Western Digital (WDC) closed at $46.60 in the latest trading session, marking a -0.28% move from the prior day. This change lagged the S&P 500's 0.22% gain on the day. Meanwhile, the Dow gained 0.49%, and the Nasdaq, a tech-heavy index, lost 0.15%.Prior to today's trading, shares of the maker of hard drives for businesses and personal computers had lost 16.3% over the past month. This has lagged the Computer and Technology sector's loss of 2.32% and the S&P 500's loss of 0.57% in that time.Investors will be hoping for strength from WDC as it approaches its next earnings release, which is expected to be January 24, 2019. In that report, analysts expect WDC to post earnings of $1.59 per share. This would mark a year-over-year decline of 59.75%. Meanwhile, the Zacks Consensus Estimate for revenue is projecting net sales of $4.31 billion, down 19.31% from the year-ago period.For the full year, our Zacks Consensus Estimates are projecting earnings of $7.30 per share and revenue of $18.13 billion, which would represent changes of -50.44% and -12.17%, respectively, from the prior year.It is also important to note the recent changes to analyst estimates for WDC. These revisions help to show the ever-changing nature of near-term business trends. As a result, we can interpret positive estimate revisions as a good sign for 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 40.79% lower within the past month. WDC is currently sporting a Zacks Rank of #5 (Strong Sell).Valuation is also important, so investors should note that WDC has a Forward P/E ratio of 6.4 right now. This valuation marks a discount compared to its industry's average Forward P/E of 15.55.Also, we should mention that WDC has a PEG ratio of 0.34. 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. Computer- Storage Devices stocks are, on average, holding a PEG ratio of 1.1 based on yesterday's closing prices.The Computer- Storage Devices industry is part of the Computer and Technology sector. This group has a Zacks Industry Rank of 173, putting it in the bottom 33% of all 250+ industries.The Zacks Industry Rank includes is listed in order from best to worst in terms of the average Zacks Rank of the individual companies within each of these sectors. Our research shows that the top 50% rated industries outperform the bottom half by a factor of 2 to 1.Make sure to utilize Zacks. Com to follow all of these stock-moving metrics, and more, in the coming trading sessions.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 Western Digital Corporation (WDC): Free Stock Analysis Report To read this article on Zacks.com click here.