U.S. Options

As previously announced in the August 17, 2023 Alert, the MIAX Options Exchange Interface specifications have been updated for the following changes:

1. MIAX Options: Resting quote canceled due to replacement quote reject
   1. MIAX Express Interface (MEI) v2.10:
      1. New cancel reason “A” in Cancel Notification
   2. Rollout Schedule:
      1. Day 1, Wednesday, Sept 27 2023 - Symbols beginning with Z (Matching Engine 21)
      2. Day 2, Thursday, Sept 28, 2023 -   Symbols beginning with letters U – YY (Matching Engine 18 - 20)
      3. Day 3, Friday, Sept 29, 2023 – Symbols beginning with A - HZO  (Matching Engines 1 – 8)
      4. Day 4, Monday, October 02, 2023 - All remaining symbols (Matching Engines 9-17 and 22-24)
2. ToM Feed v2.5 – Priority Customer Message Types – mandatory change 
   1. The MIAX Options Exchange will introduce new Top of Market (ToM) message types for single sided ToM Best Bid or Offer (BBO) messages
   2. When a new Priority Customer Order is entered and improves the BBO, ToM will publish the following additional message types with the existing BBO information:
      1. Simple Top of Market Best Bid or Offer Message – Compact Format
         1. “h” = Simple Top of Market on Bid side with Priority Customer Order improves best bid
         2. “i” = Simple Top of Market on Offer side with Priority Customer Order improves best offer
      2. Simple Top of Market Best Bid or Offer Message – Wide Format
         1. “j” = Simple Top of Market on Bid side with Priority Customer Order improves best bid
         2. “k” = Simple Top of Market on Offer side with Priority Customer Order improves best offer
   3. The new message types will only be sent upon entry of a Priority Customer Order that improves the BBO and not for subsequent order or BBO updates.
   4. NOTE: This change is targeted for October 18, 2023 
      1. The ToM Feed will continue to publish the BBO messages with the existing message types for BBO updates that do not meet any of the above scenarios. The new message types only indicate that a BBO update is due to a Priority Customer Order establishing a new aggressive BBO.
3. MIAX Options – Added MIAX Sapphire Support
   1. FIX Order Interface (FOI) v2.6c and
      FIX Drop Copy (FXD) v2.6b:
      1. Execution Report (MsgType=8) – Tag #207(SecurityExchange): Added “SPHR” value
   2. Clearing Trade Drop (CTD) v2.6c:
      1. Trade Message – Execution Exchange Field: Added “S” value
   3. NOTE: These changes are applicable on the MIAX Sapphire Options industry test dates and activation date. 

These changes will be available in the MIAX Options Exchanges Firm Test Bed (FTB2) environment on September 12, 2023.

Additional details on updated interface specifications can be found on the miaxglobal.com website at MIAX Options Interface Specifications.

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