At an American Bankers Association event, Sen. Jon Tester, D-Mont., who's up for reelection this year, said that he hopes the Durbin-Marshall credit card bill won't go anywhere and criticized the Federal Reserve's debit interchange proposal.

Credit card late fees are annoying, but that's why they work as a disincentive to prevent late payments. By making them much smaller, the CFPB will actually be working against the interests of low-income consumers.

Wells Fargo unveiled a new credit card and is bolstering how it rewards customers for their spending, crucial steps in Chief Executive Officer Charlie Scharf's mission to make the fourth-largest U.S. bank a bigger player in a space long dominated by rivals.

Banks and trade groups denounced the Consumer Financial Protection Bureau's final rule to cut credit card late fees to $8, saying they will do everything possible to kill the rule.

The two companies in the largest bank merger since the 2008 financial crisis released details of their agreement. It leaves the door open for Discover to field better offers, though the payments company would pay a break-up fee of 4% if it accepts one.

In the wake of the largest U.S. bank deal in more than 15 years, industry executives offered mixed views about the prospects for more big acquisitions. They also spoke about the deal's impact on competition in the credit card business.

Lenders collected an estimated $25 billion in additional interest income last year by raising the average margin on annual percentage rates, or the amount above the prime rate, according to the Consumer Financial Protection Bureau.