What: JetBlue Airways (NASDAQ:JBLU) put together another big rally last month, with the stock surging 15%, according to S&P Capital IQ data. This performance helped catapult JetBlue stock to levels not seen since 2003.

JBLU Chart

JetBlue Airways September stock performance. Data by YCharts.

So what: JetBlue's gains come as the company has continued to post the best unit revenue statistics in the airline industry. While mid-single-digit unit revenue declines will be fairly common across the industry for Q3, JetBlue expects its unit revenue to be roughly flat in the quarter.

JetBlue has benefited enormously in 2015 from its relatively concentrated route network. It has seen robust demand in its top markets, such as New York, Boston, and Fort Lauderdale. Meanwhile, it has very little exposure to cities such as Dallas and Chicago where price competition has been pretty brutal this year.

Another key driver of unit revenue and profit growth this year has been the growth and maturation of JetBlue's Mint premium transcontinental service. JetBlue has implemented several price increases for its premium seating due to strong demand and is adding more flights out of New York later this month. It also plans to expand Mint to Boston in 2016.

Jetblue Premium Cabin

Customers love JetBlue's Mint premium seating. Photo: JetBlue.

Of course, like other airlines, JetBlue is also profiting from the sharp drop in oil prices since last summer. The net result is that analysts expect JetBlue's adjusted earnings per share to rocket higher from $0.70 in 2014 to $1.89 in 2015.

Now what: While a number of analysts and investors think that JetBlue stock is running out of steam after surging about 150% in the past 12 months, there's plenty of upside left for the next few years.

Indeed, of the $450 million in profit improvement opportunities outlined at JetBlue's investor day last fall, the bulk of the gains will come in the 2016-2018 period. (That $450 million estimate seems quite conservative, too.) Finally, JetBlue will continue growing at a high single-digit pace for the foreseeable future, driving earnings growth.

JetBlue stock may not be able to double in the next year as it has in the past 12 months. Nevertheless, its abundant profit growth opportunities should keep the stock moving higher over the next several years.

Adam Levine-Weinberg is long January 2017 $17 calls on JetBlue Airways. The Motley Fool has no position in any of the stocks mentioned. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.