Mr Rajaratnam was charged with 11 counts of securities fraud and conspiracy, while Ms Chiesi faced 10 counts regarding profits made from a variety of trades.
Six others arrested in relation to the investigation have announced their intention to plead guilty but both Mr Rajaratnam and Ms Chiesi intend to fight the case and prove their innocence, their lawyers said.
John Dowd, representing Mr Rajaratnam, said: "Mr Rajaratnam is innocent and looks forward to his day in court when a jury of his fellow citizens will examine and evaluate all of the evidence."
Insider trading is alleged to have taken place on shares belonging to a diverse range of companies, from Google to Hilton Hotels.
Hector Ruiz, the former chief executive officer of technology company Advanced Micro Devices (AMD), resigned from his position as chairman of Globalfoundries earlier this year after he was implicated in the scandal.
Media reports alleged he had passed on information about the formation of Globalfoundries to Ms Chiesi.
Mr Ruiz has not been charged by prosecutors over the allegations.
By Gary Cooper