It seems there is an error in the question, as "UCDT" was mentioned instead of "USDT" which refers to Tether. I will provide a brief article about USDT and its market position.
*Tether (USDT)*
Tether, also known as USDT, is a stablecoin designed to maintain a 1:1 value with the US dollar. It is widely used in the cryptocurrency market to facilitate trading and cross-border payments.