Contingent Forced Opening (CFO)
If an Opening Price is unable to be established by 9:45 a.m. ET, Cboe will initiate a Contingent Forced Open (CFO) for the security. All queued RHO orders will be submitted to the exchange book in time priority. RHO orders that are routable may be routed away if they are marketable and liquidity is not available on the local exchange book.
What if there are no crossing RHO orders at the Opening Price?
In the event that a symbol has no crossing RHO orders, the exchange will conclude the Opening Match with no trades and immediately submit all RHO orders to the exchange order book in time priority.
What order modifiers are disallowed on RHO orders for the Market Opening?
Cboe will reject RHO orders received prior to the Opening Match if marked as Post Only or if a non-zero minimum quantity is specified. Cboe will also reject RHO orders that are marked as ISO if received prior to 9:30 a.m. ET. If an RHO ISO is received after 9:30 a.m. ET but before the Opening Match is completed, then the RHO ISO will be allowed to execute against continuous book liquidity up to the order’s limit price, and any remaining quantity will be queued for participation in the Opening Match.
| RHO Order Modifier | 2:30 - 9:30 a.m. (BZX and EDGX only) | 8:55 p.m. - 9:30 a.m. (EDGX only effective 12/07/26) | 6:00 - 9:30 a.m. (BYX and EDGA only) | 9:30 a.m. to Opening Match or CFO | After Opening Match or CFO |
|---|---|---|---|---|---|
| Post Only | Rejected | Rejected | Rejected | Rejected | Accepted |
| MinQty | Rejected | Rejected | Rejected | Rejected | Accepted (must also be hidden) |
| ISO | Rejected | Rejected | Rejected | Accepted (remaining quantity queued for Opening Process) | Accepted |
Is Match Trade Prevention (MTP) honored on the Opening Match?
No, MTP is not honored on the Opening Match. However, MTP instructions on RHO orders will be honored if an RHO order is not executed in the Opening Match and is subsequently submitted to the exchange order book.