Sam Altman Takes the Stand: OpenAI CEO Reveals Musk Demanded 90% Equity in Landmark Trial

The courtroom drama that has gripped Silicon Valley for three weeks reached its crescendo this week as OpenAI CEO Sam Altman took the witness stand in Oakland, California, delivering some of the most consequential testimony yet in Elon Musk’s lawsuit against the company he helped found. The revelations that emerged — including Musk’s alleged demand for a staggering 90% equity stake — have redrawn the contours of one of the most contentious legal battles in the history of artificial intelligence.

The 90% Revelation

The most explosive moment of Altman’s testimony came when he described Elon Musk’s early equity demands during OpenAI’s formative years. “An early number that Mr. Musk threw out was that he should have 90% of the equity to start,” Altman told the jury. He added that while that figure softened over subsequent negotiations, Musk’s insistence on majority control remained a constant theme. “It then softened, but it always was a majority,” Altman said.

The disclosure cuts to the heart of Musk’s lawsuit, which alleges that Altman, OpenAI president Greg Brockman, and Microsoft conspired to transform what was meant to be a nonprofit AI safety organization into a for-profit enterprise for personal enrichment — what Musk’s legal team has characterized as “stealing a charity.” Altman’s framing inverts that narrative entirely: Musk, by this account, was not a selfless patron of AI safety but an aspiring majority owner who walked away when his control demands were rejected.

“It feels difficult to even wrap my head around that framing,” Altman said when confronted with Musk’s central accusation.

A Defense of Character Under Fire

Altman’s testimony was never going to be a comfortable experience. Attorney Steven Molo, representing Musk, deployed a systematic assault on the OpenAI CEO’s credibility, drawing on a parade of unflattering accounts from former colleagues and associates. Testimony from Mira Murati, Ilya Sutskever, and former board member Helen Toner — all of whom have previously described Altman in ways that range from “not consistently candid” to outright untrustworthy — was marshaled to paint a picture of a calculated and self-serving executive.

Molo pressed Altman about a text message he sent Musk on February 18, 2023, shortly after Musk had resigned from OpenAI’s board in 2018, in which Altman wrote: “I’m tremendously thankful for everything you’ve done to help. I don’t think that OpenAI would have happened without you.” The implication was that Altman’s public gratitude was performative, a stark contrast to actions that allegedly undermined Musk’s vision for the organization.

“Are you completely trustworthy?” Molo asked at one point. Altman replied that he believed himself to be “an honest and trustworthy businessperson.”

The Microsoft Question

One of the more surprising disclosures to emerge from Altman’s time on the stand concerned his brief ouster from OpenAI in November 2023. Altman confirmed that after the board fired him, Microsoft CEO Satya Nadella offered him a position at the tech giant, along with the opportunity for OpenAI’s employees to transition to Microsoft. Altman said he seriously considered the offer but ultimately chose to return to OpenAI because of his commitment to its mission.

This account has particular resonance given that Microsoft’s $13 billion investment in OpenAI is central to Musk’s argument that the nonprofit was effectively captured by corporate interests. By Altman’s telling, he could have taken the easy path to Microsoft and “made a ton of money,” but instead chose the harder road of returning to an organization he believed in — a narrative of mission-driven sacrifice that his legal team is clearly eager to establish.

What’s Actually at Stake

The trial, now in its third week before U.S. District Judge Yvonne Gonzalez Rogers in Oakland, carries consequences that extend well beyond the two combatants. Musk is seeking injunctive relief that could force OpenAI to restructure — potentially unwinding its controversial shift from a nonprofit to a capped-profit company, or at minimum constraining how the organization deploys its now-vast resources.

The company that emerged from Altman’s return in late 2023 is almost unrecognizable from the scrappy nonprofit Musk co-founded in 2015. OpenAI’s most recent valuation reached $300 billion following a mega-round led by SoftBank, and the company has aggressively expanded into enterprise software, hardware partnerships, and government contracting. Whether that transformation constitutes a betrayal of OpenAI’s founding mission — or its only logical evolution — is precisely the question the advisory jury must now weigh.

Notably, several key witnesses have already testified with sharply divergent accounts. Microsoft CEO Satya Nadella, who testified last week, stated flatly that Musk never raised concerns with him about the company’s investment in OpenAI. That testimony undermined Musk’s portrayal of himself as an AI safety hawk sidelined by corporate capture. Former board member Helen Toner, whose critical assessment of Altman contributed to his 2023 firing, provided testimony that Musk’s team has leaned on heavily.

Closing Arguments and the Road to Verdict

Closing arguments are scheduled for Thursday, May 15. An advisory jury is expected to render its opinion on any actual wrongdoing by the week of May 18, after which Judge Gonzalez Rogers will make the final determination on both liability and remedies. She has indicated that she will likely follow the advisory jury’s recommendation.

Legal analysts tracking the case have noted that even a partial victory for Musk — say, a finding that OpenAI’s nonprofit directors breached their fiduciary duties — could create significant complications for the company’s planned conversion to a full for-profit entity. OpenAI’s legal team has framed the entire conversion as a practical necessity: without the ability to offer equity and raise institutional capital, the company argued, it simply could not compete with well-resourced rivals.

“The only way to raise the amount of money needed to develop safe and powerful artificial intelligence was to shift to a for-profit structure,” Altman said. “The mission remains the same.”

An Industry Watching Closely

The tech industry has followed this trial with unusual intensity, not merely because of the personalities involved but because the legal questions it raises have no clean precedent. Can a nonprofit pivot to for-profit without betraying its founding mission? What obligations do AI organizations have to their stated public-benefit goals when commercial pressures mount? And how much does the personal power struggle between two of the world’s most prominent tech figures — Altman’s measured incrementalism versus Musk’s combative maximalism — actually matter to the outcome?

Altman’s testimony did not resolve those questions, but it sharpened them considerably. Whatever the jury decides, the trial has already produced a rare thing in Silicon Valley: a detailed, adversarial accounting of what actually happened inside one of the world’s most consequential technology organizations during its most formative years.

The verdict, when it comes, will be read as something far larger than a ruling on a single lawsuit.