REXX

Rex Energy Corporation

An independent oil and gas exploration and production company, Rex Energy hunted for natural gas and oil in the Appalachian Basin's Marcellus and Utica shale formations, using hydraulic fracturing to pull fuel from deep underground. Founded in 2007 and based in State College, Pennsylvania—home of Penn State University—the company went public that same year. Its name comes from the Latin word for "king," and its shale-gas fields helped feed the region's drilling boom before it filed for bankruptcy in 2018.