The stock market was mixed on Thursday, with major indexes finishing on either side of the unchanged mark. Absent big news on the geopolitical or macroeconomic fronts, investors seemed to focus largely on earnings season, which will hit its high point in the next week or two. A flurry of financial reports made news for many individual companies, and Southwest Airlines (NYSE:LUV), Triumph Group (NYSE:TGI), and Xilinx (NASDAQ:XLNX) were among the top performers. Here's why they did so well.

Southwest gains altitude

Check out the latest Southwest Airlines earnings call transcript.

Shares of Southwest Airlines rose 6% after the airline giant reported promising results for the fourth quarter. Southwest said that it made money for the 46th year in a row, and CEO Gary Kelly highlighted not only the many milestones the airline passed during 2018 but also its prospects for 2019. Among its top priorities are opening routes to Hawaii, as well as controlling capacity growth and making smart decisions about its route structure and flight schedules. Despite some short-term negative impacts from the government shutdown, Southwest stock looks like it's been cleared for takeoff.

Airplane on tarmac in a desert environment, with Southwest colors and logo on it.

Image source: Southwest.

Triumph gets a win

Check out the latest Triumph Group earnings call transcript.

Elsewhere in the aerospace industry, Triumph Group saw its stock climb 26% in the wake of an agreement with a key supply customer. Aircraft manufacturer Bombardier said that it will acquire Triumph's wing manufacturing operations and assets associated with the Global 7500 business aircraft program, paying what Bombardier called "a nominal cash consideration." The move will help Bombardier in its efforts to play up the prospects for Global 7500 sales, as the aircraft just entered service in December. For Triumph, the deal is seen boosting cash flow in fiscal 2020, and despite the lack of details, investors seem convinced that the move will give Triumph greater certainty in its future business prospects and more of an ability to seek growth opportunities.

Xilinx rides chips higher

Check out the latest Xilinx earnings call transcript.

Finally, shares of Xilinx jumped more than 18%. The semiconductor manufacturer said that revenue soared 34% in its fiscal third quarter compared to the prior-year period, with particular strength in products for the communications industry. Xilinx had good success in the Asia-Pacific region, where sales were higher by nearly half over the past 12 months, and the company's lineup of advanced products dramatically outpaced sales of its core lines. CEO Victor Peng also expects solid results ahead, and with plenty of good news from some of Xilinx's rivals, the entire chip sector did quite well today.

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.