Elon Musk sued OpenAI, Sam Altman, Greg Brockman, and Microsoft in federal court in California. He claimed they betrayed OpenAI’s nonprofit founding mission by converting it into a for-profit enterprise, and sought up to roughly $150B in disgorgement. On May 18, 2026, an advisory jury found all his claims time-barred without reaching the merits, the court adopted the verdict, and Musk is appealing to the Ninth Circuit.
Latest development May 18, 2026
On May 18, 2026, a unanimous nine-member advisory jury found all of Musk’s claims time-barred after less than two hours of deliberation. Judge Yvonne Gonzalez Rogers adopted the verdict. Musk’s counsel announced an appeal to the Ninth Circuit, arguing that the case turned on a calendar technicality and that the continuing-violation doctrine should extend the limitations period.
Why it matters
The appeal will decide whether Musk’s challenge to OpenAI’s conversion from a nonprofit research lab into a for-profit company came too late. A reversal would revive untried merits questions about whether OpenAI’s founding commitments were enforceable and were broken, and who can enforce them.
Background
Elon Musk, an OpenAI co-founder and early funder, sued Sam Altman, Greg Brockman, OpenAI, and Microsoft. He alleges that they induced his support with promises that OpenAI would remain a nonprofit developing AI for the benefit of humanity. He claims they then diverted the enterprise to private gain, culminating in OpenAI’s October 2025 restructuring into a public benefit corporation controlled by the OpenAI Foundation.
Musk first sued in California state court in February 2024. He withdrew that complaint in June 2024, a day before a scheduled hearing on OpenAI’s demurrer. In August 2024, he refiled in the U.S. District Court for the Northern District of California with expanded fraud claims. Later amendments added X.AI Corp. as a plaintiff and antitrust theories against Microsoft.
In March 2025, Judge Yvonne Gonzalez Rogers denied a preliminary injunction against the conversion but ordered an expedited trial. In April 2025, OpenAI counterclaimed, calling Musk’s campaign, including a $97.4B “sham” takeover bid, bad-faith harassment. In May 2025, the court sent fraud and unjust-enrichment claims to trial and excluded false-advertising and breach-of-fiduciary-duty theories. A three-week trial began in Oakland on April 27, 2026. Jurors heard from Altman, Brockman, Microsoft CEO Satya Nadella, and Musk himself.
On May 18, 2026, a nine-member advisory jury unanimously found all of Musk’s claims time-barred after less than two hours of deliberation. Judge Gonzalez Rogers adopted the verdict, resolving the case on limitations grounds without deciding whether OpenAI betrayed its founding promises. Musk had sought up to roughly $150B in disgorgement, removal of Altman and Brockman, and an unwinding of the restructuring. He dismissed the outcome as a technicality and is pursuing a Ninth Circuit appeal, invoking among other things the continuing-violation doctrine.
Timeline 8 events
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JudgmentAdvisory jury finds claims time-barred and court adopts verdict
Nine jurors unanimously found the claims untimely after less than two hours of deliberation. Judge Gonzalez Rogers adopted the verdict, and Musk announced a Ninth Circuit appeal.
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HearingJury trial begins in Oakland
Over three weeks, jurors heard testimony from Altman, Brockman, Microsoft CEO Satya Nadella, and Musk.
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OrderCourt narrows Musk’s claims for trial
Fraud and unjust-enrichment claims proceeded. The court excluded false-advertising and breach-of-fiduciary-duty theories.
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FilingOpenAI counterclaims against Musk
OpenAI accused Musk of a bad-faith harassment campaign, including a “sham” $97.4B takeover bid for OpenAI’s assets.
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OrderCourt denies preliminary injunction and orders expedited trial
Judge Gonzalez Rogers declined to block the for-profit conversion, finding likelihood of success a toss-up. She offered an expedited trial on the core claims.
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FilingMusk refiles in federal court
Musk refiled in the U.S. District Court for the Northern District of California with expanded fraud claims. Later amendments added X.AI Corp. as a plaintiff and antitrust theories against Microsoft.
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OrderMusk withdraws the state suit
Musk withdrew the complaint without explanation a day before a scheduled hearing on OpenAI’s demurrer.
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FilingMusk sues OpenAI and Altman in California state court
Experimental AI forecast
How it is madeHow will the Ninth Circuit resolve Musk’s appeal of the judgment that his claims against OpenAI are time-barred, by September 30, 2028?
- Ninth Circuit affirms time-bar ruling55%
- Still pending on September 30, 202824%
- Ninth Circuit revives Musk’s claims12%
- Appeal dismissed or withdrawn5%
- Musk and OpenAI settle4%
- Resolves by
- Sep 30, 2028in 23 months
- Record confidence
- Medium
The Ninth Circuit is most likely to affirm the judgment that Musk’s claims are time-barred, at 55%, by September 30, 2028. The strongest reason is that accrual and notice findings adopted after a full trial get deferential clear-error review, and the advisory jury was unanimous.
How it resolves. Resolves on the Ninth Circuit’s first merits disposition (opinion or memorandum) of Musk’s appeal from the May 18, 2026, judgment, as shown on the public docket. “Affirms” means the time-bar judgment is upheld in full. “Revives” means the court reverses or vacates the judgment as to at least one claim against any respondent. “Settles” means a publicly reported settlement ending the appeal. “Dismissed or withdrawn” means the appeal ends by jurisdictional dismissal or voluntary dismissal without a reported settlement. If none of these has occurred by September 30, 2028, the question resolves as still pending. Later en banc or Supreme Court review does not change the resolution.
Reasoning
Starting point. Ninth Circuit appeals from civil judgments in private commercial cases decided after trial, especially limitations findings.: Federal courts of appeals reverse roughly 10% to 15% of private civil judgments. Post-trial fact findings reviewed for clear error are reversed less often.
Federal appellate courts reverse about 10% to 15% of private civil judgments, and less often when the appeal attacks post-trial fact findings. Here the court adopted a unanimous advisory jury’s limitations verdict, so the underlying findings on when Musk knew or should have known of his claims are reviewed for clear error. Musk’s best path is a legal argument, such as the continuing-violation doctrine or accrual tied to the October 2025 restructuring, which gets de novo review. That raises reversal odds somewhat above a pure fact appeal, so I put revival of at least one claim at 12%. Timing is the main uncertainty. Ninth Circuit civil appeals that are argued often take 15 to 24 months from notice to decision, and the record does not show the notice date or whether OpenAI’s counterclaims remain pending, which could affect finality. That supports a 24% chance the appeal is still open on the resolve date. Settlement looks unlikely given the parties’ public hostility, Musk’s resources, and OpenAI’s interest in a clean precedent after winning at trial. A jurisdictional dismissal or voluntary withdrawal is a small residual risk.
Deferential clear-error review of trial limitations findings · Unanimous advisory jury verdict adopted by the court · Continuing-violation argument offers a de novo legal issue · Ninth Circuit timelines and possible finality questions from counterclaims · Low settlement incentive for OpenAI after trial win
Generated automatically by Claude Opus 5.5 on Sep 24, 2026 from this case’s record on this site, and published without editorial review. The probabilities are the model’s judgment, not measured frequencies, and they are scored publicly as cases resolve. Not legal or investment advice. How the forecasts are made
Disclosure: Anthropic, which makes the model that wrote this forecast, competes with or has commercial ties to a party to this case.