@nguyenkhaha bitcoin isn't a marketplace but I think what you are trying to say is that bitcoin has the best marketplace? But it isn't the thing that OP is looking for, he's looking for a trading platform as he mentioned about cryptopia.
choose from the first 50.
I didn't have time to try all of them but all I can say that there's a few exchange there that has been receiving a lot of negative feedback from its users before.