Will the battle for Spirit set off a rush for airline deals? Here's what could happen

JetBlue Airways plane seen at Cancun International Airport. On Wednesday, 23 March 2022, in Cancun International Airport, Cancun, Quintana Roo, Mexico.
Artur Widak | Nurphoto | Getty Images

JetBlue Airways last week disclosed a surprise bid for Spirit Airlines, sparking a battle for the discounter that in February announced a tie-up with fellow budget carrier Frontier Airlines.

JetBlue's bid for Spirit came almost 14 years to the day that Delta Air Lines announced its industry-shaping combination with Northwest Airlines. That set off a wave of airline deal-making over the following eight years that has left four airlines — American, United, Delta and Southwest — in control of about 80% of the U.S. market.