shares of ansys inc anss slid 315 to 24803 thursday on what proved to be an allaround rough trading session for the stock market with the sp 500 index spx falling 249 to 389575 and dow jones industrial average djia falling 225 to 3320222 the stocks fall snapped a threeday winning streak ansys inc closed 16519 short of its 52week high 41322 which the company achieved on december 28th the stock demonstrated a mixed performance when compared to some of its competitors thursday as microsoft corp