USGS analysis establishes that magnitude 10.0 or larger earthquakes cannot occur because no known fault is long enough to generate the necessary seismic moment; a qualifying rupture would need to span much of the planet. The largest instrumentally recorded event remains the 9.5 Valdivia quake of 1960 along Chile’s subduction zone, with theoretical upper limits for any single segment estimated at 9.6–9.7 under optimal full-rupture conditions. No developments in monitoring data, tectonic models, or recent seismicity have altered this physical constraint through mid-2026. Trader consensus at 99.4% “No” therefore reflects this robust evidence rather than forecast uncertainty. The only conceivable shifts would require unprecedented multi-fault linkage or revised magnitude scaling laws, both viewed as implausible within the brief remaining window.