shares of regeneron pharmaceuticals inc regn rallied 121 to 83035 thursday on what proved to be an allaround favorable trading session for the stock market with the sp 500 index spx rising 133 to 414622 and the dow jones industrial average djia rising 114 to 3402969 this was the stocks second consecutive day of gains regeneron pharmaceuticals inc closed 720 below its 52week high 83755 which the company achieved on april 5th the stock demonstrated a mixed performance when compared to some of