The OpenAI CEO says he didn’t take equity in the white-hot startup because he doesn’t need the money.

But Altman’s voracious investing habit over the past decade has put him at the center of a web of startups, some of which stand to benefit from the AI boom.

But Altman, 38, has a head-spinning number of investments in plenty of other companies he believes will make him a lot more money in the future. Over the past decade, he has become one of Silicon Valley’s most prodigious angel investors, making around 400 investments in companies such as Reddit, Stripe and Asana, along with AI startups like Cerebras and Humane.

He has made many of his investments through Hydrazine Capital, a San Francisco–based venture firm he founded that invests capital from him as well as others like Peter Thiel, and through Apollo Projects, an investment fund he launched with his brothers, Jack and Max Altman.

Altman is also a limited partner in Altman Capital—a venture firm founded by his brothers, which has backed startups such as Verifiable, Owner and Finch.

And through Y Combinator, the famed incubator he led for five years, he has stakes in Instacart and hundreds of other startups. Last November, he announced a $375 million personal investment in nuclear fusion startup Helion, a staggering sum that was his largest personal check to date. And if that wasn’t enough, Altman also has his fingers in two special purpose acquisition vehicles— AltC Acquisition and Bridgetown Holdings—that have sought to buy other companies.

In an interview with The Information, Altman said he’s mindful of conflicts of interest arising from his investments. As a result, he said, he has tried to avoid backing new AI startups over the past two years. And as running OpenAI has consumed more of his time since the launch of ChatGPT, he has cut back on the pace of other investments as well.
“I don’t do much anymore,” Altman said of investing. “I used to be super proactive—I would try to show up in offices and like to do stuff for people, and that’s what I’m not doing [now].” He later added over text message that he will continue to do smaller investments of around $100,000 once in a while but has not made a major investment since November. Altman didn’t respond to a request for comment about what the total value of his portfolio is.