The expiry of August's stock-market options could add some spice to Friday's trading session already reeling from global events and fears of rising interest rates.
US stock option contracts with a notional value of $2.2 trillion are set to expire, according to traders, about average for an off-month expiration.
Monthly options expire every month as the name suggests, but once a quarter - in March, June, September and December - an event known as 'Triple Witching' takes place, causing notional value of expiring options to swell as quarterly and sometimes calendar-year options expire along with monthlies and weeklies.
Sessions where monthly options expire often see higher-than-normal volatility, and options-market analysts warned that the same could happen on Friday.
Investors are already braced for further falls in stocks on Friday with futures for the Dow, S&P and Nasdaq all pointing downwards as the losing streak on Wall Street continues.