Credit Suisse analyst Jose Caiado De Sousa upgraded Spirit Airlines to Outperform from Neutral and raised his price target on the shares to $77 from $59. Following a "massive" Q4 unit revenue guidance boost last week, the analyst sees further upside in the equity into H1 of 2019, with expected continued momentum in non-ticket revenue production amid a lower oil environment and a benign competitive backdrop. The company appears to be an "underappreciated" RASM story as it continues to execute well, with plenty of company-specific ancillary initiatives as it unleashes the value of its technology investments, he contends.