My order didn't trigger today and I was hoping someone could tell me why. It was entered via TWS with the following properties: contract: JPY on GLOBEX (japanese yen) order type: stop stop price: 0.8640 order time in force: GTD good after time: 20060921 08:20:00 EST expiration date: 20060921 expiration time: 15:00:00 EST FA allocation: single account order attributes: I only specified "Hidden" Once 8:20 hit this morning I expected it to be "live" and the current price was above the buy stop price, so I expected it to fill immediately but it didn't. After watching it for a minute or two and verifying the settings I changed it to a market order and it filled immediately. Does anyone have any idea why it wouldn't fill immediately otherwise? Does specifying "hidden" somehow prevent this? Since it's GLOBEX and a simulated stop anyway I figured hidden just meant it wouldn't appear in the market depth until the stop price was met then it would just be sent as a market order. The TIF and good after date are done so it will only be valid during side by side hours of the CME pit, since that's what I'm basing the buy/sell decisions on (but I don't actually want it to go to the pit so I can be mugged). Also I thought maybe the FA account specified didn't have permissions or enough margin (even though I was certain it did) but the fact that it filled after switching it to a market order means that isn't the case. Has anyone seen this behavior before and there's something I should have specified differently?