Anthropic, PBC filed a Form S-1 with the SEC on 26 October 2026. Two numbers in it will be quoted all week, and they point in opposite directions.

Net loss for the 6 months ended 30 June 2026: 80,748 million dollars. Operating loss for the same period: 693 million.

Both are in the same table.

The loss is the valuation, booked as an expense

Between the operating line and the net loss sits an entry called change in fair value of convertible notes, derivative liabilities and SAFEs. For the first half of 2026 it is 72,388 million dollars. For the whole of 2025 it was 34,308 million.

The filing explains the cause in its own footnote: the changes were "primarily driven by an increase in the fair value of our outstanding convertible promissory notes resulting from an increase in our enterprise valuation during each of the respective periods".

Read that again. The company became more valuable, the notes convertible into its stock became more valuable, and the accounting records that as a loss. No cash left the building. A reader who sees 80 billion and pictures 80 billion dollars being spent has the picture upside down.

What the operating line actually did

Revenue tells its own story: 41 million in 2023, 386 million in 2024, 4,585 million in 2025, and 16,286 million in the first half of 2026 alone. The same half of 2025 was 1,163 million, so the comparable period grew about 14 times.

Operating expenses for the half came to 16,979 million. Compute and infrastructure was 8,945 million, personnel 3,152 million, and other operating and administrative 1,714 million.

The line that moved most is sales, marketing and partnerships: 120 million in the first half of 2025, 3,168 million in the first half of 2026. More than 26 times, in a year, from a company whose reputation was built on research rather than go-to-market.

Set revenue against expenses and the operating loss is 693 million on 16,286 million of revenue. An operating margin of about minus 4 percent. The equivalent figure for full-year 2025 was minus 176 percent.

The adjusted numbers, and what they leave out

Anthropic also reports non-GAAP measures, and on those it is profitable: adjusted operating income of 1,618 million for the half, an adjusted operating margin of 10 percent, and adjusted net income of 2,671 million. A year earlier both were losses.

Hold that at arm's length. Adjusted figures are the company's own construction, and the gap between the 4 percent GAAP operating margin and the 10 percent adjusted one is largely stock-based compensation, which was 2,200 million for the half against 286 million a year earlier. Stock compensation is a real cost to existing shareholders even though no cash moves.

The honest summary is narrower than either headline: a business roughly at operating break-even, growing fast, carrying an enormous non-cash accounting charge and an expanding equity cost.

Five customers, a quarter of the revenue

The risk factors carry the number worth keeping. For the 9 months ended 30 September 2026, no single customer was more than 10 percent of revenue, but the top 5 customers were approximately 25 percent of it. The filing adds that many of those customers are not on long-term contracts, or hold contracts expiring soon, and can reduce or stop spending at any time.

Against that, net revenue retention is reported at approximately 900 percent as of 30 September 2026, where an enterprise customer is defined in the filing as one with 100,000 dollars or more of revenue on a trailing twelve month basis. Headcount was approximately 5,300 as of the same date.

What to watch

  • Read the operating loss line, not the net loss line, if the question is whether the business works.
  • Expect the fair-value charge to keep growing while the valuation does, and to reverse character entirely once the notes convert at a listing.
  • Watch the sales and marketing line against revenue in the next filing. A 26-fold increase either buys durable revenue or it does not, and one half-year cannot tell you.
  • Treat the 900 percent retention figure as a statement about existing accounts expanding, not about new ones arriving.
  • Note the 1,500 million Bartz settlement sitting in the 2025 operating expenses. Litigation over training data is a line item now, not a hypothetical.

What is not established

  • What the company will be valued at, or how much it intends to raise. The filing I read states neither.
  • When it lists. No date is in the document.
  • Who the top 5 customers are. The filing does not name them.
  • What the 8,757 million dollar other expense in the half consists of. It sits below the operating line without a summary explanation in the section I read.
  • Whether the first half of 2026 is representative. The filing says plainly that it is not necessarily indicative of the full year.
  • Whether adjusted operating income stays positive once stock compensation grows further after a listing.