Elon Musk's $134 billion lawsuit against OpenAI, Sam Altman, and Microsoft is set to begin trial on Monday in Oakland, California. The case, presided over by US District Judge Yvonne Gonzalez Rogers, has been narrowed to two key claims: unjust enrichment and breach of charitable trust. Musk initially filed the lawsuit in November 2024, following his $38 million donation to OpenAI, which was founded as a nonprofit in 2015. He alleges that OpenAI's shift to a capped-profit model, supported by over $13 billion from Microsoft, violated its original mission and enriched insiders at the expense of early donors. The trial will determine whether OpenAI and Microsoft were unjustly enriched by the restructuring and if OpenAI breached its charitable mission. Musk's legal team has requested that any damages awarded be directed to OpenAI's charitable arm. Jury selection begins Monday, with the proceedings expected to reveal internal communications from OpenAI's early years. Musk is also pursuing an antitrust case against Apple and OpenAI while developing xAI as a competitor to Altman's company.