Elon Musk’s last co-founder reportedly leaves xAI

TechCrunch / 3/29/2026

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Key Points

  • Reports from Business Insider say xAI’s remaining two co-founders, Manuel Kroiss and Ross Nordeen, have left the company, following earlier departures of most of the founding group.
  • Kroiss reportedly told people he was leaving, and BI reports Nordeen exited the company on Friday, leaving xAI effectively with no remaining original co-founders.
  • Musk has said xAI “was not built right” and is now being rebuilt from the ground up, framing the leadership churn as part of a broader restart.
  • The article ties the shakeup to xAI’s recent acquisition by Musk’s SpaceX and the prospect of SpaceX’s planned IPO, indicating organizational consolidation and heightened corporate scrutiny.
  • Both Kroiss and Nordeen had close roles to Musk, with Kroiss leading pretraining and Nordeen serving as a key operator, suggesting operational disruption and possible shifts in xAI’s technical roadmap.

Earlier this month, it looked like all but two of Elon Musk’s 11 co-founders at his AI startup xAI had departed the company. Now, according to Business Insider, the remaining two co-founders, Manuel Kroiss and Ross Nordeen, have left as well.

BI said on Wednesday that Kroiss had told people that he’s leaving xAI, then reported that Nordeen left the company on Friday.

Musk recently claimed xAI “was not built right [the] first time around,” so it’s now “being rebuilt from the foundations up.” The company was recently acquired by Musk’s SpaceX, bringing SpaceX, xAI, and X (formerly Twitter) together under one corporate umbrella, all as SpaceX is reportedly planning to go public.

Kroiss and Nordeen both reported directly to Musk, according to BI, with Kroiss leading the company’s pretraining team, while Nordeen was Musk’s “right-hand operator.” Nordeen reportedly came to xAI from Tesla, and was involved in planning major layoffs at Twitter after Musk acquired the company in 2022.

TechCrunch has reached out to xAI for comment.