USD$USDE is an emerging synthetic stablecoin developed by Ethina Labs, designed to provide a solution for a decentralized, scalable, and censorship-resistant stablecoin. This article will provide a detailed explanation of the USD mechanism, sources of income, and how to maintain stability through a delta hedging strategy and a production and redemption mechanism. It will also explore various models for earning USD, including mining USD and flexible savings, as well as its potential to provide passive income.