Fuel oil's 6.38% gain to 5,349 RMB/t made it the only category to leap more than 6% today. Off the screen, the real driver is bonded bunker-fuel (VLSFO) hitting its restocking node - international transshipment vessels are concentrating at Zhoushan for bunkering, and a wave of buying has pulled spot supply tight.

That tightness immediately reshuffled feedstock allocation. Domestic coking residue and bonded bunker fuel were already competing for the same residue stream; with bunkering demand now more urgent, independents are routing more residue to bunker blending, squeezing coking feedstock. The result: fuel oil strong, bitumen following but passively, and the FO-BIT spread widening to 583.

For traders running regional spreads, the focus today is Zhoushan's premium versus Singapore. If Zhoushan's rush for vessels lifts the local premium, the VLSFO arbitrage to Southeast Asia opens; conversely, once restocking eases, this rally can unwind just as fast.