Most people do this, this isn't unique to Costco or Southwest Airlines. That's why future contracts exist. Although it rarely guarantees a delivery, it does all

Most people do this, this isn't unique to Costco or Southwest Airlines. That's why future contracts exist. Although it rarely guarantees a delivery, it does allow you to hedge against increases/decreases as a company. You can take a look at APU0000708111 and see how crazy it's been the past 2-3 months.