sell and buy back is best method to minim your lost 
but sometimes hold is best solution for long investmen
but sometimes hold is best solution for long investmen
Yes holding will give you best returns in long term as price will surely be higher in next few years so if you don't want to take any risk of investing then holding is the best option for you which can give you guaranteed profits in long term.
As for me thinking that investments of holding will bring bigger returns as long term goals will really provide a good results in the future. So as the day went by it will be more exciting to wake up for another day, then the other day will became more important to you as you expect it to rise even more. The bitcoim amount you are holding can be much more progressive and when you decide at the right price for you to sell your assets and enjoy the profit which we can get from that invested capital.