The NR-BR spread — now the decisive threshold for economic re-evaluation of compound substitution. NR futures and BR prices remain under active market adjustment. The spread narrows to its tightest level in six weeks. This approaches the lower bound of the recent historical range. The narrowing is not demand-driven but supply-mismatched: adverse weather in Southern Thailand and logistics disruption in North Sumatra constrain natural rubber supply. Meanwhile, domestic tire factory operating rate remains stable, yet finished-goods inventory days rise, suppressing restocking appetite. Import breakeven shifts upward: mixed rubber landed cost at Qingdao bonded warehouse is elevated. Mixed rubber trades at a discount to NR futures — arbitrage window closed. Crucially, USD/CNY movement masks underlying pressure: regional freight indices show upward momentum. SNSUC Research Institute estimates that further price divergence between NR and BR could activate the substitution trigger — altering NR share in tire compounds. For SNSUC clients, this is the actionable window: lock in BR procurement and defer NR imports. Refiners and tire makers can rebalance feedstock mix now — not later.