Close Navigation

Market-on-Close Order

Trading Term

A market-on-close (MOC) order is a directive to execute a trade at or as close as possible to the official closing price of a trading session. These orders are typically used by institutional investors seeking to align trades with daily index prices or to minimize tracking error in portfolios tied to benchmarks. Because they are executed at the close, MOC orders help avoid slippage caused by intraday price fluctuations.

MOC orders are particularly important in portfolio rebalancing, fund NAV calculations, and end-of-day trading strategies. Exchanges typically impose submission deadlines for these orders—such as 15 minutes before the close—to manage order imbalances. Once the cutoff is reached, the orders are aggregated and executed during the closing auction, where the final price is determined by supply and demand dynamics.

While MOC orders offer the advantage of precise timing, they also carry risks, especially in volatile markets or during periods of news-driven activity. A large imbalance between buy and sell MOC orders can cause significant closing price moves. Traders must be aware and understand exchange rules, potential liquidity constraints, and the impact of high-frequency trading at the close when employing this order type as part of their strategy.

IBKR Campus Newsletters

This website uses cookies to collect usage information in order to offer a better browsing experience. By browsing this site or by clicking on the "ACCEPT COOKIES" button you accept our Cookie Policy.