TXSE Auction Functionality in UAT Beginning July 15

Dear Member,

As previously announced in notice TXSE-2026-013 and in accordance with the technical specifications posted on our website, TXSE will implement auction functionality in the UAT environment only, beginning Wednesday, July 15. We encourage members to review new auction related messages and values across all order entry, drop copy, and market data protocols.

During UAT testing, TXSE will conduct opening and closing auctions for the following TXSE-listed test securities:

• ZZZTT
• ZZZTE
• ZZZTX
• ZZZTA
• ZZZTS

In addition, the following test symbols will be available for auction testing in UAT:

• ZZZTH
• ZZZTO
• ZZZTW
• ZZZTD
• ZZZTY

If you have any questions, please contact Market Operations at marketops@txse.com.