The Manhattan District Attorney's office is prosecuting three stock promoters for allegedly conspiring with companies to drive up the prices of their penny stocks. The DA's office, which is also prosecuting five co-conspirators, alleges the defendants defrauded investors out of more than $290 million.

According to prosecutors, stock promoters Anthony Thompson, Eric Van Nguyen and Jay Fung sent out email blasts and press releases promoting stocks from certain companies in which they, unbeknownst to the investors, owned millions of shares of that stock. They would allegedly collude with the five other defendants to drive up the prices of the stock, eventually selling off the stock they owned and forcing the stock value to collapse.

"These individuals, as alleged in the indictment, are charged with using their positions as stock promoters and company insiders to inflate their own profits through fraud and deceit, and at the expense of the investing public,” DA Cy Vance said in a statement. “We will not allow this kind of manipulation to occur in our markets.” Per a press release:

With millions of shares in the hands of the defendants and other participants, THOMPSON, VAN NGUYEN and FUNG coordinated with corporate insiders to issue press releases as part of their promotional campaigns. Potential investors received false and misleading emails encouraging them to purchase shares in the companies. As demand for the stock rose and drove up the market price, the defendants and other participants are charged with liquidating, or “dumping,” their own shares, while ceasing to email promotional materials. As a result, the price of the stock abruptly plummeted, leaving public investors with nearly worthless stock

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Prosecutors say all eight defendants—Thompson, Nguyen and Fung, along with Hanna Schmieder, Kenneth Oxsalida, Joseph Dervali, Luz Rodriguez and Christopher Balseiro—made about $30 million off the scheme, which was reportedly ongoing from April 2009 to May 2012. Thompson and Fung have been charged with grand larceny, scheme to defraud and securities fraud; they were both released on $1 million bail yesterday. Nguyen has not been arrested yet, according to authorities.

Thompson, Fung, Schmieder and Oxsalida have all pleaded not guilty. Thompson's attorney says her client was simply issuing paid advertisement for the stock. "It’s advertising,” the attorney, Miranda Fritz, said in court. “You might as well indict ‘Mad Men,’ if they actually existed.”