shares of merck  co inc mrk slipped 055 to 7595 tuesday on what proved to be an allaround poor trading session for the stock market with the sp 500 index spx falling 101 to 430476 and dow jones industrial average djia falling 142 to 3359661 merck  co inc closed 1545 below its 52week high 9140 which the company achieved on november 4th the stock demonstrated a mixed performance when compared to some of its competitors tuesday as johnson  johnson jnj fell 136 to 16114 roche holding ag part cert rhhvf rose 352 to 37890 and pfizer inc pfe fell 206 to 4753 trading volume 90 m remained 40 million below its 50day average volume of 131 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