On October 16, the rolling sell - offs coincided with an event known as «triple witching,» which describes the circumstances when monthly expirations of options and futures contracts occurred on the same day. (federalreservehistory.org)
The price of the option will be determined based on the difference between the stock price and the exercise price, the volatility of the underlying stock (where greater volatility leads to a higher price) and the time to expiration of the option contract (where a longer time period leads to a higher price). (firstasset.com)
Assume the stock declined from $ 65 to $ 55 just prior to expiration of the option. (fidelity.com)