SWA was the last major airline to engage in strategic hedging, and came under considerable investor pressure to stop doing that (since it means they can’t lower fares as much when oil is cheap). So they stopped, and investors apparently don’t want airlines to be futures traders disguised as airlines. They prefer credit card referral marketing agencies disguised as airlines.

Now the airlines simply raise fares in lockstep when oil gets expensive, or simply go out of business, like Spirit did last week.