> What's to stop a company like that from buying a bank and setting up its own credit card? They can set up their own credit card network, sure. If they want t

> What's to stop a company like that from buying a bank and setting up its own credit card? They can set up their own credit card network, sure. If they want to issue their own credit card with existing network like visa or mastercard, they need permission from visa or mastercard. These payment networks have huge network effects. I can't imagine anyone really entering that market.