Anthropic’s public IPO filing puts its losses on the record for the first time

Anthropic has filed for an initial public offering with the Securities and Exchange Commission, Bloomberg reported. For the first time, outsiders can read the company’s financials, including what it may be losing, and not only what it earns.

A public S-1 follows the June confidential draft

The filing itself is a preliminary Form S-1 for Anthropic, PBC, posted on the SEC’s EDGAR system and dated October 26. Its cover registers Class A common stock, with the number of shares left blank and a notice that the document is not complete and may change. As is usual for a preliminary filing, no offering price is set.

It is the second step. Anthropic said earlier this year that it had confidentially submitted a draft registration statement to the SEC on June 1, a move the company described as giving it the option to go public once the SEC finishes its review. Making the S-1 public is what exposes the numbers to everyone, not just regulators.

Bloomberg’s public summary does not give figures, and its video page offers little beyond the headline. We could not open the full text of the filing in time for this report, so the details below come from secondary coverage and should be read as reported, not confirmed.

The reported numbers are large, and mostly accounting

Bloomberg has previously reported a 2025 net loss of almost $42 billion for Anthropic, a figure the S-1 still had to confirm. The Ringer, citing a leaked draft, said that roughly $34 billion of it came from an accounting adjustment on convertible financing rather than cash spent. Reports on the new filing are similar in kind: AI Weekly, summarizing what it attributes to a Wall Street Journal report, puts first-half 2026 revenue at $16.3 billion against a net loss of $80.7 billion, again mostly non-cash charges tied to the rising value of convertible instruments. The same summary says about a quarter of revenue comes from two customers without long-term contracts. We have not verified these figures against the filing.

The distinction matters for readers. A loss driven by revaluing financing instruments says something different from a loss driven by cash burn, and the S-1’s own cash flow and operating loss lines are where that split can be checked. Earlier reporting put the 2025 operating loss above $8 billion.

What the filing does not settle yet

Several basics are still unconfirmed in what we could read: the exchange, the ticker, the underwriters, how many shares will be sold and at what price. A valuation near $965 billion was reported after a $65 billion round, and one summary cites a target near $2 trillion; neither comes from a source we could confirm, and the second sits uneasily with the first.

Analysts have also flagged that Anthropic books sales made through cloud partners on a gross basis, which lifts headline revenue compared with companies that report net. How that policy is explained in the prospectus will decide how comparable its revenue is to rivals’.

Context: AI’s capital appetite meets public markets

The filing lands in a week when AI financing is already under scrutiny. Meta has sought up to $95 billion in stock sales, and we explained how AI chips and customer contracts became loan collateral. A listed Anthropic would add a frontier lab whose spending commitments, customer concentration and accounting choices investors can read line by line.

For now, the reliable facts are limited: the S-1 exists, it is public, and the SEC review continues. The terms and the audited detail are what to watch for in the amended filings that normally follow.