Natural rubber remains firm: front-month at ¥18,750/t (+0.48%). Although Southeast Asian regions are in peak season, intermittent rainfall and logistics disruptions have unsettled processors' delivery rhythms, exchange warehouse receipts sit at a multi-year low, and spot premiums are resilient. By contrast, butadiene rubber at ¥14,930/t (-0.27%) is pressured by softer butadiene feedstock and squeezed margins; tire makers, facing sluggish replacement demand, are digesting inventories and cautious on synthetic-rubber procurement. The natural-to-butadiene spread has thus widened to ¥3,820/t. SNSUC Research Institute notes that rubber grades (natural and butadiene rubber) are listed in the sourcing hall with bonded storage; buyers can use cross-grade, cross-position combo listings to hedge timing mismatches and lock quality and delivery point via digital receipts, avoiding chase-the-rally risk under peak-season weather premiums.