Earlier this week, the Investment Industry Regulatory Organization of Canada (IIROC) published Notice 11-0277 relating to securities trading halts in coordination with the application of "circuit breakers" on U.S. markets for the fourth quarter of 2011.  In the U.S., trading halts occur based on trigger levels of 10%, 20% and 30% drops of the Dow Jones Industrial Average, calculated at the beginning of each quarter using the previous month's average closing value. The NYSE thresholds for the third quarter of 2011 are 1,100 points, 2,250 points and 3,350 points respectively.

It is IIROC's policy that it will coordinate trading halts with U.S. markets, but for days when Canadian markets are open and American markets are closed, IIROC has published related triggers based on drops in the S&P/TSX Composite Index. The TSX trigger levels are: Level 1 (10%) - 1,200 points; Level 2 (20%) - 2,450 points and Level 3 (30%) - 3,650 points, and result in trading halts ranging from 30 minutes to the balance of the trading session, depending on the time of day and magnitude of the market decline. Triggering the Level 1 threshold between 2:00 and 2:30 p.m., for example, would result in a 30 minute halt in trading, while trading would be shut down for the rest of the day should a Level 3 halt occur. The threshold levels for the third quarter have decreased from those for the third quarter of 2011.