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 partnership with Disney, but shuttered the app in April 2026.

Major year on the market

OpenAI announced its IPO in what is shaping up to be a banner year for public offerings of AI companies. In addition to Anthropic, another rival, Elon Musk’s SpaceX, which owns his artificial intelligence company xAI, is also imminently slated to go public at an expected valuation of $1.75tn.

OpenAI closed a funding round of $122bn in March, pegging its value at around $852bn, according to the Wall Street Journal. The company achieved the mammoth valuation even after showing difficulty turning a profit and missing key revenue and new user targets.

The IPO filing comes on the heels of OpenAI’s win in a lawsuit brought by Musk over claims that the company illegally converted from a non-profit to for-profit company, unjustly enriching itself and its founders. Musk’s suit sought to have OpenAI revert back to a non-profit, which could have kneecapped its ambitions to go public. A panel of nine jurors ruled, however, that the case fell outside the statute of limitations and that OpenAI was not liable. Altman’s leadership and trustworthiness was also scrutinized during the trial with Musk, which exposed new details about OpenAI’s fractious corporate past.

The startup may face other legal roadblocks as it moves forward with its Wall Street debut. It’s been sued in more than a dozen cases where individuals allege ChatGPT has exacerbated mental health crises acting as a “suicide coach” and provoking violent acts such as mass shootings in Canada and Florida.

Despite the public and investor scrutiny, OpenAI has continued to land massive partnerships with companies including Microsoft, Google and Nvidia, as well as with the Trump administration.