shares of carmax inc kmx shed 281 to 9697 tuesday on what proved to be an allaround dismal trading session for the stock market with the sp 500 index spx falling 042 to 412247 and dow jones industrial average djia falling 018 to 3277441 carmax inc closed 5901 below its 52week high 15598 which the company reached on november 8th the stock underperformed when compared to some of its competitors tuesday as copart inc cprt fell 203 to 12641 autonation inc an fell 155 to 12114 and penske automotive group inc pag fell 153 to 11466 trading volume 709418 remained 735829 below its 50day average volume of 14 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