What happened

Shares of discount airline Spirit Airlines Incorporated (NYSE:SAVE) jumped nearly 14% in early Thursday trading after the company announced fiscal third-quarter earnings that beat analyst expectations. Spirit reported $0.94 per share in pro forma profits for Q3 2017, $0.04 ahead of Wall Street's estimates. Revenues were likewise ahead of schedule, coming in at $687.2 million for the quarter, above analysts' expected $686.6 million.

Spirit Airlines stock has retraced somewhat since its morning pop but was still up 9.5% as of 11:35 a.m. EDT.

Spirit airplane on the tarmac

Everything's looking sunnier for Spirit this morning. Image source: Spirit Airlines.

So what

So much for how Spirit performed relative to analyst expectations. Now how did it perform objectively? Year over year, spirit grew its revenues by 11%. That's the good news. The bad news is that operating costs surged even faster, rising 20% year over year and driving down Spirit's operating profits by 23% in consequence.

On the bottom line, net income per diluted share fell 26% in comparison to last year's Q3, landing at $0.87 per share -- bad news no doubt, but thanks to the even lower expectations out of Wall Street, Spirit shares are soaring regardless.

Now what

Could we see a repeat of this dynamic next quarter? Maybe. Spirit Airlines management declined to give guidance on Q4 earnings in its report. Analysts, however, are not feeling optimistic.

If expectations for Q3 were low, then expectations for Q4 look positively subterranean, with Wall Street projecting just $0.45 in per-share profit in the year's final quarter. (That's barely half what Spirit earned in last year's Q4.) With the "multiple hurricanes" that afflicted Spirit in Q3 2017 now behind the company, Spirit could surprise to the upside once again.