The E-mini S&P 500 issue on April 26, 2005, was related to a match engine operating system error causing the corruption of data. While recovery from this type of failure is normally automatic in the CME Globex Trading Engine, internal safeguards detected an anomalous data condition that prevented the automatic failover until the data corruption could be repaired. This resulted in the suspension of matching for E-mini S&P 500 contracts as of 09:52:53 CT. All other CME Globex traded products remained open as did all CME open outcry markets.

Immediately following the suspension of matching, the issue was escalated to the hardware vendor.  As soon as the remedy was received from the vendor, the E-mini S&P 500 markets were scheduled for re-opening at 12:45 CT with a 15-minute pre-opening.  Prior to the resumption of trading, CME took the following steps to mitigate risks to E-mini S&P 500 customers:

All "day" and "session" orders were cancelled.

All orders entered as Good Till Cancelled (GTC) or Good Through Date (GTD) that had been acknowledged remained working.

All orders not acknowledged as working were cancelled.

If you have any questions regarding this notice, please contact Marilee Radecki at 312.930.8193, email mradecki@cme.com, or Kevin Brady at 312.648.3653, email kbrady@cme.com

Thank you.