The board split sharply today. Natural rubber front-month settled at ¥20,095 a tonne, up 5.54%, and butadiene rubber at ¥16,000, up 3.96% — both rubber lines moving together on disrupted tapping in southern Thailand plus post-holiday restocking by tire makers. Bitumen, meanwhile, dropped 3.5% to ¥5,013, and fuel oil barely moved, up 0.36%.

The divergence says one thing: the downstream cost pass-through is broken. Rubber is driven by the supply side — weather and inventories — while bitumen is driven by demand — seasonally weaker infrastructure starts. The two do not share a logic chain. Traders who still run the old "crude up, so everything downstream should rise" script are misreading the tape.

For our 13-category supply book, this kind of split is an opening, not a headache. When rubber spot is tight, the pricing power on our Southeast Asian origins strengthens; when bitumen softens, we can lock winter-storage volumes for clients at lower levels. Crack-spread windows like this usually last two to four weeks, so we roll positions on that cadence rather than betting one direction.

One flag: NR's single-day +5.54% is nearing overbought. Spot follows but end-user uptake is fading, so anyone running a basis trade should watch the ¥20,500 line.