Paper BCH on leverage are the majority of volume, while spot volume is extremely low.
If spot is pushed up the insurance funds cant cover the margin positions and the exchanges go bankrupt/customers lose all their assets and exchanges lose their business permanently. Incentivizing exchanges to try keep the market the way it is so they can stay in business.
Basically leveraged exchanges are most likely manipulated since the volumes dont match actual market activity.
There are allegations that the exchanges themselves trade against their own customers since they know margin call thresholds and have unlimited money on an exchange they control.
Additionally traders are incentivized to sell/short their actual BCH on spot and buy a futures contract (paper BCH) for a profit/free loan.