What is Quadruple Witching? Definition, Formula, and Example
Quadruple witching is the quarterly expiration day when stock index futures, stock index options, single-stock options, and single-stock futures all expire simultaneously, producing some of the highest-volume trading sessions of the year.
What is Quadruple Witching?
Quadruple witching is the simultaneous expiration of four classes of derivative contracts: stock index futures, stock index options, single-stock options, and single-stock futures. It occurs four times a year, on the third Friday of March, June, September, and December. Because traders must close, roll, or exercise enormous derivative positions on the same day, quadruple witching sessions routinely rank among the highest-volume days of the year, with the final hour — the "witching hour" — concentrating the bulk of the action. Since single-stock futures stopped trading in the U.S. in 2020, the day is functionally "triple witching," but the older name persists and the mechanics are unchanged.
How Quadruple Witching Works
The mechanics are a calendar collision. Each contract class expires on its own schedule, and four schedules intersect on the third Friday of each quarter-end month:
1. Stock index futures (e.g., E-mini S&P 500) expire quarterly on the third Friday of March, June, September, and December, settling to a special opening quotation of the index.
2. Stock index options (SPX options and similar) include quarterly expirations on the same date.
3. Single-stock options expire on the third Friday of every month — so they land on the quarterly date automatically.
4. Single-stock futures historically shared the same quarterly cycle.
On the day itself, index arbitrageurs unwind hedged positions — long stock baskets against short futures, for instance — which forces large buy or sell programs into the cash market at the open (for futures settlement) and at the close (for option and index-rebalancing flows). Market-on-close imbalances on quad witching regularly run into the billions of dollars.
Worked Example
Take a quadruple witching Friday such as the June expiration. An index arbitrage desk holds a basis trade: long $2 billion of S&P 500 component stocks in index weights, short the equivalent in E-mini futures. At the open, the futures settle against the Special Opening Quotation (SOQ) of the S&P 500, and the desk simultaneously unwinds its stock basket with market-on-open sell orders. Hundreds of millions of dollars of stock changes hands in the first minutes of trading, spiking volume without reflecting any directional view.
Meanwhile, at the close, expiring SPX and single-stock options force delta-hedge unwinds. If dealers are net short calls at the 5,500 strike and the index closes above it, they must buy stock into the close; below it, they sell. Add the quarterly index rebalances that often coincide, and closing-auction volume in names like AAPL and MSFT can run three to five times a normal Friday. Total U.S. equity volume on quad witching days frequently exceeds 15–20 billion shares versus a typical 10–11 billion.
When Traders Pay Attention to Quadruple Witching
- Volume and liquidity planning. Execution desks schedule large orders to exploit the deep closing liquidity, or avoid the witching hour if they don't want rebalance-flow noise in their fills.
- Volatility positioning. Intraday ranges around the open and close widen; short-dated option traders position for the gamma-driven chop near big strikes.
- Pinning analysis. Heavy open interest at round strikes pulls index prices toward them into expiration — the same force behind max pain.
- Roll tracking. Futures traders watch the roll from the expiring contract to the next quarter in the days before, since the bulk of open interest migrates well before expiration Friday.
Limitations and Common Misconceptions
The biggest misconception is that quadruple witching is directionally bearish or bullish. It is neither. The flows are mechanical unwinds, not opinions; any price distortion tends to mean-revert in the following sessions. Academic studies find elevated volume and modestly elevated volatility on witching days, but no reliable directional edge.
Second, the "witching hour" effect has migrated: much of the roll now happens in the week before expiration, diluting the single-day impact compared with the 1990s. Third, the name is an anachronism — with single-stock futures gone from U.S. markets, only three contract types expire, making it identical to triple witching in practice. Finally, monthly option expirations and even weekly 0DTE expirations now generate comparable pin-and-unwind dynamics, so quad witching is the largest, but no longer the only, expiration event that matters.