Today I entered a limit buy order and the TWS displayed the green color. About 15 minutes later when the market was still well above my price my order disappeared from my screen. I received no fill (naturally) at that time. Later the price traded much below my price, still no fill, and never did I get a fill. Questions: What went wrong? Are not such orders entered and held at GLobex? The market closed at the high of the day, therefore had I been filled I would be better off. Do I take it up with anyone, and if so will it do me any good?