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.

Of these, perhaps no stock market trend is more popular than value investing, which is a strategy that has proven to be successful in all sorts of market environments. Value investors use fundamental analysis and traditional valuation metrics to find stocks that they believe are being undervalued by the market at large.

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 company value investors might notice is Reinsurance Group of America (RGA Quick QuoteRGA - Free Report) . RGA is currently sporting a Zacks Rank of #2 (Buy), as well as an A grade for Value.

We should also highlight that RGA has a P/B ratio of 1.37. 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. This company's current P/B looks solid when compared to its industry's average P/B of 1.78. Over the past 12 months, RGA's P/B has been as high as 1.40 and as low as 1.14, with a median of 1.23.

Value investors also love the P/S ratio, which is calculated by simply dividing a stock's price with the company's sales. This is a prefered metric because revenue can't really be manipulated, so sales are often a truer performance indicator. RGA has a P/S ratio of 0.61. This compares to its industry's average P/S of 0.94.

These are only a few of the key metrics included in Reinsurance Group of America'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, RGA looks like an impressive value stock at the moment.