Overview
- The concentrated options and futures expiry occurred on Friday, September 18, 2026, when roughly $7 trillion of U.S. contracts ran out, a level Citadel Securities says ranks as the second-largest on record.
- Citadel reported that about 60% of the notional activity hit at the market open, which can change how trades move prices by collapsing or shifting liquidity into a short time window.
- Dealer positioning showed positive net dealer gamma of about $883 million and a cited ‘gamma flip’ level near 761.34, meaning market makers were providing a degree of support around that price but that support could vanish if prices fall below the threshold.
- The expiry came two days after the Federal Reserve raised its target rate by 25 basis points to 3.75%–4.00%, adding policy uncertainty that could amplify moves once the options-driven hedges and rolls complete.
- History and market models warn of near-term downside risk: past September expiries finished lower about three out of four times five trading days later, so traders should watch whether key support bands around 760–762 hold as positions are rolled or closed.