Live feed18:05:22·1606dINSIDERFilingvia QuantisnowSEC Form 4: Usher Christopher Theron covered exercise/tax liability with 8,639 shares, decreasing direct ownership by 2% to 341,749 units (withholding tax)ByQuantisnow·Wall Street's wire, on your screen.IO· Ion Geophysical CorporationEnergyOriginal source