At the opening order
A term used to describe a market or limit order that is executed at the start or near the opening of each trading day. If the order is not filled it is cancelled. Most equities experience a huge surge in price movement up or down before the market opens. A trader trying to enter a stock at a lower price could do so by executing a market or limit order at the start of each trading day. However prices at the start of the trading day seems to jump up in price and then falls back down towards the end. Most short traders execute orders at the start of the market to take advantage of the uptick rule in shorting stocks.