Anthropic's recent Claude 5.5 family releases, including Opus 5.5 in late September 2026 and Fable 5.1 earlier in the month, have driven its dominant 75.5% implied probability by topping independent leaderboards across reasoning, coding, agentic tasks, and intelligence indices with scores like 87-96 on composite benchmarks. These models outperform OpenAI's GPT-6 Astra and Google's Gemini variants in efficiency, context handling, and real-world evaluations while offering competitive pricing. Trader consensus reflects Anthropic's sustained edge in frontier capabilities amid ongoing competition, though OpenAI's upcoming DevDay announcements and potential model updates remain key swing factors that could shift sentiment before year-end.