A bank might be interested in American Express to grow their card issuing business and to push further into the high growth/return payments sector. American Express generates a ~25% ROE vs banks ~9-12%. And banks with traditional retail deposits have a much lower cost of funding (Wells Fargo sub-40 bps vs American Express at ~150 bps), which would drive synergies.

...a few questions come to mind; 1) would the Fed approve such a large deal (American Express mkt cap of $56 B, Wells Fargo $254 B), 2) how would a bank view the charge card product which is 56% of USCS billed biz, 3) would a bank issuer then shift away from the other card networks and use American Express’s network, 4) how would it impact Global Network Services, where American Express acts solely as the network for other banks (Wells Fargo is a GNS customer), 5) does Wells Fargo want a closed-loop network to better compete in the new digital world, similar to what JPMorgan Chase (JPM) is building with ChaseNet, and 6) would a bank, who’s main interest is asset growth, potentially undervalue the scarcity value of a global network.