Models
Anthropic's Opus 5.5 undercuts its own flagship
At $4 and $20 per million tokens, the new workhorse lands 60% under Fable 5.1 on the same day OpenAI halved GPT-6 Sol's price.
Anthropic released Claude Opus 5.5 on Monday at $4 per million input tokens and $20 per million output, and positioned it as the practical pick: the company says it performs at the level of flagship Fable 5.1 on most work while costing 40% less to run than Opus 5. Fable 5.1 stays at $10 and $50 per million tokens.
The same day, OpenAI made GPT-6 Sol 50% cheaper at $2 and $10 per million tokens and introduced Luna at $0.10 and $0.50. Within 24 hours, the mid-tier of the market repriced twice, and the distance between flagship quality and commodity price narrowed again.
Buyers are the immediate beneficiaries. The strategic story is harder: margins at the mid-tier are compressing exactly as capital costs for compute reach record highs, which makes the next round of efficiency claims worth watching closely.