Anthropic's Compute Bill Ate 58% of Revenue Last Quarter

Anthropic spent 58% of its revenue on compute last quarter, up from 48% the quarter before. The figure comes from a filing the company released on Monday, an update to the S-1 it published last week that extends financial disclosures through September 30.

The numbers cut both ways. Revenue reached $17 billion, up from $11.5 billion in the previous quarter — growth of nearly 50% in three months, which signals durable demand. But the operating loss grew over the same period, driven in large part by rising compute costs.

The timing matters. Anthropic is inching toward its IPO, and this is the moment when a company wants to show investors that margins are improving. Instead, they are getting worse.

What does the filing show?

The original S-1, filed last week, disclosed financials only through June 30 of this year. The Monday update added one more quarter of data, through September 30. That extra quarter is where the margin deterioration shows up.

A chart in the filing tracks revenue earned for every dollar spent on compute. That ratio had grown steadily since the start of 2025. It peaked at just over 2x this past quarter, then fell back to 1.72x.

Compute spend for the quarter hit $10 billion. The filing breaks out a key part of it:

• $5.0 billion of that compute sits under short-term commitments
• The filing states these commitments "currently costs significantly more than comparable compute procured under our multi-year commitments"
• The rest of the bill reflects longer-arrangement capacity

The mechanism is simple. Demand grew faster than Anthropic's committed capacity. The company had to scramble for compute on the spot. Short-term capacity costs more. Margins compressed.

Who is Anthropic paying?

Some of these deals have already surfaced in public. Anthropic has been paying SpaceX $1.25 billion a month for compute. It has also signed multi-billion dollar deals with Nscale, Akamai and Volta.

In industry terms, these suppliers are neoclouds, not hyperscalers. They are smaller outfits that offer more flexible compute deals at higher rates. That flexibility is exactly what Anthropic needed when demand outran its long-term capacity, and exactly what made its unit economics worse in the third quarter.

There is no sign Anthropic can do without them soon. The filing says so directly: "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."

Can Anthropic fix this?

The company is trying to build its own compute base under a project it calls "Anthropic Direct." The Monday filing discusses the effort at length. But demand is growing so fast that these efforts cannot keep pace, and the neoclouds will remain the best available option for the near term.

Many indications, according to the source reporting, imply the margin shift is more of a blip than a long-term problem. The $5.0 billion in expensive short-term compute should fade as multi-year arrangements with cloud service providers come online. But the filing itself makes clear the absolute bill keeps rising.

Why it matters beyond Anthropic

In one sense, these are champagne problems. As long as revenue grows at nearly 50% a quarter, few investors will worry about high compute costs. And if demand slows down, investors may take comfort in a compute picture that has gotten a lot sunnier by then, with cheaper committed capacity replacing spot purchases.

But the filing is also a reminder of how much AI labs depend on the trillion-dollar infrastructure buildout, and how vulnerable they are to hiccups in that process. It is easy to imagine the data center buildout slowing over the next year if bond markets get skittish or local opposition intensifies.

Anthropic can do little about either risk. Either one would make an already messy compute picture a whole lot messier. For now, the future of Anthropic and other labs will be at the mercy of compute prices.