Anthropic’s September 22 release of Claude Opus 5.5 cut listed output token pricing to $20 per million, 20% below the $25 rate that held for Opus 5 since July, while cache reads fell 60% to $0.20 per million. The company reports the model delivers comparable performance to its higher-priced Fable 5.1 on most tasks yet costs roughly 40% less on typical workloads due to both lower rates and reduced token consumption, plus over 30% faster output generation. Traders are weighing these efficiency gains and sustained premium positioning against competitive pressure from other frontier labs, potential further 5.5-family releases, and any pre-IPO pricing adjustments that could push the effective or listed rate lower before year-end.