What Is Triple Witching? The June 2026 Tape

Triple witching is the quarterly expiration day — the third Friday of March, June, September, and December — when stock index futures, index options, and single-stock options all reach expiration together. Four times a year, an unusually large stack of derivative positions has to be settled, rolled forward, or closed on the same session, and the tape shows it: witching days are reliably among the heaviest trading sessions of their month. June 2026's edition came with a twist that makes it the perfect teaching example — it happened on a Thursday.

What expires on a triple witching day?

Three families of contracts share the quarterly date: stock index futures (and options on those futures), index options, and single-stock options. The name "quadruple witching" circulated after single-stock futures joined the calendar; those products have since faded in the US, and the terms are used loosely for the same four dates. Monthly single-stock options expire on the third Friday of every month — what makes the quarterly dates special is the index futures and options cycle stacking on top, and the index-tracking money that rebalances around the same session.

The witching hours are concentrated, and it helps to know the two settlement styles. Many index options and index futures are AM-settled: they stop trading the prior afternoon and settle against a price computed from the constituent stocks' opening prints — which funnels flow into that morning's opening auctions. Single-stock and ETF options are PM-settled, living until the 4:00 PM close. The result is a day with two gravitational moments: a heavy open, and an enormous closing auction where expiring positions and index-rebalancing flows meet at one price.

The third piece of the day is not a derivative at all. The major index families schedule constituent rebalances — adds, deletes, share-count updates — to take effect on these same quarterly Fridays, and index-tracking funds execute those changes at the close. Rebalance flow and expiration flow share the same auction on the same afternoon, which is a large part of why the volume numbers below look the way they do.

Why June 2026's witching fell on a Thursday

The third Friday of June 2026 was June 19 — Juneteenth, a federal holiday on which US exchanges are closed. By exchange rule, expirations scheduled for a holiday move to the prior trading day, so the entire quarterly stack expired on Thursday, June 18. The tape confirms both halves: June 19 printed no bars at all, and June 18 drew the month's biggest expiration cluster. Here is the contract volume traded June 1-18, grouped by which expiration date the contracts carried:

SELECT toString(expiry) AS expiry,
       round(sum(vol) / 1e6, 1) AS contracts_mm
FROM (
    SELECT toDateOrNull(concat('20', substring(ticker, length(ticker) - 14, 6))) AS expiry,
           toFloat64(volume) AS vol
    FROM global_markets.options_minute_aggs
    WHERE window_start >= '2026-06-01 04:00:00'
      AND window_start < '2026-06-19 04:00:00'
)
WHERE expiry IS NOT NULL
GROUP BY expiry
ORDER BY contracts_mm DESC
LIMIT 8

Contracts expiring 2026-06-18 drew 193.7 million contracts of trading in those fourteen sessions — versus 113.1 million for the next-biggest expiration date (2026-06-12). No other date came close: the quarterly expiry is where open positions concentrate, and the volume follows it.

What the stock tape showed on witching day

Options are half the story. The shares side — total market-wide share volume, day by day through June:

SELECT toDate(toTimeZone(window_start, 'America/New_York')) AS day,
       round(sum(toFloat64(volume)) / 1e9, 1) AS shares_b
FROM global_markets.delayed_stocks_minute_aggs
WHERE window_start >= '2026-06-01 04:00:00'
  AND window_start < '2026-07-01 04:00:00'
GROUP BY day
ORDER BY day

Notice the gap in the series where June 19 would sit — the market was closed — and the spike the day before. Put against the month:

WITH daily AS (
    SELECT toDate(toTimeZone(window_start, 'America/New_York')) AS day,
           sum(toFloat64(volume)) / 1e9 AS shares_b
    FROM global_markets.delayed_stocks_minute_aggs
    WHERE window_start >= '2026-06-01 04:00:00'
      AND window_start < '2026-07-01 04:00:00'
    GROUP BY day
)
SELECT round(anyIf(shares_b, day = '2026-06-18'), 1) AS witching_day_shares_b,
       round(quantileDeterministic(0.5)(shares_b, cityHash64(toString(day))), 1) AS june_median_shares_b,
       round(anyIf(shares_b, day = '2026-06-18') / quantileDeterministic(0.5)(shares_b, cityHash64(toString(day))), 2) AS times_the_median,
       round(anyIf(shares_b, day = '2026-06-18') - max(shares_b), 2) AS gap_to_month_max
FROM daily

June 18 traded 26.7 billion shares against a June median of 20.1 billion — about 1.33x a typical session, and the single heaviest session of the month. That premium is the witching signature. It is worth noting what the signature is made of: expiring index products settling, options positions being rolled to later dates, and index funds executing scheduled rebalances that the index providers deliberately place on these dates. All three flows are calendar-driven and known in advance.

Does triple witching move prices?

Volume, demonstrably. Direction, no — a heavy session is not a directional session, and June 18, 2026 was an ordinary trading day by price. The honest framing: witching concentrates scheduled, mechanical flow, and mechanical flow is two-sided by construction (every expiring position that gets rolled is closed in one contract and opened in another). Traders who care about witching days mostly care for practical reasons: liquidity is deep, the closing auction is enormous, and short-term volume statistics — including relative volume — need the context so the spike is not misread as news. Anyone screening for unusual activity on a witching day will find the whole market lighting up the screen at once; the calendar, not any single stock's story, is the common denominator, and knowing the four dates in advance is the cheapest filter there is.

Triple witching FAQ

When is the next triple witching day?

The dates are the third Fridays of March, June, September, and December. For 2026: March 20, June 18 (moved from Friday June 19, the Juneteenth holiday), September 18, and December 18.

What is the difference between triple and quadruple witching?

"Quadruple" added single-stock futures to the three classic expiring families (index futures, index options, single-stock options). US single-stock futures have since faded away, and both terms now describe the same four quarterly dates.

Why is trading volume so high on witching days?

The quarterly date is where open derivative positions concentrate, and expiration forces a decision on every one of them: settle, close, or roll. On top of that, index providers schedule rebalances for the same sessions. June 2026's edition ran 1.33x the month's median share volume.

Do options ever expire on a holiday?

No. When a scheduled expiration Friday is an exchange holiday — like June 19, 2026 — the expiration moves to the preceding trading day. When do options expire covers the full calendar, including the weekly and daily expiration cycles.

Every panel is a stored, versioned query over the real tape — expand the SQL to see the measurement, or explore any session on the Strasmore terminal.