Actually, Bitcoin has no influencers that can manipulate the price. I mean that for example in terms of Ethereum it is Vitalik Buterin who can influence a lot on a Bitcoin's price. Nevertheless, there can be different news that have impact on people so they pump or dump it. Of course, some people will say that Elon Musk manipulates the market, but do strong holders really care about his tweets?
If the manipulation would result in an increase of value, then they do care because they are holding with the goal to see a good price so they can sell. Though we cannot pinpoint who really is manipulating the market, it's very obvious that the whales do manipulate based on the price movement of bitcoin, the high volatility is the living proof that manipulation is happening.