USD/KRW plunged 1.08% to 1359.67 — the largest one-day drop since June 21, 2026. This was not driven by domestic Korean data (Korea’s Aug CPI y/y: 2.1%, down from 2.3%), but by surging U.S. Treasury yields combined with intensified BoJ intervention signals: USD/JPY rose 0.07% to 157.32, forcing JPY strength and exposing KRW vulnerability. KRW became the hardest-hit leg of the USD’s three-way divergence — its depreciation outpaced both CNY (USD/CNY -0.06%) and EUR (EUR/USD +0.03%). For SNSUC’s transshipment clients, this sharp KRW move directly compresses gross margins on KRW-denominated Northeast Asia fuel oil arbitrage, especially Busan-based physical deals — fuel oil futures fell 2.46% to ¥4,122/t, confirming dual negative feedback from price and FX. Geopolitically, Hormuz vessel count held at 3 (unchanged from prior day), yet Brent–WTI spread narrowed 0.12 USD to 3.97 — well below the 4.50 USD threshold signaling material supply risk (industry benchmark). Risk premium is now being priced out by macro forces, not geopolitics. EUR/CNY edged up 0.02% to 7.6779, reflecting persistent Eurozone inflation, but no ECB policy shift triggered a breakout. The critical signal is the widening gap between USD/JPY and USD/KRW — now 153.65 points — pushing offshore RMB NDF implied volatility to 8.2% (Bloomberg: USDCNYV1M), the highest since September 1. While the import FX lock window remains open (USD/CNY = 6.6953, ±120 pts still viable), rising volatility has lifted options hedging costs. View: bearish KRW/USD; neutral CNY/USD. If USD/KRW breaks 1355, expect heightened speculation of Korea’s FX Stabilization Fund intervention — recommend SNSUC clients deploy T+1 spot conversion + 1-month forward protection for KRW contracts. Reversal trigger: USD/KRW closes two consecutive days above 1365 AND Hormuz vessels fall to 2.