Anthropic’s established release cadence after Fable 5.1 in early September 2026 drives current trader sentiment, with Polymarket pricing December 31 at 94% and November 30 near 80% for public availability of a qualifying Fable 5.2+ model. The large language model line has shown steady gains in agentic coding, long-context reasoning, and prompt caching efficiency, positioning the next iteration as a logical follow-on within weeks to months. Earlier October deadlines resolved negatively amid no official announcement or API update, while November 19 sits at roughly 60%, reflecting uncertainty around internal testing, safety reviews, and competitive pressures from peers like OpenAI. Upcoming catalysts include potential earnings commentary or benchmark leaks that could accelerate or delay rollout before year-end.