Traders assign a 93.6% implied probability to “No” for a magnitude 9.0 or greater earthquake before 2027 primarily because USGS historical catalogs document only a handful of such events globally since 1900, with the most recent confirmed at 9.1 in 2011 and none exceeding 8.8 in 2025–2026. These megathrust ruptures require simultaneous failure across hundreds of kilometers of subduction-zone plate boundaries, which exhibit recurrence intervals typically spanning decades to centuries. With roughly four months remaining, the short time window further compresses the already low base rate of roughly one event every 20–50 years. No current monitoring data show anomalous strain accumulation or foreshock sequences that would elevate near-term odds. An unexpected megathrust failure in zones such as Cascadia or Nankai remains possible but would represent a departure from established seismic patterns and observational records.