Buyout talk played a big role in several stocks' moves.
News & Analysis: Achillion Pharmaceuticals
Alexion Pharmaceuticals will reportedly buy clinical-stage rival Achillion Pharmaceuticals in an all-cash deal.
Investors are responding enthusiastically to a key FDA designation for the biotech's leading pipeline candidate.
Positive results announced earlier this week from an early-stage study led to another day of big gains for this clinical-stage biotech.
The biotech stock is enjoying a second day of big gains after the company reported promising results for experimental drug ACH-5228.
Great results from an early-stage clinical study provided a big boost to this small biotech.
Reaching a key clinical study milestone provided a nice boost to the biotech stock.
The aftermath from its disappointing pipeline update early in the week continued to hurt the biotech stock.
Reverberations from the biotech's pipeline update on Monday continued to weigh on the stock.
Achillion's interim data peek failed to impress investors.
Worries about an imminent clinical update sent the stock lower.