OpenAI confidentially files for initial public offering on US stock market

OpenAI has filed confidentially to go public on the US stock market, according to a company blogpost published on Monday. The artificial intelligence giant’s debut on Wall Street is expected to be one of the most highly valued listings in market history with a valuation at more than $850bn.

“We recently submitted a confidential S-1. We expect it to leak so we’re just announcing it,” the company’s post reads. “We have not decided on timing yet; it may be a while because there are things we want to do that are likely easier as a private company. But it’s a complicated set of tradeoffs and this gives us the option to go public sooner if that ends up being best.”

An S-1 is an investor prospectus submitted to the US Securities and Exchange Commission (SEC) in advance of an initial public offering (IPO). The confidential filing will give regulators a period to review and discuss the company’s financial disclosures before investors and the public are able to view them.

OpenAI’s chief rival Anthropic, which makes the popular Claude chatbot, announced last week that it was also filing to go public on the US stock market.

OpenAI’s approaching IPO will mark the culmination of a meteoric rise since its founding as a non-profit research lab in 2015, led by Sam Altman, its CEO. After working on generative artificial intelligence in beta for several years, the company publicly released ChatGPT in 2022 and converted to a for-profit structure.

The chatbot immediately took off, rapidly accruing hundreds of millions of users, and dramatically changed the way the world works – from entertainment to healthcare to education and jobs. Dozens of other tech companies followed suit, releasing their own rival chatbots.

OpenAI has searched for a major hit with in the wake of ChatGPT’s release, with recent reports pointing to ambitions to expand the scope of the chatbot into an app with a diverse range of functions beyond text, image and code generation. The company has failed to find another success on the same level, though.

OpenAI tried to expand into devices, acquiring iPhone designer Jony Ive’s startup for billions in stock in early 2025. It also launched a video generation app, Sora, in late 2024, inked a major with Disney, but the app in April 2026.