If non-government folk did this it would be a crime. Not that government folk would ever prosecute Wall Street denizens because we all know that are pure and without sin.
Back in 2008, Bush's Treasury Secretary Hank Paulson was telling the public that Freddie Mac and Fannie Mae stock was solid. That same day behind closed doors, he was (nudge, nudge, wink, wink) telling hedge fund managers and his old Goldman Sachs buddies that just maybe the Feds were going to wipe out the stock equity of the two mortgage companies.
The crime is insider trading and no effort has been made to find out who profited from Paulson's secret disclosure. Paulson's actions constitute conspiracy, allegedly.
Hat tip to Atrios for discovering this.