Microcap fraud, stocks of small companies of under $250 million market capitalization are deceptively promoted, then sold to an unwary public. This type of fraud has been estimated to cost investors $1-3 billion annually. Microcap fraud includes pump and dump schemes involving boiler rooms and scams on the internet.
Boiler rooms or boiler houses are stock brokerages that put undue pressure on clients to trade using telesales, usually in pursuit of microcap fraud schemes.