That is because of the psychology of markets. Markets move down at a faster rate than they do, up. I'm not talking about longer term trends or bubbles. As the price rises, it hits peoples' sell point. To make the most profit you not only have to be early, but get rid of as much as possible as close to the top as possible. So dumps happen. It quickly turns into a race for the exits and this cascading effect is seen as "panic". Then it slows and the price is allowed to rise again until it reaches someone's selling point, but this point isn't as high as it was the first time because they think "everyone else is going to sell at X. So if I sell at X-1, I still get a good price but I get out before the next big rush". This is where front running comes into play. Then the lower highs create extra worry and more dumps begin to push the price down further. This cycle happens over and over until there are no remaining sellers. This is what we are witnessing right now. Currently (20:07 16-1-2015), we are in one of the retrace periods, and with lessening sellers, there won't be too many of these left and we will hit the bottom. The point where buyers finally enter with enough strength to overcome the relentless selling and begin to push back.