These Stocks Just Dropped by 40% and 15% -- Should You Buy the Dip?

It might be a great time to buy low.Earnings season can be a volatile time in the stock market. Some corporations produce financial results that are impressive enough to send their share prices soaring, while others move in the exact opposite direction. Medical device specialist DexCom (DXCM -7.88%) and social media platform Pinterest (PINS -0.21%) are in the latter group.Both failed to impress investors with their second-quarter results. DexCom's stock dropped by about 40% in one day, while Pinterest's dec ...