The proven Zacks Rank system focuses on earnings estimates and estimate revisions to find winning stocks. Nevertheless, we know that our readers all have their own perspectives, so we are always looking at the latest trends in value, growth, and momentum to find strong picks.Of these, value investing is easily one of the most popular ways to find great stocks in any market environment. Value investors rely on traditional forms of analysis on key valuation metrics to find stocks that they believe are undervalued, leaving room for profits.Luckily, Zacks has developed its own Style Scores system in an effort to find stocks with specific traits. Value investors will be interested in the system's "Value" category. Stocks with both "A" grades in the Value category and high Zacks Ranks are among the strongest value stocks on the market right now.One company to watch right now is ArcBest (ARCB). ARCB is currently holding a Zacks Rank of #2 (Buy) and a Value grade of A. The stock is trading with P/E ratio of 10.93 right now. For comparison, its industry sports an average P/E of 21.10. Over the past year, ARCB's Forward P/E has been as high as 20.26 and as low as 10.10, with a median of 12.58.We should also highlight that ARCB has a P/B ratio of 2.63. 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. ARCB's current P/B looks attractive when compared to its industry's average P/B of 4.42. Over the past year, ARCB's P/B has been as high as 3.24 and as low as 1.42, with a median of 2.14.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. ARCB has a P/S ratio of 0.67. This compares to its industry's average P/S of 1.34.Finally, investors will want to recognize that ARCB has a P/CF ratio of 9.03. 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. ARCB's current P/CF looks attractive when compared to its industry's average P/CF of 18.45. Over the past year, ARCB's P/CF has been as high as 11.47 and as low as 5.59, with a median of 8.10.USA Truck (USAK) may be another strong Transportation - Truck stock to add to your shortlist. USAK is a # 1 (Strong Buy) stock with a Value grade of A.USA Truck also has a P/B ratio of 1.75 compared to its industry's price-to-book ratio of 4.42. Over the past year, its P/B ratio has been as high as 2.10, as low as 0.92, with a median of 1.54.These figures are just a handful of the metrics value investors tend to look at, but they help show that ArcBest and USA Truck are likely being undervalued right now. Considering this, as well as the strength of its earnings outlook, ARCB and USAK feels like a great value stock at the moment. Breakout Biotech Stocks with Triple-Digit Profit Potential The biotech sector is projected to surge beyond $2.4 trillion by 2028 as scientists develop treatments for thousands of diseases. They’re also finding ways to edit the human genome to literally erase our vulnerability to these diseases. Zacks has just released Century of Biology: 7 Biotech Stocks to Buy Right Now to help investors profit from 7 stocks poised for outperformance. Recommendations from previous editions of this report have produced gains of +205%, +258% and +477%. The stocks in this report could perform even better.See these 7 breakthrough 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 ArcBest Corporation (ARCB): Free Stock Analysis Report USA Truck, Inc. (USAK): Free Stock Analysis Report To read this article on Zacks.com click here.