Triple witching hour
Triple 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 every March, June, September, and December. Those days are the expiration of three kinds of securities:
The simultaneous expirations generally increases the trading volume of options, futures and the underlying stocks, and occasionally increases volatility of prices of related securities.
Concept and usage
The term "triple witching" refers to the extra volatility resulting from the expiration dates of the three financing instruments, and is based on the witching hour denoting the active time for witches.
It is used often and is considered industry jargon.
- "Quadruple Witching". Investopedia.