Create a Market-on-Open Order
MOO (market-on-open) is a market order executed at the market's open at the market price.
To create a MOO order
Click the Ask price to create a BUY order, or the Bid price to create a SELL order.
In the Type field, select MKT as the order type.
In the TIF field, select OPG as the time in force.
To transmit the order, click the "T" in the Status field.
For a more detailed description of MOO orders visit the Order Types information page.