The extreme rarity of magnitude 9.0+ megathrust events underpins the 97.1% market-implied probability of no occurrence before 2027. USGS historical catalogs show only a handful worldwide since 1900, with an average recurrence on the order of decades for great earthquakes exceeding 8.0 on the moment magnitude scale; none have reached 9.0 since the 2011 Tōhoku event. Paleoseismic and instrumental records indicate typical intervals of 300–500 years or longer along major subduction zones, with no anomalous foreshock activity or strain accumulation signals reported in current USGS or equivalent monitoring data. While a sudden full-margin rupture on the Cascadia or Nankai Trough remains theoretically possible within the narrow remaining window, time-dependent models assign such short-term odds well below 5%, consistent with trader consensus on the absence of enabling tectonic conditions.