Nah, fact is you think P&D is legal. The perpetrators of a pump-and-dump scheme already have an established position in the company's stock and will sell their positions after the hype has led to a higher share price - that’s illegal under security laws.
FYI, A Telegram pump and dump group is a group of individuals who use the Telegram messaging app to coordinate buying and selling of a particular stock, cryptocurrency, or other asset at the same time to create an artificial increase in its price. That’s called Manipulation.
So all the speculation rooms on Telegram are illegal ROTF