Dumps and pumps are part of all crypto currencies, the same way as others currencies and markets assets. At Bitcoin we do have a lot whales that make all the magic happens, while with others markets are banks and big fortunes that make pression in the price, but both markets are week against bad news.
Bitcoin as i had said before is finding its new value, some people expected to it reach the 700 dollars or above ammounts, some people said 500 -600 dollars would be the new value of bitcoin has nothing that could affect the price last year of 250-300 dollars to make such change. Soo bitcoin will for sure being test new values and the community support over the next months.