NEW YORK ( TheStreet) -- Shares of Optimer Pharmaceuticals (Nasdaq: OPTR) were gapping down Friday morning with an open price 10.5% lower than Thursday's closing price. The stock closed at $14.64 Thursday and opened today's trading at $13.10. The average volume for Optimer has been 1.3 million shares per day over the past 30 days. Optimer has a market cap of $668.8 million and is part of the health care sector and drugs industry. Shares are up 29.4% year to date as of the close of trading on Thursday. Optimer Pharmaceuticals, Inc., a biopharmaceutical company, focuses on discovering, developing, and commercializing hospital specialty products worldwide. It develops products that treat gastrointestinal infections and related diseases. TheStreet Ratings rates Optimer as a sell. The company's weaknesses can be seen in multiple areas, such as its unimpressive growth in net income and weak operating cash flow. You can view the full Optimer Ratings Report. Get more investment ideas from our investment research center. Interested in other stocks that are gapping down? Get free SMS text alerts sent to you when the action happens by texting DOWN to 95370 or select from multiple alert options.