Pump and Dump: These types of schemes are quick manipulations of the stock price. The schemers buy thinly traded stocks and then transmit optimistic messages about the stocks, which cause  investors to buy, thus driving up the price. The ownership interest that the schemers have in the particular stock is not disclosed. The schemers then sell the stock for significant gains. Their messages are transmitted through official looking e-mails, bulletin board posts or Web sites.
Dump and Diss: This is the pump and dump scheme in reverse. The schemers short-sell a stock and then transmit negative messages to investors causing the investors to sell, which in turn drives down the price. No disclosure is made of the negative position that the schemers have in the stock. They then buy the lower valued stock to fill their earlier sell orders and make a profit on the difference.
Insider Trading: The recipients of non-public information use the insider information to trade ahead of the information’s release, and subsequently realize profits.
Unregistered Offerings: Purported issuers of securities offer and/or sell securities through the Web without being registered or exempt from federal and state securities laws.
Pre-IPO Offerings: Purported issuers offer and/or sell shares of their company to investors based on the premise that the company soon will be going public. Some of these companies do not exist or are marginally successful.
Private Placement Offerings: Purported issuers offer and/or sell shares of their company with the usual promise of high returns, with the help of slick promotional materials. The companies turn out to be nonexistent.
Prime Bank Offerings: Purported sellers offer and/or sell interests in some type of prime bank instrument. The investors are advised to put their money into the prime banks of Europe in a program that generally is available only to the very wealthy, but because there is a “shortage” for the particular program, it is being offered for a smaller minimum investment. Prime bank instruments do not exist.