You only need one, but here are four.Are you looking for a stock demonstrating phenomenal growth with incredible opportunities? One that's profitable and trades at a reasonable valuation? Then MercadoLibre (MELI -2.56%) fits the bill. Read on to see why.1. A never-ending growth machineYou might be surprised to learn that MercadLibre is almost as old as Amazon. However, its Latin American population didn't catch onto the internet as quickly as people did in the U.S. Only recently has MercadoLibre expanded it ...