OpenAI’s September 2026 resolution of the Navier-Stokes Millennium Prize Problem using an internal large language model and roughly 10,000 coordinated AI agents has anchored trader consensus at 78.5% implied probability. The result, verified via Lean formalization after 88 hours of compute, showcased scaled reinforcement learning and multi-agent orchestration that outpaced prior benchmarks. Although triggered by rumors involving Anthropic-affiliated work on related fluid equations and accompanied by credit disputes, the achievement highlighted OpenAI’s lead in applied mathematical reasoning. Subsequent October releases of hundreds of additional proofs on open problems further widened the perceived gap. Anthropic’s strengths in IMO benchmarks, Fermat formalization, and Riemann variants remain notable but have not yet matched full Millennium Prize resolution, leaving OpenAI positioned for the next breakthrough ahead of regulatory or timeline shifts.