OpenAI's recent demonstration of AI-driven mathematical breakthroughs, including its September 2026 solution to the Navier-Stokes Millennium Prize Problem via an internal frontier model and 10,000 coordinated agents in 88 hours, underpins the 78.5% implied probability. This effort followed rumors of related progress by NYU mathematician Tristan Buckmaster and Anthropic researcher Levent Alpöge on simpler fluid equations, yet OpenAI delivered a Lean-verified result resolving key statements of the problem while noting substantial headway on a second Millennium Prize challenge. Anthropic's involvement remained limited to an unaffiliated side project without company-scale resources, reinforcing trader views of OpenAI's edge in large language model capabilities, reinforcement learning pipelines, and compute-intensive agent orchestration for tackling unresolved conjectures. Key near-term catalysts include OpenAI's next formal releases and any independent Anthropic model benchmarks on comparable problems.