OP, those exchanges are not real cryptocurrency exchanges. I believe they do not let you buy and sell real Bitcoins. But they let you trade only in the movements of its price, like a futures market.
Yes, I know those exchanges aren't real crypto exchanges as we know it but those are more reliable than the ones we usually use.
They do let you buy/sell.
Anyway, I found a list from a link posted on the "exchange board"
https://www.allfxbrokers.com/brokers/deposit-options/bitcoinRegulated brokers can get scammed as irregulated.
Decantralized exchanges is the most safe way.
dumbass