On the 25th I was short 4 contracts and sleeping cozily in my bed when to my horror I discovered that my stop market orders were never filled once the price had penetrated the stop intraday. I got a "remote connection error" in the orderbook (while I'm asleep and two hours after my stop had been "active"). My 5R became a -2.28R trade extraordinarily quickly. I called up my broker (MB trading) last night and after some phone calls they investigated it and called me back saying the problem was at the exchange and that the exchange just doesn't fill you sometimes. They refunded my brokerage fees ($1.5), and said the only thing I could do was to set alerts when my orders don't get filled and immediately call their risk/trading department. Unfortunately that is not possibly for me as I'm still working part-time and am not always there to monitor my trades. So I doubt I will be continuing to position trade (short-term holdings for a few days) this market at the current time. Does this happen often on futures exchanges (which ones)? has anyone else had a similar experience? How is it possible that a stop is just "cancelled" once the stop price is exceeded?