shares of carmax inc kmx slid 152 to 14303 tuesday on what proved to be an allaround poor trading session for the stock market with the sp 500 index spx falling 204 to 435263 and dow jones industrial average djia falling 163 to 3429999 the stocks fall snapped a fourday winning streak carmax inc closed 395 short of its 52week high 14698 which the company achieved on september 27th the stock demonstrated a mixed performance when compared to some of its competitors tuesday as copart inc cprt fell 380 to 14114 autonation inc an fell 155 to 12248 and penske automotive group inc pag fell 139 to 10483 trading volume 11 m eclipsed its 50day average volume of 835287 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