The date on which several derivatives contracts expire concurrently is referred to as quadruple witching. This occurs with four different kinds of contracts, including single stock futures, stock options, stock index futures, and stock index options. Four times a year, on the third Fridays of March, June, September, and December, there are quadruple witching dates. The final hour of trading on these days usually sees the most activity as traders try to close out their positions on these contracts.
