Because it will grow again at the end of the year this way you can still make a little bit profit say it goes to 10k at then and it is 6k now than you will make 4k profit and that is a lot so i would buy and keep till the end.
Since past few weeks, the market price of bitcoin is continuously increasing and is going up and up. If you want to have bitcoin in your wallet, then this is the time when you have to take advantage of this opportunity. It is because of the reason that with each passing day, the market price of bitcoin will go up. So it will be very much difficult for you to buy bitcoin at the time when It will have market value of 10000$ or so.