I think it depends on you're luck with the particular coin even if the coin is very trusted which is proven and tested for a long term of investment if you are not lucky in it then you need to let go with it and find another good altcoins to buy, its depend on our own decision and own strategy we need to go to coin that give us profit not just selecting a top altcoins.
In picking a good coin, there's lots of things to consider.
First you have to pick a coin that isn't a scam which isn't an easy task considering the amount of coins that are being released in today's time.
Second even if a coin isn't a scam there's no guarantee that that coin will have value in due time.
Third even with a success, we can't be sure if it can be maintained in the long run