The bittrex cryptocurrency exchange is good,one of the market leaders .
It has a large number of pairs to trade.The functionality is good and more than necessary, especially I like the analytical component. There are no delays in the execution of transactions, all orders are triggered instantly. The exchange's Commission is not the smallest – 0.25% from each auction.
Security is good, in addition, you should enable 2FA. KCY is very fast. But this is not very good for beginners. The Android app is poorly optimized.