They really are, big whales do manipulating the bitcoin price. Those groups are just doing the dumping and pumping the coins, so they are making a lot of profits consistently for having that advantage. One of them is the chinese group which have the half amount of bitcoin network.
Yes those big fishes manipulate the coins by creating more demand and less supply or else by creating more supply and less demand to increase or decrease the value of bitcoin and i think even some government officials will be indirectly involved in this.