A three year FBI investigation into insider trading around the country is about to break, the Wall Street Journal reports.

Federal agents have investigated consultants, hedge funds, mutual fund managers and investment banks, including bankers at Goldman Sachs.

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The criminal and civil probes, which authorities say could eclipse the impact on the financial industry of any previous such investigation, are examining whether multiple insider-trading rings reaped illegal profits totaling tens of millions of dollars, the people say. Some charges could be brought before year-end, they say.

The investigations, if they bear fruit, have the potential to expose a culture of pervasive insider trading in U.S. financial markets, including new ways non-public information is passed to traders through experts tied to specific industries or companies, federal authorities say.

Possible charges against Goldman include whether the bank leaked information about transactions, including health care mergers.. The FBI also investigated Goldman in the takeover of Advanced Medical Optics by Abbott Laboratories in 2009, when Advance Medical Optics shares jumped 143% on the day of the takeover.

The investigation is huge. It also focuses on "expert networks" that pay industry insiders to talk to hedge funds and other institutional investors. (In the early days of these networks, back in the early 2000s, the services were a great way to get inside information. In the following years, the companies tightened their compliance procedures, but the government is clearly taking a close look at current practices.)

Many huge hedge funds and investors are also involved in the probes, including SAC Capital, Jennison, Citadel, Janus, Wellington, and MFS. The latter firms are among the most prestigious mutual-fund managers in the country.

One small research firm sent an email to its clients at the above firms that reveals just how aggressive and widespread the probe is:

John Kinnucan, a principal at Broadband Research LLC in Portland, Ore., sent an email on Oct. 26 to roughly 20 hedge-fund and mutual-fund clients telling of a visit by the Federal Bureau of Investigation.

"Today two fresh faced eager beavers from the FBI showed up unannounced (obviously) on my doorstep thoroughly convinced that my clients have been trading on copious inside information," the email said. "(They obviously have been recording my cell phone conversations for quite some time, with what motivation I have no idea.) We obviously beg to differ, so have therefore declined the young gentleman's gracious offer to wear a wire and therefore ensnare you in their devious web."

If the charges stemming from this probe have the same scope as the probe, it will shake Wall Street to its core. Institutional investors have long had access to vastly more information than amateurs, despite encouraging talk of a "level playing field." If some of these information-gathering practices are now judged to be illegal or risky, it could radically change the institutional money management game.

Read the full story at the Journal >