It's not a glitch. It really happens. It has nothing to do with IB (or whoever you send the order through). I get fills like that almost daily. Often, what will happen is that you will get the tail end of a larger order. Picture the following offers on Island:
48 @ 30.90
200 @ 30.95 <-- You
100 @ 31.00
Someone sends an order to Island to buy 50 shares at 31. They get 48@30.90 and 2@30.95 (from you). Note that this leaves the book looking like:
198 @ 30.95
100 @ 31.00
So the same thing will happen to the guy at 31 if someone wants to buy 200 shares.
It's kind of like a hot potato being passed around.
And yes, there are goofballs out there that think they can make money in a tiny account trading 10 shares of a $30 stock (and giving up $15 commish to their broker). Fortunately, they don't last long, and the market is attracting fewer of them now
Instinet and REDIBook (for listed only now) have separate round-lot and odd-lot order books. If you post your round-lot orders there (instead of SMART), you will not get odd-lot fills. By contrast, putting your order on Island away from the market, you may sometimes get odd-lot fills if there is no other odd-lot liquidity further in. When this happens for 90 shares, 0.30 from the inside, I'm generally happy
If you leave the 198-share order resting there after getting the 2-share partial, and then get the rest of it hit later, you will only be charged $2. If you cancel the order and re-place it, you will be charged $1 for the 2-share fill. Can anyone state for sure what happens (commission-wise) when you change the order after the partial? Does it matter what you change (price, size, etc.)?
Does ARCA really protect from odd-lot fills on Naz, but not listed? That seems odd.
Nas
