The mix of houses sold can have a major effect on the average price, especially when sales volume is low. I don't believe the market for detached homes in Toronto slumped as much as the averages might indicate, and neither has it gone up by much right now. It's just that more expensive homes ($4 million plus) seemed to have stopped selling in recent months, and maybe some more of them sold in September. That's likely accounting for most of the fluctuations in the averages.