Gilead's Shares Hit A New 52-Week Low: Here Are 2 Reasons Why

Shares of

lost more than 5 percent on Friday and hit a new 52-week low of $82.41 after the company

a change to its senior leadership. Effective March 10, 2016, Gilead's current Chairman and CEO John Martin will assume the role of Executive Chairman of the company. Replacing Martin will be John Milligan, the company's current President and Chief Operating Officer. Martin joined Gilead in 1990 and was named CEO in 1996 and Chairman of the Board in 2008. Milligan also joined the company in 1990 and was named Chief Operating Officer in 2007 and President in 2008. Investors and traders were also reacting to

's

Firece Biotech,

Merck's new drug will compete "toe-to-toe" with Gilead's Hep C "goliath," Sovaldi.