The FBI has raided the offices of three hedge funds as the Justice Department begins a wide-ranging crackdown on patterns of insider trading in the financial industry.

The raids on the offices of Level Global Investors in New York, Diamondback Capital Management in Connecticut, and Loch Capital Management in Boston are said to be part of a wide-ranging investigation into insider trading rings, according to Reuters. The investigation follows in the wake of last year’s Galleon Group insider trading scandal, which taught federal investigators how to follow patterns of tip-offs and trades. They are focusing more on serial patterns of trades rather than one-time stock tips.

“What the Galleon case has showed us is that many of these players have repeat access to insider information and engage in insider trading over and over again,” SEC associate director of enforcement Scott Friestad said at a conference in New York on Monday, according to The Wall Street Journal.

The SEC has been taking a tougher approach to enforcement in the financial industry, as well as in financial reporting. On Monday, it proposed rules for improving the oversight of investment advisers as well as the rules for security-based swap repositories. The passage of the Dodd-Frank Wall Street Reform and Consumer Protection Act earlier this year is giving the SEC extra tools and added impetus to crack down on illegal activity in the financial world and avoid being labeled as "asleep at the switch," as it was in the aftermath of the financial crisis.