The two rubber curves diverged today: BR closed at 16,170 RMB/t, up 1.51%, while NR sat at 19,700, up 0.43%. BR moved faster, pulling the NR-BR spread from above 3,800 RMB/t down to 3,530. The direction of that spread matters - synthetic no longer trades at a wide discount to natural, and the economics of synthetic blend ratios are shifting.

BR's strength traces back to butadiene. Several butadiene units are in maintenance, keeping spot tight and lifting BR's cost base. On the NR side, the rainfall disruption across Southeast Asia has eased and Qingdao destocking has slowed, leaving fewer bullish narratives to push the price.

For tire makers, the move is not simply 'blend more synthetic.' It is about spread hedging: lock a portion of BR on long-term terms while NR is relatively cheap, and hedge the NR exposure with futures. At a 3,530 spread, the blend-switch threshold is rising, but it has not yet flipped to an NR-dominated regime.