On August 22nd, according to The Block reported yesterday that Tron DAO Reserve on Wednesday withdrew about $750 million worth of bitcoin, which was previously used to support the USDD stablecoin. Tron founder Justin Sun said users need not worry, explaining that the move is to improve capital efficiency, because the long-term mortgage rate of USDD was over 300%. USDD is currently mainly backed by Tron's native token, TRX. Sun compares the mechanism of USDD to the DAI of the Maker DAO, emphasizing its security. Currently, USDD has about $744 million in circulation, making it the seventh largest stablecoin. Although official data shows a collateral rate of over 230%, third-party agency Bluechip estimates that the actual collateral rate may be only 53%.