Nadex Adds Strikes on a Discretionary Basis in its Index Binary Contracts for Trade Date August 18, 2011 Only

Pursuant to Section 5c(c)(1) of the Commodity Exchange Act, Commission Regulation §40.6(c), and Nadex Rules 12.49(f)(ix), 12.51(f)(ix), 12.59(f)(x), 12.61(f)(x), 12.63(f)(x), and 12.65(f)(x), Nadex has added twenty-one additional strike levels on a discretionary basis in its FTSE 100®, Germany 30, US 500, US SmallCap 2000, US Tech 100, and Wall St 30 Daily Binary Contracts for trade date August 18, 2011 only, due to volatility in the underlying market on that day.