exchanges are simply platforms to match buyers and sellers.
the price of bitcoin is deviating from other exchanges in order to profit from the imbalance.
the price of a bitcoin on exchange A is $58,500. The price of bitcoin on exchange B is $59,200. This means you can buy a bitcoin on exchange A and immediately transfer it to exchange B to pocket a $700 profit immediately (in reality, you need to deduct all kinds of fees + account for transferring times etc).