In the coming days, Huobi will change over from its current HUSD system to the new ERC-20 token
Source: https://cointelegraph.com/news/huobi-transitions-from-current-husd-system-to-new-erc-20-token
Huobi Transitions From Current HUSD System to New ERC-20 Token
July 17, 2019
CoinTelegraph