It's always hard to pinpoint the exact factor behind the price of bitcoin dropping, but to my knowledge, it seems that one of the factors that caused the price of bitcoin to fall so deeply was the statement issued by the FED regarding tapering off. This makes a number of investors afraid of the emergence of various speculations. However, I believe that in the longer term bitcoin remains bullish although it may seem that the current bearishness continues at least until the end of December.