 Shares of OpGen Inc. OPGN, -4.17 rocketed 31.9 in active premarket trading Monday, after the precision medicine company provided a revenue update following the recent Food and Drug Administration clearance of its Acuitas AMR Gene Panel to aid in the diagnosis of severe infections. Trading volume spiked to 5.1 million shares ahead of the open, compared with the full-day average of about 1.8 million shares. 