Geophysical constraints and historical records drive the overwhelming 99.4% market-implied odds against a magnitude 10.0 or greater earthquake before 2027. The moment magnitude scale ties maximum size to fault rupture length, and no known fault on Earth is long enough to generate such an event—USGS assessments confirm magnitudes of 10 or higher are physically impossible, with the largest recorded quake at 9.5 during the 1960 Valdivia event in Chile. Current global seismic monitoring through mid-2026 shows typical activity, including several magnitude 7+ events but none approaching 8.0, consistent with long-term averages and no anomalous precursors. While forecast models carry inherent uncertainty and rare multi-segment ruptures remain theoretically discussed in some subduction zones, none approach the energy release or scale required for magnitude 10 within the brief remaining window.