I think that the best option for investing in the long term is to choose old and well-known coins, such as ZEC, LTC, ETH, EOS and not buy useless coins that can disappear at any time. For example, in addition to well-known coins, I buy and hold a small part of little-known coins, for example HBZ, XYO and some others with an active team, a large community and MVP (for me, this is an indicator of the team's work).