Live feed09:00:31·528dINSIDERFilingvia QuantisnowPresident and CEO Duff Mark exercised 25,000 shares at a strike of $3.15 and covered exercise/tax liability with 7,443 shares, increasing direct ownership by 16% to 130,609 units (SEC Form 4)ByQuantisnow·Wall Street's wire, on your screen.PESI· Perma-Fix Environmental Services Inc.IndustrialsOriginal source