**Claude Fable 5.1, released September 1, 2026, retained the $10 input / $50 output per million tokens pricing first set with Fable 5 in June 2026, making it Anthropic’s highest-cost frontier model for demanding agentic and reasoning workloads.** Newer 5.5-series releases (Opus 5.5 at $4/$20 and Sonnet 5.5 at $2/$10) introduced materially lower output rates while delivering comparable performance on many tasks, highlighting Anthropic’s strategy of tiered pricing. No official details have emerged on a Fable 5.2 or later variant, so market odds reflect uncertainty around whether the next iteration will debut at the established high output rate, adopt reductions seen elsewhere in the lineup, or delay entirely amid competitive pressure from OpenAI’s GPT-6 models and internal cost-optimization efforts. Traders monitor Anthropic’s release cadence and pricing announcements for resolution signals.