Half of the original founding team at Elon Musk's artificial intelligence startup xAI has now departed after two co-founders resigned in rapid succession this week, raising fresh questions about talent retention ahead of an expected initial public offering.

The exodus comes at a delicate moment for xAI, which was valued at more than $200 billion when it was integrated with Musk's SpaceX rocket company last week.

The merged entity is expected to go public as early as this summer.

The company has also faced consumer backlash and regulatory scrutiny in multiple countries after its Grok chatbot and image generation tools enabled the mass creation of deepfake pornographic images, including of minors.

Tony Wu announced his resignation late Monday in a post on X, the social media platform owned by Musk, writing that it was "time for my next chapter."

Less than 24 hours later, fellow co-founder Jimmy Ba followed suit, calling Tuesday his last day and thanking Musk for "bringing us together on this incredible journey."

The back-to-back exits bring the total number of departed co-founders to six out of the 12-member team that launched xAI in 2023 with the ambitious goal of challenging ChatGPT-maker OpenAI, Google and Anthropic. Other key staffers have also left in recent months.

Ba, a prominent AI researcher, played a central role in the development of Grok chatbot models, including work on the forthcoming Grok 4.

"It's time to recalibrate my gradient on the big picture," he wrote.

Wu helped build the company's core reasoning capabilities.

Musk appeared to acknowledge the turnover during an all-hands meeting on Tuesday evening, according to The New York Times, telling staff that the company was reorganizing.

"When this happens, there's some people who are better suited for the early stages of a company and less suited for the later stages," he said, according to the newspaper.

In the same meeting, Musk outlined sweeping ambitions for the merged xAI-SpaceX entity, including plans for a lunar factory to manufacture AI satellites, a space catapult to launch them into orbit, and data centers in space to expand xAI's computing power.

The churn at xAI mirrors a wider pattern of staff turnover across the AI industry, where a fierce war for top talent has driven pay packages into the tens of millions of dollars and, reportedly in one case, past the billion-dollar mark.