(Reuter) - Notch up another one in favor of the government in a crackdown on Wall Street.

Mathew Martoma, a former portfolio manager at billionaire Steven A. Cohen's SAC Capital Advisors hedge fund, was found guilty on Thursday of engaging in what prosecutors called the most lucrative insider trading scheme in U.S. history.

A federal jury in New York found Martoma guilty on all three of the conspiracy and securities fraud charges that he faced, over a scheme that allowed SAC Capital to make profits and avoid losses of $275 million.

This is the eighth guilty verdict tied to billionaire Steven A. Cohen's $14 billion hedge fund.

The reputation of the hedge fund and its founder has been tarnished greatly by the government's decade long investigation into unlawful activity.