I've heard of Huobi, but 0% fees? How do they make money?
Interest on margin trading is that part of it?
I think that's all of it. Apparently their interest rate is something like 0.4% per day. And if I understood the articles correctly (reading between the lines), you probably can't withdraw if you owe them anything, so they are probably operating with very little risk.
Seems like a good business plan, but it's more Vegas than stock market. OTOH, I would imagine that with such a business, you get the additional non-deductible expenses of paying off the mob and government, so maybe the margins really aren't all that.