Decode Market Maker Hedging to Find Real Support, Resistance & Momentum
SPX dashboard: price chart with GEX Flip & Max Pain overlaid, Gamma Exposure bars (Split View), Volume by strike, Gamma History, and Gamma Profile. The expiration selector is open: switch between 0DTE, weekly, monthly, or a custom range to see dealer positioning at every horizon.
Most traders spend years watching the market bounce off levels nobody drew and trend on days nobody predicted, and file it all under noise. A large part of that "noise" is mechanical. When someone buys or sells an option, a dealer takes the other side, and that dealer hedges by buying or selling the underlying. Not sometimes, not when they feel like it: on every tick, by mandate. Multiply that across millions of contracts and you get persistent, measurable pressure at specific prices. Gamma exposure is the map of that pressure, and this site exists to put the map in front of you and teach you to read it.
A word on who is behind this, since you should know whose judgment you are trusting. GEX Metrix is a three-person operation: a trader with a risk-management background, a developer, and a tester. But the writing is not divided up. Every page on this site is written by me, the trader, with more than twenty years in the markets and a past life developing risk-management software. No content team, no ghostwriters. That matters here more than on most sites, because a recurring theme in these pages is holding data vendors to account for what their numbers actually are. It would be a strange thing to demand from others and not deliver myself.
The site has three layers, and the menu above mirrors them. There is the topic (gamma exposure, dealer hedging, and the market structure behind both), the tool (a live dashboard that turns the day's options data into levels you can trade against), and the library (essays and guides that go as deep as you want to go). You do not need the tool to get value from the essays, and you do not need the essays to use the tool, but they were built to feed each other.
Gamma exposure tools run from free to $720 a month, and every one of them says "live" and "edge" on the pricing page. The differences are real, but they live in one place the marketing never mentions: what the data underneath actually is. Every GEX product on the market sits on one of six rungs.
Yesterday's OI + delayed Greeks (free at the low end, and quietly inside some paid tools). The classic naive map, and the cheapest rung. It still carries a measured edge; the flaw is staleness, not the method. The misleading part is selling it as "live positioning."
Yesterday's OI + live Greeks (where many paid subscriptions actually sit; the price will not tell you, because vendors do not disclose the rung). Gamma recomputed on live prices, so the values update all day. The structure underneath is still yesterday's positions. Only a model can move the OI itself.
Modeled intraday OI + delayed data (free, here). The first rung where positioning moves during the session: a trained model estimates intraday OI migration on the verified overnight base. This is our Free tier, labeled as the estimate it is, error rates published.
Modeled intraday OI + live data. Live tape classification (opening vs closing intent, trade by trade) feeding the model. Classification works wherever there is a tape, so this rung covers every instrument and exchange, provided the data sources are bundled into one consolidated view. Our Plus tier is being built around this; it is the highest rung reachable without buying exchange positioning data, and that data is only complete for SPX anyway (no ES, and only a slice of SPY).
Exchange-marked positioning data ($250–720/mo dashboards). Built on Cboe's Open-Close feed: better raw inputs, complete for SPX only, minutes of lag, and an edge nobody selling it has ever published in quantified terms.
The raw institutional stack ($10k–50k/mo). Full OPRA feed, tick quotes, trade-by-trade records, co-location. For hedge funds and quant firms. For everyone else, it is the price-check on the five rungs below it.
Which rung you need depends on how you trade, and for most discretionary traders the honest answer is cheaper than the marketing wants it to be. The full orientation (with vendors, prices, and a trader-type guide) is in The GEX Data Ladder. The data mechanics behind it are in the intraday OI problem.
Most people learn the Greeks as pricing math. That is the boring half. The useful half (if you trade direction) is that Gamma, Delta, Vanna and Charm tell you where market makers are forced to buy and sell the underlying itself.
Dealers hedge continuously, by rule. No opinion involved. So their buying and selling lands at predictable price levels. Those levels show up on your chart as support, resistance, and shifts in how fast the market moves.
GEX and the related Greeks sharpen timing, strike selection, and risk management:
You do not need to touch an option. Dealer hedging moves the underlying directly:
On a 1% move, hundreds of billions in 0DTE notional has to be re-hedged. That hedging is the structure on your chart.
People ask me for the workflow more than they ask me for the theory, so here it is. This is the same routine I run every morning before the open, and it takes about five minutes once you have done it a few times. If any of the terms below are new to you, start with the GEX primer and come back.
That is the whole framework. Levels first, regime second, entries last. The rest of this page and every article on the site is detail hanging off those three steps.
Here is the dirty secret of most gamma dashboards: the Open Interest behind every level you see was frozen at last night's close. The OCC publishes OI once per day, after settlement. There is no live feed. So a "naive" gamma dashboard computes its walls from yesterday's positioning and shows you that same map at 9:30, at noon, and at 3:55 as if nothing traded in between. On a slow mid-cycle day that is a tolerable approximation. On a 0DTE-heavy day, where most of the gamma that matters was opened this morning, it can put the walls in the wrong place entirely.
I have written at length about why real-time OI does not exist and what every vendor claiming it is actually doing (the intraday OI problem is the honest version of that story). The short version: anyone showing you "live OI" is showing you an estimate. The difference between platforms is whether they admit it, and how good the estimate is.
GEX Metrix runs an Intraday OI Model on top of the verified overnight baseline. It watches the session's actual options volume strike by strike and estimates how positioning has shifted since the morning snapshot. The gamma map you see in the afternoon reflects what was traded today, not just what existed yesterday. And because I do not believe in black boxes, the model is explicitly labeled and you can switch between the Model view and the Naive view with one click. Flip between them on a heavy 0DTE afternoon and you will see exactly why this matters: sometimes the two maps agree, and sometimes the naive map has a wall where the model shows open air. Watching where they diverge is a signal in itself.
Three tiers, and I will describe them the way I would describe them to a friend rather than the way a pricing page usually does. If you have read the intraday OI essays, you already know the hierarchy: positioning estimates range from a naive frozen snapshot up to live tick-level classification. Free and Plus climb exactly that ladder. Free is for learning the framework and checking levels every morning, Plus is the tier I built the whole roadmap around, and Pro adds the second-order Greeks and the full snapshot history on top.
Technical analysis draws lines on price history. GEX shows where dealers are obligated to act, whatever the chart pattern says. I use both, but they are doing very different jobs.
| Traditional TA | GEX Analysis |
|---|---|
| Based on past price action | Based on current positioning |
| Levels drawn subjectively | Levels calculated from real OI |
| Can not predict volatility regime | Predicts range vs trending day |
| Does not update intraday | Updates with options flow |
| Single input: price | Four layers: Gamma + Delta + Vanna + Charm |
Shorter reference pages, one per concept. What each Greek means, where it sits on the GEX Metrix dashboard, and what I check when I open it.
The foundation. How gamma concentration turns into support, resistance and vol regimes, and how all of it gets drawn on the chart.
The guideES, NQ, RTY, CL, GC. How I use gamma walls, the flip level and negative gamma zones when the instrument is a future, not an option.
For futures tradersThe directional tilt sitting in dealer books right now. Worth a look before you pick a side.
Read itThe second-order Greeks behind vol-driven rallies and end-of-week drift. They sit in the Pro tier; this page explains what they show and when I bother checking them.
What they showHow aggressive call buying traps dealers in a buying loop, and what the buildup looks like in the data before price goes vertical.
The mechanicsMonthly and quarterly expiration patterns, pin risk, and the vol expansion that tends to follow. What I plan around each cycle, and why quarterlies hit harder.
The calendarSame-day expiries are most of SPX volume now. What that flow does to intraday structure, session after session.
Every sessionLonger pieces where I work through the mechanics: how dealer hedging actually operates, where the data comes from, and where the popular narratives fall apart. Written for traders who care how the machine works under the dashboard. The first two are original research on our own data, not commentary.
Everyone repeats the same two claims: positive gamma pins price, negative gamma accelerates it. We put both on trial with a controlled event study at 1-minute resolution. One survived every test we threw at it. The other never showed up.
Read the studyThe technical write-up of the Intraday OI Model itself: how a gradient-boosted model classifies opening versus closing flow from 15-minute snapshots, what its error rates are, and how it transfers to instruments it has never seen.
Under the hoodGamma tools run from free to $720 a month and all of them say "live" and "edge." Six rungs sort the whole market by what the data underneath actually is: who sits where, what it costs, and the caveat nobody advertises. My own tiers included.
Get orientedIf GEX is new to you, this is the one to read first. The formula, positive and negative gamma regimes, the four price levels I actually watch, and a simple pre-session routine for SPX.
Start hereA walk through my own morning routine. What I look at first on the chart, how each panel maps to a decision, and how the historical snapshots reveal regime shifts before price does.
Read itThree products on one index, and they behave differently enough that it matters. Settlement, sizing, who trades what, and which GEX signal I would trust for each kind of trader.
The comparisonOI counts contracts. GEX weighs them. A deep OTM strike with thousands of open contracts can be pure noise, and gamma weighting is how you filter for the levels dealers actually defend.
Full pieceOptions volume grew 150% in a decade while stock volume grew 30%. That shift is the reason dealer hedging now shows up on every intraday chart, and it is why GEX signals keep getting cleaner. I trace how it happened.
Read the whole thingOn June 4, 2026 FINRA killed the PDT designation and its $25,000 minimum, replacing them with a real-time intraday margin framework. That 2001 rule quietly routed a generation of small accounts into 0DTE options. I go through what changed and where the flow goes next.
What it means for 0DTEThe plumbing behind every level on the dashboard. An order hits a dealer's book, delta gets computed, hedges go out in the underlying. Step by step, no mystique.
Have a lookEvery platform showing "live OI" is showing an estimate, mine included. The tape can not tell an opening trade from a closing one, and I walk through the four scenarios that make true intraday OI structurally impossible.
Read whyOCC publishes open interest once, after the close. So at the open your gamma map is as accurate as it will get, and it decays from there. I cover the volume-to-OI ratio I use to track that decay, plus the hierarchy of intraday OI models, from a static baseline up to full OPRA condition-code processing.
Go deeperVIX futures give you a monthly macro read. SPX ATM implied vol gives you day-by-day resolution down to individual event dates, and you can build it without any futures data at all. How each curve is constructed and what each one actually measures.
Both methodsBackwardation flags crash risk, but acting on the first inversion is usually the wrong trade. It persisted for months in 2008 and again through COVID. The signal I wait for is the near-term segment flipping back to contango, confirmed by price action and GEX structure.
The signalIV against realized, term structure, skew across strikes, put/call ratios. The vol context I want before I trust any gamma level, with interactive charts you can flip between regimes.
Have a lookArticle cards only tell you the topic. This is how the pieces actually read, pulled straight from the essays. If the tone works for you, the rest of the site will too.
"What it mostly is not, in the retail and even semi-professional tooling world, is tested. The academic literature has documented expiration-day pinning at option strikes, but the day-to-day, intraday claim (that a strike's current gamma exposure changes how price behaves when it gets there) is usually asserted, not measured."
From the gamma pinning study, in which we measured it: 2,288 strike touches, 1-minute resolution, out-of-sample replication.
"Some days SPX behaves like it is on rails. Every dip into a certain strike gets bought, every push above another strike gets sold, and by the close the index has gone nowhere. Other days the exact same chart turns into a runaway train, and every technical level you drew gets steamrolled before lunch."
From What is Gamma Exposure?, on the two market regimes and the mechanical reason they exist.
"Quiet tape, no news on the calendar, and then ES rips 30 points in fifteen minutes for no visible reason. The usual suspects get blamed: algos, 'smart money', someone who knew something. In my experience, most of these moves have a much more boring explanation."
From 0DTE Options and Gamma, on same-day expirations that now run roughly 60% of SPX volume.
"Every few months another platform launches with 'live open interest' on the feature list, and every time I see it I want to ask the same question: live from where? There is no feed to be live from. Open interest does not stream. It has no order book, no tape, no tick."
From The Intraday OI Problem, on what every "live OI" vendor is actually showing you.
"The market was dead all week, then Monday it just started trending for no reason. Pull up the calendar and the reason is usually sitting right there. Options expired on Friday. The gamma that had been sitting on price like a weighted blanket got removed over a single afternoon, and the market woke up in a different regime."
From OpEx Effects, on the expiration cycle that repeats at weekly, monthly, and quarterly amplitude.
"Almost every article on the volatility term structure ends up giving the same advice: when the curve inverts, sell. I think that advice has cost more money than the crashes it was supposed to protect against. The historical record is pretty blunt about why, and we will get to 2008 and COVID in a moment."
From Term Structure in Crashes and Reversals, on the signal worth waiting for instead.
"Every GEX level on the site comes from the same boring process: a dealer takes the other side of an options order, nets out the delta, and buys or sells the underlying to flatten it. Follow one trade through that loop and the levels on your SPX chart stop looking mysterious."
From How Market Makers Hedge Delta, which follows a real SPX morning through five timestamped snapshots.