There are three broad categories of stablecoins"1.asset-backed off-chain: stablecoins whose price is pegged to fiat currencies like the US dollar or euro; commodities like gold; or other real-world assets. The ‘off-chain’ part of this name refers to the value being attached to collateral that exists off-chain. The biggest names in this category are all fiat-backed: USDT from Tether, with a daily trading volume that regularly exceeds $10billion, Coinbase’s USDCoin, TrueUSD from TrustToken, and GUSD from Gemini. In case you were wondering, fiat literally means ‘let it be done’, and refers to currency whose value is established by government decree, rather than direct 1:1 backing by an asset such as gold or silver. Supplies of fiat currency are determined by the central bank.
2.asset-backed on-chain: stablecoins that are backed by other cryptocurrencies (HUSD,DAI,EOSDT,WBTC..).
3.algorithmic: a combination of smart contracts and algorithms adjust the supply of the coins in order to maintain price equilibrium. An interesting example of such a project was Basis. Launched in August 2017, Basis intended to maintain a stable price by incentivizing traders to buy and sell Basis tokens in response to changes in demand. This would be achieved through on-chain auctions of ‘bond’ and ‘share’ tokens. After raising $133million in funds, Basis was unable to overcome the obstacle of the SEC’s likely classification of these bond and share tokens as securities. This meant severe restrictions would be imposed on these auctions, weakening the stabilization method, among a host of other issues. As a result, CEO Nader Al-Naji elected to return the funds to their investors and shutter the project."
https://medium.com/blockdata/stablecoin-report-blockdata-a5ad83525333If stablecoins from points 1 and 2 very often come up and they are known to everyone, then few know about point 3.
Ampleforthhttps://www.ampleforth.org/https://coinmarketcap.com/currencies/ampleforth/"AMPL diversifies a dangerously correlated ecosystem."
https://www.ampleforth.org/economics/DefiDollarhttps://app.dusd.finance/https://www.coingecko.com/en/coins/defidollarWhat is DefiDollar ($DUSD)?
"DefiDollar (DUSD) is a stablecoin that uses DeFi primitives to stay close to the dollar mark. DUSD provides an avenue for diversifying your stablecoin holdings to hedge against an event where the underlying stablecoins e.g Tether (USDT), DAI deviate from their peg. DUSD is collateralised by Curve Finance LP tokens. For more details, please refer to our introduction blog."
https://medium.com/defidollar/a-curvy-defidollar-c249438c154ahttps://docs.dusd.finance/Element Zerohttps://www.elementzero.network/"Element Zero is a not-for-profit next generation payment network based on an algorithmic stablecoin creation platform. Element Zero is designed with the hope of making the world better for all, by providing a new form of payment that is protected against long-term inflation and eliminates the possibility for any volatility in the first place."
https://www.elementzero.network/white-papers/Element%20Zero%20White%20Paper%20V022819