligence company as a nonprofit with a grand purpose.

“OpenAI is a non-profit artificial intelligence research company. Our goal is to advance digital intelligence in the way that is most likely to benefit humanity as a whole, unconstrained by a need to generate financial return,” reads the company’s mission statement, published in late 2015.

Musk alleges that Altman, OpenAI’s CEO, broke the company’s founding agreement by restructuring the company and converting much of it to a for-profit enterprise. Altman and OpenAI counter that Musk, who left the firm in 2018 amid internal disputes and has since started his own rival AI business, is essentially a sore loser.

While the central disagreement may concern convoluted corporate structures and contractual agreements, the trial itself promises to be an explosive high point in the feud between the two tech billionaires. Court filings featuring emails, texts and diary entries involving Musk and Altman have already hinted at dramatic episodes in OpenAI’s history that will be detailed in full, and are rife with personal animosities and professional disputes that have shaped the AI industry.

The case also carries sizable stakes for OpenAI, which is expected to go public later this year at about a $1tn valuation. Musk is seeking a range of remedies that include the removal of Altman and OpenAI president Greg Brockman and more than $134bn in damages, which Musk says would be redistributed to OpenAI’s non-profit arm.

Jury selection in the trial starts on Monday at a federal courthouse in Oakland, with Judge Yvonne Gonzalez Rogers overseeing the proceedings. The trial is expected to last two to three weeks.

Sam Altman, con man, or Elon Musk, sore loser?

The core of Musk’s suit effectively accuses Altman of swindling him with the promise that OpenAI would operate as a nonprofit entity focused on safety and open access to artificial intelligence. Once Altman and OpenAI secured Musk’s money – about $38m – and advanced its technology, the company “flipped the narrative and proceeded to cash in” on lucrative deals with Microsoft and the creation of for-profit affiliates, Musk alleges.

Musk’s complaint opens with the line “Elon Musk’s case against Sam Altman and OpenAI is a textbook tale of altruism versus greed”. The document quickly goes on to say that Altman and the other defendants deceived and manipulated Musk about the non-profit structure, “preying on Musk’s humanitarian concern”.

“This was all hot-air philanthropy – the hook for Altman’s long con,” Musk’s complaint reads. “The perfidy and deceit are of Shakespearean proportions.”

Altman and OpenAI fired back just days after Musk filed his suit, publishing a slew of company emails and texts trying to show that Musk knew about the company’s plan to restructure all along.

OpenAI has vehemently denied all of Musk’s allegations, saying he agreed in 2017 that establishing a for-profit entity would be a necessary next step for the company and that Musk is “motivated by jealousy” and “regret for walking away”. The company also contests that Musk’s funding was an investment, stating that it was instead a tax deductible donation to the nonprofit and does not entitle him to ownership in OpenAI.

“Elon has spent years harassing OpenAI through baseless lawsuits and public attacks,” OpenAI said in a blogpost criticizing Musk’s suit. The company now maintains a dedicated webpage about the lawsuit titled “The truth about Elon Musk and OpenAI”, which calls Musk’s case a “smear” and “harassment” campaign and is filled with internal correspondence involving Musk.

Foundational disagreements

A group of tech entrepreneurs and researchers, including Musk, Altman and Brockman, founded OpenAI in 2015. Altman, then a young but increasingly influential figure in Silicon Valley, originally brought Musk into the project by emailing him with a proposition that the two of them should be the ones who guide AI’s future.

“Been thinking a lot about whether it’s possible to stop humanity from developing AI. I think the answer is almost definitely not,” Altman wrote to Musk in May 2015. “If it’s going to happen anyway, it seems like it would be good for someone other than Google to do it first.”

Altman, Musk and the other founders launched OpenAI later that year as a nonprofit organization and began recruiting top AI researchers to work on developing the technology. The relationship with Musk turned sour around 2017, however, after the billionaire grew impatient with progress and made a failed bid to exert more control over the company. He left OpenAI’s board in 2018 and stopped providing funding.

During OpenAI’s post-Musk years, it launched the wildly successful ChatGPT, raised tens of billions of dollars from Microsoft and grew to be one of the world’s most valuable private companies. Altman became the face of the AI boom and a power broker within the tech industry. As OpenAI sought even more investment in 2025, the startup gained final approval from regulators to restructure its main business into a for-profit corporation, though one technically still overseen by the original nonprofit.

Musk’s suit alleges that Altman’s dealmaking and maneuvering of OpenAI break with the fundamental mission of the company as a nonprofit to benefit humanity and amount to a breach of charitable trust. The suit also claims Altman and Brockman unjustly enriched themselves through their control of the company.

In addition to tens of billions in damages and the removal of Altman and Brockman from OpenAI’s board, Musk also wants to reverse the company’s restructuring as a for-profit entity – a move that would complicate its plans to go public. Musk is being represented in the case by Marc Toberoff, a Hollywood lawyer with a flair for the dramatic. Altman and OpenAI have taken a more traditional approach and tapped the white-shoe law firm Wachtell, Lipton, Rosen & Katz for their defense.

A nine-person jury will hear Musk’s numerous breach of contract and unjust enrichment claims over the course of the trial. Along with internal communications from Musk and key executives at OpenAI, a who’s who of Silicon Valley that includes Musk, Altman and Microsoft CEO Satya Nadella are also set to testify. The case, which is shaping up to be as much of a public relations fight as it is a legal battle, is also likely to include a fair amount of mud-slinging and salacious details as the former business partners seek to tear each other down.

Long-held rivalry may get personal

Well before Musk filed his lawsuit, he and Altman were known for publicly trading barbs. The feud ramped up after OpenAI released ChatGPT in 2022. Musk railed on the chatbot, calling it “woke” and told Tucker Carlson on Fox News that OpenAI programmers were “training the AI to lie”. Meanwhile, during a podcast with tech journalist Kara Swisher, Altman described Musk as a “jerk”.

On X, Musk’s social media platform, the billionaires have also long mocked and ridiculed each other. Musk has called Altman a “liar”, “swindler” and “Scam Altman”, while Altman has replied to Musk’s posts saying “ambien tweeting is a dangerous game” and taunted his rival by posting a screenshot with the cancellation of a $50,000 Tesla purchase. To the latter jibe, Musk shot back: “You stole a non-profit.”

The lawsuit has unearthed even more of this caustic face-off between the two tech leaders and their accomplices.

Unsealed depositions that OpenAI’s lawyers took of Musk show lines of questioning about the billionaire’s attendance to Burning Man, a raucous party in the Nevada desert, and his use of “rhino ket”, a strong drug cocktail that includes the dissociative anesthetic ketamine. They also deposed Shivon Zilis, an executive at Musk’s brain implant company and mother of four of his children, about the nature of their romantic relationship. Zilis served on OpenAI’s board from 2020 to 2023.

Musk’s lawyers have sought to have the testimony excluded from trial saying it’s “inflammatory and highly irrelevant”. OpenAI’s lawyers insist the depositions remain in the record, saying they highlight Musk’s interpersonal relationships and “state of mind” during negotiations about the future of the company.

Over the course of the trial, it’s expected that both sides will continue to keep the temperature high and bring even more of a spectacle to their dispute. In a post on X in January, Musk promised entertainment.

“Can’t wait to start the trial,” he said. “The discovery and testimony will blow your mind.”