Linda Yaccarino, CEO of X Corp., formerly Twitter, speaks with Catherine Herridge during a keynote at the Consumer Electronics Show (CES) in Las Vegas, Nevada, on January 7, 2025. Gadgets, robots and vehicles imbued with artificial intelligence will once again vie for attention at the Consumer Electronics Show, as vendors behind the scenes will seek ways to deal with tariffs threatened by US President-elect Donald Trump. The annual Consumer Electronics Show (CES) opens formally in Las Vegas on January 7, 2025, but preceding days are packed with product announcements. (Photo by Patrick T. Fallon / AFP) (Photo by PATRICK T. FALLON/AFP via Getty Images)

A co-founder of Elon Musk’s xAI has announced he’s leaving the company, marking the fourth co-founder to depart in the past year.

Tony Wu resigned from the artificial intelligence startup late on Monday, becoming the latest to leave. Previously, Igor Babuschkin, Kyle Kosic, and Christian Szegedy have also departed, while Greg Yang stepped back last month to focus on his battle with Lyme disease.

In a post on X, Wu wrote: “It’s time for my next chapter,” he said. “It is an era with full possibilities: a small team armed with AIs can move mountains and redefine what’s possible.”

Wu’s departure comes as xAI faces mounting consumer backlash and regulatory probes across multiple countries. The company’s Grok AI chatbot and image generator have been linked to mass creation and syndication of non-consensual, explicit deepfake images based on photos of real people, including children.

Musk launched xAI in 2023 with a team of 11 co-founders to compete with rivals like OpenAI and Google. The startup’s stated goal at the time was “to understand the true nature of the universe.”

Separately, last week Musk announced SpaceX has acquired xAI. In a statement, SpaceX cited expectations that global demand for AI computing will soon outpace available electricity and cooling capacity on Earth.