I'm sure that the biggest profit comes from storing tokens and coins. But this is a very difficult path, because on any growth you want to sell all the coins. And not everyone can wait for a really high price ...
It depends on what you are holding. If the coin you are holding has a good team on their project, then it is worth to hold. But if the team is not transparent and it the investors lose trust, I think it is better to let it go.