shares of arthur j gallagher  co ajg slid 144 to 19643 monday on what proved to be an allaround grim trading session for the stock market with the sp 500 index spx falling 154 to 396394 and dow jones industrial average djia falling 145 to 3384946 the stocks fall snapped an eightday winning streak arthur j gallagher  co closed 318 below its 52week high 19961 which the company reached on november 25th despite its losses the stock outperformed some of its competitors monday as marsh  mclennan cos mmc fell 200 to 16838 trading volume 852795 remained 94696 below its 50day average volume of 947491 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