So I came across bitvc, it asks no fees.
I said they must make money from advertising. Now I haven't used it so I don't know.
However!! How can you make advertising money if the members use bots to trade? Bots do not visit webpages. It almost sounds too good to be true. No fees = bot heaven.
Either a bucket shop where the exchange trade against their own customer. Or they are trying to capture the market first and charge small fee after reaching certain threshold. The same method whatsapp used before it is popular.