OpenAI filed confidential registration documents with the US Securities and Exchange Commission on June 8, 2026, taking the first formal step toward what could become one of the largest initial public offerings in history. The company, which makes ChatGPT and is the creator of the GPT series of large language models, is targeting a valuation of roughly $850 billion, though analysts covering the deal say the market capitalisation could exceed $1 trillion once trading begins.

Goldman Sachs and Morgan Stanley are managing the filing. The confidential approach allows OpenAI to work through the regulatory review process privately before making its full financial disclosure public. Companies with over $1 billion in revenue may use this route under SEC rules, revealing their prospectus publicly only a few weeks before the intended listing date.

OpenAI has not confirmed a specific timeline but indicated a public debut as early as September 2026 is possible, though the company cautioned it has not finalised a date. The filing comes shortly after rival SpaceX began trading on the Nasdaq earlier this month at a $1.77 trillion valuation, a figure that set a benchmark for how markets are pricing large, high-profile private technology companies making the leap to public markets.

OpenAI’s financials, which will become public when the company releases its formal prospectus, are expected to show rapid revenue growth alongside heavy investment in compute infrastructure. The company’s partnership with Microsoft was restructured in April 2026, ending an exclusive cloud arrangement in place since 2019 and giving OpenAI the freedom to serve customers across multiple cloud platforms, which may affect the financial picture investors see in the filing.

The IPO would transform OpenAI from a private non-profit-turned-for-profit into a publicly traded company. Sam Altman, the company’s chief executive, has previously discussed the need for external capital to fund the enormous compute costs associated with frontier AI model development. The company spent an estimated several billion dollars on training and infrastructure in 2025 alone.

Anthropic, OpenAI’s closest competitor in the large language model space, filed for its own IPO earlier this year at a $965 billion valuation. That filing set the stage for what investors are calling the AI IPO season, with two of the most closely watched technology companies in the world preparing for public listings within months of each other.

Institutional demand for the OpenAI offering is expected to be significant, driven by years of pent-up interest from investors who missed the company’s explosive private valuation growth. OpenAI was valued at $157 billion in a 2024 funding round, making the jump to an $850 billion or higher IPO valuation a roughly fivefold increase in under two years. More on the AI industry’s public market debut is available across our technology coverage. The SEC EDGAR database will carry OpenAI’s public filing once confidentiality is lifted.