Airlines negotiate contracts for fuel at most airports. The biggest varible in jet fuel prices are generally taxes. There is no real hedging available for jet fuel. Instead airlines usually place hedges or bets on the price of heating oil. If oil goes up they make a bunch of money. If oil goes down they lose money. If you google Delta and fuel hedges you will find a lot of info on the hedges this year and last.
Perhaps the biggest fuel hedge win ever was Southwest Airlines in the early 2000 era. They made 5 billion dollars on hedging and as a consequence were able to run the airline at a operational loss but still show a profit. This cratered the rest of the unhedged airlines. Every airline management team wants to be the next SW hedge win and as a consequence they have spent way to much time and money at the crap table gambling. One humerous article suggested airline CEO's need to attend Gamblers anonymous.
One interesting side effect of varying taxes and prices is a practice known as tankering. If a aircraft is flying into a airport with high fuel costs they will load extra fuel onboard up to the performance limits to minimize fuel bought at the high cost airport. It costs fuel to carry the extra fuel weight so they have computer programs to figure the break even point.
There is one last method Delta is trying to control its fuel prices or in this case the crack spread which is what is added to the price of oil to crack it into jet fuel. The bought a refinery in the NE. The jury is still out on if it was a good idea.
G