Why Under Armour, Boot Barn Holdings, and Abaxis Jumped Today

Wednesday was a generally favorable day for the stock market, with modest gains for most major benchmarks even as the Russell 2000once again hit intraday record highs. Most investors' attention was focused on the retail sector, where an especially strong performance from department store giant Macy'ssuggested that the long period of difficult conditions for brick-and-mortar retailers might finally have come to an end.

Ongoing concerns about other factors -- including the move in the 10-year Treasury yield above the 3% mark and the outcome of a possible summit between U.S. and North Korean leaders -- helped keep the gains somewhat in check. But some companies had good news that sent their shares sharply higher. Under Armour (NYSE: UA) (NYSE: UAA), Boot Barn Holdings (NYSE: BOOT), and Abaxis (NASDAQ: ABAX)were among the best performers on the day. Here's why they did so well.