OpenAI

OpenAI is a San Francisco artificial intelligence company that develops the GPT series of large language models, the ChatGPT assistant, GPT Image models and the Codex coding agent. It was founded in December 2015 as a nonprofit by Sam Altman, Elon Musk, Ilya Sutskever, Greg Brockman, Trevor Blackwell, Andrej Karpathy, John Schulman, Wojciech Zaremba and others, with $1 billion pledged by backers including Reid Hoffman, Jessica Livingston and Peter Thiel. ChatGPT launched in November 2022 and, as of September 2026, ranked as the fifth most visited website in the world.

In 2019 OpenAI created a capped-profit entity, with returns limited to 100 times investment, so it could take venture and strategic capital. Microsoft invested $1 billion in 2019, a further $2 billion through 2022, and announced a $10 billion multiyear investment in January 2023 at a $29 billion valuation. In October 2024 OpenAI raised $6.6 billion at a $157 billion valuation in a round led by Thrive Capital with Microsoft, Nvidia and SoftBank. In March 2025 it raised $40 billion at a $300 billion post-money valuation, led by SoftBank with Microsoft, Coatue, Altimeter Capital and Thrive Capital. An October 2025 employee share sale of up to $10 billion valued it at $500 billion. In February 2026 it raised $110 billion at a $730 billion valuation led by Amazon ($50 billion), SoftBank ($30 billion) and Nvidia ($30 billion), and in April 2026 it closed the round at $122 billion of committed capital at an $852 billion post-money valuation.

In October 2025 OpenAI converted its operating company into a public benefit corporation. Reported ownership lists Microsoft at about 23 to 27 percent, the nonprofit OpenAI Foundation at about 22 to 26 percent, SoftBank, Amazon and Nvidia as large holders, and employees and other investors with the remainder. Revenue was reported at $3.7 billion for 2024 and an annualized $13.1 billion in 2025, with an $8 billion operating loss projected for 2025. In August 2026 the company said its advertising business had reached a $1 billion annualized run rate. It has also made acquisitions, including Statsig for $1.1 billion in stock in 2025.

For investors, OpenAI is the largest private fundraising sequence on record and an unusual structure for venture backers: early capital entered under capped returns, and the largest checks came from strategic corporates (Microsoft, SoftBank, Nvidia, Amazon) rather than traditional funds. Thrive Capital, which led the 2024 round at $157 billion, saw the mark rise more than fivefold to $852 billion within about eighteen months, though liquidity has so far come through secondary and employee tenders rather than a public listing.