Once upon a time, all Nasdaq and OTC trades double-printed. But by the late '90s, improved technology made that largely obsolete. It is now against SEC and FINRA regulations.
In connection with DBMM, it may have to do with what this SEC Enforcement action involving Endeavor Power Corp describes:
Trading in Endeavor stock on March 7, 2013, after the promotional campaign began, appeared to exceed 1.4 million shares. However, during a telephone conversation on March 8, 2013 that was surreptitiously recorded as part of the FBI’s undercover investigation, Babini told the CI that much of the March 7, 2013 trading in Endeavor stock was “just optics.” When the CI pressed Babini for more of an explanation, Babini responded that a lot of the trading volume was due to “double prints.” A “double print” refers to the practice of structuring a trade so that that multiple trades are reported to the securities market for what is effectively a single trade, with the result being that the volume of trading reported to the market is artificially inflated.
Babini accomplished the “double print” trading effect with Endeavor stock by colluding with a broker to have the broker place orders to sell short early in the day. Then, later in the day, trades placed by Babini with the broker, at a predetermined price, would be used for the broker to acquire the shares needed to cover his short position. Both the short sales and the subsequent purchases were improperly reported as separate trades, when, in fact, it was a single trade. On March 7, 2013, at approximately 9:15 a.m., Babini arranged to have a sell order placed with the broker for 450,000 shares of Endeavor stock. The broker then executed a series of trades to sell short a total of approximately 446,721 shares of Endeavor between 9:35 a.m. and 12:14 p.m. At 12:14 p.m., immediately after placing the final short sale order, the broker purchased 450,000 shares of Endeavor pursuant to the sell order that Babini had directed to the broker about three hours earlier. Babini used the same Bank Gutenberg AG account that had been involved in funding the Endeavor promotional campaigns to place the trades with the broker. The “double print” created a misleading picture of the trading volume in Endeavor stock. Without the “double print” trading, the reported volume of Endeavor shares traded on March 7, 2013 would have been reduced by about one third, so that the reported number of Endeavor shares traded would have been reduced from 1,486,500 to roughly one million.[/I]