Dyax, Juno Therapeutics Soar Following Biotech Index Rebalance

A little before noon on Thursday, Dyax Corp. (NASDAQ: DYAX) shares soared over 10 percent and Juno Therapeutics Inc (NASDAQ: JUNO) rose about 8 percent following an expected portfolio rebalance announcement from NYSE Arca Biotechnology Index (NYSE: BTK).

Dyax and Juno Therapeutics have replaced PDL Bioscience (NASDAQ: PDLI) and Exact Sciences Corporation (NASDAQ: EXAS), of which both stocks fell about 3 percent before reports could confirm the rebalancing.

Action in all four biotech stocks was compounded as First Trust's NYSE Arca Biotech Index Fund (NYSE: FBT) would also be rebalancing. According to a note being passed around trading desks, the First Trust fund reportedly made the following transactions:

Added 1,972,00 shares of Juno Therapeutics

• Added 3,776,600 shares of Dyax Corp
• Deleted 20,076,800 shares of PDL BioPharma
• Deleted 4,559,00 shares of Exact Sciences

Just after 1:00 p.m. EDT, First Trust's NYSE Arca Biotech Index Fund traded up almost 2.3 percent.