Traders see a tight race for the top AI model by end of December 2026, with Google at 42% and Anthropic at 37.5% market-implied odds reflecting closely matched capabilities on current leaderboards. Anthropic's Claude Opus 5.5 and Fable 5.1 series lead many benchmarks following September releases, while Google's Gemini 4 Argon has posted strong results in reasoning and multimodal tasks. OpenAI's GPT-6 variants, Meta's Muse models, and others trail in implied probability, underscoring rapid iteration across labs. Key swing factors include December model updates, benchmark revisions under style control on the Chatbot Arena, and any new capability demonstrations that could alter the final ranking before resolution.