shares of regeneron pharmaceuticals inc regn shed 769 to 68049 monday on what proved to be an allaround grim trading session for the stock market with the sp 500 index spx falling 008 to 389209 and dow jones industrial average djia falling 034 to 3351765 regeneron pharmaceuticals inc closed 9851 short of its 52week high 77900 which the company reached on december 8th the stock underperformed when compared to some of its competitors monday as amgen inc amgn fell 185 to 27012 moderna inc mrna rose 200 to 18395 and gilead sciences inc gild fell 338 to 8510 trading volume 17 m eclipsed its 50day average volume of 634708 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