Looking at a company's short interest should be an integral part of an investor's due diligence. A high short interest isn't necessarily a reason shun a company, but understanding why investors are shorting the stock is important. The shorts may be wrong, but investors should be able to convince themselves of that before hitting the buy button.

In the following slideshow, you'll find info on the five most shorted biotechs on the Nasdaq -- Myraid Genetics (MYGN 1.07%), Sarepta Therapeutics (SRPT 1.95%), Questcor Pharmaceuticals (NASDAQ: QCOR), Ziopharm Oncology (TCRT -3.84%), and MannKind (MNKD 6.26%) -- and a brief explanation on why each company is hated so much.