Reserve Orders
To better protect reserve orders, Cboe handles executions against reserve orders as follows:
- The displayed and non-displayed portions of an execution against a reserve order are separated into two (2) executions on the PITCH feed.
- One execution represents the displayed size and carries the displayed OrderID. This is reported as an Execution (0x23) of the displayed portion of the order.
- The second execution represents the hidden size executed and has an obfuscated OrderID so that the displayed and hidden executions cannot be linked. This is reported by a Trade (0x2A, 0x2B, or 0x30) with the obfuscated OrderID.
- The execution against the hidden portion of the order is reported after displayed, non-displayed, and peg executions at the same price matching the Cboe Exchange Priority Rule 11.12.
- When the displayed portion of the reserve order is refreshed, the order is assigned a new OrderID on the PITCH feed. This is reported by an Add Order (0x21, 0x22, or 0x2F) when the remainder is nonzero.





