**A magnitude 10.0 or larger earthquake is considered physically impossible on Earth.** USGS data and fault mechanics show that no known fault is long enough to generate such an event; the theoretical maximum requires a rupture spanning thousands of kilometers, which does not exist. The largest recorded earthquake reached 9.5 in Chile in 1960, with subsequent events like the 1964 Alaska quake (9.2) and 2011 Tohoku quake (9.1) confirming the upper limit near 9.5. With only months remaining until 2027, the near-100% market-implied probability for “No” reflects this established geological barrier rather than short-term forecasts. The only conceivable shifts would require unprecedented revisions to seismic scaling laws or measurement errors, both viewed as highly improbable by experts.