Triple Witching Sees $7 Trillion in US Options Expire on September 18, Second-Largest Event on Record Amid Fed Rate Hike Week

Around $7 trillion in notional value of US options expired on Friday September 18, representing approximately one quarter of the market and marking the second-largest triple witching event on record, according to data from Citadel Securities reported by Bloomberg and Investing.com. The expiration, where monthly S&P 500 Index options and single stock options all expire simultaneously, occurred during the last hour of trading from 3:00 to 4:00 PM New York time, traditionally the period of highest volatility and volume. The event coincided with a volatile week that saw the Federal Reserve raise interest rates for the first time in three years on Wednesday and 10-year Treasury yields trading near 5 percent, their highest level since 2007. Markets faced the expiration amid persistent inflation driven by elevated energy costs, with the Fed signaling that further rate hikes may be needed. Bloomberg reported that over 350 firms in the S&P 500 retreated on Friday as bond yields remained elevated and traders navigated the options expiration. Triple witching matters because the simultaneous expiration of multiple derivatives contracts forces institutional investors and traders to close, roll, or adjust large positions in a compressed time window, creating mechanical trading pressure that can amplify intraday price swings regardless of underlying fundamentals. This September's $7 trillion figure, higher than typical quarterly expirations, combined with an already nervous market processing the Fed's hawkish pivot, raised the risk of sudden volatility spikes during the final trading hour. The 2026 triple witching dates are March 20, June 19, September 18, and December 18.