Hold is advisable depends on market situation. Holding coins is good if the market is down but if the market is normal and keep increasing much better to hold it in a short time to make more profit.
It will depend upon the situation and also on which coins you hold. Because if you hold those worthless or low cost coins then you may be doing wrong by holding it. Instead selling would be better option. But if you hold best of the coins then yes holding is the best way to make money.