As indicated in a previous system status notice, Cboe Options Exchange ("C1") identified a limitation in the number of available sequenced messages on proprietary market data feeds. This is a result of all proprietary Cboe market data feeds supporting a four (4) byte decimal sequence number which has a maximum value of 4,294,967,295.

Effective this morning, March 2, 2020, a patch has been deployed to allow for the proprietary Multicast TOP feed, PAR market data systems, and the floor data wall systems to remain available in the event C1 exceeds the current maximum allowed sequenced message on any PITCH market data unit.

However, the risk remains that under extreme traffic conditions the Cboe proprietary Multicast PITCH data feed may become inaccessible for one or more market data units. This situation continues to be monitored closely while a long term sequence rollover solution, detailed below, is being implemented. Should Cboe determine that it is approaching the maximum number of available Multicast PITCH message sequenced numbers for any matching unit, notification will be sent at 70%, 80%, 90%, and 95% of that maximum.

In recognition of the need for a long term solution on the Multicast PITCH feed, Cboe will be working diligently to implement a sequence rollover solution. On the Cboe Multicast PITCH feed, matching unit sequence numbers start at one (1) at the beginning of the day and are incremented by one (1) for every sequenced message within a particular symbol unit. As of a soon to be announced effective date, when the message sequence number reaches the maximum value of 4,294,967,295, the message sequence number will rollover back to one (1). Cboe will provide follow up notification regarding member testing opportunities and production release date for this solution. Please refer to the Cboe Options Multicast PITCH Specification for additional details.

Please contact the Cboe Trade Desk or your director of sales with any questions.

Cboe Trade Desk
[email protected]