shares of occidental petroleum corp oxy slid 563 to 5680 wednesday on what proved to be an allaround poor trading session for the stock market with the sp 500 index spx falling 070 to 389193 and dow jones industrial average djia falling 087 to 3187457 occidental petroleum corp closed 2033 short of its 52week high 7713 which the company achieved on august 29th the stock demonstrated a mixed performance when compared to some of its competitors wednesday as chevron corp cvx fell 433 to 15380