Fuel oil's front-month settled at 4,434 yuan per tonne, up a thin 0.36% — almost flat on the day. Bitumen, by contrast, fell 3.5% to 5,013. Both are downstream of the same refineries yet split in opposite directions, and the divergence starts with where the plant steers its runs.

On the bonded marine fuel (VLSFO) side, bunker suppliers at Zhoushan and Shanghai are racing to lock laycan for international transit vessels. Red Sea diversions have pushed some Europe-bound tonnage to top up at Asian ports, squeezing the Singapore-Zhoushan spread to a sliver; the supplier who quotes fast and holds physical stock wins the stem. For bunker traders the edge is not inventory size but the ability to string laycan, tank space and customs clearance into one line.

Domestic heavy fuel tells a different story. The bitumen drop signals the road-building season is fading and refiners have nowhere to push residue, so part of it flows into the bonded bunker pool, which in turn caps fuel oil's upside. Fuel oil looks resilient, but the support is really bitumen's glut at the other end.

Bonded bunkering is not SNSUC's core business, but it is one outlet for the seven oil grades to clear near delivery and a useful window on Asian bunker pricing. Fuel oil's 0.36% sliver says bunker demand and road demand are cancelling each other out.