In my opinion, that will possible. Not all but there are some altcoins which could always bring profit for you for long hold. Sometime those might be dump unexpectedly but those will have always recover. Thats why those are most investmented top coins. The fact is, when people invest on some random project without knowledge so that those could be on moon & makes them rich overnight! But those things makes their assets dump anyhow, even most of the time.
We cannot tell if which altcoins is that, Maybe we have that one in our wallet but we dont if have a possibility to make some noise in crypto world. Just like in the pas month I have a kind of altcoins thats not listed in any popular exchange but it making a high price in no time. And yes we can if those people invested some project in here and no one of them has making some research or studies about the project maybe they will be crying if they find out the project has going to scam only. To avoid of these kind of hobbies must better they need to learn it first of what in the world of crypto.