Anthropic S-1 says AI price cuts preserved its margins

OpenAI and Anthropic have cut prices on their main AI models in a series of moves since late June, with reductions as large as 80%. The cuts come as cheaper open-weight models from Chinese developers DeepSeek and Moonshot AI put pressure on the two U.S. labs. On the same day as Anthropic's IPO filing, October 26, its S-1 said it had lowered customers' costs without hurting its margins.

The steepest cut came on July 30, when OpenAI dropped GPT-5.6 Luna to $0.20 per million input tokens and $1.20 per million output tokens, down from $1 and $6. The company called it 80% less, and Terra, its mid-tier model, fell 20%. Anthropic's Claude Opus 5.5 is priced at $4 and $20, which is 20% below Opus 5. Its cache reads cost 60% less, and Anthropic says typical workloads run 40% cheaper.propakistani.pk+1

A rapid tit-for-tat

Developer Max Woolf, a former BuzzFeed data scientist who tracks model pricing, laid out the timeline on his blog. In August, Anthropic made a temporary Sonnet 5 launch discount permanent. On September 22, OpenAI released GPT-6 Sol and Luna at half the earlier input and output prices, the same day Anthropic released Opus 5.5. A week later, GPT-6.1 Sol halved cache pricing again. Woolf says that made the model family about 75% cheaper overall. OpenAI said its savings came from better caching and inference.openai.com+1

These cuts matter most for coding agents like Codex and Claude Code. In those tools, cache reads make up 96% to 99% of token spending. Woolf also pointed to Vercel data showing the average cost per token is now 43.3% of its April level, though total spending keeps rising.minimaxir.com

Open-weight pressure

Woolf said that "no one cuts prices by 80% unless there is some externality in play." He pointed to DeepSeek's Flash V4.1 model, which costs $0.15 for input and $0.60 for output. It is now offered by 29 providers on OpenRouter, up from 13 in May, and Cloudflare ↗ 1.39% is among those pricing near DeepSeek's own rate, he wrote. Moonshot's Kimi K3.1 Pro comes close to Opus 5.5 at half the price, and its weights are due November 4. BusinessDay, citing the Financial Times, also described the cuts as a response to cheaper Chinese competitors.businessday.ng+1

Margins under scrutiny

Anthropic filed its S-1 on October 26 to list on the Nasdaq ↘ 0.04% under the symbol "ANT." According to the filing, Opus 5.5 cut customers' cost per task by about 40% through "a combination of a lower price and improved efficiency," and "because of our compute efficiency, we have been able to make these improvements while preserving our margins," as quoted by a dev.to analysis. Anthropic's figures imply an 85% gross margin in the first half of 2026, CNBC Comcast Corporation ↗ 0.32% reported. Compute costs fell from 201% of revenue a year ago to 55%.saastr.com+3

The filing also warns that margins will "fluctuate over time" as more compute comes online. Woolf thinks prices could keep falling and may end up near "where price equals marginal cost."cnbc.com