shares of arthur j gallagher  co ajg slid 109 to 21272 wednesday on what proved to be an allaround favorable trading session for the stock market with the sp 500 index spx rising 024 to 456572 and the dow jones industrial average djia rising 031 to 3506121 this was the stocks second consecutive day of losses arthur j gallagher  co closed 791 short of its 52week high 22063 which the company reached on june 30th the stock underperformed when compared to some of its competitors wednesday as marsh  mclennan cos mmc fell 040 to 18736 trading volume 728572 remained 130552 below its 50day average volume of 859124 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