Canada’s main stock exchanges were halted for more than two hours because of a technical issue, shutting down the market just as an afternoon sell-off in U.S. equities was gaining speed.

Exchanges operated by TMX Group Ltd. stopped trading shortly before 2 p.m. Eastern time and did not re-open. The S&P/TSX Composite Index was down 1.9% at the time. Major U.S. benchmarks dropped more than 4% after falling sharply in the last hour of trading.

TMX Group will be left with a “black eye,” Thomas Caldwell, chairman of Caldwell Securities Ltd. and chairman of the rival Canadian Securities Exchange, said in a phone interview. “It’s a terrible thing to happen, particularly in a cataclysmic market that we’re currently experiencing this week that people either want to trade, need to trade, want to get out or want to get in.”

Toronto-based TMX said in a series of tweets that clients were not able to enter, modify or cancel any open orders on the Toronto Stock Exchange or the TSX Venture and TSX Alpha exchanges. At about 3:20 p.m. the company said its markets would remain closed for the rest of the day, leaving traders scrambling for alternatives. The three exchanges had seen 660 million shares traded up to that point, according to TMX Group’s website.

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. — TMX Group (@TMXGroup) February 27, 2020

High Volume

The halt comes in the midst of a week-long dive in global markets as anxiety over the spread of the coronavirus weighs on equities. Heavy selling may have contributed to the technical problem.

In the first three days of the week, investors traded an average of 305 million shares a day in TSX Composite stocks, according to Bloomberg data. That is 41% higher than the average daily volume in the three months ended Feb. 26.

“I don’t know the inside of what happened at the TSX. What I can tell you is in the last couple of days we have seen a substantial increase in order flow, in our market also,” said Jos Schmitt, President and Chief Executive Officer of Aequitas NEO Exchange Inc., a competing exchange in Toronto. Schmitt made the comments in an interview on BNN Bloomberg television.

TMX Group also halted trading in all equity derivatives on the Montreal Exchange.