Market on Close Order: How MOC Orders Work at the Closing Bell

A market on close order, or MOC order, tells your broker to buy or sell shares at the official closing price of the trading day. You do not set a price. The order joins the exchange's closing auction and fills at whatever single price that auction produces at 4:00 p.m. Eastern time.

This page is for investors and active traders who want the closing price on purpose, whether to match a benchmark, exit before an earnings report, or rebalance at day's end. It explains the auction behind the fill, the exact cutoff times on NYSE and Nasdaq, and a simple framework for choosing between MOC, limit on close, and ordinary orders. It is educational content, not financial advice.

What a market on close order does

A regular market order executes immediately at the best available price. An MOC order waits. It sits with the exchange until the end of the session, then executes in the closing auction alongside every other on-close order. Per FINRA's overview of order time qualifiers, an MOC order seeks execution as close as possible to the 4 p.m. ET close, generally must be placed at least two minutes before the close, and typically cannot be modified or canceled after that point.

The appeal is precision of timing, not precision of price. You are guaranteed to participate in the close if the order is accepted, but you will not know your fill price until the auction prints.

The closing auction: where MOC orders execute

Exchanges end the day with a single giant matching event, often called the closing auction or closing cross. All accumulated on-close interest, MOC orders, limit-on-close (LOC) orders, and eligible open-market orders are matched at one price. On Nasdaq, that price is calculated at 4:00 p.m. as the level that maximizes the number of shares matched, producing the Nasdaq Official Closing Price.

This closing price matters far beyond the auction itself. It is the benchmark print used for index funds, mutual fund NAVs, and countless performance calculations. That is why volume concentrates there: per Nasdaq's own closing cross FAQ, nearly 10% of its average daily volume occurs in the closing auction. In the minutes before the close, exchanges broadcast imbalance data showing whether buy or sell interest dominates, which lets offsetting orders step in and stabilize the final price.

MOC cutoff times on NYSE and Nasdaq

The deadlines are earlier than most beginners expect, and they differ by exchange:

Sources: the NYSE auctions page and the Nasdaq closing cross FAQ. After the cutoff, NYSE accepts only orders that offset a published imbalance. Brokers often impose their own earlier deadlines, so check your platform; when in doubt, submit MOC orders with comfortable margin rather than at 3:49.

Why traders use MOC orders

Three motives cover most real usage:

• Benchmark matching. Index funds and anyone measured against a closing benchmark want fills at the same price the benchmark uses. The closing auction is the only place that price exists.
• Event timing. Suppose a company reports earnings tonight and you want out before the news. An MOC order guarantees you exit at the day's final print rather than risking an overnight gap. The same logic works for entering ahead of an expected positive catalyst, with the same uncertainty attached.
• Discipline and convenience. An investor who cannot watch the screen can commit to the close in advance. The auction's concentrated liquidity also tends to handle size better than a random intraday minute in many large stocks.