After a solid two-year run, Gilead Sciences (GILD 0.25%) has fallen from investors graces, down for the year. The biotech has become increasingly reliant on its hepatitis C drug Sovaldi, with competition from AbbVie (ABBV -0.93%)and Merck (MRK -1.77%) around the corner.

In the slideshow below, you'll find three reasons investors are down on Gilead Sciences and thoughts on the biotech's future.