The market is comprised of speculators and miners.  The miners regularly sell, and the speculators can only speculate to the long side.  That leads to the occassional speculative spike, followed by profit taking and selling off by the miners.  This is creating a pattern of the market stepping down price levels in an orderly manner as miners lower their standard of what they are willing to sell for.  This will continue to happen until we reach <$1.00.  If shorting was possible we would already be there IMO.  Of course it could blow up at any time if we get some more dumb money coming in from a media story or something.  And then it will crash again.  I think bitcoin has already seen its all time high though, and will go down soon as a unique piece of internet history.