Decentralized USD, or USDD is an algorithmic stablecoin introduced by Justin Sun, founder of the Tron DAO. Its value is pegged to the value of the US dollar, similar to USDC, USDT, and other USD stablecoins. While it was launched by TRON DAO Reserve, it doesn't mean that the token is exclusive to that blockchain. USDD is also present on the NEAR blockchain as well as Ethereum and Binance Smart Chain.