What Is This Trial About?
A federal trial opened on April 28, 2026 in the U.S. District Court for the Northern District of California, Oakland, before Judge Yvonne Gonzalez Rogers. Elon Musk — co-founder of OpenAI, CEO of Tesla, SpaceX, and xAI — is suing OpenAI, CEO Sam Altman, President Greg Brockman, and Microsoft, alleging they breached the charitable trust on which OpenAI was founded in 2015.
The core claim: OpenAI was created as a nonprofit to develop safe, open-source AI for the benefit of humanity — and Altman and Brockman illegally steered it into a for-profit commercial venture worth $852 billion, enriching themselves at the expense of that mission.
The remedies Musk is seeking are sweeping: approximately $130 billion in damages returned to OpenAI's nonprofit foundation, Altman and Brockman removed from the board and as officers, and OpenAI's full reversion to a nonprofit structure.
Musk on the Stand: What He Testified
Musk was the first witness called when trial began. His direct testimony covered his role in founding OpenAI, his motivations, and what he says happened when the organization began taking large commercial investments.
On his founding role, Musk testified: "I came up with the idea, the name, recruited the key people, taught them everything I know, provided all the initial funding — besides that, nothing." He said he contributed at least $44 million in the company's early years, though OpenAI's lawyers pressed him on his original pledge of $1 billion, which he never fully delivered, with actual cash contributions of $38 million.
Musk testified he would not have contributed money, time, or his reputation if OpenAI had intended to be a for-profit company. He entered OpenAI's 2015 founding charter into evidence, which stated the organization would develop "open source technology for the public benefit" and was "not organized for the private gain of any person."
He said he recruited Ilya Sutskever — then at Google and, in Musk's assessment, one of the top three AI researchers in the world — to join OpenAI. He also said he personally contacted Microsoft CEO Satya Nadella to negotiate early cloud computing access for OpenAI, an ironic detail given Microsoft is now named as a co-defendant.
The Microsoft Tipping Point
Musk identified Microsoft's $10 billion investment in OpenAI, which he became aware of in fall 2022, as the moment he concluded the charitable trust had been breached. "At a $10 billion scale, there's no way Microsoft is just giving that as a donation," Musk testified. "That's an amount of money that doesn't make any sense" in a charitable context.
He said he texted Altman — "What the hell is going on? This is a bait and switch" — and that Altman had previously reassured him via text that OpenAI's technology would remain open and available to all. Musk described three phases in his view of OpenAI: "enthusiastically supportive," then "a little uncertain," then "they were looting the nonprofit."
Microsoft is named as a co-defendant accused of aiding and abetting the breach of charitable trust. Microsoft's attorney, Russell Cohen, argued in his opening statement that Microsoft had no knowledge of any breach and that Musk could have raised concerns directly with Satya Nadella.
Musk's AI Warning From the Stand
Musk used his testimony to frame the case in terms that go beyond any one company. He testified that AI could be "smarter than any human" as soon as next year, and that the technology "could also kill us all." He said his original goal in co-founding OpenAI was to counter Google's dominance in AI — he described an argument with Google co-founder Larry Page, who he says called him "a speciesist for being pro-human."
He warned that when one company controls "digital superintelligence," the stakes for who that company answers to become extreme. "All due respect to Microsoft, do you really want Microsoft controlling digital superintelligence?" Musk said from the stand.
He added that his concern about AI safety was what drove the original nonprofit structure: a lab developing AI of this consequence should not operate for private gain.
OpenAI's Defense: Sour Grapes From a Competitor
OpenAI's lead attorney, William Savitt, offered a sharply different account in his opening statement. "We are here because Mr. Musk didn't get his way at OpenAI," Savitt told the jury. "He quit, saying they would fail for sure. But my clients had the nerve to go on and succeed without him."
Savitt argued that Musk pushed for a for-profit structure himself, pledged $1 billion in funding he never delivered (actual contributions: $38 million in cash), and departed the company in 2018 after a failed attempt to take full control — including an attempt to merge OpenAI with Tesla. When he was refused, Savitt said, Musk walked, and only filed suit after founding xAI to compete directly with OpenAI.
During cross-examination, Savitt pressed Musk on whether he had any direct knowledge of OpenAI's internal safety efforts. Musk acknowledged he did not. "You just don't know," Savitt said. Musk responded: "It does worry me that a nonprofit suddenly is a for-profit with unlimited profit."
On day two of his testimony, Musk called himself "a fool" for investing in OpenAI and said the nonprofit structure gave it "the moral high ground" — a halo effect he says OpenAI exploited and then abandoned.
What the Trial Could Change
The jury's verdict is advisory — Judge Gonzalez Rogers will make the final call. But the stakes for OpenAI are severe. A ruling in Musk's favor could force OpenAI to revert to a nonprofit structure, remove Altman and Brockman from their positions, and channel up to $130 billion back into the nonprofit foundation.
The timing is critical. OpenAI is valued at $852 billion and is planning a public offering as soon as 2026. A forced nonprofit reversion would derail that IPO and fundamentally alter the company's commercial trajectory. OpenAI generates approximately $2 billion per month in revenue as of early 2026.
Additional witnesses expected to testify include Sam Altman, Greg Brockman, Microsoft CEO Satya Nadella, and several researchers involved in OpenAI's founding.
Key Facts at a Glance
| Item | Detail |
|---|
| Trial location | U.S. District Court, Oakland, California |
| Judge | Yvonne Gonzalez Rogers |
| Trial start | April 28, 2026 |
| Musk's attorney | Steven Molo (MoloLamken) |
| OpenAI's attorney | William Savitt |
| Defendants | OpenAI, Sam Altman, Greg Brockman, Microsoft |
| Damages sought | ~$130 billion |
| Musk's cash contribution to OpenAI | $38 million (pledged $1 billion) |
| OpenAI current valuation | $852 billion |
| OpenAI revenue run rate | ~$2 billion/month (early 2026) |
| Microsoft's total investment in OpenAI | Over $13 billion |
FAQ
What is Elon Musk suing OpenAI for?
Musk is suing OpenAI, Sam Altman, Greg Brockman, and Microsoft for breach of charitable trust. He alleges that OpenAI's conversion from a nonprofit to a for-profit company violated the founding mission he funded and helped establish in 2015. He is seeking around $130 billion in damages and OpenAI's reversion to a nonprofit structure.
How much did Musk actually invest in OpenAI?
Musk contributed $38 million in cash to OpenAI, according to testimony and OpenAI's lawyers. He had pledged $1 billion but did not deliver on that commitment. Musk argues his non-financial contributions — his name, reputation, and recruitment of key personnel — brought his total contribution above $100 million.
What does OpenAI say about the lawsuit?
OpenAI argues the suit is motivated by competitive jealousy. Musk left the company in 2018 after failing to gain full control, then founded xAI to compete directly. OpenAI's lead attorney argued that Musk himself pushed for a for-profit structure and only filed suit after OpenAI became one of the most valuable companies in the world.
What could happen if Musk wins?
Judge Gonzalez Rogers could order OpenAI to revert to a nonprofit structure, remove Altman and Brockman from their roles, and direct up to $130 billion in damages into OpenAI's nonprofit foundation. This would effectively end OpenAI's planned IPO and reshape its entire commercial structure.
Is Microsoft involved in the trial?
Yes. Microsoft is named as a co-defendant. Musk accuses Microsoft of aiding and abetting OpenAI's breach of charitable trust through its investments and partnerships. Microsoft has invested more than $13 billion in OpenAI and holds a license to OpenAI's IP through 2032. Microsoft's attorneys deny any knowledge of wrongdoing.
Who else will testify in the trial?
Sam Altman, Greg Brockman, and Microsoft CEO Satya Nadella are all expected to take the stand. Several researchers and engineers involved in OpenAI's founding are also anticipated witnesses. Musk's own testimony continued into day two of proceedings on April 29, 2026.