NEW YORK ( TheStreet) -- Shares of Clean Diesel Technologies (Nasdaq: CDTI) were gapping down Thursday morning with an open price 15.5% lower than Wednesday's closing price. The stock closed at $3.54 Wednesday and opened today's trading at $2.99. The average volume for Clean Diesel has been 347,600 shares per day over the past 30 days. Clean Diesel has a market cap of $23.7 million and is part of the industrial goods sector and industrial industry. Shares are up 26.4% year to date as of the close of trading on Wednesday. Clean Diesel Technologies, Inc. engages in the manufacture and distribution of emissions control systems and products for heavy duty diesel and light duty vehicle markets. The company operates in two divisions, Heavy Duty Diesel Systems and Catalyst. TheStreet Ratings rates Clean Diesel as a sell. The company's weaknesses can be seen in multiple areas, such as its generally disappointing historical performance in the stock itself, weak operating cash flow and poor profit margins. You can view the full Clean Diesel Ratings Report. Get more investment ideas from our investment research center.