Bitcoin is in a downward trend. There is more selling pressure on buyers. In an immature market like Bitcoin, there are more traders and individual investors than programmatic key institutions and software that tend to reduce price volatility.
Well aside from that I really think that the price manipulation is a relevant cause for all of this drama, And there are a lot of people have join in the dump of some, And because of these price drop there are weak hands that sure panic because of this, That is why no wonder it will sure happen anytime the value drop on the same manner, Many have join in this kind of situation where the price is low, But don't worry because when the price gets cheap there can be a panic buying that can happen.