yep, this is a common occurrence for small or mid-range exchanges. It often has to fake the volume to entice traders to come and use their services. such as Idax, Coineal, Gate, Bittrex, Lbank, ....
so we need to be alert to select good exchanges to trade. and I encourage people to only use large exchanges like Binance or MXC to increase liquidity as well as protect assets in the best way.