shares of carmax inc kmx inched 047 higher to 9661 wednesday on what proved to be an allaround favorable trading session for the stock market with the sp 500 index spx rising 059 to 395990 and the dow jones industrial average djia rising 015 to 3187484 this was the stocks fourth consecutive day of gains carmax inc closed 5937 short of its 52week high 15598 which the company achieved on november 8th the stock demonstrated a mixed performance when compared to some of its competitors wednesday