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.

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 a variety of methods, including tried-and-true valuation metrics, to find these stocks.

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.

Investors should also recognize that RGA has a P/B ratio of 1.46. Investors use the P/B ratio to look at a stock's market value versus its book value, which is defined as total assets minus total liabilities. This stock's P/B looks solid versus its industry's average P/B of 1.87. RGA's P/B has been as high as 1.51 and as low as 1.15, with a median of 1.31, over the past year.

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 popular metric because sales are harder to manipulate on an income statement, so they are often considered a better performance indicator. RGA has a P/S ratio of 0.67. This compares to its industry's average P/S of 0.88.

These are just a handful of the figures considered in Reinsurance Group of America's great Value grade. Still, they help show that the stock is likely being undervalued at the moment. Add this to the strength of its earnings outlook, and we can clearly see that RGA is an impressive value stock right now.