The surge in Reddit's stock price resulted in Altman's stake now being valued at over $613 million.

Altman, who co-founded OpenAI in 2015, revealed that he does not possess equity in the artificial intelligence startup valued at $80 billion. However, his ownership in Reddit is a different story altogether. Altman's 7.6% control of outstanding shares in the social media site makes him one of the largest shareholders, trailing only Condé Nast parent Advance Magazine Publishers and Chinese internet giant Tencent, according to the company's prospectus.

Following Thursday's trading activity, Reddit's shares climbed by an impressive 48%, closing at $50.44 on the NYSE. Altman's substantial increase in wealth is attributed to this surge, marking his stake's rise by $200 million.

However, Altman and other insiders face restrictions during the "lockup period," preventing them from selling their Reddit shares for a period of six months.

Altman, known for his past role as the president of Y Combinator and his extensive portfolio of investments in companies like Airbnb, Uber, and Stripe, has made Reddit one of his top bets. He was even a member of the company's board until early 2022 when he stepped down. Altman further solidified his position as a major Reddit investor by leading the company's $50 million Series B funding round in 2014.

Despite the recent boost in Altman's Reddit stake, it is worth noting that the company's valuation, even after Thursday's rally, remains below its peak in the private market. Altman invested $50 million at $42.47 per share and an additional $10 million at $61.79 per share. However, the returns on his initial investment have multiplied significantly over the years.

Altman's heightened financial position in Reddit serves as a relief from the controversy surrounding his leadership tenure at OpenAI. In late 2021, Altman was briefly dismissed by the OpenAI board due to a loss of confidence, but was reinstated shortly after due to pressure from employees and investors. OpenAI announced earlier this month that Altman would rejoin its board following an internal investigation by the law firm WilmerHale.

Altman has emphasized that his motivation for his current role does not lie solely in financial gain. In a testimony to U.S. senators, Altman stated, "I'm not in this current gig for the money… I'm doing this because I love it."

As Altman navigates his roles at both OpenAI and Reddit, his stake in the social media company has catapulted his wealth to new heights, setting the stage for his continued contributions to the technology and investment sectors.