While the proven Zacks Rank places an emphasis on earnings estimates and estimate revisions to find strong stocks, we also know that investors tend to develop their own individual strategies. With this in mind, we are always looking at value, growth, and momentum trends to discover great companies.

Looking at the history of these trends, perhaps none is more beloved than value investing. This strategy simply looks to identify companies that are being undervalued by the broader market. Value investors rely on traditional forms of analysis on key valuation metrics to find stocks that they believe are undervalued, leaving room for profits.

Zacks has developed the innovative Style Scores system to highlight stocks with specific traits. For example, value investors will be interested in stocks with great grades in the "Value" category. When paired with a high Zacks Rank, "A" grades in the Value category are among the strongest value stocks on the market today.

One stock to keep an eye on is United Natural Foods (UNFI Quick QuoteUNFI - Free Report) . UNFI is currently sporting a Zacks Rank of #2 (Buy), as well as a Value grade of A. The stock is trading with P/E ratio of 6.91 right now. For comparison, its industry sports an average P/E of 17.18. UNFI's Forward P/E has been as high as 13.89 and as low as 3.28, with a median of 8.49, all within the past year.

Investors should also note that UNFI holds a PEG ratio of 0.93. This popular figure is similar to the widely-used P/E ratio, but the PEG ratio also considers a company's expected EPS growth rate. UNFI's PEG compares to its industry's average PEG of 2.26. Over the last 12 months, UNFI's PEG has been as high as 1.69 and as low as 0.46, with a median of 1.11.

These figures are just a handful of the metrics value investors tend to look at, but they help show that United Natural Foods is likely being undervalued right now. Considering this, as well as the strength of its earnings outlook, UNFI feels like a great value stock at the moment.