This afternoon the TMX Group (TSX: X) announced they have halted the exchange for the rest of the day with a series of Tweets.
UPDATE 1: TMX continues to investigate the problem with order entry on TSX and TSX ALPHA. Update to follow.
— TMX Group (@TMXGroup) February 27, 2020
The thread:
UPDATE 1: TMX continues to investigate the problem with order entry on TSX and TSX ALPHA. Update to follow.
UPDATE 2: A technical halt has been declared on TSX, TSXV & TSX Alpha. In order to allow Participants to manage their orders, the market will remain in a Pre-Open state until further notice. Once an Opening Time has been determined a further update will be issued.
UPDATE 3: Clients are currently unable to enter, modify or cancel open orders on TSX, TSXV and Alpha. TMX continues to investigate the problem with order entry. Prior to re-opening, we will provide sufficient time in a pre-open state for Participants to manage their orders.
UPDATE 4: TMX continues to investigate the problem with order entry on TSX, TSXV and Alpha. We apologize for the inconvenience. Further updates will be provided.
UPDATE 5: TMX continues to investigate the problem with order entry on TSX, TSXV and Alpha. We apologize for the inconvenience. Further updates will be provided.
UPDATE 6: The technical halt will remain in effect for the remainder of the day on TSX, TSX Venture and TSX Alpha. As a result, the TSX Market on Close Facility will not run today. We apologize for the inconvenience.
The Montreal Exchange has also placed a halt on trading.
Please be aware that the Montréal Exchange will halt trading on all Equity Derivative Instruments and place all instruments in a pre opening state. Participants can cancel or modify orders.
— Montréal Exchange (@MtlExchange) February 27, 2020
At the time of publishing, the TSX Ventures is down 4.58% and the S&P/TSX Composite index is down 1.90% on the day.

Information for this briefing was found via the TMX Group Twitter account. The author has no securities or affiliations related to this organization. Not a recommendation to buy or sell. Always do additional research and consult a professional before purchasing a security. The author holds no licenses.