People have gone to jail for pump and dump, what are called stock market boiler rooms.

https://moneyweek.com/514409/great-frauds-in-history-robert-brennans-boiler-room

First Jersey Securities was a "boiler room" where salesmen would use high-pressure techniques to sell shares in worthless companies to unwitting investors. At the same time, Brennan's two other brokerages would work to manipulate the stock price upwards, giving the impression that the shares were rising in value. Those brokerages would then dump their shares, causing the price to quickly collapse. Unlike later boiler-room operators, such as Jordan Belfort, Brennan would target the wider public, spending large sums on advertising and making high-profile donations to various public causes to generate publicity (as well as discourage prosecution).