So after reading 7 answers to my question I have concluded that 1 BTC =100 million satoshie, and there is NO pool of BTCs for sale and all selling or buying takes place on the block chain from a wallet that is on the blockchain. As for new BTCs that are created by the miners, My guess is those are sold to someone that has a wallet on the block chain. Sounds like a closed loop of an operation? So could a billionaire buy a million BTCs and try to pump and dump BTC to control the value like they do in the stock market Dark Pool? I am learning a lot here. Thanks for your inputs.
You mean to manipulate the price? Not at this point, maybe in the early years of Bitcoin, but now that the volume is too big, that not even a billionaire can manipulate it's price to it's favor. As I have said, the market is one all over the world 24x7 and it's very hard to create some manipulation.
On the other hand if someone tries it, maybe it might turn out bad for him and instead of making profits, he might have lose a lot of money along the way. So not only it's not possible, it's not also advisable to do not.