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 American Equity Investment (AEL Quick QuoteAEL - Free Report) . AEL is currently sporting a Zacks Rank of #1 (Strong Buy) and an A for Value. The stock is trading with P/E ratio of 5.32 right now. For comparison, its industry sports an average P/E of 9.49. Over the last 12 months, AEL's Forward P/E has been as high as 8.64 and as low as 5.14, with a median of 7.01.

Another valuation metric that we should highlight is AEL's P/B ratio of 0.66. 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 stock's P/B looks solid versus its industry's average P/B of 1.79. AEL's P/B has been as high as 1.24 and as low as 0.48, with a median of 0.71, over the past year.

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