Tether (USDT) is a cryptocurrency stablecoin pegged to the U.S. dollar and backed "100% by Tether's reserves," according its website.
Tether is owned by iFinex, the Hong Kong-registered company that also owns the crypto exchange BitFinex.
Tether was launched as RealCoin in July 2014 and was rebranded as Tether in November 2014. It started trading in February 2015.
Originally based on the Bitcoin blockchain, Tether now supports Bitcoin's Omni and Liquid protocols as well as the Ethereum, TRON, EOS, Algorand, Solana, OMG Network, and Bitcoin Cash (SLP) blockchains.
YTether belongs to a fast-growing breed of cryptocurrencies called stablecoins, which aim to keep the price of their tokens stable, most commonly by tying it to the price of a traditional currency like the U.S. dollar. (Tether also issues tokens pegged to the euro, the offshore Chinese yuan, and gold, none with more than a small fraction of the market cap of its U.S. dollar-pegged USDT tokens.)
The peg to a traditional currency, often backed by collateral reserves made up entirely or mostly of the pegged currency, is meant to ensure stablecoins aren't subject to the same price volatility as more speculative cryptocurrencies like Bitcoin.
Tether helps investors move funds between cryptocurrency markets and the traditional financial system, minimizing volatility as a result of its 1-for-1 peg to the U.S. dollar.