shares of carmax inc kmx slid 330 to 10958 wednesday on what proved to be an allaround mixed trading session for the stock market with the sp 500 index spx rising 009 to 447501 and the dow jones industrial average djia falling 016 to 3493427 the stocks fall snapped a twoday winning streak carmax inc closed 4640 below its 52week high 15598 which the company reached on november 8th the stock underperformed when compared to some of its competitors wednesday as copart inc cprt rose 007 to 12687 autonation inc an rose 206 to 11112 and penske automotive group inc pag rose 222 to 10271 trading volume 16 m eclipsed its 50day average volume of 15 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