shares of arthur j gallagher  co ajg shed 105 to 21405 friday on what proved to be an allaround grim trading session for the stock market with the sp 500 index spx falling 029 to 439895 and dow jones industrial average djia falling 055 to 3373488 arthur j gallagher  co closed 658 below its 52week high 22063 which the company achieved on june 30th the stock underperformed when compared to some of its competitors friday as marsh  mclennan cos mmc fell 090 to 18399 trading volume 578766 remained 344895 below its 50day average volume of 923661 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