Elon Musk’s artificial intelligence company xAI has experienced the resignation of two co-founders within just 48 hours. The departures highlight growing instability at the firm as it integrates with SpaceX and faces regulatory challenges across multiple regions.
University of Toronto professor Jimmy Ba, whose research shaped xAI’s Grok 4 AI models, announced his exit on Tuesday in a post on X. He thanked Musk and said, “Grateful to have helped cofound at the start.” This came a day after fellow co-founder Tony Wu revealed his own departure.
The exits coincide with xAI’s recent merger with Musk’s SpaceX aerospace business earlier this month. Documents viewed by CNBC valued SpaceX at $1 trillion and xAI at $250 billion in the record-breaking all-stock deal. SpaceX now prepares for a potential stock market listing later this year.
Ba joins other pioneers who have left Musk’s AI venture, including Igor Babuschkin, Kyle Kosic, and Christian Szegedy. Greg Yang stepped back last month to focus on treatment for Lyme disease.
xAI launched in 2023 with Musk and 11 others to rival OpenAI and Google. Its original mission was to “understand the true nature of the universe,” according to the company’s website at launch. The firm later used an all-stock transaction in March 2025 to acquire social platform X, formerly Twitter, valuing it at $33 billion.
These resignations unfold as xAI contends with investigations in Europe, Asia, and the United States. Regulators launched probes after the Grok AI chatbot and image generator enabled widespread creation of non-consensual explicit images known as deepfake pornography. The visuals used photographs of real people, including children.