Company had $363m in special items in Q4 which is reflected in the loss for GAAP accounting. Unfortunately, few companies use GAAP standards and like Spirit, report on "adjusted" earnings. So once NK takes out their $363 in special items, they show a profit. So as far as Wall St is concerned, they dont are about the GAAP loss, they care about the adjusted earnings beating estimated by a ton. Its why the stock is up in after hours. The company posted a profit as far as they are concerned.

In case anyone is curious, $348m of that loss was described as...

"2022 includes legal, advisory, and other fees related to the former Agreement and Plan of Merger with Frontier Group Holdings, Inc. and Top Gun Acquisition Corp. (the “Frontier Merger Agreement”), the unsolicited proposal by JetBlue to acquire all of the Company's outstanding shares in an all-cash transaction, and the Agreement and Plan of Merger with JetBlue and Sundown Acquisition Corp. (the "JetBlue Merger Agreement"). In addition, 2022 includes costs associated with the retention bonus programs under the Frontier Merger Agreement and the JetBlue Merger Agreement"