Not every company in biotech land is loved by investors. In fact, many biotechs top the list of companies with high short interest as a percentage of float.

As of the end of February, Myriad Genetics (MYGN 0.59%) was the second-most shorted company as a percentage of float. Sarepta Therapeutics (SRPT 0.14%) came in at No. 9. OncoMed Pharmaceuticals (OMED)VIVUS (VVUS), and MannKind (MNKD 1.22%) rounded out the top five most-shorted biotechs. 

In the slideshow below, you can see their metrics and reasons why some investors don't like them.

Fear not if your favorite biotech makes the list; Questcor Pharmaceuticals and Ziopharm Oncology, which were in last month's list, fell back in favor -- at least somewhat -- dropping off the top-five list.