FedEx Corp FDX has hit a rough patch, with its recent quarterly results leaving investors concerned. The stock plummeted over 15% during midday trading on Friday on the earnings news, wiping out gains made during this past quarter.With the drop, FedEx investors have seen only a 1.56% gain over the past year and less than 1% year-to-date.Earnings Miss: A Tough Quarter For FedExReporting first-quarter revenue and earnings that fell short of analyst expectations, the logistics giant cited a "challenging quarte ...