The Ethereum dApp Synthetix has a "DeFi" version of those. It's extremely inefficient and relies on centralized Chainlink oracles but it's permissionless and th

The Ethereum dApp Synthetix has a "DeFi" version of those. It's extremely inefficient and relies on centralized Chainlink oracles but it's permissionless and the assets keep their pegs. The Korean project Luna has I believe a similar system although it's even more of a decentralization theater.