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 rely on traditional forms of analysis on key valuation metrics to find stocks that they believe are undervalued, leaving room for profits.

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.

One company to watch right now is American Airlines (AAL Quick QuoteAAL - Free Report) . AAL is currently sporting a Zacks Rank of #2 (Buy) and an A for Value. The stock holds a P/E ratio of 8.04, while its industry has an average P/E of 16.41. Over the past 52 weeks, AAL's Forward P/E has been as high as 9.05 and as low as 4.01, with a median of 5.99.

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 popular metric because sales are harder to manipulate on an income statement, so they are often considered a better performance indicator. AAL has a P/S ratio of 0.21. This compares to its industry's average P/S of 0.59.

Value investors will likely look at more than just these metrics, but the above data helps show that American Airlines is likely undervalued currently. And when considering the strength of its earnings outlook, AAL sticks out at as one of the market's strongest value stocks.