Commercial tank utilization at Ningbo, Zhoushan and Yangshan ports has hit 92.3% (per SNSUC Logistics Dispatch Center’s real-time berth monitoring), up 3.7 ppts w/w — confirming material tankage tightness in East China. Fuel oil futures surged 2.54% to ¥4,476/t; asphalt rose 1.53% to ¥5,294/t. This concurrent strength is not demand-driven but reflects ‘in-tank profit capture’: when storage capacity becomes the binding constraint, demurrage becomes the most sensitive price amplifier. Today’s observed average demurrage stands at ¥3,650/day — up 18% from ¥3,100 on Sep 8, the highest since Q3 2026. At this level, it breaches routine operational thresholds for traders: if discharge and tank release cannot be completed within 48 hours of vessel arrival, incremental cost hits ¥7,300/day — equivalent to 0.16% of fuel oil cargo value (converted from WTI $102.22/bbl). Regional haul economics have deteriorated in tandem: weighted average freight + demurrage cost for fuel oil distribution from Zhoushan to Yangtze River refineries now reaches ¥186/t, erasing net margin beyond 300 km; hauls over 500 km are already unprofitable. In contrast, natural rubber (-1.73%) and butadiene rubber (-3.24%) declined — confirming pressure is isolated to fuel-oil logistics nodes, not synthetic rubber chains. For SNSUC clients: shift from ‘vessel schedule alignment’ to ‘tank schedule alignment’. Prioritize booking of available bonded tank space in Zhoushan with ≤7-day lead time, or activate SNSUC’s blockchain-based warehouse receipt pledge channel to accelerate turnover. Importers should avoid concentrating arrivals post-Sep 20 — risk of demurrage breaching ¥4,000/day and triggering mandatory port diversion. Upside risk: Brent-WTI spread sustaining >$4.50/bbl *and* fuel oil inventories falling >1.2% w/w; downside trigger: fuel oil futures breaking below ¥4,320/t *or* East China tank utilization falling to ≤88%.