Anthropic's third quarter brought in almost $17 billion in revenue and still ended with an operating loss. In an amended IPO prospectus filed with the Securities and Exchange Commission this morning, the Claude maker put most of the swing on $5.0 billion of short-term compute, which costs it more than capacity bought under long-term contracts, and $2.0 billion in non-cash charges from its employee donation matching program.

Revenue for the three months ended Sept. 30 was $16.96 billion. That compares with $1.38 billion a year earlier and $11.56 billion in the second quarter. The operating line went the other way: a $567 million loss, after $974 million of operating income in the June quarter, the only quarter with operating income in the filing's quarterly table. The original S-1, which WebProNews covered last week, stopped at June 30. Figures shared with prospective investors in mid-October had put the quarter at $16.8 billion.

Abstract illustration of rising glowing bars beside a dense grid of server lights, with one amber bar dipping below a baseline

Paying up for capacity it couldn't wait for

Compute and infrastructure expenses reached $9.86 billion, or 58% of revenue, up from 48% in the second quarter. Anthropic says it usually contracts compute 12 to 18 months before the capacity shows up. When customer demand or research needs run past that pipeline, it buys short-term capacity at a higher price, and the filing says that will keep growing for now: "We expect our use of short-term compute to continue to increase in the near term and to in turn compress our operating margin and Adjusted Operating Margin as a result."

The non-GAAP view held up better. Adjusted operating income rose to $2.5 billion from $2.2 billion in the second quarter, though the adjusted margin slipped to 15% from 19%. Price cuts on new model versions, along with contractual discounts, offset about $600 million of usage-driven revenue gains between the two quarters. The only other quarter-to-quarter change where the filing puts a number on price cuts came at the end of 2025, at about $70 million.