Investors looking for stocks in the Banks - Foreign sector might want to consider either BNP Paribas SA (BNPQY) or Hang Seng Bank Ltd. (HSNGY). But which of these two stocks presents investors with the better value opportunity right now? Let's take a closer look.We have found that the best way to discover great value opportunities is to pair a strong Zacks Rank with a great grade in the Value category of our Style Scores system. The Zacks Rank favors stocks with strong earnings estimate revision trends, and our Style Scores highlight companies with specific traits.BNP Paribas SA has a Zacks Rank of #2 (Buy), while Hang Seng Bank Ltd. has a Zacks Rank of #5 (Strong Sell) right now. The Zacks Rank favors stocks that have recently seen positive revisions to their earnings estimates, so investors should rest assured that BNPQY has an improving earnings outlook. However, value investors will care about much more than just this.Value investors are also interested in a number of tried-and-true valuation metrics that help show when a company is undervalued at its current share price levels.Our Value category grades stocks based on a number of key metrics, including the tried-and-true P/E ratio, the P/S ratio, earnings yield, and cash flow per share, as well as a variety of other fundamentals that value investors frequently use.BNPQY currently has a forward P/E ratio of 10.21, while HSNGY has a forward P/E of 17.30. We also note that BNPQY has a PEG ratio of 1.33. This popular figure is similar to the widely-used P/E ratio, but the PEG ratio also considers a company's expected EPS growth rate. HSNGY currently has a PEG ratio of 1.94.Another notable valuation metric for BNPQY is its P/B ratio of 0.59. The P/B ratio is used to compare a stock's market value with its book value, which is defined as total assets minus total liabilities. For comparison, HSNGY has a P/B of 1.64.Based on these metrics and many more, BNPQY holds a Value grade of B, while HSNGY has a Value grade of C.BNPQY stands above HSNGY thanks to its solid earnings outlook, and based on these valuation figures, we also feel that BNPQY is the superior value option right 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 BNP Paribas SA (BNPQY): Free Stock Analysis Report Hang Seng Bank Ltd. (HSNGY): Free Stock Analysis Report To read this article on Zacks.com click here.