The decline of price is part of the risk if trading in any investment instrument they experiencing the same and if you buy at the time the price is lower than 10,000 usd level it is safe to stay hold and if you want to cut further loss you must always watch the news concerning crypto trading
It is not only bitcoin whose market value is falling since past few days, but all the coins which are there in the world of crypto currency are facing the similar kind of situation as the market price of almost all the famous crypto coins is falling down very much significantly. At such kind of situation, you really need to control your nerves so that you may not end up acing any kind of wrong decision of selling any of your coin.