The functional beverage company was crushed like one of its cans in June. Things could get better later this summer.June was cruel for Celsius Holdings (CELH 1.58%) investors. Shares of the functional energy drink specialist fell nearly 30% last month, and have plummeted 40% since third-party reports began detailing softening sales trends in late May.Long-term shareholders are still faring well. Celsius stock is a 38-bagger over the last five years. Despite the June swoon, the shares are still trading margi ...