October 28, 2019 17:11:08
Post Mortem: Cboe Options Exchange Floor Disruption
SCI System(s) Affected: PAR, Matching Engines
Incident Description: Disruption
At 9:30AM ET, the vendor processing equity legs of complex orders for Cboe Options Exchange ("C1") experienced a technical issue. In response, as part of its normal procedures the Cboe Trade Desk issued a command to redirect processing of complex orders with equity legs to the trading floor (PAR system).
Due to a software defect, this action resulted in the PAR order processing systems becoming overwhelmed with order traffic. This ultimately required disabling routing to the trading floor at 10:05:22 AM ET. All orders remaining on PAR were cancelled, and after extensive troubleshooting the decision was made to restart the PAR system at 12:30 PM ET.
The intra-day PAR system restart resolved most issues with processing and representing orders on the floor. However, sporadic issues resulting from delayed market data continued until 2:29 PM ET.
Members Affected: C1 floor brokers and TPHs routing orders to the floor.
Corrective Action: The underlying software defect has been identified and will be patched for tomorrow. Cboe will examine all issues identified during the troubleshooting and floor system restart process to ensure all items are fully addressed.