The split today is not inside crude but between the heavy-oil chain and the rubber chain, each going its own way. Fuel oil closed at 4,947 yuan a tonne, up 3.71%; bitumen at 4,454 yuan, off 0.36%. Natural rubber sat at 19,890 yuan, down 0.08%, and butadiene rubber at 15,935 yuan, down 0.25%.

One block rallies, the other sits flat on the floor, and the crack spread widens at both ends. The heavy-oil side - fuel oil and bitumen - tracks the crude rebound, while rubber is stuck behind downstream tire inventories.

For SNSUC's thirteen categories, that split means one pricing model will not fit both. The call for the data terminal: run the heavy-oil and rubber chains as two separate curves, not one volatility model.

SNSUC digital warehouse receipts now cover both cargo types, but the pledged discount rate should be quoted separately - rubber turns slower than fuel oil, so the capital carry cost is different.