MIAX Options And MIAX Emerald Exchanges Trading Issue On 16 March 2020 - Trading Disruption

On March 16, 2020, a conflict with multiple system configuration messages caused the MIAX Options and MIAX Emerald Exchanges to send Done-for-Day messages to FIX customers at 1:26 PM ET. For firms that were configured to receive Done-for-Day messages, the Exchanges were unable to send updates through the FIX system for orders that were open at the time of the errant Done-for-Day messages. To minimize the risk to FIX trading participants, the MIAX Options and MIAX Emerald Exchanges halted trading at 1:50 PM ET.

After the halts, all open orders on the books were cancelled and FIX customers were informed of the actions taken. MIAX Emerald reopened for trading at 3:20 PM ET and remained open for the balance of the trading day.  MIAX Options inadvertently reopened trading on four (4) trading clouds for five (5) minutes beginning at 3:20 PM ET.  During that period, eight (8) trades occurred. Trading Operations and Regulatory personnel cancelled those trades. Those clouds were halted at 3:25 PM and the MIAX Options Exchange remained halted for the balance of the trading day. 

Members Affected:  FIX customers with orders open at 1:26 PM ET that had ports configured for Done-for-Day messages.

Corrective Action:  MIAX system configuration messages were adjusted to avoid the conflict that occurred on March 16, 2020 and were effective for the opening of trading on March 17, 2020.