shares of public storage psa slid 200 to 28578 wednesday on what proved to be an allaround poor trading session for the stock market with the sp 500 index spx falling 156 to 392886 and dow jones industrial average djia falling 181 to 3329696 public storage closed 13598 short of its 52week high 42176 which the company achieved on april 21st the stock underperformed when compared to some of its competitors wednesday as extra space storage inc exr fell 149 to 15082 and cubesmart cube fell 125 to 4186 trading volume 10 m eclipsed its 50day average volume of 878446 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