Anthropic, the AI lab behind Claude, has filed confidentially for an initial public offering, the company said in a blog post Monday.

The company, which is valued at close to $1 trillion, submitted a draft registration statement to the U.S. Securities and Exchange Commission for a proposed initial public offering. Anthropic has yet to list the number of shares or set the price. Anthropic said the proposed initial public offering will depend on market conditions and other factors.

The filing comes less than a week after Anthropic raised $65 billion in a Series H funding round that pushed its valuation to $965 billion. The round, which was co-led by Altimeter Capital, Dragoneer, Greenoaks, Sequoia Capital, Capital Group, Coatue, and D1 Capital Partners, attracted a bevy of institutional and strategic investors in anticipation of an IPO.

Anthropic’s confidential filing landed in an already white-hot IPO season that includes SpaceX’s initial public offering that is targeting a $2 trillion valuation. SpaceX is seeking to raise more than $75 billion.

A confidential IPO filing allows a company to begin preparing for a potential public offering without publicly disclosing detailed financial information, risks, or other internal business details. Anthropic will evaluate the IPO privately and without the critical eye of the public. If it follows through, Anthropic will file an S-1 registration document that will contain detailed information about the company’s financials, legal matters, risks, and a breakdown of who holds the most voting power.

Anthropic’s filing also comes as its rival OpenAI continues to raise funding, notably a $122 billion round in March at an $852 billion post-money valuation and prepares for its own IPO. OpenAI is expected to file for an initial public offering, setting the stage for an IPO season that will pit the two largest AI labs against each other and test the market’s resolve and interest in artificial intelligence.

Anthropic, now an AI powerhouse that has landed top-tier enterprise customers, was once considered an underdog in the emerging world of large language models. The startup was founded in 2021 by former OpenAI employees and was seen for years as a distant competitor to OpenAI and its AI chatbot, ChatGPT.

The company has drawn in investors and customers with growing capabilities and a focus on enterprise services. That has translated to eye-popping revenue growth. The company said recently that its revenue run-rate had surpassed $47 billion, up from $9 billion at the end of 2025.

That revenue growth rate could accelerate as Anthropic makes its Mythos model more widely available. Anthropic previewed Mythos in April but has kept access restricted — warning software developers that the model had discovered thousands of high-severity bugs that would need to be fixed before it could be made public.

The generative AI lab is poised to give the European Union’s cybersecurity agency access to Mythos, Bloomberg reported Monday morning, citing anonymous sources.