Stocks that are the subject of pump-and-dump schemes are sometimes called "chop stocks."

Fraudulent OTC stocks - Con artists promote stock in companies that do not exist or start a pump-and-dump scheme for an OTC stock.

The commission said Mr. Park had operated a classic pump-and-dump scheme, buying shares of stocks that he would then recommend to participants in his chat room.

At worst, they handsomely reward managers who run their companies as pump-and-dump schemes; executives at Enron and many other companies got rich thanks to stock prices that soared before they collapsed.

"We're hoping to head off a potential pump-and-dump scheme before investors' monies are at risk," said John Reed Stark, the chief of the office of Internet enforcement at the agency.

According to the Securities and Exchange Commission, Ruettiger ran a "pump-and-dump" scheme that enticed investors to bid up the stock of his sports drink company, Rudy Nutrition.

A short-selling scheme is similar to the "pump-and-dump" scheme.

As it was, Mr. Reifler yesterday became the fifth person to plead guilty to charges relating to that pump-and-dump scheme.

Even worse, Gotham's publication of upbeat research about one company, even as the fund was quietly selling its shares, looked very much like a classic pump-and-dump scheme.

As other investors bought, he sold, in a classic pump-and-dump scheme, Securities and Exchange Commission officials said.