RE:RE:RE:RE:RE:RE:Hard to put a positive spin on this...I'm providing 1st hand knowledge, not conjecture...I still keep in touch with a 1/2 dozen canadian traders.
Canadian trading desks have execution traders(actively shop blocks of stock, active on the various exchanges, ECN's, ATS's, dark pools) and they also employ prop. traders who mostly day/weekly trade. They can interact, cross stock but client orders always must take precendent.
The short, likely is prop guys who are making a very short term trade, not some hedge fund loading on a major short. Nothing to be concerned with. Trust me.