Which billionaire founded the sports apparel company Under Armour?

The billionaire who founded the sports apparel company Under Armour is Kevin Plank.

Plank was a University of Maryland football player who disliked how quickly the cotton T-shirts worn under his jersey became saturated with sweat. He noticed that his compression shorts stayed relatively dry, inspiring him to create a lightweight, moisture-wicking performance shirt.

Under Armour was founded on September 25, 1996, when Plank was 24. He began developing and selling the first prototypes from his grandmother’s townhouse in Washington, D.C., carrying apparel in his car and pitching it to athletes and teams. The company moved its operations to Baltimore in 1998, where it remains headquartered.

Under Armour’s name is sometimes confused with older sportswear brands or their founders. Bill Bowerman co-founded Nike, Phil Knight co-founded Nike, and Adolf Dassler founded Adidas. Plank’s breakthrough was not a shoe or a traditional cotton jersey, but technical athletic clothing designed to keep athletes dry and comfortable.