Market participants were left scratching their heads following a temporary outage at the Toronto Stock Exchange.

The Toronto Stock Exchange on Nov. 30 experienced an outage stemming from technical issues. Although the problem was rectified within a few hours, no reason was given for the outage, and some market observers said the exchange could have provided more transparency during the disruption.

The TMX suspended trading for nearly two hours on Nov. 30, following an issue occurring during the pre-open session with symbols that began with the letters M through Z. Currently, there is no further information available as to what caused the problem. TMX Select and TSX Venture Exchange operated as normal.

“The TMX let us know that they would be reopening at 11:15 in the affected symbols, but that is all the information we had,” Alison Crosthwait, managing director and head of global market structure research at Instinet, told Markets Media. “They also moved us into a preopening state after the initial open so that orders could be cancelled. Any time out of the market is significant and in this case an hour and forty-five minutes was long. I wouldn’t say the situation was rectified promptly but without knowing what the situation was it is hard to evaluate their performance.”

According to Crosthwait, outages at TMX are a rare occurrence, with the last outage occurring on Dec. 17, 2008, and lasting from 9:48am through the rest of the day. “You can be sure this is something the TSX takes very seriously and works hard to prevent,” said Crosthwait.

“TMX Group regrets this unfortunate and rare disruption to our normal market operations and the inconvenience this caused our customers,” said Tom Kloet, TMX Group chief executive officer in a statement. “Technical and market operations teams went into action immediately, focusing on restoring the market to full operational performance as rapidly as possible. We are continuing to investigate the root cause to ensure that the problem does not recur.”

On Aug. 31, Chi-X Canada experienced a system issue that resulted in the alternative trading system being shut down for the final hours of the trading day. The official statement from Chi-X Canada was that a code change was made that resulted in a malfunction of their matching engine.