OneChicago: June 30, 2015 Leap Second Event

On June 30, 2015, a leap second will be added after 18:59:59 CDT. A leap second is a second which is added to the Coordinated Universal Time in order to synchronize atomic clocks with astronomical time. On June 30, 2015, clocks will advance as follows: 18:59:59, 18:59:60, 19:00:00.

OneChicago, LLC (“OneChicago”) is sending this Notice to Members (“NTM”) 2015-22 to inform market participants that while OneChicago markets are not open during the June 30, 2015 leap second event; OneChicago has taken all the appropriate steps to prepare our systems. Further, we will be monitoring our systems during the leap second to ensure that all systems will be operational for the regular OneChicago market open on Wednesday July 1, 2015