The "gamma flip" is the index level where aggregate dealer gamma changes sign: above it, hedging is assumed to dampen moves; below it, to amplify them. It gets quoted as a hard number, often to the point, as though it always exists and always matters.
We compute it daily for the S&P 500. Over the 34 sessions from 17 July to 4 September 2026, the level was absent on 16 of them — no sign change anywhere within ±10% of spot. That is the part almost nobody mentions, and it changes how the number should be used.
Gamma exposure is summed per strike and signed by an assumed dealer convention. Near-the-money strikes dominate, so the aggregate is positive where call open interest is concentrated and negative where put open interest is. Walk the index level up and down and the sum crosses zero somewhere. That crossing is the flip.
It is not a support or resistance level. It is the point where the sign of an estimated hedging flow changes — and the estimate rests on an assumption about dealer positioning that nobody publishes (the full caveat is here).
When aggregate gamma is negative across the entire ±10% band, there is no crossing to report. That happened on 16 of 34 sessions — 47% of the time. Those were not quiet days:
| Date | SPX | Total GEX | Flip |
|---|---|---|---|
| 2026-07-24 | 7,411.98 | −$32.8bn | none |
| 2026-08-18 | 7,691.76 | −$26.9bn | none |
| 2026-08-24 | 7,649.34 | −$40.2bn | none |
| 2026-09-01 | 7,654.59 | −$35.4bn | none |
"No flip" is information, not a gap in the data. It says the whole tradable range sits on the amplifying side. A site that always prints a number is either widening its search range until it finds one, or filling in the blank.
On the 18 sessions where a flip existed, it usually sat within about 1.5% of spot — close enough to be crossed in a session or two. But not always:
| Date | SPX | Flip | Distance |
|---|---|---|---|
| 2026-08-14 | 7,798.99 | 7,800 | +0.01% |
| 2026-08-19 | 7,716.02 | 8,075 | +4.65% |
| 2026-08-21 | 7,674.37 | 6,920 | −9.83% |
| 2026-08-26 | 7,675.70 | 6,920 | −9.85% |
| 2026-09-04 | 7,747.71 | 7,810 | +0.80% |
On 14 August the flip sat one point from spot. That is a level worth watching: hedging behaviour would invert on any ordinary move.
On 21 August it sat 9.8% below. A flip that far away is not a level to trade around — it is just the edge of our search window, telling you gamma was negative across everything in between. Quoting "the flip is 6,920" without the distance makes a structural fact look like a target.
Our SPX gamma estimate ranged from −$40.2bn to +$282.9bn over these 34 sessions. The single largest reading, $282.9bn on 13 August, fell to $97.6bn the next day — down 65% in one session.
Very little positioning changed overnight. What changed is which contracts were still alive: gamma is largest near expiry, so a large series rolling off removes most of the total at once. The same mechanic runs the Nikkei, where a single SQ removed 156,105 contracts of open interest in one session (→ SQ explained).
So comparing a gamma total across an expiry boundary tells you almost nothing. Compare within a cycle, or compare the shape rather than the level.
We publish the SPX flip level, the total, and the profile by strike every business day, alongside the same estimate for the Nikkei 225 built from JPX settlement data.
→ Live SPX gamma and flip level ・ → How the estimate is built ・ → Nikkei 225 dashboard