Do you have any links or a succinct explanation of how it works, then?

Pump & dump is roughly the following:

1) Be rich/famous enough for people to pay attention to what you do

2) Pump a bunch of resources into something (company, stocks, whatever)

3) Everyone concludes there must be value, because you're investing your own cash

4) Others start investing, increasing the value further

5) You sell (dump) your stake at the new price before everyone realises they've invested in something worthless.

Say you invest $1 million in $1 shares and the extra investment/interest from others raises the share price to $1.20, you sell everything and get $200k profit for no work. Everyone else is left holding shares which turn out to be worthless.

Read the book The wolf of the wall street. It is quite entertaining and describes the pump-and-dump scheme really well:

https://www.amazon.com/Wolf-Wall-Street-Jordan-Belfort/dp/05...