The clearest signal in today's tape is the rhythm mismatch between products. Fuel oil rose 5.31% to ¥5,295/t and bitumen gained 4.96% to ¥4,828/t; both sit downstream of heavy-oil cracking and moved up together on run-rate and bunker-stocking demand. On the other side, natural rubber slipped 0.36% to ¥19,545/t while butadiene rubber climbed 2.82% to ¥16,380/t — same family, opposite direction.

The split runs on two separate drivers. The heavy-oil chain tracks refinery margin and shipping activity; bitumen leans on infrastructure spend and fuel oil on bunker demand, both supported pre-heating-season stocking in the northern hemisphere. Inside rubber, natural rubber follows producing-region weather and import arrivals, while butadiene rubber follows butadiene monomer and tire-plant runs — this week tire makers restocked and lifted butadiene rubber, but replacement-tire demand never caught up, leaving natural rubber soft.

For SNSUC's 13-category data model this means one curve can no longer explain every product. We split the heavy-oil chain (fuel oil, bitumen, crude-linked) and the rubber chain (natural and butadiene rubber) into two independent monitoring lines, each firing its own spread alert, so a crude rally no longer screams that everything is strong.

On the data side, the live page pulls 11 real quotes and the 13 categories sit on 34 real listings in the backend — no simulated fills. A split day like this is exactly when you see whether the model truly separates.