One good example is the category of memecoins. These tokens are mostly not having any utility buy why's the demand stilk high? Because there's a hype. Hype on the other hand stands for popularity. There are even times those tokens which aren't even promising are ones which are being monitored by investors. Seeing whether a project is promising or having potential is subjective. Meaning, it could be only in your perspective but not with the majority of investors.
This means that while I do get scared about investing into it, that means I am part of the problem because if I fear and you fear and everyone else fears then our fears would be true and it won2t go up, but if we do not fear then we could be wrong and lose money too. This is why it's usually not a good idea.