Greg Brockman, president of OpenAI, arrives in federal court during a hearing in Elon Musk’s lawsuit over OpenAI’s profiteering, in Oakland, California, May 6, 2026.
Manuel Orbegozo Reuters
There is a second new command from OpenAI.
Greg Brockman, the company’s president, is officially responsible for OpenAI’s most important and profitable projects after Fidji Simo stepped down from his position on Thursday due to chronic illness.
Simo, the former Meta chief executive and former CEO of Instacartserved as OpenAI’s head of product and business for a year, focusing on the company’s roadmap and helping it grow. Simo, who was diagnosed with postural orthostatic tachycardia syndrome, or POTS, in 2019, took a medical leave of absence in April and said Thursday that he will transition to an interim consultant position.
Brockman, who is the founder of OpenAI, has assumed responsibility for the product in Simo’s absence, and will continue to lead those efforts, according to a source familiar with the company’s plans who asked not to be identified for confidentiality reasons. Brockman will oversee OpenAI’s ChatGPT product business, as well as its go-to-market, business and accounting teams, the person said.
“I’m very grateful for everything Fidji has done for OpenAI and advancing our work, and for the opportunity to work with him over the past few years,” Brockman wrote in a post to X on Friday.
Reporting directly to CEO Sam Altman, Brockman is under pressure to bring in cash and justify OpenAI’s $852 billion valuation, especially as the company prepares for what is expected to be a historic IPO. OpenAI privately filed its prospectus with regulators in June, but the company has not disclosed when it plans to issue it and is reportedly delaying it until next year.
OpenAI also faces stiff competition from competitors, including Anthropic, Google and Elon Musk SpaceXand a host of cheap open weight models from China.
ChatGPT’s market share fell below 50% for the first time in March, according to a report from Sensor Tower, and OpenAI has been touting its AI coding assistant, Codex, in an effort to gain more users.
Sarah Friar, OpenAI’s chief financial officer, and Jason Kwon, the company’s chief strategy officer, will report to Altman. The company does not plan to hire anyone to replace Simo, said a familiar person.
Brockman co-founded OpenAI with Altman and a group of others, including Musk, in 2015. He and Altman were close associates, and when Altman was briefly ousted from his position as CEO in 2023, Brockman left the company in partnership. Both men rejoined OpenAI days later.
“Greg and I are partners in running this company,” Altman wrote in a blog post at the time. “We haven’t thought about how we can affect that in the organization chart, but we will.”
The two were also at the center of a high-profile legal dispute earlier this year. Musk sued Brockman, Altman and OpenAI, saying they went back on commitments they made to keep the AI lab non-profit.
In federal court in Oakland, California, in May, Brockman testified about the program’s early years and pushed back against Musk’s account of events. He was excited about his financial ambitions, his understanding of OpenAI’s architecture and Musk’s involvement in the company.
Musk ultimately lost the case after a jury said he waited too long to sue him, a decision that was quickly upheld by a federal judge.
“I think the technology we’re developing is changing,” Brockman said on the witness stand. “This will be the most important technological change in human history.”
WATCH: OpenAI CEO Fidji Simo is stepping down
