Acala USD (aUSD) stablecoin protocol enables a decentralized, cross-chain stable currency that serves as the native stablecoin of the Polkadot and Kusama ecosystem. aUSD is minted from a variety of reserve assets. This allows holders of the reserve assets to earn, spend, trade, and access other services without price volatility while retaining ownership of their reserve assets. Acala USD is pegged to the US Dollar. aUSD can be trustlessly integrated by any blockchain connected to Polkadot or Kusama, as well as applications deployed on those chains. aUSD can also be integrated cross-chain on any other connected blockchain network.

Anyone can mint aUSD using accepted reserve assets, and each aUSD is backed by a surplus value of reserve assets (collateral assets). The reserve assets are also cross-chain by nature, which can include Polkadot native assets (DOT and DOT derivatives), KSM and KSM derivatives like LKSM, Acala's native token ACA, and Karura's native token KAR. In the future, the protocol can also accept parachain assets and cross-chain assets like Bitcoin (BTC) and Ether (ETH) as collateral assets if they meet the risk requirements and are accepted via Acala governance. 

The aUSD stablecoin protocol is deployed on both Acala serving the Polkadot ecosystem and on Karura for serving the Kusama ecosystem.