BR closed at CNY 14,965/t, up 1.87%, against NR at CNY 18,850/t, up 0.53%. Butadiene rubber leads, yet the two still trade inverted (BR sits CNY 3,885/t below NR). Butadiene plant turnarounds have tightened supply, pushing tire makers to cut the natural-rubber blend ratio and raise butadiene content — and SNSUC's rubber transshipment mix shifts with it.