Sam Altman is an American entrepreneur, investor, and executive best known for scaling startup accelerator Y Combinator and co-founding OpenAI.12 Under his leadership YC backed breakout companies such as Airbnb, Stripe, and Coinbase, expanding its combined portfolio valuation to over $400 billion.3 At OpenAI he has raised multibillion-dollar rounds, launched products like ChatGPT, and become a leading public voice on the safe development of artificial general intelligence.45
From Loopt Founder to YC Leader
Altman dropped out of Stanford in 2005 to create mobile-location startup Loopt, which he sold to Green Dot for $43 million in 2012.6 He then joined Y Combinator as a part-time partner, becoming its president in 2014 and chairman in 2016, where he introduced YC Fellowship and YC Research to broaden the accelerator's reach.27
Steering OpenAI Toward Beneficial AGI
In 2015 Altman co-founded OpenAI alongside Elon Musk, Ilya Sutskever, and others with the mission to ensure AGI benefits all of humanity.8 As CEO he brokered a strategic partnership with Microsoft worth more than $10 billion, oversaw the release of GPT-3, GPT-4, and ChatGPT, and has championed safety research to align increasingly capable models with human values.49
Investing and Advising on AI Policy
Beyond OpenAI, Altman personally invests in frontier-tech ventures such as nuclear-fusion startup Helion and crypto exchange Coinbase, and serves on the boards of several high-growth companies.3 He frequently testifies before U.S. and international lawmakers, urging coordinated regulation of advanced AI systems to mitigate societal risks while preserving innovation.10