MOC and MOO Order Cutoff Times: NYSE & Nasdaq

MOC and MOO order cutoff times are the daily deadlines for getting an order into an exchange auction rather than into ordinary continuous trading. As of August 2026, the NYSE and Nasdaq both stop accepting market-on-close (MOC) and limit-on-close (LOC) orders at 3:50 p.m. ET, and both stop accepting market-on-open (MOO) and limit-on-open (LOO) orders at 9:28 a.m. ET. Past those lines the order is committed: pulling it or shrinking it is either barred outright or allowed only to fix a documented error.

What MOO, LOO, MOC and LOC orders are

Four order types point at the two auctions that bookend the trading day.

• MOO, market-on-open: no price attached, executes at the official opening price.
• LOO, limit-on-open: carries a price limit and joins the opening auction only at that limit or better.
• MOC, market-on-close: no price attached, executes at the official closing price.
• LOC, limit-on-close: carries a price limit and joins the closing auction only at that limit or better.

The market and limit halves behave the way they do during the session, a trade-off our market order versus limit order guide covers in full: a market order buys certainty of execution, a limit order buys certainty of price. Auction orders add a constraint that resting orders do not have. A day order sitting on the book can be pulled at any point before the bell, as the order time in force guide describes. An auction order cannot, once its cutoff has passed.

MOC and MOO order cutoff times on NYSE and Nasdaq

Every time below is Eastern and current as of August 2026. Two clocks matter for each auction: the entry cutoff, and the later moment the order stops being cancellable.

The opening auction timeline

• 9:28 a.m., Nasdaq entry cutoff. MOO and LOO orders for the Nasdaq Opening Cross stop being accepted, and the ones already sitting there can no longer be cancelled or modified (Nasdaq Equity Rule 4752). Certain limit-on-open orders are still taken after 9:28 a.m. on an entry-only basis.
• 9:28 a.m., Nasdaq imbalance publication starts. The opening imbalance message begins going out at the same instant entry closes, and updates until the 9:30 a.m. open.
• 9:28 a.m., NYSE entry cutoff. NYSE applies the same deadline to orders designated for its opening auction (NYSE Rule 7.35A) and publishes imbalance information through the pre-open.

The closing auction timeline

• 3:50 p.m., entry cutoff on both exchanges. MOC and LOC orders stop being accepted (Nasdaq Equity Rule 4754; NYSE Rule 7.35B). After 3:50 p.m. NYSE takes new orders only on the side that offsets a published imbalance, until 4:00 p.m.
• 3:50 p.m., Nasdaq locks. An MOC or LOC on Nasdaq cannot be cancelled or modified past the cutoff. Nasdaq's imbalance-only order type stays open later on the offsetting side, and Rule 4754 carries the current window for it.
• 3:50 p.m., imbalance publication starts. Nasdaq sends an abbreviated imbalance message every ten seconds from 3:50 p.m., then the full order imbalance indicator every second from 3:55 p.m. NYSE begins publishing its closing auction imbalance at 3:50 p.m. as well.
• 3:50 p.m. to 3:58 p.m., the NYSE error window. Only a documented legitimate error may be cancelled in this stretch, meaning a mistake in price, size, side, or the security itself.
• 3:58 p.m., NYSE locks. No cancellation or size reduction of an MOC or LOC after this point.

Read the two timelines together and the retail-facing summary is short. Once the clock passes 3:50 p.m., an MOC order is going to trade at whatever price the auction produces.

Why the cutoffs exist at all

An auction matches every eligible order at one price at one instant, and the exchange has to know what it is holding before it can tell anyone about it. The cutoff freezes the auction book. The stretch between that freeze and the auction itself is the publication window, and the window is the entire point of an early deadline: for ten minutes the exchange broadcasts how many shares sit unmatched on which side, along with the price where the book would clear if the auction ran at that second.

A trader who sees a large buy imbalance at 3:51 p.m. can bring sell interest to meet it. The more offsetting size that arrives during those ten minutes, the smaller the gap the auction has left to fill at 4:00 p.m. Without a cutoff there would be no settled picture to publish, and no interval in which anyone could answer it. Our closing auction explainer walks through how the single clearing price gets computed once the window shuts, and the opening auction guide does the same for the morning.

How big is the close, really?

The volume curve of a normal session is lopsided. The opening and closing minutes carry far more shares than the middle of the day, and the closing bucket sits alone at the top. The panel below cuts SPY into five-minute slices of Eastern clock time over the past few months of sessions and plots each slice's share of total regular-session volume.

SELECT
    formatDateTime(toDateTime(bucket_minute * 60, 'UTC'), '%H:%i')        AS et_time,
    round(100 * bucket_volume / sum(bucket_volume) OVER (), 3)           AS pct_of_session_volume
FROM
(
    SELECT
        intDiv(et_minute_of_day, 5) * 5 AS bucket_minute,
        sum(volume)                     AS bucket_volume
    FROM
    (
        SELECT
            toHour(toTimeZone(window_start, 'America/New_York')) * 60
                + toMinute(toTimeZone(window_start, 'America/New_York')) AS et_minute_of_day,
            volume
        FROM global_markets.delayed_stocks_minute_aggs
        WHERE ticker = 'SPY'
          AND window_start >= today() - 75
          AND window_start <  today() - 2
    )
    WHERE et_minute_of_day >= 570 AND et_minute_of_day <= 960
    GROUP BY bucket_minute
)
ORDER BY et_time

The bucket stamped 09:30 holds 3.057% of the session's shares. The final bucket, stamped 16:00, holds 0.713%, and that bar is essentially one trade: the official closing auction print, plus whatever else changed hands in the same minute. The slices through the middle of the session are visibly thinner than either end.

The concentration is not identical across stocks. The next panel runs the same split for 8 household names, comparing the first five minutes of the session against the last five plus the closing print.

SELECT
    ticker,
    round(100 * sumIf(volume, et_minute_of_day >= 955) / sum(volume), 2) AS close_window_pct,
    round(100 * sumIf(volume, et_minute_of_day <  575) / sum(volume), 2) AS open_window_pct
FROM
(
    SELECT
        ticker,
        toHour(toTimeZone(window_start, 'America/New_York')) * 60
            + toMinute(toTimeZone(window_start, 'America/New_York')) AS et_minute_of_day,
        volume
    FROM global_markets.delayed_stocks_minute_aggs
    WHERE ticker IN ('SPY', 'AAPL', 'MSFT', 'NVDA', 'KO', 'JNJ', 'PG', 'XOM')
      AND window_start >= today() - 75
      AND window_start <  today() - 2
)
WHERE et_minute_of_day >= 570 AND et_minute_of_day <= 960
GROUP BY ticker
ORDER BY close_window_pct DESC

JNJ carries the heaviest closing concentration of the group, at 12.74% of its regular-session volume in the closing window, against 6.81% for NVDA at the other end of the list. The same shape shows up in every name at different magnitudes.

Has the closing auction been growing?

The monthly view uses the same two windows on SPY, back across two years of sessions.

SELECT
    formatDateTime(month_start, '%Y-%m')                                 AS month,
    round(100 * sumIf(volume, et_minute_of_day >= 955) / sum(volume), 2) AS close_window_pct,
    round(100 * sumIf(volume, et_minute_of_day <  575) / sum(volume), 2) AS open_window_pct
FROM
(
    SELECT
        toStartOfMonth(toTimeZone(window_start, 'America/New_York'))     AS month_start,
        toHour(toTimeZone(window_start, 'America/New_York')) * 60
            + toMinute(toTimeZone(window_start, 'America/New_York'))     AS et_minute_of_day,
        volume
    FROM global_markets.delayed_stocks_minute_aggs
    WHERE ticker = 'SPY'
      AND window_start >= toStartOfMonth(today() - 730)
      AND window_start <  today() - 2
)
WHERE et_minute_of_day >= 570 AND et_minute_of_day <= 960
GROUP BY month_start
ORDER BY month_start

Over the 25 months plotted, the closing window ran 10.72% of regular-session volume in the first month and 8.2% in the latest, which is still partial. The opening window sits alongside it for scale. Month-to-month moves in this series coincide with index rebalance dates and quarterly expirations, which land unevenly across the calendar.

What the imbalance window looks like on one session

Quarter ends put the heaviest load on the closing auction. Funds that track an index trade at the official close on rebalance dates, and June 30, 2026 was one of those dates. The trace below follows SPY minute by minute across the final half hour of that session, a fixed historical window that will read the same a year from now.

SELECT
    formatDateTime(toTimeZone(window_start, 'America/New_York'), '%H:%i') AS et_time,
    round(volume / 1e6, 2)                                               AS volume_mm
FROM global_markets.delayed_stocks_minute_aggs
WHERE ticker = 'SPY'
  AND window_start >= toDateTime('2026-06-30 19:30:00', 'UTC')
  AND window_start <= toDateTime('2026-06-30 20:00:00', 'UTC')
ORDER BY window_start

Volume in the 15:30 minute measured 0.13 million shares. The 3:50 p.m. entry cutoff falls two thirds of the way along the axis, and every bar to the right of it sits inside the published imbalance window, the stretch when the exchange is broadcasting unmatched size and contra interest can still arrive. The final bar, stamped 16:00, opens at the bell and holds 1.07 million shares of tape volume. Read the panel for the profile of the half hour rather than for any single minute.

What an MOC order does in a thin stock

Here is the consequence for anyone typing one into a retail platform. An MOC is a market order aimed at the single largest print of the day, and it stops being retractable at 3:50 p.m. In a heavily traded name that print absorbs size comfortably. In a thin one the auction can be a small slice of an already small day, and the clearing price can settle well away from the last quote you looked at.

Two details soften the edges. An LOC caps the price you will accept, at the cost of possibly not trading at all, the same trade-off the stop order versus stop limit order comparison covers in a different setting. And many brokers impose their own deadline for auction orders, sometimes several minutes ahead of the exchange cutoff. The broker's clock is the one that binds you, so check it before you need it.

Where to re-check these times

Both exchanges have moved these deadlines. NYSE ran a 3:45 p.m. MOC and LOC cutoff for years before pushing it to 3:50 p.m., and Nasdaq reworked how its opening imbalance data goes out in 2021. Changes surface publicly as SEC filings under Rule 19b-4 ahead of the effective date. The durable places to look are the rulebooks themselves: Nasdaq Equity Rule 4752 for the Opening Cross and Rule 4754 for the Closing Cross, and NYSE Rules 7.35A and 7.35B for the two auctions. A broker help page lags amendments. The rule text does not.

FAQ

What time is the MOC order cutoff?

3:50 p.m. ET on both the NYSE and Nasdaq as of August 2026. An MOC entered later is rejected by Nasdaq, and taken by NYSE only on the side that offsets a published imbalance, up to 4:00 p.m.

Can you cancel an MOC order after the cutoff?

Generally no. Nasdaq stops cancels and modifications at the 3:50 p.m. cutoff. NYSE permits a cancel between 3:50 p.m. and 3:58 p.m. only to correct a documented legitimate error, and none at all after 3:58 p.m.

What is the difference between MOC and LOC orders?

An MOC takes the official closing price whatever it turns out to be. An LOC carries a price limit and participates only if the closing price is at or better than that limit, which means it can end the day unfilled.

When does closing auction imbalance data start publishing?

At the 3:50 p.m. cutoff. Nasdaq sends an abbreviated imbalance message every ten seconds from 3:50 p.m. and the full indicator every second from 3:55 p.m. NYSE begins publishing its closing imbalance at 3:50 p.m. and updates it into the close.

What time is the MOO order cutoff?

9:28 a.m. ET, two minutes ahead of the 9:30 a.m. open, on both exchanges. Nasdaq begins publishing opening imbalance information at the same moment entry closes.

Every panel here ships with the exact SQL beneath it, expand any one to see how the number was counted. To run the same closing-window split on a ticker you follow, ask for it in plain English on the Strasmore terminal.