Actually it's a quadropoly considering it's Visa, MasterCard, American Express, and Discover.

In regards to breaking up credit card networks, the solution is to make the whole thing decentralized by raiding the big 4 for treason and nationalizing the networks into a single open interbank network that anyone can join, while also allowing customers to hop between card providers such as banks if one starts screwing with them.

Actually it's a quadropoly considering it's visa, MasterCard, american express, and discover.