Anthropic’s Claude Fable series drives the market, with Fable 5.1 launching publicly on September 1, 2026, after the earlier Fable 5 release faced temporary U.S. export controls. Trader sentiment centers on unverified September leaks pointing to a completed pretraining run and possible early-October rollout of a 5.2+ model, fueling the heaviest volume on October 20–22 dates. Competitive pressure from Zhipu’s GLM-5.2 open-weights release, OpenAI’s GPT-5.x cadence, and ongoing benchmark leadership in coding and reasoning tasks accelerate expectations, yet Anthropic has issued no official model card, API identifier, or announcement. Historical release patterns and the lack of confirmed public access keep “no release by October 31” live as a meaningful hedge while near-term catalysts like earnings commentary or Azure listings could shift odds quickly.