Glossary term
Quad Witching
The third Friday of March, June, September and December, when stock-index futures, index options, single-stock options and single-stock futures all expire on the same day. Volume spikes, the close is distorted by hedging flows, and a month’s positioning is settled.
AI-generated — produced automatically by Closelook’s systems under this site’s editorial policy.
What it means
Four kinds of derivative contracts share an expiry on the third Friday of each quarter-end month. Traders who hedged with options must roll, close or let positions settle; market makers who sold options unwind the stock they held against them; index funds rebalance on the same close. The result is the heaviest volume of the quarter, an opening and closing auction that can move prices without news, and a session in which a large part of the open interest that pinned prices to certain strikes disappears.
The Monday after is often the cleaner read: with the expiring positions gone, the market shows where it wants to trade without the hedging weight.
Why it matters for the AI trade
Options on the chip ETF and the largest AI names carry some of the deepest open interest in the market, and their strikes act as magnets into an expiry. September 2026’s expiry fell on the 18th, two days after a Federal Reserve decision and in the week the chip index lost its $505 line; we treated the expiry close as the session that would decide whether the loss was a shake-out or a change of trend. A level recovered into an expiry is weaker evidence than one recovered after it.
How Closelook uses it
The Morning 10 calendar point flags the expiry every quarter with the levels the week is measured from; the gamma and open interest entries explain the mechanics that pin prices; the expiration entry covers the general case.
Common questions
- When is quad witching?
- The third Friday of March, June, September and December. Monthly expiries on the other third Fridays involve only options and are quieter.
- Why is it called witching?
- From the old phrase “witching hour” for the last hour of trading on expiry days, when prices moved unpredictably. Triple witching was the term until single-stock futures added a fourth contract in 2002.
- Should I trade on a quad witching day?
- Closelook does not give trading advice. As a matter of record, we read levels crossed on the expiry close with less confidence than levels crossed the following week, because part of the day’s flow is mechanical.