Both rubber complexes rose on 6 September, but by markedly different magnitudes: butadiene rubber front-month printed RMB 15,590/t, up 4.91% and the largest gain in three weeks, while natural rubber printed RMB 19,155/t, up 2.05%. Synthetic gained close to 2.4x natural.

The gap reflects cost structure rather than speculative preference. Butadiene rubber is priced off butadiene, a by-product of the petrochemical cracking chain with low supply elasticity. Once cracker run rates contract, tightening butadiene supply passes through to synthetic rubber quotes almost rigidly. Natural rubber is priced off plantation tapping, driven more by weather and tapping schedules, so its pass-through path is longer and blunter.

Downstream, tyre makers restocked across both lines and transactions followed prices up. But restocking is not the same as an established demand trend: whether natural rubber sustains depends on weather in producing regions, while synthetic depends on whether the butadiene supply gap persists.

Worth noting that USD/CNY weakened to 6.7108 the same day, marginally easing import cost pressure. For East China synthetic rubber buyers, the price rise and the FX move point in opposite directions; the net effect is a modest narrowing of negotiating room, not a reason to chase. Rubber sits at the higher end of price elasticity among SNSUC’s 13 traded categories, where procurement timing affects final cost more than the absolute price level.

Sources: INE / SHFE / DCE front-month futures and FX quotes (delayed), synced via the SNSUC market module. For reference only, not trading advice.