August 1, 2025
Equities Notice 2025-026

TMX Equity Trading Notice

Proposed Market on Open Auction Amendments - Specification Details

Further to Equities Trading Notice 2025-022, TMX Equities is pleased to provide specification details related to the proposed amendments to the Market on Open Auction for each of Toronto Stock Exchange and TSX Venture Exchange (subject to regulatory approval). The updated specifications are now available on our TMX Webstore. The Market on Open changes overview is available here.

The amendments are expected to be implemented in Q4 2025 (subject to regulatory approval), with GTE availability at the end of August 2025.

Specification Changes Summary:

Specifications	Technical Changes Summary
Broadcast Feeds v11.7.0	New message type: "Opening Auction Notification Message" New tags: #572: OpeningImbalanceSide #573: OpeningImbalanceVolume #574: OpeningAuction #578: OpeningPairedVolume New values: #5:BusinessAction ‘PairedVolume' TSX and TSXV only ‘OddlotImbalance' TSX and TSXV only #6:BusinessClass ‘OpeningAuction' TSX and TSXV only #184: RTAutofill "O" - Opening allocation, TSX and TSXV only
Binary Level 1 v2.9.0	New field: "OpeningAuction"
Binary Level 2 v3.7.0	New message types: Oddlot Imbalance Opening Paired Volume New fields: Opening Imbalance Volume Opening Imbalance Side Opening Auction Opening Paired Volume
FIX Spec v7.6.0	Market on Open orders (MOO) may be entered using the following combination of FIX tags: #40: OrdType = "1" (Market) #59: TimeInForce = "2" (OPG) Both Market on Open and Limit on Open orders (LOO) now support oddlots and mixed lots in addition to boardlots. New tag value: #6784: TSXRTAutoFill = "O" (Opening Allocation; TSX and TSXV)
QRTMD Level 1 TSX & TSXV v2.11.0	New message type: ‘P' - Opening Paired Volume New fields: Opening Auction Opening Paired Volume
QRTMD Level 2 TSX & TSXV v2.7.0	New message type: "Opening Auction Notification Message" New tags: #572: OpeningImbalanceSide #573: OpeningImbalanceVolume #574: OpeningAuction #578: OpeningPairedVolume New values: #5:BusinessAction ‘PairedVolume' TSX and TSXV only ‘OddlotImbalance' TSX and TSXV only #6:BusinessClass ‘OpeningAuction' TSX and TSXV only

For more information regarding this notice, please contact the Account Management Team.