The 89.5% market-implied probability of no megaquake (magnitude 8.0 or greater anywhere on Earth) by June 30 stems primarily from the low baseline rate of such events—typically one to two globally per year on average, with high month-to-month variability and no reliable short-term precursors. USGS catalogs through late May 2026 show no magnitude 8+ quakes this year, only smaller events up to 6.9, consistent with normal background seismicity. The April 2026 magnitude 7.7 off northern Japan temporarily raised local aftershock-related odds of a follow-on megaquake to about 1% for a brief window, but that risk has since subsided without escalation, and no global monitoring agencies report elevated signals such as unusual strain accumulation or swarm activity. Traders price in this absence of triggering conditions against historical patterns where M8+ events remain unpredictable on 30-day horizons.