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What You’ll Learn

How Hermes’s GEX analysis views work, what they each answer, and how to use them together throughout the trading day.

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Quick GEX Primer

If you already know this, skip to the chart guides.
Every option has gamma — the rate at which its delta changes as the underlying moves. As spot changes, options hedges often need to be updated. Gamma helps estimate how sensitive that rebalancing pressure can be. Gamma exposure (GEX) rolls this up across an entire strike or chain:
This formula is a simplified mental model for reading the chart. Hermes handles the calculation details for the selected view and displays the result as strike-level context. The sign convention used in Hermes charts is dealer-positive:
  • Positive GEX (green): dealer-positive gamma. This can dampen realized movement near large positive GEX strikes.
  • Negative GEX (red): dealer-negative gamma. This can amplify realized movement when spot trades near large negative GEX strikes.
Why it matters for 0DTE: Gamma is highest closest to expiration. On SPX 0DTE, gamma exposure near spot can be large enough to change how sensitive the index is around key strikes. The GEX charts help frame where that sensitivity is concentrated. Two related positioning layers in Hermes:
  • Flow GEX: GEX added by classified intraday options trades as they happen. It does not use open interest as a proxy for today’s activity. The GEX Combined, GEX Interval, Net Drift, and Net Flow charts are all flow views.
  • Position GEX: open-interest-backed exposure from the latest options snapshot. This slower structural layer appears on the GEX Ladder, which shows Flow GEX, Position GEX, and their sum (Net GEX) side by side for every strike.
Think of Hermes flow GEX as a running ledger of gamma being added or removed throughout the day. Open interest is the slower snapshot layer that helps frame where existing positioning may matter.

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Filters and Settings

Every GEX chart prints the filters behind it in its own subtitle — for example OTM | At Ask, Above Ask | Excl. Complex on Net Flow. Reading that line is the fastest way to know exactly what produced the picture. The standard views share the same defaults:
  • OTM only — the charts focus on out-of-the-money activity so the view is not dominated by deeper in-the-money positioning.
  • Exclude Complex/Tied/Floor — multi-leg and tied activity is removed from the flow so single-print reads are not over-weighted by spread legs.
  • Trade sides — which print classifications feed the chart. GEX Combined, GEX Interval, the Ladder, and Net Drift use the full side set; Net Flow deliberately counts only At Ask + Above Ask (that selectivity is its whole point).
Each panel’s settings popover also offers:
  • Trade Date — load a cached historical session, or clear back to Today.
  • Chart Panes — toggle a chart’s lower panels (e.g. the Call/Put GEX and Net DEX panes on GEX Combined, the volume panes on Net Drift, the per-minute bars on Net Flow) when a panel is short on space.
  • Strike Range on GEX Combined — narrow the visible strike window.
Live GEX chart panels refresh every 1 minute. Each chart and the GEX Ladder show how many minutes have passed since the last successful refresh. Historical dates load as cached snapshots instead of polling continuously.

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Using the Charts Together

No single chart tells the whole story. Here’s a workflow:

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Morning Routine (9:30 – 10:30 AM)

  1. GEX Combined: Identify the key levels for the day. Where is spot relative to the Flow line? Where are the biggest positive and negative GEX areas? These frame stabilization and acceleration zones.
  2. GEX Ladder: Scan near spot for tags such as Spot, Pin Zone, Call Resistance, Put Support, Acceleration Zone, Gamma Cliff, Zero Gamma, Flow Flip, Conflict, and Low Concentration.
  3. GEX Interval: Watch the opening flow. Big bubbles in the first 30 minutes often mark where the day’s gamma structure started building.
  4. Net Drift / Net Flow: Is early call-side or put-side concentration building? Compare the first-hour lean with price and GEX context.

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Intraday (10:30 AM – 3:00 PM)

  1. GEX Interval: Watch for new bubbles appearing. Is fresh flow aligning with or diverging from price? Are new strikes lighting up above or below spot?
  2. GEX Ladder: Check whether the nearest rows are tagged as support, resistance, pinning, acceleration, conflict, or low concentration.
  3. Net Drift: Has the directional lean shifted? Where are the lines crossing?
  4. GEX Combined: Spot approaching a negative-gamma area? Treat that as acceleration context. Spot pinning near positive GEX? Treat that as stabilizing context.

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Closing Hour (3:00 – 4:00 PM)

  1. GEX Combined: Look at the current GEX wall closest to spot and compare it with price behavior into the close.
  2. Net Flow: Is ask-side premium still coming in late? Closing flow can reveal hedging or positioning activity into expiration.
  3. GEX Interval: Last-hour bubbles often reveal position liquidation or gamma hedging — patterns look different than midday flow.
  4. GEX Ladder: Re-check tags near spot before assuming a wall or magnet still matters into the close.

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Signals Worth Watching

Bullish setup:
  • GEX Combined: big green wall 5–15 points above spot
  • Net Drift: call line above put line and diverging
  • Net Flow: green area dominant
  • GEX Interval: recent green bubbles stacked at strikes above spot
  • GEX Ladder: nearby rows tagged Put Support or Pin Zone with positive Net GEX
Bearish setup:
  • GEX Combined: spot below the Flow line, red areas below
  • Net Drift: put line rising, call line flat or falling
  • Net Flow: red area growing
  • GEX Interval: red bubbles appearing at strikes near or below spot
  • GEX Ladder: nearby rows tagged Acceleration Zone or showing negative Net GEX near spot
Chop warning:
  • GEX Combined: spot near the Flow line with balanced walls on both sides
  • Net Drift: both lines rising in parallel
  • Net Flow: net flow near zero
  • GEX Interval: bubbles scattered, no clear pattern
  • GEX Ladder: nearby rows tagged Conflict or Low Concentration

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FAQ

Many gamma tools emphasize slower position snapshots. Hermes separates Flow GEX from Position GEX so you can compare fresh intraday activity with the slower structural layer. They answer different questions: position views frame where outstanding exposure is concentrated, while flow views show where new exposure is building today.
Different platforms use different inputs, timing, filters, and sign conventions. Hermes exposes the filters in the panel so you can see whether you are looking at intraday flow, position context, or a comparison of the two.
Sides describe where an options print landed relative to the quoted market around that moment. The charts use those buckets to separate aggressive buyer-leaning prints, seller-leaning prints, and less directional prints. The buckets you’ll see in the settings and subtitles are:
  • Above Ask — paid more than the ask (very aggressive buy)
  • At Ask — paid the ask (aggressive buy)
  • Mid — at or near the midpoint (no reliable buy/sell read)
  • At Bid — sold the bid (aggressive sell)
  • Below Bid — took less than the bid (very aggressive sell)
Mid-market prints are treated honestly: they count toward activity and concentration, but Net Drift excludes them from its buy-minus-sell netting because their direction is unknown.
Only At Ask and Above Ask prints. These are trades where the buyer paid the offer or worse — they wanted in NOW and didn’t wait for a better price. See the Net Flow guide for why that selectivity is the chart’s whole point.