Geophysical constraints make a magnitude 10.0 earthquake before 2027 extraordinarily unlikely, driving the market's 98.8% implied probability for "No." USGS analysis shows that an Mw 10 event would require a continuous fault rupture spanning roughly 14,000 km with substantial slip—far exceeding Earth's longest subduction zones or plate boundaries, which max out near 6,000–7,000 km. The 1960 Valdivia quake at 9.5 remains the historical maximum, and current global seismic monitoring reveals no strain accumulation or foreshock patterns capable of approaching that threshold in the remaining months of 2026. While theoretical models allow for rare mega-events over geologic timescales, no realistic near-term development could produce the necessary rupture length or energy release.