Anthropic files for its IPO: what the S-1 says about Claude

What happened

Anthropic, PBC filed a Form S-1 with the US Securities and Exchange Commission on October 26, 2026. An S-1 is the public document a company files before it sells shares on a stock exchange for the first time. Anthropic has applied to list its Class A shares on the Nasdaq Global Select Market under the symbol ANT.

The price range, the number of shares and the listing date are left blank in this version. They get filled in a later amendment, close to the sale. Nothing changes for Claude subscribers or API customers because of the filing itself.

This page reports what the filing says. It is not investment advice.

The numbers in the filing

The company is not profitable on paper. It reports a net loss of $80.7 billion for the first half of 2026, but $72.4 billion of that is an accounting charge: its convertible notes are worth more because Anthropic's valuation went up. The operating loss for the half was $693 million, down from $2.1 billion a year earlier. The filing says plainly that growth at these rates should not be expected to continue.

Other figures, as of September 30, 2026:

• More than 11,900 customers paying $100,000 or more over the past twelve months, more than 1,900 paying $1 million or more, and about 250 paying $10 million or more. No single customer is above 10% of revenue.
• Net revenue retention of about 900%: existing business customers spend roughly nine times what they spent a year before. Claude Pro and Max subscribers are left out of that figure.
• Claude Opus 5.5 cut customers' cost per task by about 40% compared with Claude Opus 5, according to the filing.

What it says about the products you use

• Claude Code is described as the product that “most concretely defined what autonomous AI work looks like”. It went into research preview in February 2025.
• Claude Cowork, in research preview since January 2026, was adopted faster by September 30 than Claude Code was at the same point after its launch.
• Cowork and Claude.ai are merging. The filing says that since September 2026 Anthropic has been folding Cowork into the Claude app, so a chat can turn into a multi-step task in the same conversation.

Who will control the company

Buyers of the listed shares will have little say. Just before the IPO a single Class F share goes to a company owned by the seven co-founders, and it carries 50.1% of the votes on ordinary shareholder matters. Separately, the Long-Term Benefit Trust, five trustees with no financial stake, elects the majority of the board through Class T shares. Anthropic stays a public benefit corporation, and it has put 5% of its fully diluted shares into its own Anthropic Public Benefit Fund.

What it means for you

1. Using Claude or Claude Code: nothing changes today. Plans, prices and limits are not touched by the filing.
2. Using Cowork: expect it to keep moving into the main Claude app rather than stay a separate product. Our Claude review tracks what each plan includes.
3. Want the shares? There is no price and no date yet. Those come in an amendment to the S-1, which you can follow on the SEC's EDGAR page for Anthropic.

The filing's own story is that Claude is moving from answering prompts to doing long tasks on its own. The two prompts below are for that kind of work.

Try it

I'm going to paste sections of a long document (an annual report, S-1, contract or policy). Work through it in this order:
1) In five bullet points, what does this section actually commit to or disclose? Quote the sentence each point comes from.
2) List every number with its unit and the date or period it refers to. Keep figures exactly as written.
3) Flag anything that is a forecast, an estimate or a "we believe" rather than a reported fact.
4) Name what a careful reader would want to know that this section does not say.
Do not add information that is not in the text.

Section:
[paste here]

You're going to work on the task below for a while without me. Before you start, write:
- the finished result in one sentence,
- the steps you plan to take, each one ending in something I can look at,
- the decisions you will NOT make on your own (stop and ask me instead).
Then work through the steps. After each one, add a two-line status: what's done, what's next. If something blocks you, stop and say exactly what you need.

Task: [describe the task and where the files or data are]

Sources

• Anthropic, PBC, Form S-1 registration statement, filed October 26, 2026
• SEC EDGAR, Anthropic, PBC filings, checked October 27, 2026