TMX said the outage, that began on the Montreal Exchange at 1:37:25pm EDT and almost two minutes later on the TSX, TSX Venture Exchange and TSX Alpha Exchange, was caused by a hardware failure in a central storage appliance of the trading system.

It said the incident was not the result of a cybersecurity attack and said it began remediation measures but given the timing, it "could not engage disaster recovery systems in time" to ensure an orderly market re-open and closing session.

"We apologise to all of our valued clients across Canada's capital markets and around the world, and to all of TMX Group's stakeholders for Friday's interruption in trading," TMX CEO Lou Eccleston said on the weekend.

"TMX is committed to applying the lessons learned from this incident to help us prevent such issues from recurring in the future."

TMX had issued a series of tweets on Friday alerting people to the issue as it investigated, which prompted responses from the witty to hacking queries to a broker saying "this is really ruining my Friday afternoon".

Canada's stock market last suffered a major outage nearly a decade ago, Reuters reported, when a system fault linked to data feeds shut down trading for a full day in December 2008.