Sorry, supply / demand is at an imbalance. Domestic inventories are at record levels which is why VLO exporting as much as they are. The guy asked why the stock is going down. supply / demand is obviously a chief reason. Effects pricing.
Look at fundamentals. Crack spreads are disappearing and domestic demand is shrinking. Latin America seems to be the lone bright spot at the moment for Valero. So at this moment, the forecast is bleak for refiners. Of course this could all change quickly if spot price of gasoline, and distillates reverse their plummet.