Leaks from early September about a fresh pretraining run for Anthropic’s Claude Fable line have shaped trader consensus around an early-October large language model release, with October 6 holding the highest implied probability at roughly 33 percent. Fable 5.1 launched September 1 without any subsequent official model card or API identifier for a 5.2-or-higher successor, leaving the exact timing dependent on whether Anthropic opts for a stealth routing update or a formal announcement. The wide distribution across October dates reflects uncertainty over development timelines, potential regulatory reviews, and competitive positioning against other frontier models, while the low odds on a post-October 31 release signal strong market belief that the rumored cycle will conclude soon.