Trader consensus on Polymarket reflects a 92% implied probability for no megaquake—a magnitude 9.0+ event—by June 30, driven by the extreme rarity of such quakes and lack of detectable precursors across major subduction zones monitored by the USGS. Globally, only five M9+ events have occurred since 1900, averaging one every two decades, with the last being Japan's 2011 M9.1 Tohoku rupture. Recent developments, including a M7.4 offshore Japan on April 20, prompted a brief advisory from Japan's Meteorological Agency citing slightly elevated odds (around 1%) for a Nankai Trough megaquake if followed by another M7+, but USGS aftershock forecasts and seismic data show no escalation. Realistic challenges include unforeseen rupture cascades on locked faults like Cascadia or Sumatra, though current strain metrics and model consensus indicate low near-term risk; watch USGS real-time feeds for shifts.