Long term holding is beneficial because during market downturn you will not be at risk as you will have time to hold more and whenever the market is in your favor you can sell your asset in order to get advantage. Remember that holding will minimise your loss but selling immediately due to fear will become a cause of dropping.
Patience is the only key that will help you to reach your destination by holding firm and decide to sell when you think that now is the best time to take your profit. But it does not mean that you will hold forever because sometimes your coins will reach the peak and if you wait more then there is a possibility that after missing the chance you will have to wait for more years.