shares of norfolk southern corp nsc slid 139 to 20518 wednesday on what proved to be an allaround rough trading session for the stock market with the sp 500 index spx falling 070 to 389193 and dow jones industrial average djia falling 087 to 3187457 norfolk southern corp closed 8637 short of its 52week high 29155 which the company achieved on march 31st despite its losses the stock outperformed some of its competitors wednesday as union pacific corp unp fell 159 to 19204 trading volume 20 m eclipsed its 50day average volume of 16 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