It is not about buy it all, but to manipulate the price.
They buy on current prices and then dump it with large volume and take losses (since they can afford to).
This will scare most investors who will leave.
Just who is going to buy back 'all' this Bitcoin? It may be easy for 'Actors with unlimited purchasing power' to buy Bitcoin, but that does not mean they will be able to sell it. You clearly have no idea how a market works. Price is determined by supply and demand. 'Actors with unlimited purchasing power' cannot change the supply, as this is set by the difficulty of the network. The only way to lower the price would be to reduce demand, 'Economics 101'.
I find it laughable, how so many people hear about Bitcoin, then all of a sudden think they are market guru's and economists.
No, the market is not always determined by supply and demand. Look what happened to gold and silver over the past year. The price dropped, demand went sky high, and the priced dropped more.
It is very much possible to manipulate markets...
The same people that sell something, can be the same people that buy it at the same time.
They would take a loss... but they wouldn't care. What's more or less fiat currency to a central banker?