Altman was born in Chicago in 1985 and grew up in Clayton, Missouri, where he got his first computer, an Apple Macintosh, at eight. He studied computer science at Stanford University for two years and dropped out in 2005, at 19, to co-found Loopt, a location-based social networking app. As chief executive he raised more than $30 million in venture capital, but the app never gained much traction, and Green Dot Corporation bought the company for $43.4 million in March 2012.
Altman became a part-time partner at the startup accelerator Y Combinator in 2011 and its president in February 2014, replacing co-founder Paul Graham. He aimed to expand YC to fund 1,000 new companies a year and to back more "hard technology" startups. In April 2012 he co-founded Hydrazine Capital, a venture fund seeded partly with his Loopt proceeds, and by June 2024 his portfolio held stakes in more than 400 companies, including Stripe, Reddit and the fusion company Helion Energy. For eight days in 2014 he was Reddit's chief executive.
Altman co-founded OpenAI as a nonprofit in 2015 with Greg Brockman, Elon Musk and others, and left YC to become its CEO in 2019. He oversaw the launch of ChatGPT in November 2022, which made him one of the best-known figures of the AI boom. In 2023 OpenAI's board removed him for not being "consistently candid"; after a backlash from employees and investors he was reinstated five days later and a new board was formed. According to Forbes, he holds no equity in OpenAI.
Outside OpenAI, Altman co-founded AltC Acquisition Corp, a special-purpose acquisition company that merged with the nuclear fission company Oklo in May 2024, and chaired Oklo until April 2025, when he stepped down to avoid conflicts of interest with OpenAI. In 2026 he also left Helion's board as OpenAI and Helion explore working together. In September he said "right now would be an ill-advised moment to go public" and that OpenAI "will definitely do a humanoid". In October his post calling Cerebras "a close partner" lifted the chipmaker's stock, though the gain lasted only a few days.
Sources · written 16 October 2026
