Prosecutors say Rajaratnam played a key role in a $52 million insider trading case that has resulted in charges against 21 people.
Rajaratnam, one of America's richest billionaires, declined comment after the court appearance. He remains free on $100 million bail.
Prosecutors say they'll turn over 100 hours of intercepted phone calls between defendants in the case to attorneys for the defendants this week.
They asked for a trial in June or July, but federal judge Richard Holwell said it was too soon to set a trial date.