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.On top of the Zacks Rank, investors can also look at our innovative Style Scores system to find stocks with specific traits. For example, value investors will want to focus on the "Value" category. Stocks with high Zacks Ranks and "A" grades for Value will be some of the highest-quality value stocks on the market today.One company to watch right now is Sunoco LP (SUN). SUN is currently sporting a Zacks Rank of #2 (Buy), as well as an A grade for Value. The stock is trading with a P/E ratio of 7.93, which compares to its industry's average of 12.10. SUN's Forward P/E has been as high as 9.73 and as low as 7.12, with a median of 8.19, all within the past year.Finally, we should also recognize that SUN has a P/CF ratio of 4.47. This figure highlights a company's operating cash flow and can be used to find firms that are undervalued when considering their impressive cash outlook. SUN's P/CF compares to its industry's average P/CF of 7.56. Over the past 52 weeks, SUN's P/CF has been as high as 6.79 and as low as 3.88, with a median of 5.13.These are only a few of the key metrics included in Sunoco LP'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, SUN looks like an impressive value stock at the moment. Zacks Names "Single Best Pick to Double" From thousands of stocks, 5 Zacks experts each have chosen their favorite to skyrocket +100% or more in months to come. From those 5, Director of Research Sheraz Mian hand-picks one to have the most explosive upside of all. You know this company from its past glory days, but few would expect that it's poised for a monster turnaround. Fresh from a successful repositioning and flush with A-list celeb endorsements, it could rival or surpass other recent Zacks' Stocks Set to Double like Boston Beer Company which shot up +143.0% in a little more than 9 months and Nvidia which boomed +175.9% in one year.Free: See Our Top Stock and 4 Runners Up >>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 Sunoco LP (SUN): Free Stock Analysis Report To read this article on Zacks.com click here.