Anthropic's New S-1 Filing: Compute Took 58% of Revenue

Anthropic's updated S-1 filing on Monday shows compute taking 58% of revenue last quarter, up from 48% the quarter before. Margins moved the wrong way.

The filing extended the disclosures in last week's S-1 by one quarter — the earlier version covered through 30 June, the new data runs through 30 September. That extra quarter is where the story is.

The numbers

Revenue reached $17 billion, up from $11.5 billion the previous quarter. Growth is not the problem. The operating loss grew alongside it, largely on compute costs, and the ratio the filing tracks most clearly — revenue per dollar spent on compute — had been climbing steadily since the start of 2025, peaked at just over 2x last quarter, then fell back to 1.72x.

The quarterly compute bill hit $10 billion. The filing breaks out the painful part: "$5.0 billion of compute under short-term commitments, which currently costs significantly more than comparable compute procured under our multi-year commitments."

Why it got more expensive

Demand grew faster than contracted capacity, so Anthropic bought at spot-like rates. Some of those arrangements are public: the company has been paying SpaceX $1.25 billion a month for compute, alongside multi-billion dollar deals with Nscale, Akamai and Volta. These are neoclouds rather than hyperscalers — smaller providers offering more flexible terms at higher prices.

That is the trade in one line. Flexibility bought capacity; it cost margin.

What the company says next

The filing does not forecast relief: "We expect compute and infrastructure expenses to increase in absolute dollars and remain our largest operating expense for the foreseeable future as additional committed compute becomes available to us under multi-year arrangements with CSPs, and as we continue to invest in additional compute."

There is a longer-term play. The company discusses building its own compute base under a project it calls "Anthropic Direct." On the current demand curve, that effort is unlikely to displace the neoclouds soon.

How to read it if you build on Claude

Two readings, and they are not in conflict.

The sanguine one is in the filing's own arithmetic: with revenue growing at nearly 50% a quarter, a compressed compute margin is a growth cost, and one quarter of worse ratios after a steady climb since the start of 2025 looks more like a blip than a trend line.

The cautious one is structural. A lab paying premium short-term rates for $5.0 billion of a $10 billion quarterly compute bill is exposed to the pace of the data-center buildout, which the filing’s coverage ties to bond markets and local opposition — neither of which the company controls. If you are negotiating multi-year pricing or committing an application to one vendor's rate card, that exposure is the thing to price in, not the headline revenue number.

What to watch next quarter: whether the revenue-per-compute-dollar ratio recovers toward 2x, and whether the short-term commitment share of the compute bill shrinks as multi-year capacity comes online.