Heating oil pricing

wwally

Can anyone explain how the heating oil supply chain works wrt prices and payments? There's obviously a long chain from a barrel of crude oil to my boiler, but I'd like to know specifically:--

At what point in time does my supplier get charged for his stock of oil? Is it when he orders it (like a domestic customer), when he gets a delivery or when he sells it on to me? Is it a spot price or fixed under contract?

Oil is such a volatile product I feel this must be hard to manage for a wholesaler - so he doesn't end up with tankfuls of high-priced oil, for example.

Hoenir

Above local wholesalers you've organisations such as 

https://www.world-kinect.com/

JonnySegway

The supplier will obviously buy in bulk and hedge it, by that I mean insure against price, explanation here https://fueloilnews.com/2005/10/01/the-basics-of-hedging/