On Sept 12, front-month natural rubber settled at CNY 19,150/t, down 0.98%, while butadiene rubber fell 3.84% to CNY 14,910/t. Their spread has widened from around CNY 3,600 at the start of the month to CNY 4,240/t, near the high end for the year.

The butadiene rubber sell-off is driven by softer feedstock butadiene and a downward revision to tire-plant operating rates. For truck-tire makers, when butadiene rubber is more than CNY 4,000/t cheaper than natural rubber, the blend ratio shifts toward butadiene; the current gap makes that substitution pay.

Natural rubber, however, has a floor from plantation weather and warehouse-receipt cancellation timing, so downside is limited. On procurement, cover butadiene rubber on a need-to basis into October and wait for a natural rubber dip before rebuilding inventory — don't chase a single leg at the spread extreme.