NorthWestern Co. (NASDAQ:NWE – Get Free Report) was down 3.8% during mid-day trading on Tuesday . The company traded as low as $55.38 and last traded at $55.39. Approximately 139,833 shares traded hands during mid-day trading, a decline of 57% from the average daily volume of 328,571 shares. The stock had previously closed at $57.60. […]