Recent major explosive activity at Anak Krakatau in early September 2026, producing sustained ash plumes reaching 15 km and generating volcanic lightning, has shifted trader focus toward exactly one VEI ≥4 event for the year. On the Volcanic Explosivity Index, such plume heights and ejecta volumes near or above 0.1 km³ dense-rock equivalent meet the threshold for VEI 4 classification, consistent with Smithsonian Global Volcanism Program criteria used for market resolution. Through mid-2026, official records showed no confirmed VEI ≥4 eruptions amid 47 total events, most limited to VEI ≤3 or effusive styles at sites like Kīlauea and Semeru. Historical annual rates average roughly 0.5–1 such events, with quiet periods common absent caldera unrest or major stratospheric signals, keeping the probability of zero or multiple outcomes secondary unless new monitoring data revise the Krakatau assessment or additional intensifications occur before year-end.