There`s no single manipulator,who is rich and powerfull enough to push the prices down.
...
There are several big holders (e.g. the Winklevoss twins) who own a 5-digit or
even a 6-digit amount of BTC. They could completely wipe out the market with
a few huge market sells. Even 5000-1000 BTC would be enough to wipe
out the order book on most exchanges.
You seriously underestimate the amount of coins that some BTC whales actually
own.