Secure Financial Transaction Infrastructure (SFTI) SFTI is a private communications network for the financial industry that is designed to be more resistant to man-made and natural disasters, while speeding recovery after a crisis. This highly reliable network offers firms access to SIAC for the New York Stock Exchange, the American Stock Exchange, Clearing Corporation and Market Data services. SFTI B2B, available through SIAC’s subsidiary, Sector, Inc., utilizes the SFTI infrastructure to carry order traffic and other financial data to additional Exchanges, Market Centers & Content Service Providers.