No 10.0-magnitude earthquake is possible before 2027, as confirmed by USGS analysis linking maximum magnitude directly to fault rupture length, with no known fault segment long enough to generate such an event. The planet's largest recorded quake reached only 9.5 during Chile's 1960 Valdivia event on a roughly 1,000-kilometer rupture; current global monitoring shows 2026 activity capped well below 8.0. Traders assign 99.4% probability to "No" because seismic data and fault mechanics preclude this outcome under established models, though rare revisions to magnitude scaling or an unprecedented multi-fault cascade could theoretically alter assessments if new observations emerge. USGS networks will continue providing authoritative measurements through year-end.