The beauty brand posted strong growth in the second quarter, but it wasn't enough for Wall Street. It has been a wild week for e.l.f. Beauty (ELF -14.87%) shareholders. After rising earlier in the week along with the broad market, the stock dropped by 15% after the company posted second-quarter earnings. An affordable beauty brand, e.l.f. Beauty is posting strong growth and expanding rapidly internationally. However, its results were below Wall Street's expectations for the high-priced stock. Here's why e.l ...