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The FBI is investigating whether high-speed trading firms trade on non-public information, the Wall Street Journal reports.

The agency is working with the SEC and CFTC.

Bloomberg's Keri Geiger and Patricia Hurtado also have an update:

"The Federal Bureau of Investigation's inquiry stems from a multiyear crackdown on insider trading, which has led to at least 79 convictions of hedge-fund traders and others. Agents are examining whether traders abuse information to act ahead of orders by institutional investors, according to the person, who asked not to be named because the probe is confidential. Even trades based on computer algorithms could amount to wire fraud, securities fraud or insider trading."

CNBC's Eamon Javers said an FBI spokesman is urging anyone with information about high-frequency trading abuses to call the bureau.
An FBI spokesman tells me: "we want people to contact us." Says traders with tips about HFT should call 212-384-1000.
- Eamon Javers (@EamonJavers) March 31, 2014
The report comes after Michael Lewis appeared on "60 Minutes" to argue that high-frequency traders have "rigged" the stock market.