Under Armour started when the founder, a former football player, wanted a shirt that wouldn’t be soaked with sweat after a few minutes of playing football. He developed a compression shirt made of material that stayed dry and invested a few thousand dollars in producing 500 shirts. Those shirts were given to former teammates to try and they loved them. Word spread, people wanted more, and the company was born. It has since expanded into many kinds of activewear and footwear but still targets a niche market: those who don’t want sweaty clothes when they exercise