NEW YORK ( TheStreet) -- Shares of Cerus Corporation (Nasdaq: CERS) were gapping down Friday morning with an open price 10.7% lower than Thursday's closing price. The stock closed at $3.36 Thursday and opened today's trading at $3. The average volume for Cerus has been 700,300 shares per day over the past 30 days. Cerus has a market cap of $131.2 million and is part of the health care sector and drugs industry. Shares are up 36.6% year to date as of the close of trading on Thursday. Cerus Corporation, a biomedical products company, engages in the development and commercialization of the INTERCEPT Blood System. The company's INTERCEPT system is designed to inactivate blood-borne pathogens in donated blood components intended for transfusion. TheStreet Ratings rates Cerus as sell. Among the areas we feel are negative, one of the most important has been an overall disappointing return on equity. You can view the full Cerus Ratings Report. Get more investment ideas from our investment research center.