Actually Bitcoin is the best long-term investment and hold. if you invest in bitcoin for long-term it will be wise wise decision and you will most benefited. the price of Bitcoin is getting very high and end of the year 2018 bitcoin price will be $25K because bitcoin is decentralized digital currency now bitcoin is most popular and most demand-able.
I think it depends upon the need because of you need cash money for your daily needs and you dont have any cash in your hands then you will have to sell some of your holdings. Otherwise holding is far better than selling because investment in bitcoin should be for long term if you want big profits. I feel that if you dont need money then no need to sell bitcoin.