Shares of Human Genome Sciences surged on Thursday, nearly doubling after the company rejected an unsolicited buyout bid worth $2.6 billion in cash from GlaxoSmithKline .
On the news, the NYSE Arca Biotech Index is having its best day since December 2010.
Among the best performing stocks in the index, Gilead Sciences stock rose after one of its drugs showed positive results from a key hepatitis-C study.
Source: Ian Wilson
GlaxoSmithKline
Below are some of the largest biotech deals announced (including bids and letters of intent) in the last six months.
