NEW YORK ( TheStreet) -- Westport Innovations (Nasdaq: WPRT) is trading at unusually high volume Tuesday with 3.4 million shares changing hands. It is currently at 4.2 times its average daily volume and trading down $1.01 (-2.3%) at $42.65 as of 3:50 p.m. ET. Westport Innovations has a market cap of $1.84 billion and is part of the consumer goods sector and automotive industry. Shares are up 31.3% year to date as of the close of trading on Monday. Westport Innovations Inc. provides alternative fuel, low-emissions technologies that enable engines to operate on fuels, such as compressed natural gas, liquefied natural gas, hydrogen, and biofuels. TheStreet Ratings rates Westport Innovations as a sell. The company's weaknesses can be seen in multiple areas, such as its deteriorating net income, poor profit margins and weak operating cash flow. You can view the full Westport Innovations Ratings Report. See all heavy volume stocks in our stocks moving on unusual volume list or get investment ideas from our investment research center. Interested in other stocks that are falling on unusually high volume? Get free SMS text alerts sent to you when the action happens by texting HVDOWN to 95370 or select from multiple alert options.