NEW YORK ( TheStreet) -- Shares of Align Technology (Nasdaq: ALGN) were gapping up Friday morning with an open price 20.7% higher than Thursday's closing price. The stock closed at $17.81 Thursday and opened today's trading at $21.49. The average volume for Align Technology has been 649,300 shares per day over the past 30 days. Align Technology has a market cap of $1.4 billion and is part of the health care sector and health services industry. Shares are down 8.9% year to date as of the close of trading on Thursday. Align Technology, Inc. designs, manufactures, and markets the invisalign system for treating malocclusion or the misalignment of teeth. Invisalign corrects malocclusion using a series of clear, nearly invisible, removable appliances that gently move teeth to a desired final position. The company has a P/E ratio of 25.4, equal to the average health services industry P/E ratio and above the S&P 500 P/E ratio of 17.7. TheStreet Ratings rates Align Technology as a buy. The company's strengths can be seen in multiple areas, such as its robust revenue growth, largely solid financial position with reasonable debt levels by most measures, expanding profit margins, reasonable valuation levels and notable return on equity. We feel these strengths outweigh the fact that the company has had lackluster performance in the stock itself. You can view the full Align Technology Ratings Report. Get more investment ideas from our investment research center. Interested in other stocks that are gapping up? Get free SMS text alerts sent to you when the action happens by texting UP to 95370 or select from multiple alert options.