Steven Cohen's hedge fund, SAC Capital Advisors, pleaded not guilty to insider trading charges in federal court on Friday.
The firm's general counsel, Peter Nussbaum, flanked by five high-powered defense lawyers, entered the plea before U.S. District Judge Laura Taylor Swain in New York.
U.S. prosecutors unsealed an indictment against the firm on Thursday, charging SAC Capital with presiding over a culture that encouraged traders to tap personal networks of contacts for inside information about publicly traded companies.
(Read more: Cramer: SAC Capital playing you for a dope?)
Government-obtained evidence includes "court-authorized wiretaps" and "a large number of electronic recordings," including emails and instant messages, Antonia Apps, an assistant U.S. attorney who has prosecuted numerous insider trading cases, told the judge.
"In short, a tremendous volume," Apps said of the evidence.
Ted Wells, a lawyer representing SAC Capital, said he was "most concerned" with obtaining statements that former employees of the $14 billion hedge fund have provided the government.
Several former employees, including Noah Freeman, Jon Horvath, Donald Longueuil and Wesley Wang, have already pleaded guilty to charges of criminal insider trading. No criminal charges have been brought against Cohen.
On Thursday, SAC Capital Advisors was charged with wire fraud and four counts of securities fraud; prosecutors allege the crimes were carried out from 1999 through at least 2010.
U.S. Attorney Preet Bharara said at a press conference Thursday that SAC was "a magnet for market cheaters" and that the firm had "a tremendous tolerance for questionable conduct."
Cohen himself wasn't named as a defendant in the criminal case, but the charges could threaten to topple a firm that he founded and once managed $15 billion in assets.
In a statement after the charges, SAC said it "has never encouraged, promoted or tolerated insider trading and takes its compliance and management obligations seriously."
It went on, "The handful of men who admit they broke the law does not reflect the honesty,integrity and character of the thousands of men and women who have worked at SAC over the past 21 years. We will continue to operate as we work through these matters."