Here at Zacks, our focus is on the proven Zacks Rank system, which emphasizes earnings estimates and estimate revisions to find great stocks. Nevertheless, we are always paying attention to the latest value, growth, and momentum trends to underscore strong picks.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 tried-and-true metrics and fundamental analysis to find companies that they believe are undervalued at their current share price levels.Luckily, Zacks has developed its own Style Scores system in an effort to find stocks with specific traits. Value investors will be interested in the system's "Value" category. Stocks with both "A" grades in the Value category and high Zacks Ranks are among the strongest value stocks on the market right now.One stock to keep an eye on is Sonic Automotive (SAH). SAH is currently holding a Zacks Rank of #2 (Buy) and a Value grade of A. The stock has a Forward P/E ratio of 8.84. This compares to its industry's average Forward P/E of 10.01. Over the last 12 months, SAH's Forward P/E has been as high as 18.22 and as low as 3.51, with a median of 10.43.Value investors also use the P/S ratio. The P/S ratio is is calculated as price divided by 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. SAH has a P/S ratio of 0.16. This compares to its industry's average P/S of 0.41.Value investors will likely look at more than just these metrics, but the above data helps show that Sonic Automotive is likely undervalued currently. And when considering the strength of its earnings outlook, SAH sticks out at as one of the market's strongest value stocks.Want 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 Sonic Automotive, Inc. (SAH): Free Stock Analysis Report To read this article on Zacks.com click here. Zacks Investment Research