MOO

A buy or sell order, specifically requests to execute the order at the start of the market day. Orders can be placed when the market opens and no other time in the whole duration of trading. In the New York Stock Exchange, the trader can amend, cancel, or enter an order from 7:00a.m. to 9:28a.m. EST. Unlike a Limit-On-Open (LOO) order, it does not have a specific limit price. It does not guarantee it will be executed at the itemized opening price, but will be executed within a range of prices or not at all.