Quadruple Witching occurs as 4 different types of derivative instruments reach their final trading day at the same time on the same day. In the US market, the final trading day for stock options is every third Friday of each monthand the final trading day for single stock futures, options on index futures and most index futures occurs every third Friday of the quarter. On the third Friday of March, June, September and December. The combined expiration of these four derivative instruments creates the Quadruple Witching day. What Effects Does Quadruple Witching Have? On quadruple witching days, and especially during ... (full story)