⚡ Why this matters

• Frontier intelligence just got repriced twice in one afternoon. Every budget built on last quarter's token math is now wrong in your favor.
• The 90-minute gap says OpenAI was waiting with its finger on the button. Price is now a reflex, not a strategy.
• Customers were already leaving. Harvey, the legal AI company, built its own model on a Chinese open-weight base. Cuts like this are the labs answering that exit.

🔍 What happened

• Anthropic shipped Claude Opus 5.5 on September 22 at $4 per million input tokens and $20 per million output. Opus 5 was $5 and $25.
• Cache reads fall to 20 cents per million from 50 cents. Cache writes fall to $5 from $6.25. Anthropic says typical workloads cost 40 percent less than on Opus 5.
• The model has a 1 million token context window and, Anthropic says, Fable 5.1 level performance on most tasks. METR and Frontier Design tested it before release.
• Sonnet 5.5 and Haiku 5.5 follow in the coming weeks. Anthropic filed confidentially for a Nasdaq listing next month at a reported $965 billion valuation.
• About 90 minutes later OpenAI launched GPT-6 Sol at $2 and $10 per million tokens and GPT-6 Luna at 10 cents and 50 cents, both half the price of the 5.6 series.
• OpenAI says Sol makes about half as many mistakes as GPT-5.6 Sol. Both models sit below GPT-6 Astra in the lineup.

💬 Smart takes

• Dario Amodei, Anthropic CEO, September 12: "I have become convinced that fully addressing the risks requires even more prudence." Ten days later his company shipped a faster, cheaper frontier model.
• OpenAI, launch post: Sol and Luna were built with the same methods as Astra for professional work, factuality, coding and computer use. The pitch is Astra quality at Luna prices.
• Skeptic: list prices are theater when the real money moves through enterprise contracts and cloud commits. A 20 percent sticker cut may not touch what large customers pay.

🧭 Where this goes

1. LikelyGoogle matches within two weeks with a Gemini price move of its own.
2. LikelySonnet 5.5 lands under Opus 5's old price and becomes the default enterprise model.
3. PossibleOpenAI cuts Astra itself before Anthropic's IPO roadshow, to blunt the growth story.
4. Wild Carda lab introduces per-task pricing and the per-token price war ends because the unit disappears.