Anthropic's amended S-1 shows $17.0B in third-quarter revenue and an operating loss driven by short-term compute

Anthropic filed an amended S-1 registration statement with the SEC on November 2, a week after its original IPO filing, adding results for the quarter ended September 30. Revenue was $17.0 billion for the quarter, up 1,127% year over year and up from $11.6 billion in the second quarter. Revenue for the first nine months of 2026 was $33.2 billion. The filing is direct about the pace: "We do not expect our revenue will continue to grow at comparable rates." As of September 30, Anthropic had more than 11,900 customers paying it $100,000 or more over the trailing twelve months, up from more than 950 a year earlier, and more than 1,900 paying $1 million or more.

Where the quarter's money went

Anthropic swung from $974 million of operating income in the second quarter to a $567 million operating loss in the third. The filing attributes the loss primarily to $5.0 billion of compute under short-term commitments and $2.0 billion of non-cash charges tied to its donation matching program. Most of its compute is contracted under multi-year commitments procured 12 to 18 months ahead; when customer demand or research needs exceed that capacity, it buys short-term compute that currently costs significantly more. Anthropic expects its use of short-term compute to keep rising in the near term and to compress its margins. Its Adjusted Operating Margin fell from 19% to 15% between the two quarters.

The third-quarter net loss was $23.3 billion, most of it a $21.9 billion change in the fair value of convertible notes, derivative liabilities and SAFEs rather than operating cash. Anthropic also reports purchase commitments and lease agreements totalling about $895.4 billion, substantially all for compute and infrastructure, with about $69.8 billion due in the twelve months after September 30. The filing also says Anthropic has changed, and may change again, usage limits, rate limits, or model and product capabilities.

Why it matters

The filing describes a supplier whose demand is running ahead of the capacity it contracted in advance, and which is paying more to close the gap. For a business spending on Claude, that makes capacity and limits a live question, not a fixed term. Check what your contract says about rate limits and model deprecation, keep a fallback model tested on your most important workflows, and measure what each workload produces, so you know which ones to protect if limits tighten.