Elon Musk will take the stand for his third day of testimony on Thursday, in a blockbuster trial that could help determine the future of companies racing to dominate artificial intelligence.

Elon Musk on Thursday sparred with an attorney for OpenAI during his third day of testimony in the contentious trial over the company’s pivot from nonprofit status to a for-profit venture valued at hu...

“I was a fool who provided them free funding to create a startup,” Musk said during his testimony on Wednesday.