Pump and Dump is a common term used in crypto. This refers to someone or something causing a surge in the price of a coin.
People with a lot of authority could put out a message on twitter about a certain coin causing the price to skyrocket (pump). Then it will fall back down once people start to sell and take profit (dump).
Just be careful not to buy into one of these. That’s why it is always important to do your own due diligence on a coin.
And now nothing that has to do with crypto