As I've menioned before I have 3 trading accounts...my RSP, and TFSA accounts which are not marginable, and hence (at least as far as I understand it) the shares held therin are not available to be loaned out for the purposes of selling short

But I also have an "open" account, which is marginable...I'm not a fan of buying on margin, but to trade options (which I do on occassion) you're required to have a margin account. My understanding is that with a margin account, that my broker can loan out the shares to parties looking to sell short.

When I engaged in some buying yesterday I purchased small lots in each of my 3 accounts. The trades into my TFSA and RSP accounts both appeared on the tape. The trade into my open margin account however did not, at least not as it appeared with my broker. With my broker it showed a fill at (I believe) 12:53 in one lot....on the tape however it showed up much later in 2 separate lots. I suspect the reason is because the shares I was sold, that they were short...potentially right out of my own account.

With that in mind I have put a sell order in for a portion of the shares in my margin account...it is my understanding that by having them "on order" that prevents them from being loaned out for the purposes of shorting.

In fact I'm thinking of placing them all on order, at a price well above the current trading range.