Bitcoin is always volatile. Im sure there are people that manipulate the price but there is no way to change that until more people/money enter the market. At that point, it will be harder for whales to control the market.
Even with tons of money invested into market there will be still manipulation. Just look at gold, its market cap is around 10 times bigger than bitcoins and there's still news about it being manipulated by big corporations, and it is supposed to be a regulated market. So with bitcoin there's no surprise that there is whales manipulation on prices as the market is not regulated and people can do whatever they want from fake orders to pumps and dumps. And in all fairness, I don't mind it, that's how the markets should be, a wild wild west and only strongest can survive it.