US artificial intelligence (AI) company Anthropic publicly filed its prospectus for an initial public offering (IPO) on Monday, which could become the largest stock market debut in history.

The filing, a registration statement on Form S-1 with the US Securities and Exchange Commission, did not set the number of shares to be sold or a price range. Anthropic intends to list its Class A common stock on the Nasdaq Global Select Market under the ticker symbol ANT, according to a release on the company's website.

Both the company and existing shareholders will sell shares, with Goldman Sachs and Morgan Stanley named first among 24 underwriters. The company is expected to begin trading in mid-November, and backers hope for a valuation of up to $2 trillion, though some investors have weighed a figure closer to $1.5 trillion, according to Reuters.

The prospectus offers the first detailed look at the finances of the developer of the Claude AI models. Revenues reached $16.29 billion in the first half of 2026, up from $1.16 billion year on year, after growing from $41 million in 2023 to $386 million in 2024 and $4.59 billion in 2025. Revenues in the second quarter alone were $11.56 billion, and the company reported its first quarterly operating profit of $974 million.

The headline losses are far larger, but most stem from accounting charges rather than cash spending. Anthropic recorded a net loss of $80.7 billion in the first half of 2026, of which $72.4 billion came from changes in the fair value of convertible notes and other instruments as the company's own valuation climbed. Its operating loss for the period was $693 million, while operating cash flow turned positive at $3.93 billion. Cash and short-term investments totaled $131.7 billion at June 30.

The filing warns that this rapid pace may not last. "We cannot assure you [revenue] will continue to grow at all," the company said in the prospectus, which also notes it is on track for a second consecutive quarter of adjusted operating profit.

Spending on computing power remains the central cost. Anthropic spent nearly $9 billion on computing resources and infrastructure in the first half of 2026, and has committed to $518 billion in future infrastructure spending. It has agreed to spend at least $110 billion with Amazon through April 2036 and at least $114.5 billion with Google through July 2033. Amazon holds $6.2 billion of notes that convert into non-voting stock, capped at 12% of the company.

By September 30, more than 1,900 customers generated at least $1 million each in trailing annual revenue, and more than 11,900 generated at least $100,000, up from 950 a year earlier. Existing customers spend roughly nine times what they did a year ago, but two unnamed customers accounted for about 23% of revenues in the first half of 2026.

Public investors will be able to buy the shares but will not steer the company. A single Class F share held by the seven co-founders carries 50.1% of every stockholder vote, and a trust will elect a majority of the board. A Public Benefit Fund will hold 5% of the company in non-voting shares, and each co-founder has pledged to give 80% of their personal Anthropic equity to philanthropic causes.

The prospectus devotes sections to risk factors, including warnings that advanced AI could pose "catastrophic or existential risks to humanity" and that liability from extreme harm could exceed what any insurer can cover.

Anthropic raised $65 billion in May at a $965-billion valuation. A debut above $2 trillion would surpass SpaceX's $1.77-trillion listing in June, the current record. Reuters has reported Anthropic's third-quarter revenue of $16.8 billion and forward projections pointing to revenue of about $190 billion to $200 billion in 2028.