I have always used the coinmarketcap rating to select the best exchanges for trading that have large trading volumes of exactly the coins that I own.  Nevertheless, you need to constantly monitor the operation of the exchange, because at some point problems may arise, such as the situation with Bitrex.  Of course, today I completely switched to trading on Binance, but nevertheless I use even little significant exchanges to trade not very famous coins that I have in my portfolio.
If we talk about the Okex exchange, then in some respects this resource surpasses some of the famous exchanges.  Moreover, in cryptocurrency exchanges this cryptocurrency exchange is in the top twenty.  The only thing I didn’t like was the poor ability to translate into Russian, as well as banners in Chinese, because very interesting and useful information pops up, but learning about it no longer provides an opportunity. This primarily concerns the video on futures trading, which is shown at the entrance to the site, but in an inaccessible language.  In addition, you must pass KYC for trouble-free work of the trader.