The extreme rarity of magnitude 9.0+ megathrust earthquakes, combined with the short remaining window through December 2026, underpins the 93.2% market-implied probability of "No." USGS historical catalogs document only five instrumentally recorded M9+ events since 1900, with recurrence intervals typically spanning 25–50 years or longer based on paleoseismic records from major subduction zones. The most recent was the 2011 Tōhoku event, and recent activity—including the 2025 Kamchatka M8.8 sequence—has not approached the threshold or signaled accelerating stress accumulation toward a full-margin rupture. While an unforeseen failure in zones such as Cascadia remains theoretically possible given incomplete knowledge of local fault dynamics, current monitoring data and low near-term probabilities reinforce trader consensus against occurrence before 2027.