Holding on to some coins for a long time I have faced a huge loss which I will never be able to recover. However, the wise thing to do is not to store certain coins for long periods of time. If the market is up, it should be sold wisely.
What many people do not understand is that if you want to hold an asset of any kind then that asset needs to be solid and have great fundamentals, if this is not the case then it is not worth holding such an asset, this is why in this market the only coin worth holding for the long term is bitcoin, you can trade altcoins if you want as good profits can be obtained with them but holding them is not a good idea, now there are a few exceptions like ethereum, but that is all what they are, and as such you must avoid holding altcoins for any significant amount of time or you will eventually get burned.