The SHFE front-month rubber contract settled at 19,870 yuan/t today, up 4.36% on the day; butadiene rubber closed at 15,950 yuan/t, up 3.64%. The gap between the two widened back to 3,920 yuan/t from around 3,500 a week earlier.

A wider spread restores the economics of 'more natural rubber, less butadiene' in tire compounds. Each 5-point gain in natural-rubber share per formula cuts butadiene use, and at today's spread that trims raw-material cost by roughly 0.8–1.2 yuan per tire. At a 5-million-tire monthly run, one compound switch can save several million yuan a quarter.

On SNSUC's bonded zone, the pledge haircut on natural-rubber warehouse receipts rose about 2 points with the spot move. The same 5,000-ton lot now frees roughly 1.9 million yuan more in credit line. The SHA-256 fingerprint of each receipt is recomputed in the browser, so title confirmation clears without bank due diligence and funding lands T+0.

One operating note: this rubber rally is fund-driven and fast. Bonded-zone free stock is not tight, so chase-buying for inventory should weigh both the paper gain and the loan-to-value ratio, not just the unit price.