Tether (USDT) is a type of cryptocurrency known as a stablecoin, which aims to keep cryptocurrency valuations stable. Tether is pegged to traditional fiat currencies like the US dollar, the Euro, or the Yen, which means that for every USDT in circulation, there is an equivalent sum of traditional currency held in reserve. This approach intends to combine the benefits of digital currency — such as speed, security, and minimal transaction costs — with the stable value of a fiat currency.