Altman owns 12.2 million shares of Reddit. With the company’s share price now sitting at $114 a share, that makes Altman’s stake in Reddit worth about $1.4 billion. Reddit shares soared 40% on Wednesday on the back of an earnings report that projected a rosy future. It reported 100 million daily users and had turned a profit for the first time. 

All that made for a lucrative run-up for Altman and Reddit’s other shareholders, which include a hodgepodge of various investors: Chinese tech company Tencent; Advance Publications, the owner of Condé Nast; and Vy Capital, a highly secretive Dubai-based investment firm that funded part of Elon Musk’s acquisition of Twitter. 

Reddit is hardly Altman’s only savvy investment. Before becoming one of the business and tech world’s most famous executives for his leadership at OpenAI, Altman was a prominent investor in Silicon Valley. His perch atop the famed startup accelerator Y Combinator gave him ready access to a stream of young and talented executives, eager for his guidance and money. Some of Altman’s most successful bets include investments in startups turned behemoths like Airbnb, Uber, and Stripe.

Altman crossed paths with Reddit in the company’s earliest days. In 2005, Reddit cofounders Alexis Ohanian, Steve Huffman, and Aaron Swartz were in the inaugural class (or “batch” as it’s referred to) of Y Combinator, when it was still run by cofounder Paul Graham. At the time, Altman was working on his first startup, called Loopt. In 2014, Altman would become the president of Y Combinator, giving him a first look at what would become prominent startups in their infancy. 

Also in 2014, Altman led Reddit’s $50 million Series B funding. In a blog post announcing the investment, Altman harkened back to the time he’d spent with Reddit’s cofounders when they were at Y Combinator. 

“I was probably in the first dozen people to use the site, and I shudder to imagine the number of hours I have spent there,” Altman wrote. 

From there, Altman kept investing in Reddit. In 2021, he put in $50 million during Reddit’s Series E raise. Later that year, Altman added $10 million into Reddit’s coffers, as the company kept raising money. His investments earned him a major stake in Reddit, including voting shares.

When Reddit went public in March, Altman ended up having even more shares than Huffman, the company’s CEO, according to Reddit’s IPO prospectus. 

Altman was also on the board of Reddit through 2021. In January 2022, Reddit announced he would step down from the board after serving for seven years.