Musk v Altman et al

Musk v. Altman et al. (Case No. 4:24-cv-04722-YGR) is a landmark lawsuit in which Elon Musk alleges that OpenAI cofounders Sam Altman and Greg Brockman breached a charitable trust and were unjustly enriched by Musk's donations, after promising that OpenAI would remain a nonprofit. Originally filed as a 26-claim complaint including fraud and constructive fraud, the case was narrowed to two claims on April 24–25, 2026, when Musk voluntarily dismissed his fraud claims ahead of trial. Jury selection begins April 27, 2026, before Judge Yvonne Gonzalez Rogers in the United States District Court for the Northern District of California (Oakland).<ref name="justia">Justia: Musk v. Altman et al Docket</ref><ref name="businessinsider">Business Insider, "Elon Musk vs. Sam Altman: The stakes for OpenAI and Microsoft," April 2026</ref><ref name="musk-drops-fraud">Fortune, "Elon Musk drops fraud claims against OpenAI ahead of trial," April 25, 2026</ref><ref name="cybernews-drops">Cybernews, "Musk drops fraud claims in OpenAI lawsuit, two claims head to trial," April 25, 2026</ref><ref name="justia">Justia: Musk v. Altman et al Docket</ref><ref name="businessinsider">Business Insider, "Elon Musk vs. Sam Altman: The stakes for OpenAI and Microsoft," April 2026</ref>

Field	Detail
Case Name	Musk v. Altman et al.
Court	U.S. District Court, Northern District of California (Oakland)
Case Number	4:24-cv-04722-YGR
Judge	Hon. Yvonne Gonzalez Rogers
Filed	August 5, 2024
Plaintiff	Elon Musk
Defendants	OpenAI Inc., OpenAI L.L.C., OpenAI Startup Fund I L.P., Sam Altman, Greg Brockman, Microsoft Corporation
Claims	Breach of charitable trust, unjust enrichment (fraud claims dropped April 25, 2026)
Status	Bench trial with advisory jury begins April 27, 2026 (narrowed to 2 claims after Musk dropped fraud claims)
Key Pre-Trial Rulings	Jan. 15, 2026: Judge Gonzalez Rogers largely denied OpenAI's summary judgment motion, finding disputed facts on charitable trust, fiduciary duties, and reliance; Microsoft won partial summary judgment but aiding-and-abetting claim survived; March 2026: Court admitted expert testimony from Dr. Stuart Russell (UC Berkeley, AI safety) on AI company incentives, and Dr. C. Paul Wazzan (damages, $25B–$134B range)

Background

Musk co-founded OpenAI in December 2015 as a nonprofit research laboratory dedicated to ensuring AI benefits all of humanity. He resigned from the board in February 2018. The complaint alleges that Musk donated approximately $38–45 million based on explicit promises that OpenAI would remain a nonprofit and open-source. In 2019, OpenAI created a capped-profit subsidiary and accepted a $1 billion investment from Microsoft. By 2025, OpenAI had converted to a fully for-profit entity valued at over $800 billion.<ref name="businessinsider" />

Claims

As of April 25, 2026, the case has been narrowed to two remaining claims after Musk voluntarily dismissed his fraud claims:

Breach of charitable trust: OpenAI's founders violated their founding agreement to keep OpenAI nonprofit and open, and Musk's donations were made in charitable trust for a nonprofit purpose.<ref name="musk-drops-fraud">Fortune, "Elon Musk drops fraud claims against OpenAI ahead of trial," April 25, 2026</ref><ref name="cybernews-drops">Cybernews, "Musk drops fraud claims in OpenAI lawsuit, two claims head to trial," April 25, 2026</ref>
Unjust enrichment: Altman, Brockman, and OpenAI were unjustly enriched by Musk's charitable donations after abandoning the nonprofit mission.<ref name="musk-drops-fraud" />

Dismissed claims (April 24–25, 2026):

Fraud and constructive fraud: Musk voluntarily dismissed these claims on April 24–25, 2026, stating he wanted to "streamline" the case. Judge Gonzalez Rogers approved the dismissal.<ref name="musk-drops-fraud" /><ref name="straitstimes">The Straits Times, "US judge dismisses Musk's fraud claims in OpenAI case at his request," April 25, 2026</ref>

Earlier dismissed claims:

Aiding and abetting breach: Previously trimmed along with other claims as the case narrowed toward trial.
Promissory estoppel and breach of contract: Previously subsumed or trimmed as the case evolved toward the charitable trust theory.

Remedies Sought

Musk seeks:

Reverting OpenAI to nonprofit status and unwinding the for-profit conversion<ref name="businessinsider" />
Removing Sam Altman as director of the nonprofit and officer of the for-profit entity, and stripping his equity<ref name="businessinsider" />
Removing Greg Brockman as president and stripping his equity<ref name="businessinsider" />
Billions in financial disgorgement — up to $134 billion per a January 2026 expert filing<ref name="chatgptiseatingtheworld" />
Disgorgement of ill-gotten gains<ref name="businessinsider" />

Pre-Trial Developments

In the final weeks before trial, several significant filings and rulings shaped the case:

April 7, 2026: Musk amended his requested remedies, dropping personal monetary claims (previously seeking approximately $134 billion in disgorgement) and focusing instead on equitable relief, including restructuring OpenAI to unwind the for-profit conversion.<ref name="localnews-apr7">Local News Matters, "Musk v. Altman: It's Not About the Money — Elon Goes All In With Bid to Reshape OpenAI," April 24, 2026</ref>
April 10, 2026: OpenAI responded by calling Musk's amendment a "legal ambush" and "sandbagging," accusing him of contradicting prior statements about his sought remedies.<ref name="localnews-apr7" />
April 17, 2026: Judge Gonzalez Rogers considered bifurcating the trial into a liability phase followed by a remedies phase, and barred both parties from mentioning remedies to the advisory jury during the liability phase.<ref name="localnews-apr7" />
April 24-25, 2026: Musk voluntarily dismissed his fraud and constructive fraud claims, narrowing the case to two remaining claims: breach of charitable trust and unjust enrichment. The strategic move was intended to streamline the trial by focusing on outcomes rather than intent.<ref name="musk-drops-fraud">Fortune, "Elon Musk drops fraud claims against OpenAI ahead of trial," April 25, 2026</ref><ref name="cybernews-drops">Cybernews, "Musk drops fraud claims in OpenAI lawsuit, two claims head to trial," April 25, 2026</ref>

Key evidence expected at trial includes a 2017 Greg Brockman diary entry calling the nonprofit commitment "a lie," a 2017 Sam Altman email expressing enthusiasm for the nonprofit structure amid Musk's funding threats, and unsealed 2025 discovery materials (emails, texts, Slack messages) alleging public nonprofit promises masked private for-profit plans. Judge Gonzalez Rogers cited "ample evidence" in her January 15, 2026 ruling denying most dismissal motions.<ref name="thenextweb">The Next Web, "Musk v. Altman trial: Credibility of OpenAI's nonprofit claims at stake," April 2026</ref>

Expected witnesses include Musk, Altman, Microsoft CEO Satya Nadella, and former OpenAI executives Mira Murati and Ilya Sutskever. Pretrial filings also revealed personal details including Shivon Zilis (OpenAI board member and mother of four of Musk's children) relaying information to him, and text messages from Mark Zuckerberg offering Musk favors including DOGE assistance and a joint bid for OpenAI.<ref name="chosun">Chosun Ilbo, "Musk v. Altman Pre-Trial Filings," April 24, 2026</ref>

As of April 23, 2026, prediction markets (Polymarket) gave Musk approximately a 35% chance of winning.<ref name="polymarket">Local News Matters, April 24, 2026</ref>

Trial Schedule

April 27, 2026: Jury selection begins at 8:00 a.m. PT in Oakland federal courthouse<ref name="chatgptiseatingtheworld">ChatGPT is Eating the World, "The Trial of the Century: Elon Musk v. Sam Altman Starts Monday, April 27," January 17, 2026</ref>
April 28, 2026: Opening statements expected<ref name="abs-cbn">ABS-CBN, "Billionaire Elon Musk enters courtroom showdown with OpenAI," April 25, 2026</ref>
Phase 1 (Advisory Jury Verdict): The jury will hear arguments on the two remaining claims (breach of charitable trust and unjust enrichment) and issue an advisory verdict that is non-binding on Judge Gonzalez Rogers. Approx. 100 potential jurors summoned from seven Bay Area counties; voir dire allows unlimited for-cause challenges and four peremptory challenges per side.<ref name="bloomberg-jury">Bloomberg Government, "Musk v. Altman Case Will Test Jury Process for Rich and Famous," April 2026</ref>
Phase 2 (Remedies): If liability found, Judge Gonzalez Rogers will hear arguments on remedies and issue a final ruling, starting approximately May 18, 2026<ref name="chatgptiseatingtheworld" />

Trial schedule: Monday–Friday, 8:30 a.m. to 1:40 p.m. PT, with two 20-minute breaks.<ref name="chatgptiseatingtheworld" />

Key Evidence

Greg Brockman's private diary entries documenting awareness of for-profit intentions before Musk's departure: "can't see us turning this into a for-profit without a very nasty fight" and calling it "morally bankrupt" to "steal" the company from Musk<ref name="businessinsider" />
Communications involving Mark Zuckerberg and Shivon Zilis<ref name="chatgptiseatingtheworld" />
Testimony from former board members including Tasha McCauley regarding OpenAI's internal governance<ref name="businessinsider" />
Expert witness testimony from Dr. C. Paul Wazzan (damages expert), who calculated potential damages up to $134 billion — comprising up to $109 billion from OpenAI and up to $25 billion from Microsoft — though this does not include punitive damages<ref name="chatgptiseatingtheworld" /><ref name="localnews">Local News Matters, "Musk v. Altman trial date looms as judge hands wins and setbacks to both sides," April 23, 2026</ref>
Potential testimony from Microsoft CEO Satya Nadella<ref name="businessinsider" />

OpenAI's Defense

OpenAI characterizes Musk's lawsuit as a "harassment campaign" driven by "ego, jealousy and a desire to slow down a competitor," suggesting Musk is using litigation to harm a rival through his own xAI company. OpenAI has filed counterclaims alleging Musk's anti-competitive behavior and has urged the California and Delaware attorneys general to investigate.<ref name="businessinsider" />

On January 8, 2026, Judge Gonzalez Rogers ruled that fraud claims require jury resolution due to factual disputes, allowing the case to proceed to trial. However, on April 24–25, 2026, Musk voluntarily dismissed his own fraud claims to streamline the case, reducing it to two claims (breach of charitable trust and unjust enrichment).<ref name="chatgptiseatingtheworld" /><ref name="musk-drops-fraud" />

April 27, 2026: Bench trial with advisory jury begins at 8:00 a.m. PT in Oakland federal courthouse; jury selection commences<ref name="reuters-trial">Reuters, Elon Musk's trial against Sam Altman to reveal the ongoing power struggle for OpenAI</ref><ref name="guardian-trial">The Guardian, Elon Musk and Sam Altman face off in court over OpenAI's founding mission</ref><ref name="law360-trial">Law360, Musk Trial To Test Limits Of OpenAI's Nonprofit Promises</ref>

Pre-Trial Rulings

Summary Judgment (January 15, 2026)

Judge Gonzalez Rogers largely denied OpenAI's motion for summary judgment on January 15, 2026, finding genuine disputes of material fact on whether a charitable trust existed, whether defendants breached fiduciary duties, and whether Musk reasonably relied on Altman's representations. Microsoft won a partial victory, but the claim that it aided and abetted OpenAI's breach survived.<ref name="localnews" />

Expert Testimony Rulings

The court admitted testimony from two key experts:

Dr. Stuart Russell, UC Berkeley professor and AI safety authority, will testify that AI companies have strong incentives to pursue artificial general intelligence despite safety risks, supporting Musk's argument that OpenAI's for-profit pivot created dangerous misalignment.<ref name="localnews" />
Dr. C. Paul Wazzan, Musk's damages expert, calculated potential recovery between $25 billion and $134 billion, with the upper range divided between OpenAI's gains ($109 billion) and Microsoft's potential liability ($25 billion). The judge found Wazzan's valuation methodology adequately supported despite OpenAI's objections about lack of accepted standards for valuing Silicon Valley startups.<ref name="localnews" />

Significance

This case is one of the most consequential legal battles in AI industry history. A finding of liability could force OpenAI to abandon its for-profit structure, potentially unwinding its Microsoft partnership and reshaping AI company governance. Even an OpenAI victory will expose internal governance concerns through public trial evidence.<ref name="businessinsider" /><ref name="chatgptiseatingtheworld" />

References