Whales are indeed one of the reasons why the cryptocurrency market is being manipulated. They want to make a profit by controlling the market and making people panic about the state of the market that has been controlled by the whales. Pump and dump will happen according to their plan. Many FUDs are spread to make the market price crash and buy them cheap and then make good news to take profits. Very simple, but market manipulation like the whales must be detected so as not to get caught up in the game.
And whales do not necessary mean one person like how people like to think either. I bet you a lot of powerful companies pool funds together to form a whale. Exchanges seem to do this very well,,, even better they use our money and pool together to manipulate the market and make us liquidate when we should not:)