Mostly it is better to hold coins that have some kind of future. Anyway, most of coins are not worth of holding in a long term and i'd rather sell those after some peak
You have a very good view of the market at this time. I also think that this is the best time of year 2018 to buy Bitcoin, because in the coming months when investors return to the market, bitcoin and other altcoin will increase very strongly and the opportunity for you is very few. Buy bitcoin right now and keep it till the end of the year and you'll see what bitcoin has done.