The market cap of Tether, which is backed by both USD and crypto, was much higher on May 19, 2025 than that of other crypto-collateralized stablecoins, such as Resolv USR. For many people, stablecoins are associated with fiat currencies - especially the U.S. dollar - although they have other ways to maintain their stability. Crypto-backed stablecoins, for instance, try to maintain an excess supply of another cryptocurrency - often Ethereum (ETH). Dai, for example, before it got replaced with USDS, required at least 1.5 times its own value in collateral, meaning it needs a deposit of at least 1,500 U.S. dollars' worth in Ethereum whenever 1,000 Dai is borrowed in a Decentralized Finance (DeFi) smart contract.