The USGS has long established that earthquakes of magnitude 10 or larger cannot occur on Earth, as no known fault is sufficiently long to generate such energy release, directly supporting the 94.9% market-implied odds against this outcome before 2027. The historical maximum remains the 9.5-magnitude Valdivia event in Chile in 1960, with all subsequent monitoring showing typical activity well below this threshold and no model runs or observational data indicating a shift. Seismologists emphasize magnitude scaling with rupture length, rendering a 10.0 quake physically implausible absent radical revisions to plate tectonics understanding. While continuous USGS data releases could theoretically reveal new fault behaviors, the consensus reflects robust physical limits rather than forecast uncertainty.