Investors looking for stocks in the Financial Transaction Services sector might want to consider either Global Payments (GPN) or MasterCard (MA) . But which of these two companies is the best option for those looking for undervalued stocks? 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 is a proven strategy that targets companies with positive ea ...