The AI Investor(@The_AI_Investor):Both frontier labs cut prices on the same day. Anthropic launched Claude Opus 5.5 at $4 input and $20 output per million tokens, 40% cheaper to run than Opus 5 while matching Fable 5.1 on most tasks. Roughly an hour later OpenAI answered with GPT-6 Sol at $2 and $10 and Luna at $0.10 and $0.50, at least half off GPT-5.6 promo rates. The contest has moved to cost per completed task rather than benchmark crowns, and Anthropic itself says benchmark margins are a less reliable guide to real world differences. Cache reads tell the story: both landed at $0.20 per million, 60 to 90% below prior rates, since Anthropic says cache reads are most of the agentic coding bill.

2026.09.23 16:34

Both frontier labs cut prices on the same day. Anthropic launched Claude Opus 5.5 at $4 input and $20 output per million tokens, 40% cheaper to run than Opus 5 while matching Fable 5.1 on most tasks. Roughly an hour later OpenAI answered with GPT-6 Sol at $2 and $10 and Luna at $0.10 and $0.50, at least half off GPT-5.6 promo rates. The contest has moved to cost per completed task rather than benchmark crowns, and Anthropic itself says benchmark margins are a less reliable guide to real world differences. Cache reads tell the story: both landed at $0.20 per million, 60 to 90% below prior rates, since Anthropic says cache reads are most of the agentic coding bill.