shares of carmax inc kmx slumped 048 to 15395 monday on what proved to be an allaround favorable trading session for the stock market with the sp 500 index spx rising 009 to 470170 and the dow jones industrial average djia rising 029 to 3643222 the stocks fall snapped a sixday winning streak carmax inc closed 079 below its 52week high 15474 which the company reached on november 5th the stock demonstrated a mixed performance when compared to some of its competitors monday as copart inc cprt rose 016 to 15417 autonation inc an fell 104 to 12236 and penske automotive group inc pag fell 078 to 11099 trading volume 15 m eclipsed its 50day average volume of 11 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