Lots of people with weak hands sell as soon as the first sign of trouble appears.
There's still a lot of these people around. They are trying to hold out, but if shit hits the fan they will sell it all in the blink of an eye. Watch out for a large collapse in the world economy because thats what will set them off. If nothing really bad happens in the economy and there's no panic than I think we are looking at the bottom right now at 4K. It'll be a slow march back to 20K, but with the next having coming in 1.5 years I think that will help it along nicely as we near it.