ASX Options Expiry and Settlement Explained

ASX options expiry lands on a Thursday, which is the first thing to fix if you arrived here from a US expiration calendar. Monthly exchange traded options on the Australian Securities Exchange expire on the third Thursday of the contract month. One date carries two different settlement rules: single stock options are American style and deliver shares, while index options over the S&P/ASX 200 are European style and cash settle against a level built from opening prices on expiry morning. Compare that with when US options expire, where the standard monthly date is the third Friday and the settlement print comes from a different part of the day.

When do ASX options expire?

ASX publishes one rule for monthly contracts: expiry is the third Thursday of the contract month. Weekly options expire on a Thursday as well, week after week. ASX Clear keeps the right to move an expiry date, and the exchange's published expiry calendar is the authority for any given month, so check it before you write a date into anything that matters.

A lot of older material still describes ASX equity option expiry as the Thursday before the last Friday of the month. That was the earlier convention, and it survives in broker education pages and forum answers that still rank. The two rules can sit a week apart in the same month. Work from the current contract specification and the calendar rather than the folklore.

ASX single stock options: American style, and you receive shares

Standard ASX options over an individual company have four features worth memorising:

• Exercise style is American, so the holder can exercise on any trading day up to and including expiry day.
• One contract normally covers 100 shares of the underlying company.
• Settlement is physical. An exercised call delivers the shares through the ASX cash market, against payment of the strike.
• Expiring series keep trading on expiry day. Normal trading in equity options runs to 4:20pm Sydney time, followed by a late trading phase to 5:00pm.

American exercise is the practical difference for anyone holding a short call over a dividend paying name, since an early exercise can arrive at any point in the contract's life. The US equivalent mechanics are covered in how stock settlement works.

ASX index options: European style, cash settled on the open

Options over the S&P/ASX 200 index, the XJO series, work on the opposite pattern. Exercise is European, so there is no early exercise at all. There are no shares to deliver either, since an index is not a deliverable asset. The contract cash settles.

Two timing rules define expiry day. Trading in the expiring index option series ceases at 12:00pm Sydney time. The cash settlement level is the Opening Price Index Calculation, usually published around 10:10am Sydney time, and it is assembled from the first traded price of each constituent stock on expiry day. If a constituent has not traded at all by the close, its previous traded price stands in.

The ASX does not open every stock at once. Securities open in five alphabetical groups spread across roughly nine minutes: numbers and A to B at 10:00:00, C to F at 10:02:15, G to M at 10:04:30, N to R at 10:06:45, and S to Z at 10:09:00, each with a random offset of up to fifteen seconds. The settlement level blends first prices struck at those separate moments. No trader could have bought or sold the index at that number, which is exactly the situation described in AM settled versus PM settled options.

How far does an opening print sit from a tradable price?

The cleanest way to see what an opening derived settlement does is to measure a deep, heavily traded market minute by minute. The panels below use US large caps, where minute history is dense, and the mechanic is identical: a price is printed at the open, and the market keeps moving after it.

WITH session_open AS (
    SELECT
        toDate(toTimeZone(window_start, 'America/New_York')) AS session_day,
        argMin(toFloat64(open), window_start)                AS first_print
    FROM global_markets.delayed_stocks_minute_aggs
    WHERE ticker = 'SPY'
      AND window_start >= today() - 300
      AND window_start <  today() - 2
      AND (toHour(toTimeZone(window_start, 'America/New_York')) * 60
           + toMinute(toTimeZone(window_start, 'America/New_York'))) >= 570
      AND (toHour(toTimeZone(window_start, 'America/New_York')) * 60
           + toMinute(toTimeZone(window_start, 'America/New_York'))) <  960
    GROUP BY session_day
)
SELECT
    formatDateTime(toTimeZone(m.window_start, 'America/New_York'), '%H:%i') AS et_time,
    round(avg(abs(toFloat64(m.close) / s.first_print - 1) * 10000), 1)      AS avg_gap_bps
FROM global_markets.delayed_stocks_minute_aggs AS m
INNER JOIN session_open AS s
    ON toDate(toTimeZone(m.window_start, 'America/New_York')) = s.session_day
WHERE m.ticker = 'SPY'
  AND m.window_start >= today() - 300
  AND m.window_start <  today() - 2
  AND (toHour(toTimeZone(m.window_start, 'America/New_York')) * 60
       + toMinute(toTimeZone(m.window_start, 'America/New_York'))) BETWEEN 570 AND 600
  AND s.first_print > 0
GROUP BY et_time
HAVING count() > 0
ORDER BY et_time

The curve starts near zero and climbs. One minute past the open, the average distance between the live price and that session's first print measured 5.7 basis points, where one basis point is a hundredth of a percent. By 10:00 local time, half an hour into the session, the average distance had reached 21.3 basis points across 31 plotted minutes. Settlement on an index built from opening prints is being struck against the left edge of that curve while everyone trading the market has already moved along it.

A second effect stacks on top. An index level is not one stock, it is hundreds, and each of them has its own first print at its own moment.

WITH opening_window AS (
    SELECT
        ticker                                               AS symbol,
        toDate(toTimeZone(window_start, 'America/New_York')) AS session_day,
        (toHour(toTimeZone(window_start, 'America/New_York')) * 60
         + toMinute(toTimeZone(window_start, 'America/New_York'))) AS et_minute,
        toFloat64(open)                                      AS bar_open,
        toFloat64(close)                                     AS bar_close
    FROM global_markets.delayed_stocks_minute_aggs
    WHERE ticker IN ('AAPL', 'MSFT', 'NVDA', 'KO', 'JNJ', 'PG', 'WMT', 'XOM')
      AND window_start >= today() - 300
      AND window_start <  today() - 2
      AND (toHour(toTimeZone(window_start, 'America/New_York')) * 60
           + toMinute(toTimeZone(window_start, 'America/New_York'))) BETWEEN 570 AND 600
)
SELECT
    symbol,
    round(avg(abs(half_hour_price / first_print - 1) * 10000), 1) AS avg_move_bps
FROM
(
    SELECT
        symbol,
        session_day,
        argMin(bar_open, et_minute)  AS first_print,
        argMax(bar_close, et_minute) AS half_hour_price
    FROM opening_window
    GROUP BY symbol, session_day
    HAVING first_print > 0
)
GROUP BY symbol
ORDER BY avg_move_bps DESC

Across 8 household names, the liveliest, NVDA, averaged 83.8 basis points of distance between its opening print and its price half an hour later. The steadiest, KO, averaged 49.9. An index settlement stitched from first prints inherits a mix of those, each captured at whatever minute that particular name happened to open.

A pinned expiry morning, minute by minute

Fixed dates make the point without moving underfoot. The panel below pins one US monthly expiry Friday, 15 May 2026, and measures SPY against its own opening print for the first hour of the session.

WITH
(
    SELECT argMin(toFloat64(open), window_start)
    FROM global_markets.delayed_stocks_minute_aggs
    WHERE ticker = 'SPY'
      AND toDate(toTimeZone(window_start, 'America/New_York')) = toDate('2026-05-15')
      AND (toHour(toTimeZone(window_start, 'America/New_York')) * 60
           + toMinute(toTimeZone(window_start, 'America/New_York'))) >= 570
) AS opening_print
SELECT
    formatDateTime(toTimeZone(window_start, 'America/New_York'), '%H:%i') AS et_time,
    round(abs(toFloat64(close) / opening_print - 1) * 10000, 1)           AS distance_from_open_bps
FROM global_markets.delayed_stocks_minute_aggs
WHERE ticker = 'SPY'
  AND toDate(toTimeZone(window_start, 'America/New_York')) = toDate('2026-05-15')
  AND (toHour(toTimeZone(window_start, 'America/New_York')) * 60
       + toMinute(toTimeZone(window_start, 'America/New_York'))) BETWEEN 570 AND 630
ORDER BY et_time

One minute after the print, the market sat 10.5 basis points away from it. By 10:30 that morning, across 61 minutes of trading, the distance was 3.9 basis points. A holder watching an opening settled contract on a morning like that has a position worth a number nobody is quoting any more.

ASX options expiry day, hour by hour in Sydney time

• 10:00am to 10:09am: ASX equities open in five staggered alphabetical groups. Each constituent's first trade feeds the index calculation.
• Around 10:10am: the Opening Price Index Calculation for the S&P/ASX 200 is published. That is the cash settlement level for expiring index options.
• 12:00pm: trading ceases in expiring index option series and in the expiring ASX SPI 200 futures contract.
• Shortly after 4:00pm: the cash market runs its closing single price auction.
• 4:20pm: normal trading ends for equity options, with a late trading phase through to 5:00pm. Expiring single stock series trade all the way to the close.

Brokers set their own exercise instruction deadlines on expiry day, and those are usually earlier than the exchange's. If you are watching from another time zone, our US market hours in Sydney time guide covers the conversion in the other direction.

Holidays, moved dates, and the index futures expiry

Australian public holidays fall near expiry more often than you would guess. Good Friday, Easter Monday and Anzac Day all sit in the April window, and state holidays close parts of the calendar as well. ASX Clear can move an expiry date when the ordinary rule would land on a non trading day, and when that happens the change appears on the published expiry calendar rather than in the contract specification. Treat the calendar as the source of truth for the month you are trading, not the rule of thumb.

One more date gets conflated with index option expiry. ASX SPI 200 futures, the index futures that trade through the Australian night, stop trading in the expiring contract at 12:00pm on the third Thursday of the settlement month and cash settle against a Special Opening Quotation of the S&P/ASX 200. That quotation is built the same way, from the first traded price of each component stock on the last trading day, whenever during the day that first trade happens. In March, June, September and December the futures expiry and the index option expiry fall on the same morning against the same calculation. Other markets place expiry on other weekdays entirely, as India's weekly expiry days show.

FAQ

What day do ASX options expire?

Monthly ASX exchange traded options expire on the third Thursday of the contract month, and weekly options expire on a Thursday. ASX Clear can change a date, so the published ASX expiry calendar is the authority for any specific month.

Are ASX index options cash settled?

Yes. S&P/ASX 200 index options are European style and cash settled. The settlement level is the Opening Price Index Calculation, assembled from the first traded price of each constituent on expiry day and usually published around 10:10am Sydney time.

What time do ASX options stop trading on expiry day?

Expiring index options cease trading at 12:00pm Sydney time on expiry Thursday, two hours after the settlement level is calculated. Single stock options keep trading through the day, with normal trading to 4:20pm and a late trading phase to 5:00pm.

Can I exercise an ASX single stock option before expiry?

Standard ASX single stock options are American style, so the holder can exercise on any trading day up to and including expiry day. Index options are European style and cannot be exercised early.

Is ASX options expiry the same as the US third Friday?

No. US monthly options settle around the third Friday, while ASX monthly options expire on the third Thursday. The settlement mechanics differ too, since ASX index options are struck on an opening calculation rather than a closing price.

Every panel above ships with the SQL that produced it, open any one to check the arithmetic. To run the opening drift measurement on a name or a date of your own, ask the question in plain English on the Strasmore terminal.