All Eleven xAI Co-Founders Are Gone and Elon Musk Says That Was the Plan

Ross Nordeen walked out of xAI on March 28, 2026, the last of eleven co-founders to leave Elon Musk's artificial intelligence startup since its founding. The company carries a $250 billion valuation after SpaceX's February acquisition and access to one of the largest GPU clusters on Earth. But it no longer has any of the senior AI researchers who helped build it.

Musk addressed the exodus publicly, calling the departures "an expected evolution at such a critical phase of scaling" and saying xAI "was not built right first time around" and is being "rebuilt from the ground up." The question is whether rebuilding a $250 billion AI company from scratch after losing every senior technical leader is a strategy or a crisis.

The Timeline of Departures

Tony Wu left February 10, 2026. Jimmy Ba resigned within 24 hours. Toby Pohlen, Zihang Dai, and Guodong Zhang followed in late February and early March. Manuel Kroiss, who led pretraining, told people he was leaving on March 27. Nordeen departed the next day, according to people with knowledge of his exit. Nordeen also lost the badge on X that identifies him as an xAI employee.

Notable co-founders included Jimmy Ba, author of the Adam optimizer widely used in machine learning; Igor Babuschkin, former Google DeepMind chief engineer; Christian Szegedy, a Google researcher; and Tony Wu, who led the reasoning team. These weren't junior engineers. They were senior AI researchers with decades of combined experience at Google, OpenAI, and DeepMind.

The shake-up follows an all-stock transaction in which SpaceX acquired xAI in a deal that values SpaceX at $1 trillion and xAI at $250 billion, for a combined $1.25 trillion. It was the largest corporate merger by valuation in history, announced February 3, 2026. The primary stated objective of the acquisition was to pioneer the development of AI data centers in space, leveraging SpaceX's launch infrastructure and satellite network.

Why the Co-Founders Left

Musk has said xAI "was not built right first time around" and needed a restructuring that would force him to part ways with some people. The departures come as Musk prepares to integrate xAI more closely with SpaceX ahead of a major public listing. On July 6, 2026, Grok, X, and Colossus folded into SpaceX under one ticker, and xAI became SpaceXAI.

For AI buyers, this is an integration story, not a benchmark one. Musk is betting that combining SpaceX's launch capabilities with xAI's AI infrastructure will create a competitive advantage that outweighs the loss of the original technical team. The challenge is that AI labs are built on talent, and xAI just lost all of its founding talent.

"You can't run an AI lab like a rocket factory," one source told tech publication The Implicator. SpaceX's culture of rapid iteration and high turnover works when you're building rockets that can be tested and redesigned based on physical results. AI research is different. Models take months to train, and the knowledge required to debug and improve them is held in the heads of senior researchers.

What xAI Is Now

Musk announced in early February that xAI was being reorganized into four divisions, though the exact structure has not been publicly detailed. The company continues to operate the Grok AI assistant on X and maintains access to one of the largest GPU clusters in the world at the Colossus data center.

SpaceXAI is preparing for what would be one of the largest public listings in history if the combined entity goes public as planned. The company's valuation assumes that the integration of space infrastructure and AI capabilities will create a moat that competitors cannot replicate.

But the departure of all eleven co-founders raises questions about whether the technical foundation of xAI remains intact. Fast Company found 80 xAI exits beyond the co-founders, suggesting the talent drain goes deeper than the headline departures. Talent research firm Refolk AI noted that Meta is not bidding on many of the departed engineers, which suggests the market views them as competent but not irreplaceable.

The SpaceX Integration Bet

Musk's thesis is that xAI's value comes from its integration with SpaceX's launch capabilities and satellite network, not from the specific researchers who designed Grok. If that's true, then losing the co-founders is painful but not fatal. The infrastructure matters more than the people.

If that's not true, then xAI just lost the institutional knowledge required to improve its models and compete with OpenAI, Anthropic, and Google. The next few months will reveal which thesis is correct. SpaceXAI will either prove that AI labs can be rebuilt from scratch through integration with adjacent infrastructure, or it will become a cautionary tale about what happens when you lose every senior technical leader in the space of six weeks.

Ross Nordeen's departure on March 28 closed the chapter on xAI's founding team. The question is what Musk builds next.