NEW YORK ( TheStreet) -- Shares of Protalix BioTherapeutics (AMEX: PLX) were gapping down Tuesday morning with an open price 19.1% lower than Monday's closing price. The stock closed at $6.19 Monday and opened today's trading at $5.01. The average volume for Protalix BioTherapeutics has been 131,600 shares per day over the past 30 days. Protalix BioTherapeutics has a market cap of $524.9 million and is part of the health care sector and drugs industry. Shares are down 38% year to date as of the close of trading on Monday. Protalix BioTherapeutics, Inc., a biopharmaceutical company, focuses on the development and commercialization of recombinant therapeutic proteins based on its proprietary ProCellEx protein expression system in the United States. TheStreet Ratings rates Protalix BioTherapeutics as a sell. The company's weaknesses can be seen in multiple areas, such as its deteriorating net income, generally disappointing historical performance in the stock itself and feeble growth in its earnings per share. You can view the full Protalix BioTherapeutics 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.