A field guide to GEX levels
Read walls, flips and strike profiles in one chart.
In this article 7 sections
What the lines represent
GEX levels summarize modeled exposure concentrations or sign changes. They are not exchange-published support, resistance or executable orders.
Read each level with its instrument, expiry, timestamp, units and selection rule. Provider definitions can differ.
A put-wall breakdown under review
Follow IWM’s $290.00 test through completed candles.
Choose a checkpoint for 1-minute detail. Later prices stay hidden.
Invalidation came first. The later decline changes nothing.
Historical review. Plans are hypothetical; fills, delivered signals and a trading edge are not proved.
- Context
- Preopen walls: call $295.00, put $290.00. Price started above the put wall. The 15-minute-delayed model was stale; alerts were suppressed. Pause until model timing and a fresh broker quote are verified. No order was authorized.
- Wait for
- Wait for a completed five-minute close below $290.00 after its first touch. 09:45–09:49 did not qualify; 09:50–09:54 closed $289.80, known at 09:55 ET.
- Execution
- Hypothetical sell-limit reference: $289.80 after 09:55; no fill assumed. Verify quote, spread, borrow and order acceptance. Size ≤ floor(risk budget / $0.43), capped by buying power and borrow, with costs reserved. No order was submitted.
- Invalidation
- Stop reference $290.23: $0.01 above the completed $290.22 high. Reference risk is $0.43 per share. A $290.00 reclaim challenges the idea; do not move the stop to rescue it.
- Management
- 1R target: $289.37. Check which reference is reached first. If both occur inside one minute, OHLC cannot establish order. Stops can slip; fills need broker evidence.
$290.00 was reclaimed by 09:57. The $290.23 stop reference was observed at 09:58, before the $289.37 target at 10:09. Keep the invalidation-first result. No fills or P&L are claimed.
Source, timestamps & selection
- Candles
- Databento XNAS.ITCH · venue OHLCV, not consolidated SIP volume. These are venue bars, not a consolidated market tape.
- Model source
- Tradier sandbox · original archived native model. Source delay: 900 seconds.
- Model built
2026-09-11T07:04:09.845438+00:00- First recorded
2026-09-11T07:08:32.318429+00:00- Open interest timestamp
- Unknown. No point-in-time open-interest clock was supplied.
- Evidence limit
- A local producer cycle recorded this model before the cash open. The producer log is mutable and has no independently sealed receipt. The first and selected records report stale=true and alerts_suppressed=true; no enabled alert, trader broadcast or execution is proved. Exact OI availability is unknown. The chart uses a different price provider. Bar-end times are the earliest theoretical observation times after a minute closes, not proven client delivery times.
- Why this day
- Four editorial examples selected after reviewing all 12 SPY/QQQ/IWM sessions from September 8–11, 2026. Hindsight selection is explicit. Untouched levels, recrossings and the invalidation-first case remain visible; no hit rate or predictive performance is claimed.
The producer record is mutable. “First recorded” describes the recorded archive; it is not proof that a trader received the same levels at that instant.
Archive fingerprints
- resource-case-study-census.json
af9379d9eb6802044356957fd6cf9a96b203eb57bddafd844c2d56ebf679de85 - cycles.parquet
cb31c638974f19aea8cd9bc5b0bc0366f088e49ed69369d72f131823138b742f - contracts-IWM.parquet
340667d74bf8ce223b2a4ee192a08c7b78d981cdb383c845c87eeff0dad87350 - IWM-preview.json
43aef114869281bc4be35467b81039be01d145ba4cede00454136a9160c7f15a
Explore the concept with a simplified model
Four references
Check the methodology behind each label.
| Reference | What it summarizes | What to verify |
|---|---|---|
| Call wall | A notable call-side exposure concentration at a strike or band. | Whether ranking uses open interest, gross call gamma or another measure. |
| Put wall | A notable put-side exposure concentration at a strike or band. | The put sign convention and the selected expiry population. |
| Gamma flip | A hypothetical underlying price where net modeled exposure changes sign. | Repricing assumptions, search range and additional crossings. |
| Gamma by strike | Contract exposures grouped by strike at a given underlying price. | Units, omitted contracts and separation of call, put and net values. |
Read the chart in five steps
Use this for preparation, then apply a separate trading plan.
- Instrument: SPY levels use SPY prices, not SPX or ES.
- Clocks: check price, open interest and model times.
- Horizon: compare windows with the same units.
- Profile: inspect the strikes or curve behind a level.
- Price: observe completed action; define entry, invalidation and risk separately.
A wall is not an order
Fictional ETF: price $100.00, call wall $102.00, put wall $98.00, flip $99.50. Price is below the call concentration and above the flip. That does not predict a target or reversal.
Evaluate the level version available before the move. Updating it afterward introduces hindsight. A crossing alone proves no fill, cost or profit.
Why a level may not matter
Stale open interest, missing expiries, changing Greeks or an incorrect inventory assumption can weaken the model. Other flows may dominate.
Cboe’s SPX 0DTE study separates gross activity from net market-maker risk. Its sample does not establish a GEX reversal rule.
Sources: Cboe — Mandy Xu: Much Ado About 0DTEs: Evaluating the Market Impact of SPX 0DTE Options.
Use Prism to inspect
Compare SPY, QQQ and IWM price, walls, flips, expiry windows and exposure by strike. Open source details before interpreting the result.
Read the data mode: a fictional demo teaches controls; a dated historical view shows archived inputs. Neither establishes live coverage or performance.
Sources and editorial notes
Read the primary references and editorial policy
Published by GEXfreak. Prism by GEXfreak is the product described in these guides. Definitions reference the primary sources below; examples and tool-selection checklists are GEXfreak’s own illustrations. This is product education, not independent investment research.
These sources explain options mechanics and data. They do not endorse Prism or validate the predictive value of its levels. Undated pages are marked below; the checked date is when the source was reviewed.
- Gamma — Options Industry Council (OCC). Publication date not stated. Checked .
- Much Ado About 0DTEs: Evaluating the Market Impact of SPX 0DTE Options — Cboe — Mandy Xu. Published 2023-09-08. Checked .
For the product’s calculation and data boundaries, read Prism’s methodology.
Read the levels together.
Compare price, expiry and strike detail in the workspace.
Demo values are fictional. Create an account to save your layout; review current access conditions on the pricing page.