# USDtb by Ethena ## Who is Ethena? Ethena is a pioneering synthetic dollar protocol built on the Ethereum blockchain, offering a crypto-native alternative to traditional financial systems. Its flagship product, USDe, is a synthetic dollar designed to provide stability and scalability without relying on conventional banking infrastructure. Find out more about [Ethena](https://ethena.fi/). ## What is USDtb? In December 2024, Ethena introduced USDtb, a stablecoin backed primarily by BlackRock's USD Institutional Digital Liquidity Fund (BUIDL). This fund invests in short-term U.S. government debt, cash, and repos, providing a stable and secure foundation for USDtb. The stablecoin's reserves are composed of approximately 90% BUIDL and 10% stablecoins like USDC to facilitate liquidity and redemptions. USDtb offers a distinct risk profile compared to Ethena's earlier synthetic dollar token, USDe, which utilizes a derivative-based trading strategy. By being fully backed by reserve assets, USDtb provides users with a more stable and reliable digital asset option. More on [USDtb](https://usdtb.money/). --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://tech.usual.money/smart-contracts/usd0-collateral/usdtb-by-ethena.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.