Almost all crypto-currencies are exchanged on online exchanges, because this method is simple and gives access to a huge pool of crypto-currency investors - speculators. Obviously, the source of the problem: speculators, which not only undermine stability, but also dictate prices.
I think those people take advantage of the weak, they are controlling the price of the coins just to maybe play with us or what ever their reason is. I think it is really possible because a lot of people are talking about whales in cryptocurrency. The way I see it being volatile is part or is just one characteristics of crptocurrency in which we have to accept.