I think that's what going on with Bitcoin right now. Goldman-Sachs comes out saying they're going to advise their clients to look into crypto, and Bitcoin starts rising fast. Then a week later their analyst says that Bitcoin could hit $4800 before falling back to the upper $2000's. Call me crazy but it seems like a gigantic whale just jumped into the Bitcoin pool with pump and dump on their mind.
RE: How Poloniex manipulates the price