There’s no such thing as a perfect hedge.It's not a perfect hedge. Obviously the refinery still has to pay for crude. What it was meant to be was reduce the premium and wild swings Delta paid for Jet fuel specifically. And I believe it meets something like 40-50% of their domestic fuel requirements.
Trainer Refinery - Wikipedia
en.wikipedia.org
The net effect right now is only 15%. But it's 15% their competitors don't have:
Why This Airline Is Actually Earning $300 Million From Higher Fuel Costs
Delta’s refinery turns a fuel shock into a rare competitive advantage worth $300 million.simpleflying.com
Except for my absolutely effing neurotic neighbours three doors down. The way she looks at the garden is frighteningly intense. He looks kinda defeated actually, now that I think about it.
Sorry. Yeah. Buy refineries. I’m also considering it if I can get the financing figured out.
