At the Close Order
An at the close order is a specific type of stock order that can be placed through a live broker or via an online brokerage account.
One of the benefits to this type of order is that it can be placed prior to the actual end of the trading day requested. How is this beneficial? Well, think about all of the self-investors and traders who hold "regular" 9-5 jobs.***ad3rdparagraphctr.shtml***
An individual can decide to place an order AND enter the actual order before going to work and still have it execute at the end of the regular trading session at the close while they're at work.
Another instance would be someone who has a stock trading system in place where the enter new positions using an at the close order as long as specific criteria are met during the trading day, or previous trading day(s).
An order entered to buy shares of a stock using an at the close order typically gets executed as a market order at the best available price unless a limit order is specified. Note: I personally, would always use a limit order when combined with an at the close order. Sudden or unexpected higher than usual volatility could create a scenario where you wind up geting a terrible fill price using a market order, especially while you're not watching.
Combined with the requirement of being a limit order, execution would only happen if the price was at or below what is specified (for buys) or at or above for new short positions.