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.Considering these trends, value investing is clearly one of the most preferred ways to find strong stocks in any type of market. Value investors use a variety of methods, including tried-and-true valuation metrics, to find these stocks.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.Petrobras (PBR) is a stock many investors are watching right now. PBR is currently sporting a Zacks Rank of #1 (Strong Buy) and an A for Value.We should also highlight that PBR has a P/B ratio of 0.95. 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 stock's P/B looks solid versus its industry's average P/B of 1.16. PBR's P/B has been as high as 1.67 and as low as 0.79, with a median of 1.01, over the past year.Finally, investors will want to recognize that PBR has a P/CF ratio of 2.26. 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 3.63. Over the past year, PBR's P/CF has been as high as 10.63 and as low as 2.04, with a median of 3.35.These figures are just a handful of the metrics value investors tend to look at, but they help show that Petrobras is likely being undervalued right now. Considering this, as well as the strength of its earnings outlook, PBR feels like a great value stock at the moment. Bitcoin, Like the Internet Itself, Could Change Everything Blockchain and cryptocurrency has sparked one of the most exciting discussion topics of a generation. Some call it the “Internet of Money” and predict it could change the way money works forever. If true, it could do to banks what Netflix did to Blockbuster and Amazon did to Sears. Experts agree we’re still in the early stages of this technology, and as it grows, it will create several investing opportunities. Zacks’ has just revealed 3 companies that can help investors capitalize on the explosive profit potential of Bitcoin and the other cryptocurrencies with significantly less volatility than buying them directly. See 3 crypto-related stocks now >>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 Petroleo Brasileiro S.A. Petrobras (PBR): Free Stock Analysis Report To read this article on Zacks.com click here. Zacks Investment Research