quadruple witching week
The week beginning on Monday prior to the Saturday expiration of any four classes of option contracts. The week leading up to options expirations can be particularly volatile because as option holders scramble to exercise their option to buy or sell the underlying assets prior the closing bell on Friday afternoon. Options not exercised by that time will expire worthless, resulting in a loss for the option holder. See Double Witching Week; Options Calendar; Triple Witching Week.