The Three Big Index ETFs Are All in Negative Dealer Gamma. The Mega-Cap Stocks That Dominate Them Are Not.

By Kresmion Research, July 20, 2026

As of Friday's close, SPY, QQQ and IWM all sat in negative dealer gamma below their zero-gamma flip levels, while their biggest holdings stayed positive. It is an unusual split, because the same mega-cap stocks make up most of the weight inside those index funds.

Kresmion's modeled gamma surface, taken at the end of Friday July 17, put net dealer gamma for the S&P 500 fund SPY at about negative 8.7 billion dollars, for the Nasdaq 100 fund QQQ at about negative 5.1 billion, and for the Russell 2000 fund IWM at about negative 1.6 billion. All three traded below their zero-gamma flip levels. The six largest US stocks were on the other side: Apple at about positive 1.0 billion, Meta positive 0.9 billion, Microsoft positive 0.7 billion, Nvidia positive 0.5 billion, Amazon positive 0.4 billion and Alphabet positive 0.2 billion. Those six are roughly a third of the S&P 500 and close to half of the Nasdaq 100 by weight, so the wrapper and the parts are pointing in opposite directions.

What the gamma surface shows

Dealer gamma exposure is a way of describing how options dealers have to trade to stay hedged. When their net gamma is positive they buy weakness and sell strength, which damps a move. When it is negative they sell weakness and buy strength, which adds to a move. The price where the aggregate flips from one to the other is the zero-gamma or gamma flip level, and it separates a calmer regime above from a jumpier one below. SpotGamma's explainer frames the same point: negative gamma hedging is pro-cyclical and can exacerbate an existing move.

On Friday, SPY at 743.29 sat below its flip near 751.67. QQQ at 695.33 sat well below its flip near 717.39. IWM at 294.04 sat below its flip near 305.72. In all three, the model puts dealers on the amplifying side. The individual mega-caps did the opposite. Apple, Microsoft, Nvidia, Meta, Amazon and Alphabet each carried positive net gamma, which puts dealers in those single names on the damping side. Netflix was the one large name with a slightly negative reading, close to zero.

Why an index and its components can sit on opposite sides

The split is less strange than it looks once you separate who buys what. A large pool of investors is persistently long the market and buys index puts as portfolio insurance, which Cboe describes as a standing pool of natural buyers of S&P 500 protection. That persistent demand leaves dealers short those puts and short gamma at the index level. Index options are the common tool for hedging a broad book, as even introductory guides to index options note.

Single-stock options tend to draw the opposite flow. Demand there skews more toward calls, from investors reaching for a move in a specific name, which leaves dealers longer gamma in the components than in the index that contains them. The academic version of this asymmetry, that end users are net long index options but net short single-stock options, is the core result of demand-based option pricing. The result is the picture on Friday: the index funds are wired to amplify a move that their own largest holdings are wired to cushion.

The part of the move that is mechanical

The number worth being careful with is the swing. SPY dealer gamma was around positive 5.3 billion dollars a week earlier and is now around negative 8.7 billion, and it would be easy to read that as a sudden surge of fear. Part of it is not. Friday July 17 was July monthly options expiration, the third Friday of the month, and Kresmion's snapshot is the first reading after it. A chunk of the positive gamma that had been sitting in expiring July contracts simply rolled off, which pushes the surface more negative on its own, before any new hedge is placed.

Two more things keep this in proportion. Kresmion has only tracked this surface since late June, about three weeks, so there is no long history to call any single reading a record. And negative index gamma is partly a standing condition rather than an event: QQQ has been negative in nearly every daily snapshot in that window, and IWM in all of them. Small-cap index gamma is almost always negative because those books are chronically put-heavy. So the reading that actually moved is SPY, which was positive as recently as a week ago and is now well below its flip, and it moved into a down week: the S&P 500 fell about 1.6 percent over the five sessions, the Nasdaq 100 fell about 4.2 percent as the AI and chip names led lower, and the VIX rose about 6 percent.

What it changes for this week

A negative-gamma index sets a condition, it does not force an outcome. The counter-evidence is in the same data. IWM has been in negative gamma every day Kresmion has tracked it and the Russell 2000 fund was close to flat on the week, so a negative reading plainly does not guarantee an amplified move. The S&P 500 drifted lower rather than gapping, despite sitting below its flip for two sessions. What negative index gamma changes is the transmission: if a catalyst does hit, the index layer is now positioned to add to the move rather than absorb it, even while dealers in Apple, Nvidia and the rest lean the other way.

That matters more given the backdrop. Kresmion's macro regime model reads Neutral and balanced, with a negative growth factor and an economic surprise index about 1.5 standard deviations below its one-year norm, the weakest input in the model. Liquidity still reads supportive and the tape is not risk-off, but the mix is soft data against firm positioning, and the calendar is busy: the next Federal Reserve rate decision is July 29. A market that sits below its index flip levels going into a data-heavy stretch is a market where a surprise gets less cushioning than usual at the wrapper level.

What would confirm or break the pattern

The test is simple and observable. If the index funds climb back above their flip levels, SPY above roughly 752, the amplifying condition switches off and this is a footnote. If they stay below with gamma still deeply negative as the week's fresh options positioning builds, the setup holds into the Fed meeting. The single cleanest tell is whether SPY gamma reverts toward zero over the next few sessions, which would confirm the swing was mostly the post-expiration roll-off, or whether it stays pinned deep in negative territory, which would say real hedging demand is holding it there. Kresmion's gamma surface updates daily, so the answer arrives on its own.

Frequently asked questions

What is dealer gamma exposure?

It is a model of how options dealers must trade to stay hedged as prices move. Positive net gamma means they buy dips and sell strength, which damps volatility. Negative net gamma means they sell dips and buy strength, which adds to a move. The level where the total flips is the zero-gamma or flip level. Kresmion models it from the listed options chain under an assumed dealer positioning convention, so it is an estimate of positioning, not a measured report of it.

Why are SPY, QQQ and IWM negative while their biggest stocks are positive?

Because index options and single-stock options attract different flow. Investors buy index puts as portfolio insurance, which leaves dealers short gamma at the index level. Single-name options draw more call demand, which leaves dealers longer gamma in the individual stocks. So the index funds and the mega-caps inside them can sit on opposite sides of zero at the same time.

Does negative index gamma mean the market is about to fall?

No. It describes a condition, not a direction or a forecast. Negative gamma means dealer hedging would amplify a move if one happens, in either direction. The Russell 2000 fund IWM has been in negative gamma every day in Kresmion's record and was roughly flat on the week, which shows the condition alone does not produce a move. This is descriptive market structure, not advice.

How much of the SPY swing is just July expiration?

Some meaningful part of it. Friday July 17 was July monthly options expiration, and the reading is the first after it, so expiring positions that had carried positive gamma rolled off and pushed the surface more negative on their own. Whether the negative reading persists once new positioning is written over the coming sessions is the thing to watch.