Triple witching is when stock options, stock index futures, and stock index options contracts all expire at the same time on the same trading day. Triple witching occurs four times a year, on the third Friday in March, June, September, and December. Since three options classes with the same underlying securities expire on the same day, it might result in higher trading volume and unexpected price behavior in the underlying assets. Similar to triple witching, option expiration also experiences double witching and quadruple witching. Double witching happens when two classes of options on the same underlying security expire on the same day. Quadruple witching happens when four classes of options on the same underlying security expire on the same day.
