In the latest trading session, Align Technology (ALGN) closed at $219.99, marking a +0.31% move from the previous day. This move outpaced the S&P 500's daily loss of 0.76%. Meanwhile, the Dow lost 0.82%, and the Nasdaq, a tech-heavy index, lost 0.9%.Prior to today's trading, shares of the maker of the Invisalign tooth-straightening system had lost 34.52% over the past month. This has lagged the Medical sector's loss of 0.16% and the S&P 500's loss of 1.41% in that time.Wall Street will be looking for positivity from ALGN as it approaches its next earnings report date. This is expected to be January 29, 2019. On that day, ALGN is projected to report earnings of $1.16 per share, which would represent a year-over-year decline of 2.52%. Meanwhile, the Zacks Consensus Estimate for revenue is projecting net sales of $512.12 million, up 21.55% from the year-ago period.ALGN's full-year Zacks Consensus Estimates are calling for earnings of $4.89 per share and revenue of $1.95 billion. These results would represent year-over-year changes of +25.71% and +32.13%, respectively.Investors should also note any recent changes to analyst estimates for ALGN. These recent revisions tend to reflect the evolving nature of short-term business trends. With this in mind, we can consider positive estimate revisions a sign of optimism about the company's business outlook.Research indicates that these estimate revisions are directly correlated with near-term share price momentum. We developed the Zacks Rank to capitalize on this phenomenon. Our system takes these estimate changes into account and delivers a clear, actionable rating model.Ranging from #1 (Strong Buy) to #5 (Strong Sell), the Zacks Rank system has a proven, outside-audited track record of outperformance, with #1 stocks returning an average of +25% annually since 1988. The Zacks Consensus EPS estimate has moved 1.94% lower within the past month. ALGN is holding a Zacks Rank of #4 (Sell) right now.Investors should also note ALGN's current valuation metrics, including its Forward P/E ratio of 44.9. Its industry sports an average Forward P/E of 20.61, so we one might conclude that ALGN is trading at a premium comparatively.It is also worth noting that ALGN currently has a PEG ratio of 1.91. This popular metric is similar to the widely-known P/E ratio, with the difference being that the PEG ratio also takes into account the company's expected earnings growth rate. The Medical - Dental Supplies industry currently had an average PEG ratio of 2 as of yesterday's close.The Medical - Dental Supplies industry is part of the Medical sector. This industry currently has a Zacks Industry Rank of 105, which puts it in the top 41% of all 250+ industries.The Zacks Industry Rank gauges the strength of our individual industry groups by measuring the average Zacks Rank of the individual stocks within the groups. Our research shows that the top 50% rated industries outperform the bottom half by a factor of 2 to 1.To follow ALGN in the coming trading sessions, be sure to utilize Zacks.com.Want the latest recommendations from Zacks Investment Research? Today, you can download 7 Best Stocks for the Next 30 Days. Click to get this free report Align Technology, Inc. (ALGN): Free Stock Analysis Report To read this article on Zacks.com click here. Zacks Investment Research