OAKLAND, Calif. — OpenAI co-founder and President Greg Brockman disclosed in a trial Monday that his stake in the firm is worth nearly $30 billion, confirming a figure that co-founder Elon Musk has pointed to in arguing that OpenAI has abandoned its mission as a nonprofit organization.

Brockman took the stand during the fourth day of the trial. Musk is suing Brockman and OpenAI CEO Sam Altman, alleging that they unlawfully converted a charity that he helped start into a for-profit business, best known for creating the popular artificial intelligence app ChatGPT.

Brockman was repeatedly asked to reconcile his nearly $30 billion stake with OpenAI’s stated mission of making AI technology to benefit all of humanity.…