Shares of Amylin Pharmaceuticals (NASDAQ:AMLN) rose 48% to $22.81 in morning trading after Bloomberg reported the company rejected a bid from Bristol-Myers Squibb for $3.5 billion, or $22 a share.Amylin Pharmaceuticals should find initial support at its 50-day moving average (MA) of $15.60 and further support at its 200-day MA of $12.20.In the last five trading sessions, the 50-day MA has climbed 1.61% while the 200-day MA has risen 0.37%.