September 23, 2019 17:45:59
Post Mortem: Cboe System Time Synchronization Issue
SCI System(s) Affected: Matching Engine
Incident Description: Disruption
Beginning at approximately 12:37pm ET today, Cboe observed a degradation in time synchronization across the Cboe BZX Equities, BYX Equities, EDGX Equities, EDGA Equities, BZX Options, EDGX Options, and C2 Options trading platforms as a result of an issue with a third-party time source vendor. Before it began reverting to normal at approximately 13:24pm ET, time appeared to have drifted as far as 300 microseconds ahead on the affected Cboe platforms.
Members Affected: The issue would have affected timestamps for any member entering orders on or receiving market data from the Cboe BZX Equities, BYX Equities, EDGX Equities, EDGA Equities, BZX Options, EDGX Options, or C2 Options trading platforms.
Corrective Action: Cboe has opened a case with its third-party time source vendor and is prepared to switch to an alternative time source if a synchronization issue recurs.