After a solid two-year run, Gilead Sciences (GILD -1.15%) 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 0.25%)and Merck (MRK -0.11%) 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.