Many exchanges manipulate volume etc so as to attract more users. While most exchanges are perfect in doing this others aren't; that is, in most exchanges you will see how bot influence price thereby making trading almost difficult.
After having a bitter experience with a certian exchange, I tend to overlook what is displayed on CMC and thus visiting the exchange in particular to be sure there is a good level of trading activities before sending any coin.
This is quite true to most of the crypto exchanges even if they are the top ones in their field.
Actually, it is not only the exchange itself but the project owners of that coin.
To portray that their coin is doing well in the trading aspect, they will place long list of their buy/sell orders to make their coin look dynamic in trading.
But you will see their true color after couple of months or more of trading because they already got tired of doing the same cycle over and over again.