While the proven Zacks Rank places an emphasis on earnings estimates and estimate revisions to find strong stocks, we also know that investors tend to develop their own individual strategies. With this in mind, we are always looking at value, growth, and momentum trends to discover great companies.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 to watch right now is Liberty Energy (LBRT). LBRT is currently sporting a Zacks Rank of #2 (Buy) and an A for Value.We should also highlight that LBRT has a P/B ratio of 2.25. The P/B is a method of comparing a stock's market value to its book value, which is defined as total assets minus total liabilities. LBRT's current P/B looks attractive when compared to its industry's average P/B of 3.53. Over the past year, LBRT's P/B has been as high as 2.84 and as low as 1.32, with a median of 1.95.Value investors also use the P/S ratio. The P/S ratio is is calculated as price divided by sales. This is a popular metric because sales are harder to manipulate on an income statement, so they are often considered a better performance indicator. LBRT has a P/S ratio of 0.86. This compares to its industry's average P/S of 0.87.Finally, our model also underscores that LBRT has a P/CF ratio of 6.62. This data point considers a firm's operating cash flow and is frequently used to find companies that are undervalued when considering their solid cash outlook. This stock's P/CF looks attractive against its industry's average P/CF of 17.29. LBRT's P/CF has been as high as 33.38 and as low as 4.84, with a median of 21.80, all within the past year.Investors could also keep in mind ProPetro Holding (PUMP), an Oil and Gas - Field Services stock with a Zacks Rank of # 2 (Buy) and Value grade of A.Additionally, ProPetro Holding has a P/B ratio of 1.46 while its industry's price-to-book ratio sits at 3.53. For PUMP, this valuation metric has been as high as 1.99, as low as 0.94, with a median of 1.30 over the past year.These are just a handful of the figures considered in Liberty Energy and ProPetro Holding'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 LBRT and PUMP is an impressive value stock right now. FREE Report: The Metaverse is Exploding! Don’t You Want to Cash In? Rising gas prices. The war in Ukraine. America's recession. Inflation. It's no wonder why the metaverse is so popular and growing every day. Becoming Spider Man and fighting Darth Vader is infinitely more appealing than spending over $5 per gallon at the pump. And that appeal is why the metaverse can provide such massive gains for investors. But do you know where to look? Do you know which metaverse stocks to buy and which to avoid? In a new FREE report from Zacks' leading stock specialist, we reveal how you could profit from the internet’s next evolution. Even though the popularity of the metaverse is spreading like wildfire, investors like you can still get in on the ground floor and cash in. Don't miss your chance to get your piece of this innovative $30 trillion opportunity - FREE.>>Yes, I want to know the top metaverse stocks for 2022>>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 Liberty Energy Inc. (LBRT): Free Stock Analysis Report ProPetro Holding Corp. (PUMP): Free Stock Analysis Report To read this article on Zacks.com click here. Zacks Investment Research