This is actually sad. Always check projects before investing but the sad one is, projects always bring good total supply that will entice investors but after token sale and listing on exchange they will certainly increase the total supply gradually and dump finally. Let's be guided though.
Make sure to foolo their telegram for update if we plan to hold them for long, in terms of altcoins or projects that are made thru ICO or new DeFi we are not sure whether these projects really plan to stay long as some were just there for the hype and once done will just disappear, make sure to be updated and study the project its still better to invest in projects that have products and useful in the community.