JPMorgan analyst Jamie Baker double upgraded Spirit Airlines (SAVE) to Overweight from Underweight with an unchanged price target of $46.

The stock closed Friday up 9c to $35.49. Down 20% year-to-date, Spirit's shares are the sector's worst performer, Baker tells investors in a research note. The sell-off took place despite the removal of the pilot overhang and the unexpected lease-to-purchase swap "which negates much of the pilot impact on CASM," the analyst adds. Further, Baker now sees a "more plausible" path back to the $4 earnings per share range next year.

The analyst this morning also downgraded shares of JetBlue (JBLU) to Neutral. He still likes the risk/reward profile on the "Big Three" relative to the discounters, and maintains Overweight ratings on American Airlines (AAL), Delta Air Lines (DAL) and United Continental (UAL).