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.
This may be a reason but we can see that this does not affect the value that hard right? yes the market shaken but not to the extent of coming to Bear market.
Those investors do not think about the future of bitcoin instead following selling their bitcoin right away after the news so that could make the price is down. But the news will not always impact the price and the price will increase higher soon. I do not rely on the news because those media blow up the news and modify it for their own purposes. So if people can calm down when they read about the bad news about bitcoin and still support bitcoin, that will not impact the price and that can give confidence to other people to still hold their bitcoin and buy more bitcoin.