Prices crash faster than they rise. If people believe a piece of FUD is important, combined with how fast the price is falling, that only encourages people to unload faster, causing a much greater dip.
Another factor we have to take in to consideration when understanding bitcoin price movements are the so called hodler's. This investor's term - unique to cryptocurrency refers to people who prefer to hold onto their bitcoin rather than sell them. This means that no matter how low the price of the cryptocurrency goes, there is never likely to be a wholesale sell-off from all investors.