If enough people believe a particular pattern produces a predictable pattern, then they will collectively make it happen. If due to publicly visible tea leaves I believe the price will drop, then I will sell as will many others who are also watching the same tea leaves. Whether or not the tea leaves have any correlation to the asset is irrelevant if the tea leaves influence behavior and behavior IS the market. You may choose to bet against the herd, but you would be ill advised to ignore the herd nor ignore what the herd is watching.
Poker is also a game of chance. But statistics and psychology help not a little.
The above is quite correct, with two caveats:
1) Collective behaviour will take you so far, but past that point there are forces that are much stronger.
2) There are still hidden variables in this game. In poker, you at least know how many cards in a deck... things like the mybitcoin fiasco (and bitomat, and mtgox a few weeks back, and so on) are the equivalent of adding two extra aces to the deck... or removing two, depending on which side you're on.
In the case of bitcoin, the hacks have set the whole experiment back quite a bit. But it will still move in the direction it would have moved without them. And perhaps, like a relationship that was destined to fail, it's better that these events happened now, early on in bitcoin's history, as opposed to three or four years from now.
