The rubber chain split wider today. Natural rubber settled at 19,865 yuan/t, essentially flat (+0.05%), while butadiene rubber (BR) settled at 15,685 yuan/t, down 2.0% on the day. The two moves pushed the NR–BR spread out to 4,180 yuan/t, the widest band in recent weeks.

BR's softness traces back to butadiene. Several butadiene units came back from maintenance and supply refilled, loosening BR's cost floor, while real tire demand has not kept pace — truck-tire destocking is slow and export orders for passenger tires are cooling. On the natural side, rainfall disruption across Southeast Asian growing regions persists and Qingdao bonded inventories keep drawing down, which keeps NR firm.

For tire makers, a wider spread means cheaper synthetic. Lifting BR's blend ratio by a notch cuts real input cost, but the natural-rubber inventory position needs repricing. We anchor the NR hedge to spread mean-reversion: each time the spread tops 4,000, trim a notch of synthetic and add a notch of natural, binding formulation flexibility to the futures position.