QC (QuickCash, Quick Money) is a stable currency issued based on the Quantum Chain smart contract. It is a blockchain project initiated by Quickcash Network Pte. Ltd. The value of the QC stablecoin is US$0.15 (≈1RMB), and it is initially locked. Users can circulate part of the QC by mortgaging digital assets. The mortgaged digital assets are mainstream digital assets such as BTC, ETH, EOS, LTC, and QTUM. Assets, the mortgage ratio is more than 150%, that is, the circulating QC stable currency is the excess digital asset mortgage credit guarantee. All pledge and circulation records are publicly displayed on the blockchain, effectively preventing excess QC from entering the circulation market, so as to ensure the stable exchange rate and free circulation of QC.