Of course.
It's debatable whether it's still possible a small group of entities can do it in the Bitcoin market. It's huge and all over the world. In alts it's borderline guaranteed. It's not illegal. It's almost certain to work. There's a ton of money in it. Why not?
The truly successful have a mindset that is the absolute opposite of the majority. They buy when things are looking horrendous and sell when everyone else is euphoric.
That's why a pump/dump called as a scam attempt at some point for several people.
The work of making fake bull/bear pretty clear it is not fair and yet people condidered it as somethinv normal , something that not illegal at all.
We cannot avoid this kind practice honestly , so just becareful.