This excerpt taken from the NDAQ 10-K filed Feb 27, 2009.
NFX Futures Registration
The fair value of NFX futures registration was valued using the cost approach, specifically the replacement cost new approach, to determine the current cost to purchase or replace the futures registration. This valuation methodology is based on the concept that a prudent investor would pay no more for an asset than the amount necessary to replace the asset.
The following is a summary of the indicated fair value for NFX futures registration: