USGS assessments confirm that magnitude 10.0 earthquakes cannot occur, as no known fault is long enough to generate such an event—the rupture would need to span much of the planet's circumference. The largest recorded quake reached only 9.5 in 1960 along Chile's subduction zone, consistent with the physical limits of crustal fault length, depth, and slip. Recent global seismicity, including 2025–2026 events up to magnitude 8.8, shows no deviation from historical patterns or model consensus on maximum magnitudes around 9.5–9.7 in optimal subduction settings. With just months remaining until 2027, the near-certain market odds reflect this established geophysical barrier, though revised magnitude estimates from rare paleoseismic data could theoretically alter long-term views.