Here at Zacks, we focus on our proven ranking system, which places an emphasis on earnings estimates and estimate revisions, to find winning stocks. But we also understand that investors develop their own strategies, so we are constantly looking at the latest trends in value, growth, and momentum to find strong companies for our readers.

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.

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 value investors might notice is Pampa Energia (PAM). PAM is currently sporting a Zacks Rank of #2 (Buy), as well as a Value grade of A. The stock is trading with a P/E ratio of 8.12, which compares to its industry's average of 16.32. Over the past 52 weeks, PAM's Forward P/E has been as high as 8.34 and as low as 3.88, with a median of 6.46.

Another notable valuation metric for PAM is its P/B ratio of 1.20. The P/B ratio pits a stock's market value against 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 2.68. PAM's P/B has been as high as 1.24 and as low as 0.61, with a median of 0.89, over the past year.

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 prefered metric because revenue can't really be manipulated, so sales are often a truer performance indicator. PAM has a P/S ratio of 2.1. This compares to its industry's average P/S of 2.11.

Finally, investors will want to recognize that PAM has a P/CF ratio of 5.76. This metric focuses on a firm's operating cash flow and is often used to find stocks that are undervalued based on the strength of their cash outlook. This stock's P/CF looks attractive against its industry's average P/CF of 12.69. Over the past 52 weeks, PAM's P/CF has been as high as 5.92 and as low as 2.29, with a median of 3.91.

These are just a handful of the figures considered in Pampa Energia's great Value grade. Still, they help show that the stock is likely being undervalued at the moment. Add this to the strength of its earnings outlook, and we can clearly see that PAM is an impressive value stock right now.