Market varies with time upon the demand to the supply availability. Beyond this the markets majority holdings were in the hands of whales. As bitcoin network is speculative, these whales have the ability to manipulate the market with the large volume holdings circulating some FUD around the community.
The right thing because they have more than a few other people to buy or sell the coins they have. So you will do it if you have more things than other people have.
whales has a very large source of money compared to retail traders. especially if they work with other whales, it will certainly be very easy for them to make the cryptocurrency market panic by selling all their assets. when retail traders start panicking and selling their stock, whales will buy it at a very cheap price.
If between whales have agreement or make deal to pump a coin, i think whales could drive the price. Whales have a lot source of money and they can control the demand or supply. By this, controlling the price is not impossible