I've had a GTC order in to buy 500 shares of XYZ for several days now. This morning at like 3:55am, I got a partial fill... of one share at my price. Now the instrument is trading back up, way off my bid. Hah. I guess, shame on me for not putting the AON qualifier? Bah Humbug. Does anyone know to what extent AON orders may be de-prioritized by a broker (IB) or by the exchanges for resting limit orders on equities?