(OAKLAND, Calif.) — Billionaire entrepreneur Elon Musk and prominent AI executive Sam Altman are facing off in court with major implications for OpenAI, the San Francisco-based tech giant led by Altman.
The federal case, which concerns OpenAI’s evolution from nonprofit to profit-seeking, kicked off on Monday in Oakland, California. Judge Yvonne Gonzalez Rogers is managing proceedings alongside nine jurors and no alternates, according to a court filing last month.
The star-studded list of potential witnesses includes Altman, Musk and Microsoft CEO Satya Nadella, among other tech luminaries, a court filing showed.
Musk sued OpenAI and Altman, its CEO, in 2024, alleging that the company abandoned its mission of benefiting humanity in a sprint toward profits.
Musk, a co-founder of OpenAI, said he reached an agreement with the company’s leaders on the nonprofit course of the firm when it launched in 2015. The company later breached that “Founding Agreement,” Musk said in a 2024 court filing, when it made ChatGPT-4 available for use by Microsoft — the tech giant got access to the then-most powerful version of its popular chatbot under an exclusive licensing agreement.
Microsoft and OpenAI have renegotiated the exclusive licensing agreement, allowing OpenAI to strike deals with other tech firms.
OpenAI has rebuked the charges, calling them “baseless.” Microsoft has also denied any wrongdoing. Musk, the world’s richest person, counts $839 billion in wealth, according to Forbes. He is seeking $150 billion in damages from the tech companies.
OpenAI, which is not publicly traded, valued itself at $852 billion after a round of funding in March. Microsoft’s value — as measured by market capitalization — stands at about $3.1 trillion.
After jury selection, the case will take place in two sections, Gonzalez Rogers said in a court filing. An initial phase will focus on liability to determine whether any of the defendants committed illegal acts. A subsequent remedies portion will assess potential damages.
Musk and the OpenAI defendants will each be afforded 22 hours to present their case during the liability phase, Gonzalez Rogers said in a court filing earlier this month. Microsoft, also a defendant, will be given five hours for its case.
Musk will plead two claims against OpenAI: unjust enrichment and breach of charitable trust, according to a legal filing last week.
“OpenAI, Inc. has been transformed into a closed-source de facto subsidiary of the largest technology company in the world: Microsoft,” Musk said in the lawsuit.
Typically, deals established between a top investor and company leadership are set out in writing with concrete terms, some experts previously told ABC News, leaving Musk in a difficult position as he attempts to invoke what they say appear to be spoken commitments made years ago without a formal contract.
For his part, Musk says in the lawsuit that the agreement was memorialized in a legal filing when OpenAI was incorporated.
In the lawsuit, Musk alleges that Altman and OpenAI President Greg Brockman reaffirmed the founding agreement in written messages over the ensuing years.
“[I] remain enthusiastic about the non-profit structure!” Altman wrote to Musk in 2017, according to the lawsuit.
Musk, who helped bankroll OpenAI, launched a rival AI company in 2023 called xAI, which built a chatbot that competes with ChatGPT.
Acknowledging his previous criticism of the pace and ambitions of AI development, Musk said in a conference call on X in July 2023 that he entered the industry reluctantly.
In the lawsuit, Musk alleges breach of contract, breach of fiduciary duty and unfair business practices.
Musk is seeking a legal order that requires OpenAI to abide by its alleged founding mission of aiding humanity and retaining its nonprofit form, as well as compensation for the funds received by OpenAI while it carried out allegedly unfair business practices.
Copyright © 2026, ABC Audio. All rights reserved.
