shares of perrigo co plc prgo slumped 077 to 4113 wednesday on what proved to be an allaround favorable trading session for the stock market with the sp 500 index spx rising 059 to 395990 and the dow jones industrial average djia rising 015 to 3187484 perrigo co plc closed 977 short of its 52week high 5090 which the company reached on september 30th the stock demonstrated a mixed performance when compared to some of its competitors wednesday as daiichi sankyo co ltd dskyf rose 069 to 2540