TerraUSD (UST) is a decentralized and algorithmic stablecoin on the Terra blockchain. It is designed to maintain a peg to the US dollar through an automated mechanism that involves its companion token LUNA. UST does not rely on collateral reserves like traditional stablecoins, but rather uses algorithms and market incentives to stabilize its price.

The key features of TerraUSD are:

• Decentralized and algorithmic stablecoin, not backed by fiat reserves
• Pegged to the US dollar through an automated system involving the LUNA token
• Scalable and yield-bearing, designed to address the limitations of other stablecoins
• Launched in September 2020 by the Terra blockchain project founded by Do Kwon and Daniel Shin

While UST has gained significant traction as a leading algorithmic stablecoin, it has also faced challenges maintaining its peg during periods of market volatility, as seen in the May 2022 de-pegging event. The stability of algorithmic stablecoins like UST remains an area of debate and ongoing development within the crypto ecosystem.