$9.6 Trillion in US Options Expiring by September 18, Citadel Reports

Record Expiration Amid Seasonal Weakness

The $9.6 trillion figure represents roughly 35% of the entire US options market. Scott Rubner, who authored the Citadel Securities report, highlighted the timing risk: the largest options expiration event on record lands during the market's weakest seasonal stretch, with downside protection at multi-year lows.

The September 18 expiration date alone accounts for roughly 23% of total US options exposure. In June 2026, an $8.3 trillion options expiration event shifted timing due to the Juneteenth holiday, ultimately producing the $7.7 trillion single-day expiration that had held the record until now.

Volatility Dynamics and Market Stabilizers

When dealers hold long-gamma positions, as they reportedly do now, they act as natural dampeners on volatility, buying dips and selling rallies. This mechanical support has helped cushion market swings. Once those positions expire, that stabilizing force disappears.

One-month S&P 500 puts, the standard insurance policy against a market drop, are unusually cheap. Downside protection is currently at its lowest levels since December 2024, raising questions about whether investors are adequately hedged heading into the expiration window.

Macro Catalysts and Rubner's View

The Non-Farm Payroll report drops on September 4, followed by the Consumer Price Index on September 11. Both releases land in the two weeks before the massive expiration, creating potential flashpoints for volatility.

Despite flagging these risks, Rubner maintains a constructive view on US equities. The report describes a market reset dynamic rather than a market crash scenario. The options market has grown enormous, driven by the rise of zero-day-to-expiry (0DTE) options, increased retail participation, and institutional adoption of options-based strategies, reshaping how dealers and investors interact with volatility itself.