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.Of these, value investing is easily one of the most popular ways to find great stocks in any market environment. Value investors use tried-and-true metrics and fundamental analysis to find companies that they believe are undervalued at their current share price levels.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 value investors might notice is Eni (E). E is currently sporting a Zacks Rank of #2 (Buy) and an A for Value. The stock is trading with a P/E ratio of 3.48, which compares to its industry's average of 6.07. E's Forward P/E has been as high as 10.35 and as low as 3.36, with a median of 7.38, all within the past year.Investors should also note that E holds a PEG ratio of 0.34. This popular metric is similar to the widely-known P/E ratio, with the difference being that the PEG ratio also takes into account the company's expected earnings growth rate. E's industry has an average PEG of 0.45 right now. Within the past year, E's PEG has been as high as 1.27 and as low as 0.33, with a median of 0.50.We should also highlight that E has a P/B ratio of 0.77. 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 1.21. E's P/B has been as high as 1.13 and as low as 0.70, with a median of 1, over the past year.Value investors also use the P/S ratio. The P/S ratio is is calculated as price divided by sales. Some people prefer this metric because sales are harder to manipulate on an income statement. This means it could be a truer performance indicator. E has a P/S ratio of 0.35. This compares to its industry's average P/S of 0.47.Finally, our model also underscores that E has a P/CF ratio of 1.93. This metric takes into account a company's operating cash flow and can be used to find stocks that are undervalued based on their solid cash outlook. E's current P/CF looks attractive when compared to its industry's average P/CF of 4.77. Over the past 52 weeks, E's P/CF has been as high as 5.94 and as low as 1.74, with a median of 3.44.Investors could also keep in mind Vista Oil & Gas (VIST), an Oil and Gas - Integrated - International stock with a Zacks Rank of # 1 (Strong Buy) and Value grade of A.Vista Oil & Gas also has a P/B ratio of 1.20 compared to its industry's price-to-book ratio of 1.21. Over the past year, its P/B ratio has been as high as 1.46, as low as 0.69, with a median of 1.03.These are just a handful of the figures considered in Eni and Vista Oil & Gas'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 E and VIST is an impressive value stock right now. Want to Know the #1 Semiconductor Stock for 2022? Few people know how promising the semiconductor market is. Over the last couple of years, disruptions to the supply chain have caused shortages in several industries. The absence of one single semiconductor can stop all operations in certain industries. This year, companies that create and produce this essential material will have incredible pricing power. For a limited time, Zacks is revealing the top semiconductor stock for 2022. You'll find it in our new Special Report, One Semiconductor Stock Stands to Gain the Most. Today, it's yours free with no obligation.>>Give me access to my free special report.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 Eni SpA (E): Free Stock Analysis Report Vista Oil & Gas, S.A.B. de C.V. Sponsored ADR (VIST): Free Stock Analysis Report To read this article on Zacks.com click here. Zacks Investment Research