The near-certain 99% market-implied odds favoring no magnitude 10.0 or larger earthquake before 2027 stem from the USGS assessment that such an event is physically impossible. Moment magnitude depends on fault rupture area, and no known subduction zone or tectonic boundary provides a continuous fault long enough—roughly the scale of an entire plate margin encircling much of the planet—to release the required energy. The historical maximum remains the 9.5 Valdivia earthquake of 1960 on a roughly 1,000-kilometer rupture; subsequent global monitoring through 2026 has recorded nothing approaching that threshold, let alone exceeding it. While model uncertainty and rare measurement revisions exist, no credible geophysical pathway supports a 10.0 within the narrow remaining window, anchoring trader consensus.