what other trading hours feature a flurry of trading activity 
the bottom linein financial markets the witching hour refers to the last trading hour on the third friday of each month when options and futures on stocks and indexes expire this period is characterized by heavy trading volumes and increased volatility as investors rush to close or roll over positions before the end of the trading day double triple and quadruple witching can occur when two three or four asset class contracts expire simultaneously these events particularly triple witching can be particularly volatile because of the concentration of expiring contracts 