The extreme rarity of magnitude 9.0+ earthquakes underpins the market's strong consensus for no such event before 2027. Global records from the USGS show these megathrust quakes occur roughly once every decade or longer on average, driven by slow strain accumulation along subduction zones, with the most recent in 2011. In the brief remaining window, current seismic monitoring reveals no anomalous activity or foreshock patterns that would signal an imminent great event. Realistic challenges include an unexpected rupture on a high-risk fault like Cascadia, though historical recurrence intervals and ongoing strain measurements indicate low near-term probability.