Booking Holdings

Booking Holdings, previously known as the Priceline Group, is the second-largest online travel agency in the world, and its execution and advantages in scale and efficiency make it a formidable challenger and a Wall Street favorite. Booking has steadily gained international market share, with 8% to 11% growth projected annually, and its share price has nearly doubled in the past five years. The next challenge for the owner of brands like Kayak and OpenTable: balancing growth goals and profit margins, which have been squeezed by high advertising costs.