SINGAPORE: Asia’s high sulphur fuel oil (HSFO) market firmed on Monday amid a flurry of bids, though downstream bunkering demand was slow after crude prices surged. Strong bidding interest emerged for HSFO on Monday, with the 380-cst HSFO cash differential climbing to $8.25 a tonne. In contrast, there was no bid for very low sulphur fuel oil (VLSFO), with the 0.5% VLSFO cash differential slumping to $1.75 a tonne amid an aggressive offer.