Elon Musk’s $134 billion lawsuit against OpenAI, Sam Altman, and Microsoft goes to trial Monday in federal court in Oakland, California, after the billionaire dropped his fraud claims days before jury selection.

US District Judge Yvonne Gonzalez Rogers approved Musk’s request Friday to narrow the case from 26 original claims down to two surviving counts of unjust enrichment and breach of charitable trust.

A Trial Years in the Making

Musk filed suit in November 2024 after donating roughly $38 million in seed funding to OpenAI. It launched as a nonprofit research lab in 2015.

He alleges Altman and co-founder Greg Brockman induced that backing with explicit promises that the organization would never pursue commercial profit.

OpenAI later restructured into a capped-profit entity and accepted more than $13 billion from Microsoft. The shift, Musk argues, enriched insiders at the expense of early donors and the public mission they were told they were funding.

In February 2025, Musk led a $97.4 billion consortium bid to take control of OpenAI’s nonprofit arm. Altman rejected the offer publicly.

What the Jury Will Decide

The trial examines whether OpenAI and Microsoft were unjustly enriched by the company’s shift to a for-profit model. It also focuses on whether OpenAI breached the terms of its original charitable mission. The second claim accuses Microsoft of aiding and abetting.If Elon Musk prevails, his attorneys have asked that any damages flow to OpenAI’s charitable arm rather than to him personally.

Musk is separately pursuing an antitrust case against Apple and OpenAI and continues to develop xAI as a direct rival to Altman’s company.

Jury selection begins Monday morning before Judge Gonzalez Rogers, who previously presided over the Epic Games antitrust case against Apple. The proceedings are expected to expose internal communications between Musk, Altman, and Brockman from OpenAI’s earliest years.