Regeneron Stock Yo-Yoes, But Hints That It Could Be Ready To Flex Its Dealmaking Muscles | Investor's Business DailyBREAKING: [Trump Names Warsh New Fed Chairman]---Regeneron stock yo-yoed after Friday's open on the potential for business development deals following a solid fourth-quarter report. RBC Capital Markets analyst Brian Abrahams suggested Regeneron Pharmaceuticals (REGN) could be on the lookout for deals in the new year. The press release reads "more direct" on the potential for business developme ...