Investors with an interest in Financial Transaction Services stocks have likely encountered both Fidelity National Information Services (FIS) and Fiserv (FI) . But which of these two stocks is more attractive to value investors? We'll need to take a closer look to find out.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 ...