Here at Zacks, we focus on our proven ranking system, which places an emphasis on earnings estimates and estimate revisions, to find winning stocks. But we also understand that investors develop their own strategies, so we are constantly looking at the latest trends in value, growth, and momentum to find strong companies for our readers.

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 use tried-and-true metrics and fundamental analysis to find companies that they believe are undervalued at their current share price levels.

On top of the Zacks Rank, investors can also look at our innovative Style Scores system to find stocks with specific traits. For example, value investors will want to focus on the "Value" category. Stocks with high Zacks Ranks and "A" grades for Value will be some of the highest-quality value stocks on the market today.

One stock to keep an eye on is Gap (GPS-Free Report) . GPS is currently sporting a Zacks Rank of #2 (Buy), as well as a Value grade of A. The stock is trading with a P/E ratio of 11.07, which compares to its industry's average of 12.07. Over the past year, GPS's Forward P/E has been as high as 11.42 and as low as 7.31, with a median of 9.28.

We also note that GPS holds a PEG ratio of 1.23. This figure is similar to the commonly-used P/E ratio, with the PEG ratio also factoring in a company's expected earnings growth rate. GPS's industry currently sports an average PEG of 1.25. Over the last 12 months, GPS's PEG has been as high as 1.27 and as low as 0.81, with a median of 1.03.

Another notable valuation metric for GPS is its P/B ratio of 1.86. The P/B is a method of comparing a stock's market value to its book value, which is defined as total assets minus total liabilities. GPS's current P/B looks attractive when compared to its industry's average P/B of 3.35. Over the past year, GPS's P/B has been as high as 3.17 and as low as 1.59, with a median of 1.91.

Value investors also use the P/S ratio. The P/S ratio is is calculated as price divided by sales. Some people prefer this metric because sales are harder to manipulate on an income statement. This means it could be a truer performance indicator. GPS has a P/S ratio of 0.41. This compares to its industry's average P/S of 0.48.

Finally, investors should note that GPS has a P/CF ratio of 5. This data point considers a firm's operating cash flow and is frequently used to find companies that are undervalued when considering their solid cash outlook. GPS's P/CF compares to its industry's average P/CF of 8.59. GPS's P/CF has been as high as 7.44 and as low as 3.93, with a median of 4.75, all within the past year.

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