Is it possible for somebody to collect all bitcoins?

[Kipsy89]

That was a joke, well, a half-joke.

I think it is going on - I think a lot (but not all) of altcoins are being produced by a ring for the purpose of hoarding bitcoins.

And that method doesn't result in buy orders, not from them.

Eventually when more people catch on, the game will be up and we will see them start selling bitcoins for cash as they move on to their next scam.
And bitcoin will drop in value.

Whoa man, I thought for a second you're really pulling this off. Man, that'd be not very nice. But have you been to the Altcoin section? That's some pretty messed up stuff there! Hundreds of altcoins. And each and every one of them seems to have their proponents who care for it!

[williamj2543]

Already there are thousands if not millions of bitcoins that are lost, meaning they are stored on a address where the private key is forgotten or lost. Also there will be some people that won't want to sell you your bitcoins.

[Harley997]

They couldn't possibly buy all coins because I'm not selling mine. As simple as that.

This is not the only reason why this would not be possible; every 10 minutes the miners "create" an additional 25 BTC via found blocks so the maximum amount of time anyone could potentially "own" "all" of the bitcoin would be for 10 minutes. 

[williamj2543]

They couldn't possibly buy all coins because I'm not selling mine. As simple as that.

This is not the only reason why this would not be possible; every 10 minutes the miners "create" an additional 25 BTC via found blocks so the maximum amount of time anyone could potentially "own" "all" of the bitcoin would be for 10 minutes. 

Unless he owned almost all the mining power. Like at least 90%.

[AliceWonder]

Already there are thousands if not millions of bitcoins that are lost, meaning they are stored on a address where the private key is forgotten or lost. Also there will be some people that won't want to sell you your bitcoins.

If I recall, some were sent to invalid addresses that can never be recovered.

The client checked for address validity but the protocol didn't, and some coding mistakes in home brew solutions sent some coins to invalid addresses and the transactions were accepted.