on my experienced in the platform you've mentioned only two of them that was really credible to me which is Bittrex and Binance, these two are proven and tested to me and has a good volume in the market as well too. Then, the rest for me is I'm not sure about it. Because there are other platforms on which I think has a high volume in the market just like Idax, Coinbene, Okex and Houbi.
What on earth would make you think that Bittrex and Binance are the only good platforms there is ?
If I'm to say that only two there were credible then I am. Going to say it is only Binance and Coinbase. You do know that Coinbase is one of the top platforms (if not the number one) we have here. And they can also be trusted all round because their site is well secured, there haven't been any bad review about them, if there is, then its just few that are not worth it.