There is a lot of dumb money in crypto. Projects like dogecoin are a perfect example.
It's anybody's guess as to what will skyrocket next because evidently the project doesn't really need to have any solid purpose or backing.
Pump and dumps are scams, so he made the money taking part in a scam. It's legal in this space as far as I know so I guess congrats to him. Meanwhile I'm spending cash on actual equities and mining projects like xmr that have a real purpose and backing. And I'm not making 4 million usd.