The company has not disclosed the nature of the trading problem, but a Toronto Stock Exchange spokesperson said the trading outage was not due to "a hack." The Ontario Securities Commission has been in contact with TMX Group and will be throughout the weekend. Also affected were the TSX Venture Exchange, a market for small capitalization stocks, and the TSX Alpha Exchange, a market geared to active traders. No flash-crashAccording to Bloomberg, about 115 million shares changed hands on Friday before the trading problem arose. A message posted to users of TD's Web Broker accounts reads:"Due to technical issues at the TMX Group Inc., Canadian order flow is currently unavailable for the TSX, TSX Venture, Montreal Exchanges and other Canadian ATS exchanges.

Source: CBC News April 27, 2018 19:05 UTC