Anthropic's IPO filing: a $974 million profit, a $66 billion loss, and a lot of blanks

Item 1. What happened

On Monday morning, October 26, 2026, Anthropic announced that it had filed a registration statement on Form S-1 with the U.S. Securities and Exchange Commission (SEC) for a proposed initial public offering, or IPO: its first sale of shares to the public. The full filing is public on the SEC's EDGAR system.

Anthropic says it intends to list its Class A shares on the Nasdaq Global Select Market under the ticker ANT. It has not set how many shares it will sell or at what price. Until the SEC declares the registration statement effective, the shares can't be sold and offers to buy can't be accepted.

The announcement post on X passed 3.4 million views within hours, and feeds filled with screenshots of the numbers. Most of them are right. What got lost is how they fit together.

Item 2. How a profit and a loss fit in one quarter

An income statement is a ladder. It starts with revenue, the money customers paid, and subtracts the costs of running the business: for Anthropic mostly compute (the chips and data centers that train and run Claude), then staff, sales and everything else. What's left is operating income: whether the business itself makes money.

Below that line come items that aren't about running the business: interest earned on cash, and changes in the value of financial contracts. What's left at the very bottom is net income, or a net loss.

For Anthropic, the big cost has been falling fast relative to sales. In January to March 2025, compute and infrastructure cost 251% of revenue, two and a half times what customers paid. By April to June 2026 it was 48%. That is what turned the operating line positive. It didn't last a second quarter: in July to September compute rose back to 58% of revenue, and the operating line was a $567 million loss. The filing blames two things: $5.0 billion of compute bought on short-term commitments, which costs much more than its multi-year contracts, and $2.0 billion of non-cash charges from its donation matching program.

Where the $66 billion comes from

Before going public, Anthropic raised much of its money through convertible notes: an investor hands over cash now, and the note turns into shares later. Anthropic chose to carry these notes on its books at their current fair value, what they're worth today. The filing says the losses on this line were "primarily driven by an increase in the fair value of our outstanding convertible promissory notes resulting from an increase in our enterprise valuation."

Put simply: the notes will become shares, the shares are worth more each time Anthropic's value goes up, and that increase counts as a cost on the income statement. From January to June 2026 that line was $72.4 billion of the $80.7 billion net loss. No cash goes out for it. Over the same six months, the business brought in $3.9 billion in cash from its operations.

Item 3. The blanks, counted

Within hours, posts were saying Anthropic had "ducked" the third quarter, July to September 2026, and that the omission meant demand had fallen. The filing itself shows something more ordinary. The sentence about revenue growth reads:

"...revenue growing from $0 at commercial launch in the first quarter of 2023 to $  for the three months ended September 30, 2026."

The number is a blank, waiting to be filled in. A short script run over the filing, downloaded from the SEC, counts about 110 blank dollar amounts, including the third quarter revenue (in three places), the total committed compute spending, and the per-share offering price used throughout. Draft S-1s often leave blanks like these and fill them in amended versions before the sale.

There's also a rule that forces the issue. The SEC's Regulation S-X, Rule 3-12 says a filing's financial statements must be updated if they are 135 days or more old when it's expected to become effective, for companies like Anthropic that aren't yet regular public filers. The S-1's statements run through June 30, 2026. That date plus 135 days is November 12, 2026, so if the offering becomes effective after that, the third quarter has to be in it.

The filing doesn't hide everything about the quarter, either: several metrics, like headcount (about 5,300 people) and net revenue retention, are given as of September 30, 2026.

November 2: the blanks start to fill. The amended filing came ten days before that deadline. The sentence above now ends "to $17.0 billion for the three months ended September 30, 2026." The same script, run over the new version, counts 86 blank dollar amounts, down from about 110. Most of what remains depends on the price: the range still reads "between $ and $", and the share counts are empty. So is one number many readers were looking for: "our Run-Rate Revenue was $ as of October 31, 2026."

Item 4. Reactions

• Aaron Levie, CEO of Box @levie, Oct 26

  Called the key stat the one showing the average Fortune 500 customer spends "less than .1% of their expenses on Anthropic," and argued it could grow 10 to 50 times.

  The S-1 says the same: under 0.1% of those customers' total expenses for July to September 2026, and under 1% for its top 10 Fortune 500 customers.

• Sarah Guo, founder of the venture firm Conviction @saranormous, Oct 26

  Pointed to the "inflection in operating profit" and a "mismatch b/w consumption based revenue and long term compute obligations."

  Much of Anthropic's revenue is pay as you go, while the filing says substantially all of its committed spending beyond 2030 falls between 2031 and 2045.

• Gary Marcus, AI researcher and critic @GaryMarcus, Oct 26

  Shared a quote from the account zerohedge saying Anthropic "ducked Q3" and that the omission means demand dropped.

  The filing leaves the quarter's revenue as a blank. It didn't show demand falling, or rising: the number wasn't there yet. The November 2 amendment puts it at $17.0 billion, up from $11.6 billion the quarter before.

• Aswath Damodaran, NYU Stern finance professor known for valuing companies @AswathDamodaran, Oct 28

  Valued Anthropic's shares at about $1.475 trillion in a blog post, below the $1.5 to $2 trillion pricing he says is rumored, so he plans to sit out the IPO if it prices well above his number.

  That's one analyst's estimate. The filing sets no price or share count yet.

Item 5. Timeline

1. Early 2023 Claude's commercial launch, with revenue starting from $0 in the first quarter.
2. 2023 to 2025 Annual revenue: $41 million, then $386 million, then $4.6 billion.
3. Jan to Mar 2025 Compute and infrastructure cost 251% of revenue.
4. Apr to Jun 2026 Revenue of $11.6 billion and the first operating profit, $974 million. Compute is down to 48% of revenue.
5. Jun 30, 2026 The S-1's financial statements end. Cash and equivalents: $112.4 billion, plus $19.3 billion in short-term investments.
6. Oct 26, 2026 Anthropic makes the S-1 public.
7. Nov 12, 2026 135 days after June 30. Effective after this date means third quarter results must be included.
8. Nov 2, 2026 Anthropic files an amended S-1 with third quarter results: revenue of $17.0 billion, an operating loss of $567 million, a net loss of $23.3 billion. Still no price range.

Item 6. What it means

Read the operating line for the business and the bottom line for the accounting. When a company has a large "change in fair value" item, check how much of the net loss it explains and look at cash flow, which shows what actually came in and went out.

An S-1 made public is a draft for an offering, not the offering itself. The first amended version arrived on November 2. Expect a price range next, then the SEC declaring it effective, and only then a sale.

The third quarter gives a new thing to watch. Revenue grew 47%, yet compute grew faster, 77%, because demand outran the capacity Anthropic had contracted for and it bought more at higher short-term prices. The filing says it expects short-term compute use to keep rising in the near term and to compress its margins. Against that sits $895.4 billion in purchase and lease commitments, about $447.5 billion of it expected by the end of 2030.

This page explains a public document. It isn't investment advice.

Item 7. Questions people are asking

Item 8. Updates

• Nov 2, 2026 Anthropic filed an amended S-1 with third quarter results. Revenue was $17.0 billion, up 47% from the quarter before and 1,127% from a year earlier. The operating line went back to a $567 million loss from a $974 million profit, and the net loss was $23.3 billion, most of it again the change in value of the convertible notes ($21.9 billion). Adjusted operating income, Anthropic's own measure, rose to $2.5 billion while its margin fell from 19% to 15%. Commitments total about $895.4 billion. More than 1,900 customers now pay $1 million or more a year. There is still no price range, and the October run-rate is a blank. CNBC has coverage. The short version, Item 2, the blanks, the income statement, the timeline and the FAQ now reflect this.
• Oct 29, 2026 Aswath Damodaran, the NYU Stern professor known for valuing companies, published his valuation on October 28: about $1.475 trillion for Anthropic's equity. He says the rumored pricing is $1.5 to $2 trillion, so he would sit out an IPO priced well above his number, though he won't bet against it. He is also critical of the control structure: several share classes with different votes, a trust that elects board members, and a public benefit company, which together leave public shareholders little say and, in his view, deserve a bigger discount. There is still no amended S-1, price range or share count on EDGAR. He is now in Reactions.
• Oct 26, 2026 This page went up. It covers everything known as of October 26, 2026.