On the first trading day of October, Brent settled at $101.14/bbl, up $3.17 on the session, while WTI closed at $91.72/bbl, up $1.44. Both benchmarks rose, but not in step: the Brent–WTI spread widened from roughly $7.69 to $9.42, a $1.73 move of about 22% in a single day.

A wider spread rewrites the landed-cost math across all seven SNSUC transshipment grades. ESPO and Sokol, priced off Brent, and Dubai and Oman, the Middle East benchmarks, all ride the Brent leg. Urals follows the G7 price-cap logic and barely tracks WTI. Basrah Light, Bonny Light and Lula each carry their own discount structure. When the spread jumps, the choice of title-transfer timing shifts: cargoes fixed early capture the discount, those fixed late inherit a higher-for-longer floating leg.

Downstream did not follow. Bitumen at ¥5,013/t actually slipped ¥3.50, while natural rubber at ¥20,095/t gained ¥5.54 and butadiene rubber at ¥16,000/t added ¥3.96. Crude up, bitumen down — refiners are squeezed on both sides of the crack. For SNSUC's lube-base-oil and fuel-oil (¥4,434/t, essentially flat) lines within the 13-category book, this is a window to turn inventory quickly rather than carry it.