Cryptocurrencies still have a wild-west feel to them. With thousands of different coins/tokens available, it is hard to predict where market share of any particular cryptocurrency will end up over the next months and years. Look for underlying value, and exchangeability. What will sustain the utility of that particular vehicle of exchange? How widely will it be owned and traded? And what items of value can it be exchanged for? If you can get comfortable with the provisional answers to those questions, you may have found the cryptocurrency you would want to buy and hold against future use!