There are clear boom and boost cycles in Bitcoin, they are useful to shed out all the noobs and leave only the strongest holders that know what they are dealing with. There's a lot of people holding Bitcoin that don't deserve to hold Bitcoin because they don't understand it, so these will be forced to panic sell. Governments and whales will keep stacking up on coins, then they will declare it world reserve currency and then the noobs that sold will complain that Bitcoin is controlled by a small elite.
That is usually the idea normally and that is intentional. Whales play with emotional manipulation which they can easily read from the charts, they know when people are getting highly greedy and they know when they are getting panicky and so many people trying to avoid the market not knowing what is next and they take advantage of all that. It is a normal thing to see and most especially in a decentralized space, and trying to understand that helps.
When a new investor gets educated about the futures of bitcoin then he may go for investing into bitcoins wildly which may result in huge pumping and the vice versa also true. Intentional pumping are known as whales manipulation more frequently in crypto environments.
Accidental manipulations are common for any markets and we have nothing to do with them. But, intentional manipulations should be prevented but that is becoming a big challenge as crypto markets are basically unregulated markets hence whales find it as their playground.