How often can/does this occur?
It can happen on every order you place with Datek, at least on Nasdaq stocks. Again, this is the major limitation of trading thru a firm that routes your orders first to Island.
What prevents my order still being open when the bid goes ABOVE my sell price?
Nothing. Unless you cancel it.
Is there any way to prevent this?
Use market orders. Choose another broker. Or pray alot.
Seriously, though, although about 80% of my orders with Datek were filled via a combination of partial fills,(within minutes of each other) it only became a real problem maybe 10% of the time. In those cases, I would get filled 15, 62, 86 or like odd fills out of a 1000-5000 share order. Then, I'd be stuck with no more fills after the stock moved away from my price. It can be annoying, but I'm not aware of anything you can do short of only using a firm that allows you to preference your orders, all of which have been discussed previously.
This was just a cost of doing business in my mind, when I used Datek for most of my orders. Thankfully, it was only a $20 expense to bail from those odd lot fills.
Hope this helps.
Len |
