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, value investing is easily one of the most popular ways to find great stocks in any market environment. Value investors use fundamental analysis and traditional valuation metrics to find stocks that they believe are being undervalued by the market at large.

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 stock to keep an eye on is PetroChina . PTR is currently sporting a Zacks Rank of #1 (Strong Buy) and an A for Value. The stock holds a P/E ratio of 8.21, while its industry has an average P/E of 11.61. Over the last 12 months, PTR's Forward P/E has been as high as 15,584.55 and as low as -1,977.46, with a median of 20.91.

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