Crude was broadly steady in the 31 August morning session: Brent at $89.27/bbl (-0.01%) and WTI at $84.40/bbl (-0.02%), with overnight macro data offering no clear direction and neither side willing to add risk. The real divergence sat downstream. Fuel oil printed RMB 3,650/t, down 0.54% and the weakest in the complex: summer power-sector peak-shaving demand is fading, while bunker lifting volumes are dragged by seasonally lighter cargo flows, nudging spot discounts wider. Bitumen bucked the trend, up 0.30% to RMB 4,610/t on two-sided support - on demand, northern provinces have entered the pre-September construction rush, releasing rigid procurement; on supply, thin processing margins keep some independent refiners at low run rates, extending inventory drawdowns. The spread therefore widened to RMB 960/t. SNSUC Research Institute views bitumen strength as seasonally grounded but limited in duration, since construction cools after October; downstream users are advised to cover September requirements through staged price locking in the current window, while fuel oil buyers may wait for further off-season price clearing before building positions. Base oil at RMB 7,939/t, paraffin wax at RMB 7,983/t and petroleum coke at RMB 2,383/t were all flat on the day, leaving complex-wide volatility subdued and reflecting a broad preference to cut exposure until direction clarifies.