Pretty cool deal Huobi has for BTC you just use Huobi Savings and get 4% on you BTC!
I wanted to share this to make sure if you holding it in a wallet - get some easy returns.
https://www.huobi.com/en-us/savings/It's nothing new since the same return of 4% is also offered by freebitco.in
They are able to guarantee these returns with mining and betting activities. and they are free to change this return at any time...
however doesn't own private keys is always a potential risk.