shares of regeneron pharmaceuticals inc regn slumped 099 to 75150 monday on what proved to be an allaround mixed trading session for the stock market with the sp 500 index spx rising 002 to 419263 and the dow jones industrial average djia falling 042 to 3328658 regeneron pharmaceuticals inc closed 8605 below its 52week high 83755 which the company achieved on april 5th the stock underperformed when compared to some of its competitors monday as amgen inc amgn rose 026 to 22399 moderna inc mrna rose 040 to 12674 and gilead sciences inc gild fell 029 to 7862 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