I have some ICOs to be holding for long time maybe around 1 up to 5 years later, they are truckcoin and EOS my reasons hold them for long because in my personal analysis fundamental of them, they are good projects based on the aspects of fundamental and they has big chance to be more expensive in the future and right now the price of then still can be called as cheap, so i could made investment into them with small amount of money and large of money, i don't guarantee they will be sucessfull in the future but based on the price of ICO token that always increase every time, why not they will be booming couples years later.