When IntercontinentalExchange (ICE) agreed to purchase NYSE Euronext for $8.2 billion, consensus was that it was just another sign of traditional exchanges' waning importance on Wall Street. What's more, analysts believe that the primary appeal of NYSE to ICE was not even its historic trading floor or equity exchange business, but rather for a London-based derivatives exchange it owns, called Liffe. Derivative exchanges have become more much profitable than equity exchanges.