Go back and look at some of the previous "mark to market gains" in the previous quarters. In essence, they have a fuel hedge portfolio out into the future and each quarter they set a value on that portfolio. If fuel seems to be headed higher they record a gain. If fuel is going lower they record a loss. Some of the "loss" they just recorded includes cancelling out some of the "gains" they recorded on the exact same hedges last quarter. If you buy a stock at $20 and then it goes to $40, you can say you "gained" $20 although until you sell you don't have that gain. If next week the stock slips back to $30, you could say you just "lost" $10, even though you never actually gained or lost anything. If fuel stays low, then some hedges will end up losing money, but a lot of this write off is just cancelling out prior "gains".

It is called hedging, not fuel investment strategy. The idea of hedging is to eliminate uncertainty in future pricing, not to try to time the market for profit. If fuel is headed always up, then hedging always wins. If fuel is headed always down, then hedging always loses. If fuel swings up and down, then sometimes you win and sometimes you lose.