It is all about Tax Loss SellingIt is not at all a mystery. It started to be of benefit to many at around $1.20. As it went down (mostly on OS junior sentiment) (but partly do to mgmt timing of info) it became beneficial to more and more people. It is evident to me anyhow, that the dealer house account traders traded it down knowing full well they can get it cheaper. Look at the calender. If you account for 3 day settlement, holidays, and come backward for the 30 day 'superficial loss' rule under Canadian tax code, you end up to this week as peak selling pressure.
I seem to recall that not all short sales are reported, as Rock has mentioned as well.
Experienced investors with deep pockets will tend to own a basket of these OSJ's. At this time of year, they are always looking for the losers in their accts. They can, and will, sell one of them at loss, but keep their industry exposure by buying others in the same group. The positive correlation between them is much higher than most here give credence to. Thus they are able to maintain the upside, but get the capital loss crystallization.
jmho
nb