$9.6 Trillion U.S. Stock Options Expiration in September — Long Gamma Protection May Fade
nashnova research
Roughly $9.6 trillion in options exposure expires by Sept 18, covering 35% of total US options open interest; the dealers' long-gamma buffer will dissolve with it, just as demand for downside protection sits at a one-year low.
$9.6 trillion expiring — how unusual is the size?
Citi strategist Scott Rubner flags about $9.6 trillion in options exposure set to expire by Sept 18 — roughly 35% of total US options open interest.
The quarterly slice alone reaches $6.2 trillion, on track to top June's $7.7 trillion triple-expiration record.
Exposure is heavily concentrated in S&P 500 (SPX) AM-settled options — a single bucket worth roughly $4.0 trillion.
What does the long-gamma fade mean?
Long gamma — a position profile where dealers passively buy dips and sell rallies — acts as a built-in shock absorber for the market.
This means → once the mass expiration clears those positions, the shock absorber disappears and the market's ability to dampen sharp swings weakens materially.
In plain terms = someone has been steadying the boat every time it rocks; after September expiry, that hand pulls back.
Why is downside protection abnormally cheap?
S&P 500 options skew — the premium for put protection relative to call demand — sits at its lowest level in the past year, at the first percentile of its range.
This means → traders are paying very little for downside hedges; the market is under-pricing potential volatility.
This reflects an still-optimistic sentiment — yet a vanishing buffer and cheap protection appearing together is precisely the precondition for amplified volatility.
市场有风险，内容仅供研究参考，不构成投资建议。