Brad Lightcap, one of the most recognizable faces of OpenAI’s senior leadership team, is leaving the company to “start something new,” he announced on Tuesday, representing the latest in a string of executive departures at the ChatGPT maker.

Lightcap did not say what the new venture is, but said he’s “not going far,” and described it as involving “a few important new things the world will need to get right” as artificial intelligence becomes more powerful and capable.

The departure comes as OpenAI is planning for an initial public offering that could value the San Francisco company at more than $1 trillion. It also comes as agentic AI models such as those made by OpenAI and Anthropic have come under increased scrutiny, following recent revelations that models from the two companies had managed to bypass safeguards and hacked into other systems.

Lightcap joined OpenAI in 2018, when few people could have predicted that the company would become a household name after the release of ChatGPT in late 2022. He went on to create the “first versions” of several operations and business teams, he said, including finance, legal, HR, corporate security, go-to-market, and partnerships.

“If you had told me then that we’d be where we are today, I wouldn’t have believed you,” Lightcap said in his announcement on X on Tuesday, which he also shared with the OpenAI team earlier today. “We grew from a small research lab to one of the most consequential companies of our time.”