USDtb is Ethena Labs's reserve-backed digital dollar stablecoin, launched in December 2024 as a complement to the protocol's synthetic dollar USDe. Unlike USDe's delta-neutral derivatives model, USDtb maintains its peg through institutional-grade tokenized Treasury reserves, primarily backed by BlackRock's USD Institutional Digital Liquidity Fund (BUIDL). The token is designed to serve both institutional and crypto-native users seeking a stable, on-chain dollar asset with transparent, regulated backing.