SPAN is a market simulation-based Value at Risk system that allows you to effectively assess risk on an overall portfolio basis. SPAN's risk based margin requirements allows for effective margin coverage while preserving efficient use of capital. SPAN assesses risk for a wide variety of financial instruments including: futures, options, physicals, equities, or any combination. Developed in 1988:

• SPAN has been reviewed and approved by market regulators and participants world-wide.
• SPAN is the official Performance Bond mechanism of over 50 exchanges and clearing organizations world-wide, making it the global standard for portfolio margining.

www.cmegroup.com/clearing/span-methodology.html