For me, selling when I can is the most important thing if a token starts pumping, selling is better than hodling everything that pumps dumps afterwards.
Definitely need to sell when the price is high, so I think that some altcoins is better not to keep for a long time as their technology may become obsolete and the coin to die !
I agree with you, but in the current market there are few coins that grow well , I think if you see such a moment then of course you need to invest as it was at the beginning of this year with eth