shares of american tower reit amt slipped 324 to 19315 monday on what proved to be an allaround positive trading session for the stock market with the sp 500 index spx rising 016 to 397753 and the dow jones industrial average djia rising 060 to 3243208 american tower reit closed 8932 short of its 52week high 28247 which the company reached on august 15th the stock underperformed when compared to some of its competitors monday as crown castle inc cci fell 154 to 12747 and sba communications corp sbac fell 203 to 25120 trading volume 23 m eclipsed its 50day average volume of 21 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