The proven Zacks Rank system focuses on earnings estimates and estimate revisions to find winning stocks. Nevertheless, we know that our readers all have their own perspectives, so we are always looking at the latest trends in value, growth, and momentum to find 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 fundamental analysis and traditional valuation metrics to find stocks that they believe are being undervalued by the market at large.

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 to watch right now is Quest Diagnostics (DGX Quick QuoteDGX - Free Report) . DGX is currently sporting a Zacks Rank of #2 (Buy), as well as a Value grade of A. The stock has a Forward P/E ratio of 16.43. This compares to its industry's average Forward P/E of 21.59. Over the last 12 months, DGX's Forward P/E has been as high as 16.79 and as low as 13.44, with a median of 15.15.

Another valuation metric that we should highlight is DGX's P/B ratio of 2.58. 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 company's current P/B looks solid when compared to its industry's average P/B of 4.35. DGX's P/B has been as high as 2.63 and as low as 2.10, with a median of 2.36, over the past year.

These are only a few of the key metrics included in Quest Diagnostics's strong Value grade, but they help show that the stock is likely undervalued right now. When factoring in the strength of its earnings outlook, DGX looks like an impressive value stock at the moment.