A move to launch crypto-based payments by Walmart or Amazon that bypasses the traditional payments system would send shivers through the nation’s banks and card-network giants.

Walmart and Amazon are reportedly exploring their own corporate stablecoins as a customer payment option, which could potentially reduce the billions of dollars the retailers pay in credit transaction fees.

Amazon’s efforts to develop a stablecoin are still in the “early stages,” according to the Journal, and there are a lot of questions to sort out. There have reportedly been discussions to use outside stablecoins to settle transactions, but there’s also the possibility the online giant could develop its own.