shares of merck  co inc mrk slid 024 to 8784 monday on what proved to be an allaround great trading session for the stock market with the sp 500 index spx rising 018 to 461367 and the dow jones industrial average djia rising 026 to 3591384 the stocks fall snapped a twoday winning streak merck  co inc closed 062 short of its 52week high 8846 which the company reached on october 29th the stock underperformed when compared to some of its competitors monday as johnson  johnson jnj rose 009 to 16302 roche holding ag part cert rhhvf rose 195 to 39149 and pfizer inc pfe fell 023 to 4364 trading volume 109 m remained 42 million below its 50day average volume of 152 m editors note this story was autogenerated by automated insights an automation technology provider using data from dow jones and factset see our market data terms of use