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 use a variety of methods, including tried-and-true valuation metrics, to find these stocks.In addition to the Zacks Rank, investors looking for stocks with specific traits can utilize our Style Scores system. Of course, value investors will be most interested in the system's "Value" category. Stocks with "A" grades for Value and high Zacks Ranks are among the best value stocks available at any given moment.Principal Financial Group (PFG) is a stock many investors are watching right now. PFG is currently holding a Zacks Rank of #2 (Buy) and a Value grade of A. The stock is trading with a P/E ratio of 10.38, which compares to its industry's average of 10.57. Over the last 12 months, PFG's Forward P/E has been as high as 11.61 and as low as 8.62, with a median of 10.17.Investors should also recognize that PFG has a P/B ratio of 1.66. The P/B ratio is used to compare a stock's market value with its book value, which is defined as total assets minus total liabilities. This stock's P/B looks attractive against its industry's average P/B of 2.14. Within the past 52 weeks, PFG's P/B has been as high as 1.82 and as low as 1.04, with a median of 1.27.Value investors also frequently use the P/S ratio. This metric is found by dividing a stock's price with the company's revenue. This is a prefered metric because revenue can't really be manipulated, so sales are often a truer performance indicator. PFG has a P/S ratio of 1.03. This compares to its industry's average P/S of 2.26.These are only a few of the key metrics included in Principal Financial Group's strong Value grade, but they help show that the stock is likely undervalued right now. When factoring in the strength of its earnings outlook, PFG looks like an impressive value stock at the moment. This Little-Known Semiconductor Stock Could Be Your Portfolio’s Hedge Against Inflation Everyone uses semiconductors. But only a small number of people know what they are and what they do. If you use a smartphone, computer, microwave, digital camera or refrigerator (and that’s just the tip of the iceberg), you have a need for semiconductors. That’s why their importance can’t be overstated and their disruption in the supply chain has such a global effect. But every cloud has a silver lining. Shockwaves to the international supply chain from the global pandemic have unearthed a tremendous opportunity for investors. And today, Zacks' leading stock strategist is revealing the one semiconductor stock that stands to gain the most in a new FREE report. It's yours at no cost and with no obligation.>>Yes, I Want to Help Protect My Portfolio During the RecessionWant 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 Principal Financial Group, Inc. (PFG): Free Stock Analysis Report To read this article on Zacks.com click here. Zacks Investment Research