Altcoin holding for 2-3 years or more are no doubt very good investment. There are many good coins to hold for future, some of them selected and mentioned are very good. But do not invest all your money single time. Break up total investment in 3 to 4 segment and buy when there is down in! interesting tokens are,SONM,Universa and NEO to hold for a long time
I observed prices from last year token tokens did not experience a significant price increase. and in my opinion for some coins like NEO it is very good as an investment