Musk, OpenAI lawyers begin closing arguments in AI trial involving Microsoft

Lawyers for Elon Musk and OpenAI began closing arguments on May 14, 2026, in a landmark trial that could affect OpenAI’s structure and Microsoft’s legal exposure as a co-defendant. Musk, who co-founded OpenAI in 2015 and invested $38 million in its early years, sued in 2024, accusing CEO Sam Altman and President Greg Brockman of shifting the company toward profit without proper notice. Jurors must first decide whether Musk filed within the statute of limitations. OpenAI argues claims tied to events before August 2021 are time-barred. If the jury finds the case was timely, it must decide whether OpenAI had a charitable trust and whether OpenAI executives breached it or were unjustly enriched at Musk’s expense. For Microsoft, jurors must determine whether it aided and abetted any breach. A judge said last month she would likely direct a verdict for defendants if jurors find Musk filed too late.