Here are three stocks with buy rank and strong value characteristics for investors to consider today, December 20th:Innoviva, Inc. (INVA): This developer of pharmaceuticalshas a Zacks Rank #1 (Strong Buy), and seen the Zacks Consensus Estimate for its current year earnings rising 18.7% over the last 60 days.Innoviva, Inc. Price and Consensus Innoviva, Inc. price-consensus-chart | Innoviva, Inc. QuoteInnoviva has a price-to-earnings ratio (P/E) of 6.92 compared with 15.80 for the industry. The company possesses a Value Score of B.Innoviva, Inc. PE Ratio (TTM) Innoviva, Inc. pe-ratio-ttm | Innoviva, Inc. QuoteEssent Group Ltd. (ESNT): This provider of private mortgage insurance and reinsurance for mortgages secured by residential properties has a Zacks Rank #2 (Buy), and seen the Zacks Consensus Estimate for its current year earnings rising 2.6% over the last 60 days.Essent Group Ltd. Price and Consensus Essent Group Ltd. price-consensus-chart | Essent Group Ltd. QuoteEssent has a price-to-earnings ratio (P/E) of 9.50 compared with 18.50 for the industry. The company possesses a Value Score of B.Essent Group Ltd. PE Ratio (TTM) Essent Group Ltd. pe-ratio-ttm | Essent Group Ltd. QuoteNavios Maritime Partners L.P. (NMM): This owner and operator of dry cargo vessels has a Zacks Rank #1 (Strong Buy), and seen the Zacks Consensus Estimate for its current year earnings rising 29.5% over the last 60 days.Navios Maritime Partners LP Price and Consensus Navios Maritime Partners LP price-consensus-chart | Navios Maritime Partners LP QuoteNavios Maritime has a price-to-earnings ratio (P/E) of 6.49 compared with 22.00 for the industry. The company possesses a Value Score of A.Navios Maritime Partners LP PE Ratio (TTM) Navios Maritime Partners LP pe-ratio-ttm | Navios Maritime Partners LP QuoteSee the full list of top ranked stocks hereLearn more about the Value score and how it is calculated here.More Stock News: This Is Bigger than the iPhone!It could become the mother of all technological revolutions. Apple sold a mere 1 billion iPhones in 10 years but a new breakthrough is expected to generate more than 27 billion devices in just 3 years, creating a $1.7 trillion market.Zacks has just released a Special Report that spotlights this fast-emerging phenomenon and 6 tickers for taking advantage of it. If you don't buy now, you may kick yourself in 2020.Click here for the 6 trades >>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 Navios Maritime Partners LP (NMM): Free Stock Analysis Report Innoviva, Inc. (INVA): Free Stock Analysis Report Essent Group Ltd. (ESNT): Free Stock Analysis Report To read this article on Zacks.com click here. Zacks Investment Research