warning that what looks like a great bargain probably isn't. @Paul T: Great information. Any idea whether other brokerages have the same custom (i.e. one limit order with two fills on same day incurs only one commission)? @gsp: You know, I have seen that.IV ticker before and had not realized what it was, so thanks for this excellent tip. My guess is that this only exists for well known third-party indexes? For funds like HXS in my example above, you can always just look at the S&P 500 index itself. That won't tell you the NAV in dollars, but it will give you an idea of the relative intraday price movement (up 1%, down 1%) etc. @CCP I have only ever had a CIBC IE account, so I'm no sure about other brokerages. I find this happens more with thinly traded stocks, or stocks with prices that are quickly rising / falling. As well, it sometimes happens when I have an order for an odd lot. IE, I'm buying 243 shares of stock x, 200 might get filled at the ask (2 lots), and the other 43 might sit there until the ask comes back down to my limit, or I adjust up to fill at the new ask price. At BMO IL (and I believe it is the same elsewhere, as there should be Canadian market rules), you can "modify" an order. Your modification will only go through if your order doesn't get filled before the modification reaches the