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 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 Ally Financial (ALLY Quick QuoteALLY - Free Report) . ALLY is currently sporting a Zacks Rank of #1 (Strong Buy), as well as an A grade for Value.

Investors will also notice that ALLY has a PEG ratio of 0.27. This metric is used similarly to the famous P/E ratio, but the PEG ratio also takes into account the stock's expected earnings growth rate. ALLY's PEG compares to its industry's average PEG of 0.46. Over the last 12 months, ALLY's PEG has been as high as 0.47 and as low as 0.27, with a median of 0.36.

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