The rubber chain turned up after hours. Natural rubber at 19,535 yuan/tonne, +0.64%; butadiene rubber at 16,475, +0.43%. That reverses the midday read of "NR slipping, BR held by tight butadiene" — both lines now climb, and the NR–BR premium widened back from ¥2,920 to ¥3,060.

The driver is cadence, not supply. The morning drop was mostly channel-inventory dislocation; buyers returned at night, signalling tyre makers re-pricing near the month's low. The yuan at 6.667 firms, so dollar-settled natural-rubber purchases cost less and the RMB account on imported rubber looks better.

For the two rubber lines among SNSUC's thirteen categories, the pricing curve moves from "premium narrowing" back to "natural-rubber premium widening". The FX dividend on the listing-formula denominator remains, but NR strength lifts the numerator, so quotes should not simply track the fall.

Butadiene tightness from maintenance under BR is unchanged; the small BR gain is cost support, not demand pull, so tyre makers need not touch the synthetic blend ratio yet.