Securities Industry Automation Corporation (SIAC) Law and Legal Definition

Securities Industry Automation Corporation (SIAC) is an independent organization established by the New York and American Stock Exchanges as a jointly owned subsidiary to provide automation, data processing, clearing and communications services.

SIAC was created on July 17, 1972 as a wholly owned subsidiary of the NYSE Euronext and American Stock Exchange. The NYSE owned two thirds of SIAC, while the AMEX owned one third. On November 1, 2006, NYSE Euronext purchased AMEX’s stake for $40 million.