What happened

Shares of World Fuel Services Corp. (INT -0.52%) took off on Friday and were up nearly 20% by 11:15 a.m. EDT. Fueling the surge were its stronger-than-expected second-quarter results.

So what

World Fuel Services recorded $31.7 million ($0.47 per share) of adjusted net income during the second quarter, which beat the consensus estimate by $0.02 per share. Driving the company's expectation-beating result was record profitability in its aviation segment. Overall, gross profit in that business increased 15% year over year due to strong government-related sales as well as solid results in its core international resale operations. That helped offset an 8% decrease in gross profit from the marine segment.

An airplane being refueled while the sun sets in the background.

Image source: Getty Images.

The company noted that its cost management initiative helped improve margins versus the first half of 2017. Overall, it indicated that it had achieved 170 of the 250-basis-point improvement in operating margins that it's targeting. Its progress toward that goal "will aid us in growing future profitability and free cash flow," according to CFO Ira Birns. Add that to the company's portfolio refinement and organic growth initiatives, and it's positioned for "improved operating performance in 2018 and 2019," according to CEO Michael Kasbar.

Now what

World Fuel Services' financial results appear to be turning the corner, which is nice to see after its rough start to the year. However, the company needs to show more than just one good quarter to convince investors that its problems are in the past. Because of that, they should continue watching from the sidelines and consider one of these top energy stocks instead.