TL;DR. Quad witching is the third Friday of March, June, September, and December — the four days each year when stock index futures, stock index options, and single-stock options all expire in the same trading session. The "quad" nickname is a leftover from single-stock futures, which stopped expiring in 2020. What actually happens on the day: volumes spike, especially into the close; market makers unwind hedges; and short-term moves get noisier — but the day itself has no reliable directional edge.
What "quad witching" actually means
The term describes a scheduled market event, not a market view. According to Wikipedia's summary of triple witching, the "witching hour" is "the last hour of the stock market trading session (3:00–4:00 p.m., New York time)" on the third Friday of March, June, September, and December, when three types of derivatives expire simultaneously. When single-stock futures also expired on the same day, traders began calling it "quadruple witching."
The name is theatrical, but the reason it exists is boring: too much stuff expires at once. Each contract type has its own expiration mechanics, and when they all sit on top of each other, the day's open and close both carry outsized flow.
Why it's "quad" but should really be "triple"
The fourth "witch" was the single-stock future — a futures contract on an individual company's stock rather than an index. In the United States, these were traded almost exclusively on OneChicago, a joint venture launched in 2002 by Cboe, CME, and CBOT. OneChicago shut down in September 2020, and with it, the entire U.S. single-stock futures market. Since then, only three derivative classes expire on the third Friday: index futures, index options, and single-stock options.
Traders and journalists kept saying "quad witching" anyway, partly out of habit and partly because it sounds better. Cboe and academic references now often call it triple witching. Both names refer to the same four days a year.
The three contract types (and where they trade)
To understand why the day matters, it helps to know exactly what expires:
| Contract type | Examples | Settlement | Last trading day |
|---|---|---|---|
| Stock index futures | E-mini S&P 500 (ES), Nasdaq-100 (NQ), Russell 2000 (RTY) | Cash, Friday open (SOQ) | Thursday |
| Stock index options (AM-settled) | SPX (traditional), NDX, RUT | Cash, Friday open (SET) | Thursday |
| Single-stock options | AAPL, NVDA, TSLA, etc. | Physical, Friday close (4pm ET) | Friday |
| Retired 2020: single-stock futures on OneChicago (delisted September 2020). | |||
The critical detail is settlement timing. AM-settled contracts (index futures and traditional SPX/NDX/RUT options) settle to a special value calculated from the Friday opening prints of the underlying index components — called the SOQ for futures and the SET for options. Their last trading day is Thursday, not Friday. PM-settled contracts (single-stock options and index option weeklies like SPXW) trade until the 4:00 p.m. Friday close.
That AM/PM split is the reason quad witching Fridays have two active windows — the open, and the last hour — rather than one.
The day's two active windows, visualized
Why volume spikes: the delta-hedge unwind
The visible reason quad witching Fridays trade heavy is that a huge amount of open interest expires at once and needs to be closed, rolled, or exercised. The less visible reason is what dealers have to do.
Every options market maker who is short calls or puts to customers hedges the delta of those positions by buying or selling the underlying stock (or the index future). As those options approach expiration, their delta collapses toward 0 or 100. When a contract expires, the dealer's hedge is no longer needed — the stock they were holding against a short call, or the short position they held against a short put, has to come off. That unwinding creates real order flow in the underlying.
Multiply that across every single-stock name with heavy open interest, every index option, and every index future rolling from one quarter to the next, and it is easy to see why the last hour of a quad witching Friday routinely prints among the highest single-hour tape volumes of any month.
2026 quad witching calendar
For 2026, the four days follow the standard third-Friday rule with one adjustment: when the third Friday is a market holiday, the last trading day for AM-settled contracts moves to the preceding Wednesday and the last trading day for PM-settled contracts moves to Thursday. That happens in June 2026 because Juneteenth (June 19) falls on Friday and the NYSE will be closed.
| Quarter | Third Friday | PM-settled last trading day | Notes |
|---|---|---|---|
| Q1 2026 | Fri Mar 20, 2026 | Fri Mar 20, 2026 | Standard |
| Q2 2026 | Fri Jun 19, 2026 (NYSE closed — Juneteenth) | Thu Jun 18, 2026 | Holiday shift |
| Q3 2026 | Fri Sep 18, 2026 | Fri Sep 18, 2026 | Next up |
| Q4 2026 | Fri Dec 18, 2026 | Fri Dec 18, 2026 | Standard |
What quad witching actually does to prices
Here the honest answer disappoints people who like drama. Volume rises. Volatility can rise, especially in the last hour. But the day's direction — up or down — is not reliably tied to it being a witching day. Academic studies going back decades have looked for an "expiration-day effect" and generally find something detectable in the tape (small return anomalies, extra volume) but nothing large or stable enough to trade profitably after costs. The Wikipedia summary echoes this: the expirations "generally increase[] the trading volume of options, futures, and their underlying stocks, occasionally increasing the volatility of prices of related securities."
The practical implication: on a quad witching day, treat intraday charts with a bit more skepticism. Prints are noisier. The tape is thicker. A move that looks like a breakout may just be a delta unwind. Wait for the following Monday if you want a clean read.
Common mistakes retail traders make
- Assuming a "pinning" edge. Stocks with heavy open interest often drift toward round strikes on expiration, but the edge is small and inconsistent — and pinning fails whenever a real news catalyst hits.
- Confusing the AM and PM settlement. A trader who is short a traditional SPX quarterly call cannot "close it on Friday." It already stopped trading Thursday and settles to SET on Friday's open.
- Buying cheap same-day options for the "spike." Zero-DTE contracts on quad witching Friday are heavily traded, but implied volatility is often already priced for the elevated flow. See Zero-DTE options explained for why buying tail lottery tickets rarely works.
- Ignoring the gamma dynamics. If dealers are net short gamma, their hedging amplifies moves; if they are long gamma, it dampens them. Which side they are on matters more than the calendar.
Related concepts and what to learn next
Quad witching sits at the intersection of options mechanics, market structure, and dealer flow. Good next steps: read up on the basic anatomy of a call and a put, then the Greeks so you can see why dealers hedge the way they do, and finally the gamma squeeze piece so you understand what happens when that hedging goes reflexive. Together those pieces explain most of what makes an expiration day feel different from a regular Friday.
Sources
- Wikipedia — Triple witching hour: definition, timing, and effect on volume and volatility.
- Wikipedia — OneChicago: single-stock-futures exchange, closed September 2020.
- Cboe SPX product specifications: last trading day and settlement conventions for SPX and SPXW.
- NYSE hours and holiday calendar: Juneteenth market closure for June 19, 2026.
- NYSE consolidated tape: source for verifying intraday volume shape on any specific quad witching day.
Disclosure: This article is for informational purposes only and is not investment advice.