If it can be executed on the open, why would it not trade? All market orders or limit orders through the opening price, sent to the primary before the opening rotation is complete, get executed at one price. This applies to NASDAQ and NYSE. I can't speak for OTCBB.
I guess that's true these days. But I know with IB years ago, this was not the case. If you sent a non-OPG order before market hours then it would just execute in continuous trading.
I believe you are correct. ON-OPEN ORDERS Specifically request an execution at the opening price. Can be limit-on-open (LOO) or market-on open (MOO). IMBALANCE-ONLY OPEN ORDERS Provides liquidity intended to offset on-open orders during the Opening Cross. Must be priced (limit), no market IO orders. IO buy/sell orders only execute at or above/below the 9:30 a.m., ET, offer/bid. <http://www.nasdaqtrader.com/trader.aspx?id=openclose>
The original question never mentioned what broker he trades at. If Interactive Brokers has special rules that other brokers don't use I'm not privy to them. That is certainly not a standard in the industry.
"ON-OPEN ORDERS Specifically request an execution at the opening price. Can be limit-on-open (LOO) or market-on open (MOO). IMBALANCE-ONLY OPEN ORDERS Provides liquidity intended to offset on-open orders during the Opening Cross. Must be priced (limit), no market IO orders. IO buy/sell orders only execute at or above/below the 9:30 a.m., ET, offer/bid. <http://www.nasdaqtrader.com/trader.aspx?id=openclose> the link is to nasdaq not interactive brokers. market orders are not accepted for ONLY OPEN ORDERS when there is imbalance at the opening.
I looked on the Nasdaq website at: http://www.nasdaqtrader.com/trader.aspx?id=openclose. I see what you are talking about. I'll give NASDAQ a call in the morning to see what happens when you enter a MKT order before the open. The dissemination of imbalances does not start until 9:28am. I still think you can enter a simple mkt order before that and get the open. I will find out.
The question for me is what happens to a market order sent after 9:28 but before 9:30. Does the exchange reject the order or make it a mkt order after the opening? I'll ask them later today.
ZDREG, You are correct. To be part of the opening auction, you must tag the order open and it must be entered before 9:28 unless it is to offset an imbalance. They told me any order not tagged open will be live pre-open, which is not what I expected. On our platforms, I thought you had to tag an order as pre-market of after hours, and that the default was regular trading hours. THat is not what I expected because I enter stock orders all the time pre-market and nothing is traded until regular trading hours. Maybe my broker "stages" the orders to protect pre-market trades. BOb