shares of merck  co inc mrk shed 108 to 10440 wednesday on what proved to be an allaround rough trading session for the stock market with the sp 500 index spx falling 165 to 393697 and dow jones industrial average djia falling 163 to 3203011 this was the stocks second consecutive day of losses merck  co inc closed 1109 below its 52week high 11549 which the company achieved on january 6th despite its losses the stock outperformed some of its competitors wednesday as johnson  johnson jnj fell 185 to 15105 and pfizer inc pfe fell 160 to 4001 trading volume 57 m remained 35 million below its 50day average volume of 92 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