The market price reflects trends compared to seasonal norms (it's all relative) and everyone is looking to get a jump on the 3-5 week trends
A few tweets on a friday pm or pre market monday am (or really whenever) by someone "influential" in commodites forecasting... can easily move markets at opening and all you need is a few guaranteed cents when you ( Wall street TBTF's) got the cash to be levered to the gills, ya kno. Would be like taking Candy from a baby.