beyhanyazar/iStock via Getty Images I have previously reviewed APA Corporation (NASDAQ:APA) and, a while ago, Callon Petroleum. Benefits from APA's acquisition of Callon, the upturn in the natural gas market, as well as long-term prospectivity/ optionality in Suriname and elsewhere, along with APA’s current bargain price lead me to upgrade APA Corporation from Hold to Buy. APA (previously known and still sometime referred to as Apache) produces gas and oil from the U.S., Egypt, and—at a maintenance leve ...