U.S. Options

The MIAX Emerald Exchange interface specifications have been updated as follows.

1. Support for IEX and MX2 Options Exchange
   1. Updates to the following Interface Specifications are as follows:
      1. FOI Interface Specification v1.3a: SecurityExchange (tag = 207) field of ExecutionReport message (MsgType = 8) to include IEX and MX2 Options Exchange MIC code
      2. FXD Interface Specification v1.2c: SecurityExchange (tag = 207) field of ExecutionReport message (MsgType = 8) to include IEX and MX2 Options Exchange MIC code
      3. CTD Interface Specification v1.2d: Execution Exchange field of Trade message (Message Type = T) to include IEX and MX2 Options Exchange Code
2. Previously announced Local Market Maker on PRIME/cPRIME Contra Functionality
   1. The functionality (previously published in the March 31, 2026 Alert) has been reverted back to its prior state.
   2. Updates to the FOI Interface Specification v1.3a are as follows:
      1. New Order Cross message to exclude Market Maker (MM) as a valid “CustomerOrFirm” value for PRIME.
      2. New Order Cross – Multileg message to exclude Market Maker (MM) as a valid “CustomerOrFirm” value for cPRIME.

Additional Details:

• These changes are available in the MIAX Emerald Exchange's Firm Test Bed (FTB2) environment.
• Visit MIAX Emerald Interface Specifications for additional details.

Please contact MIAX Trading Operations at TradingOperations@miaxglobal.com or (609) 897-7302 to discuss any specific issues, update configurations and to arrange interface testing.