Expectations, Not Predictions
Gamma Sonar surfaces what market makers are mechanically obligated to do based on their options positions — not what the market will do next. Every tool on this platform answers one question: where do dealer hedging flows create structural pressure, and how strong is that pressure right now?
When we show a call wall at 6950, we're not predicting the market will stop there. We're showing you where the largest concentration of call gamma sits — a level where positive gamma hedging creates mechanical selling pressure as price approaches from below. Whether that pressure holds depends on the strength of the buying against it.
This is a critical distinction. Structural levels describe where forces concentrate and what type of force exists. They don't determine outcomes. A call wall can be breached. A support zone can collapse. What Gamma Sonar gives you is the map of the terrain — you still have to navigate it.
The Positioning Assumption
Every gamma exposure platform — Gamma Sonar included — operates on a core assumption: dealers are net short options. This means we assume market makers sold calls (from covered call flow) and sold puts (from protective put buying), making them short gamma at most strikes.
The aggregate behavior — positive GEX above spot dampens rallies, negative GEX below amplifies selloffs — is well-documented and empirically observed. But the per-strike mechanics are an approximation. We teach this honestly because understanding the model's limitations makes you a better user of the data.
What GEX Tells You vs. What It Doesn't
| GEX Tells You | GEX Does NOT Tell You |
|---|---|
| Where hedging pressure concentrates | Whether that pressure will hold |
| The current structural environment (regime) | What specific event will cause a transition |
| Where mechanical support/resistance exists | Whether external forces will overpower structure |
| How the range should behave given current positioning | Which direction price will move within that range |
| When structural stress is elevated (SSS) | The exact timing of a regime break |
Why 60-Second Refresh Matters
Most GEX platforms update every 15-30 minutes using end-of-day greeks. Gamma Sonar recomputes from live ThetaData greeks every 60 seconds for SPX, SPY, and QQQ, with the remaining 92 tickers cycling every 60-120 seconds.
Why this matters: gamma is a function of spot price, time to expiry, and implied volatility — all of which change continuously. A call wall at 6950 computed at 9:31 AM may have shifted to 6925 by 10:00 AM as 0DTE options decay and new trades reshape the OI landscape. Stale GEX is worse than no GEX because it gives you false confidence in levels that no longer exist.
The First Screen
When you log in, you land on the Pressure Field — the core tool showing GEX across strikes for your selected ticker. Before you look at anything else, orient yourself with the topbar.
Reading the Topbar
The topbar is your at-a-glance dashboard. Left to right:
- Underlying selector: Your active ticker. Click the + to add to your watchlist (max 5). Type any ticker to search the 95-ticker universe.
- Spot price: Live spot with change from prior close. Green = up, red = down.
- NET GEX: Total gamma exposure across all strikes. Positive = dealers long gamma (dampening). Negative = dealers short gamma (amplifying).
- CALL WALL: Strike with highest positive GEX above spot. Resistance.
- PUT WALL: Strike with highest negative GEX below spot. Support boundary.
- FLIP: Where net GEX crosses zero. The regime change point.
- GVWAP: Gamma-weighted average price. The gravity center.
- REGIME: Current structural classification. Color-coded by type.
The Sidebar
Tools are organized by function, not by importance. Here's the mental model:
| Section | What It Answers | When to Check |
|---|---|---|
| PRIMARY | What's the structure right now? | Always — these are your core tools |
| STRUCTURE | How is the structure distributed across strikes and time? | When you need deeper context on the shape |
| VOLATILITY | What is vol doing relative to structure? | When implied or realized vol seems unusual |
| FLOW | What are large players actually doing right now? | When you see big prints or unusual activity |
| INSTITUTIONAL | What does the full structural picture look like? | For comprehensive analysis and cross-asset context |
Switching Tickers
Click the underlying selector in the topbar and type any ticker. The platform validates against the 95-ticker universe — if you type GOOG, it auto-corrects to GOOGL. Invalid tickers are rejected.
When you switch tickers, the WebSocket sends a subscribe message to the server, which immediately returns the cached snapshot for that ticker. All tools update simultaneously — there's no per-tool loading. If you select an expiry filter, it resets on ticker switch to prevent stale filters.
Reading the Bars
The Pressure Field displays gamma exposure per strike as horizontal bars. The default layer is GEX:
- Green bars (right of center): Positive GEX — call gamma. Dealers are assumed short calls at these strikes. As price approaches from below, dealer selling creates resistance.
- Red bars (left of center): Negative GEX — put gamma. Dealers are assumed short puts. As price approaches from above, dealer selling creates downward acceleration.
The longest bar is the dominant structural level. In GEX mode, the longest green bar above spot is typically the call wall, and the longest red bar below is near the put wall.
The Tag System
Each strike can carry a tag on the right side:
| Tag | Color | Meaning |
|---|---|---|
| CALL WALL | Green | Largest positive GEX above spot — primary resistance |
| PUT WALL | Red | Largest negative GEX below spot — support boundary |
| FLIP | Gold | Where net GEX crosses zero — regime transition point |
| ▶ [price] | Teal | Current spot price location |
| EM+ / EM- | Gold outline | Expected move upper and lower boundaries |
| IV+ / IV- | Blue outline | Implied volatility range boundaries |
Layer Tabs
The Pressure Field has 6 layers. Each shows the same strikes with a different greek overlaid:
GEX (Default)
Gamma exposure per strike. This is your primary view — it shows where hedging pressure concentrates. Use this 80% of the time.
DELTA
Net dealer delta exposure. Shows directional lean at each strike. Useful for understanding whether the aggregate structure is bullish or bearish at a specific price level.
VANNA
Delta sensitivity to volatility changes. Shows where a VIX spike or drop would force the largest hedging adjustments. Green = vanna support (vol drop → dealer buying). Red = vanna resistance (vol drop → dealer selling). Most useful when VIX is elevated and moving.
CHARM
Delta decay per day — the passive directional flow from time passing. Green = charm buying (puts decaying → dealers buy back short futures). Red = charm selling (calls decaying → dealers sell futures). Most useful in the afternoon (1:30-3:00 PM) when external flows are lowest.
OI
Net open interest (call OI - put OI) per strike. Shows where positioning is concentrated regardless of greek exposure. Useful for identifying strikes with heavy activity that may become structural levels tomorrow.
STACK
All greeks side-by-side in column format: GEX, Delta, Charm, Vanna, Call OI, Put OI, Net OI, plus OI change %. This is your comprehensive view — use it when you need the full picture at every strike without switching layers.
Expected Move Zones
The Pressure Field highlights two zones with subtle left-border coloring:
- Gold border: Straddle-implied expected move range — where the options market prices the move for the nearest expiry.
- Blue border: IV-implied range — a wider band based on implied volatility.
Strikes inside the expected move zone are where the market "expects" price to stay. Strikes outside are where a breakout would signal a larger-than-expected move.
Expiry Filtering
Click ▼ ALL EXPIRIES in the header to open the expiry selector. You can filter the Pressure Field to show GEX from only specific expirations:
- 0DTE: Today's expiring options only — shows the most immediately active gamma.
- This Week: Options expiring within 7 days.
- Monthly: The nearest monthly expiration.
- Individual dates: Click any specific expiry date.
When you filter, the call wall, put wall, flip level, GVWAP, and net GEX all recompute from the filtered data. This lets you see how the structure changes when you isolate 0DTE gamma versus longer-dated positioning.
The Structural Landscape
Call Wall — Resistance
The strike with the highest positive GEX above spot. In a positive-gamma environment, this is where dealer selling pressure peaks. As price approaches the call wall from below, market makers who are short calls must sell more underlying to stay delta neutral — this selling absorbs buying pressure and creates resistance.
The call wall is not a ceiling. It's a zone of maximum friction. Strong institutional buying can push through it, but the push requires more force than at other levels. When the call wall is breached, the regime shifts to ESCAPE_VELOCITY — dealers are now forced to buy (chase), and the former resistance becomes acceleration.
Put Wall — Support Boundary
The strike with the highest negative GEX below spot. This marks the edge of the positive-gamma support zone. Above the put wall, the aggregate mean-reversion behavior of positive gamma cushions dips. Below the put wall, that cushion disappears.
The put wall is not a floor — it's the boundary where the structural support environment changes. Breaking below it doesn't mean instant collapse, but it means the dampening force that was cushioning pullbacks is no longer present.
Flip Level — The Regime Threshold
Where net GEX crosses zero. Above the flip, aggregate GEX is positive (dampening). Below the flip, aggregate GEX turns negative (amplifying). This is the single most important level for understanding market character.
When spot is well above the flip, you're in a regime where dealer hedging dampens moves. When spot approaches the flip, you're approaching the transition zone where market character can change rapidly. The SSS monitor tracks flip proximity as one of its key precursors.
GVWAP — The Gravity Center
Gamma-Weighted Average Price. Computed as the OI-and-GEX-weighted average of all strike prices. This is where gamma structure is "centered." Price tends to revert toward GVWAP when no strong directional force is present — it's the mean-reversion anchor in a positive-gamma environment.
How Levels Shift Intraday
Structural levels are not static. They recompute every 60 seconds based on live greeks. Here's what causes them to move:
- Spot movement: As price moves, the relative gamma at each strike changes (gamma is a function of distance from spot).
- Time decay: As 0DTE options decay, their gamma increases explosively near the money. A strike that was unremarkable at 9:30 AM can become the dominant structural level by 2:00 PM.
- New positioning: Large trades (visible on Flow Tape) can add or remove OI at specific strikes, reshaping the entire GEX profile.
- IV changes: A VIX spike spreads gamma more broadly, flattening the profile. A VIX drop concentrates gamma near ATM strikes.
The Regime Classifier evaluates spot position, GEX distribution, flip proximity, and wall distances every 60 seconds. It requires 2 consecutive confirmations before transitioning (hysteresis) to prevent noise. Here's what each regime means and what to do:
The Structural Stress Monitor is Gamma Sonar's most original feature. No competitor has an equivalent. SSS doesn't predict direction — it detects when the structural conditions for a regime transition are accumulating.
What SSS Measures
SSS tracks 15 precursor signals that historically precede regime transitions. Each precursor is a measurable structural condition — flip proximity, wall erosion, GEX velocity, skew shifts, P/C ratio changes, and more. When enough precursors activate simultaneously, the probability of a regime transition rises.
The 5 Levels
| Level | Score | What It Means | What To Do |
|---|---|---|---|
| NORMAL | 0-29 | Structure is stable. Dealer hedging aligned with expectations. | Trade the current regime with confidence. No structural concern. |
| WATCH | 30-49 | One or more precursors elevated. Structure beginning to show stress. | Stay in your trade but tighten stops. Monitor which precursors are firing. |
| CAUTION | 50-69 | Multiple precursors active. Regime transition probability elevated. | Reduce position size. Prepare for potential regime change. Don't initiate new mean-reversion trades. |
| IMMINENT | 70-84 | Transition likely within 30 minutes. Structural conditions unstable. | Close or hedge existing positions. The current structural framework is unreliable. |
| CONFIRMED | 85-100 | Regime shift detected. New structural state establishing. | Re-evaluate everything. The map has changed. Old levels may no longer apply. |
Reading the Precursors
The SSS panel shows each precursor with a value and color coding. The most important precursors to watch:
- FLIP PROXIMITY: How close spot is to the gamma flip level. Low = high stress.
- PUT WALL EROSION: Whether the put wall is weakening (GEX decreasing at that strike). Rising erosion means support is degrading.
- GEX VELOCITY: Rate of change in net GEX. Rapid drops signal structural deterioration.
- GVWAP DIVERGENCE: Spot pulling away from GVWAP. High divergence means price is drifting from the structural center.
Straddle-Based vs. IV-Based
Gamma Sonar computes the expected move using the ATM straddle price when available. The straddle price (call mid + put mid) divided by the anchor price gives the expected percentage move. This is more accurate than backing out IV and recomputing because it captures real supply/demand dynamics in the options market.
When straddle prices aren't available (pre-market or thin liquidity), the system falls back to IV-based computation using the √(DTE/365) × 0.7979 formula.
The Move Budget
The Move Budget is the most actionable part of this tool. It shows you:
- Expected range: Where the market is "supposed to" move by expiry, centered on yesterday's close (the anchor).
- Realized move so far: How much of that range has been consumed.
- Consumed %: The ratio of realized to expected.
NEARING RANGE (70-100%): Getting close to the expected boundary. If you're holding a directional position, this is where risk/reward starts to deteriorate.
OVEREXTENDED (100%+): Realized move exceeds what the market priced. Either the options market mispriced the move, or the current move is extreme and may be subject to reversion.
Multi-Timeframe Expected Moves
The tool shows expected ranges for three timeframes simultaneously:
- 0DTE / Nearest: Today's expected range. Most useful for intraday traders.
- Weekly: The nearest weekly expiry range. Useful for swing context.
- Monthly: The nearest monthly range. Structural context for longer-term positioning.
Comparing timeframes tells you something important: if the 0DTE range is ±0.8% but the weekly is ±2.5%, there's a lot more room on the weekly horizon even if the daily move has been large.
Fractional DTE
For 0DTE, the expected move range shrinks throughout the day as trading time remaining decreases. The tool uses fractional DTE based on trading minutes remaining (out of 390 minutes per session), not calendar days. This means the expected range naturally compresses as the afternoon progresses — matching reality where less time = less expected movement.
What Makes Flow Tape Different
Every broker shows options trades. Flow Tape shows options trades with server-side enrichment — every trade is classified before it reaches your screen:
- Side detection: BUY or SELL, determined by composite scoring (trade price vs. bid/ask, exchange rules, adaptive trade classification).
- Open/Close estimation: Is this a new position or someone closing? Uses volume-to-OI ratio analysis.
- Impact classification: BULLISH, BEARISH, or NEUTRAL based on side + option type + open/close.
- Dealer side: If the customer bought, the dealer sold (SHORT). If the customer sold, the dealer bought (LONG).
- OI Exceedance: Flagged when a single trade exceeds the entire open interest at that strike/expiry — a highly unusual event.
- Wall Proximity: Flagged when the trade occurs at or near a structural level (call wall, put wall, flip).
Trade Types
| Type | What It Is | Why It Matters |
|---|---|---|
| BLOCK | 100+ contracts in a single print | Institutional-size order, likely a deliberate position |
| SWEEP | Multi-exchange simultaneous execution | Aggressive urgency — willing to pay across multiple venues to get filled immediately |
| RETAIL | Smaller orders, single exchange | Background noise — filter these out for cleaner signal |
The Sentiment Bar
The green/red bar at the top of Flow Tape shows the session's cumulative bullish vs bearish premium. A 60/40 split means 60% of premium has been on bullish trades. This is a rough directional indicator — not a signal, but useful context.
Filtering for Signal
Flow Tape's default filters (BLOCK + SWEEP, $25K minimum premium) are designed to show you only trades that represent deliberate institutional positioning. If the tape is too noisy, increase the minimum premium. If it's too quiet, add RETAIL trades or lower the size threshold.
OI Exceedance flag: A single trade exceeding total open interest at that strike. This is rare and almost always significant — it means someone opened a position larger than everything that existed before.
Cluster of same-direction prints: Multiple BLOCKs on the same ticker, same direction, within minutes. Likely a single institution building a position across multiple executions.
Skew Dynamics
What it shows: The 25-delta and 10-delta put/call IV spread, updated live with session history.
When to check: When you want to know if downside protection is getting expensive (skew expanding) or cheap (skew compressing). Rising skew suggests institutional hedging demand is increasing — often a precursor to a selloff or at minimum increased anxiety.
What to look for: Divergence between skew and price. If skew is rising while price is flat, someone is quietly buying protection. If skew is compressing during a selloff, put sellers are stepping in — potential support signal.
IV Surface
What it shows: Implied volatility across all strikes and expirations as a heatmap. Hot colors = high IV, cool colors = low IV.
When to check: When you want to see where vol is cheap or expensive relative to the surface. Useful for identifying strikes where IV is anomalously high (potential overpriced hedge) or low (potential cheap gamma).
Vanna/Charm Surface
What it shows: Vanna and charm exposure per strike, broken down by expiry, with a confluence mode showing where both greeks align.
When to check: In the afternoon when charm flows become dominant. The charm tab shows where passive buying or selling pressure will build as options decay. The vanna tab shows where a VIX move would create the largest delta adjustments.
RVX Spread
What it shows: Realized volatility (20-day historical) versus implied volatility (ATM), with session history.
When to check: When you want to know if the market is pricing too much or too little volatility. A positive spread (IV > RV) means options are expensive relative to recent history. A negative spread means options are cheap — potential opportunity for long gamma positions.
P/C Monitor
What it shows: Put/call OI ratios broken down by ITM, ATM, and OTM zones, with call and put OI anchors and a gravity zone metric.
When to check: When you want to understand the speculative positioning tilt. Heavy OTM call buying suggests bullish speculation. Heavy OTM put buying suggests hedging demand or bearish speculation.
Anchor tracking: The call anchor (OI-weighted average call strike) and put anchor (OI-weighted average put strike) show where the center of mass of bullish and bearish positioning sits. Multi-day anchor history lets you see if these centers are drifting.
Pin Risk Monitor
What it shows: Gamma acceleration and pin probability per strike for the nearest expiry.
When to check: On expiration days, especially in the final 2 hours. High pin probability at a specific strike means charm and gamma flows are pulling price toward that level. Useful for 0DTE traders timing their entries around the pin.
Dealer Inventory
What it shows: GEX split between "live" (0-7 DTE) and "dormant" (8+ DTE) positions, plus volume and turnover data.
When to check: When you want to know how much of today's gamma structure is from near-term positions that will expire soon versus longer-term structural positioning. High live ratio means today's structure is heavily influenced by 0DTE — it will change dramatically tomorrow.
Max Pain Tracker
What it shows: The strike where total option holder losses are maximized, with multi-expiry breakdown and a pin probability estimate.
When to check: Near expiration, especially on monthly/weekly OPEX. Max pain matters most when gamma is thin and charm is dominant — the passive time-decay flows naturally channel price toward max pain in the absence of strong directional forces.
GVWAP
What it shows: GVWAP with session history, spread from spot, and reversion probability based on GEX magnitude.
When to check: When price diverges significantly from GVWAP. In positive gamma environments, price tends to revert toward GVWAP. The wider the divergence, the stronger the mean-reversion expectation — but this only works when GEX is positive.
Hedging Velocity
What it shows: Actual dealer hedging flow versus theoretical requirement, displayed as a ratio.
When to check: When you want to know if dealers are keeping up with their hedging obligations. UNDER = catch-up flow likely. OVER = flow exhaustion possible. ALIGNED = structure behaving as expected.
Cross-Asset Positioning
Cross-Asset shows all tickers in your universe with their spot, change%, regime, IV, GEX, call wall, and put wall — updated live. The chart panel shows normalized % change for selected tickers, backfilled from session history so you see the full session even if you navigate to the tool mid-day.
How to use it: Look for divergences. If SPX is in COMPRESSION but QQQ is in ESCAPE_VELOCITY, there's a sector rotation happening. If GLD is trending opposite to SPX, risk-off flows may be building. Click any ticker row to toggle it on the chart.
Sorting
Click the column headers to sort by ticker, change%, GEX, IV, or regime. Sorting by change% descending shows you what's moving the most. Sorting by GEX shows you which tickers have the strongest/weakest structural environments.
Equity Screener
The Screener shows the same data in a more compact table format with filter buttons for regime type, negative GEX toggle, and alert-only mode. Use it to quickly find:
- Tickers in ESCAPE_VELOCITY: Active breakouts with dealer buying acceleration.
- Tickers with negative GEX: Names where moves are amplified — trend-following opportunities.
- High ATM IV names: Where the options market sees the most uncertainty.
The Trading Day Timeline
Pre-Market (6:30–9:30 AM ET)
First Hour (9:30–10:30 AM ET)
Midday (10:30 AM–1:30 PM ET)
Afternoon (1:30–3:00 PM ET)
Into the Close (3:00–4:00 PM ET)
This chapter exists because we believe you make better decisions when you understand the boundaries of your tools. Every platform has limitations. We'd rather tell you ours than have you discover them with money on the line.
The Positioning Assumption
Our approach works because: The aggregate behavior of the market demonstrably follows positive/negative gamma mechanics. Positive GEX environments produce lower realized volatility. Negative GEX environments produce higher realized volatility. The call wall and put wall act as observable support/resistance zones with statistical significance across thousands of sessions.
Our approach can fail when: A specific strike's actual positioning is the opposite of what we assume. A large dealer could be long calls at a strike we label as resistance — in that case, the "resistance" doesn't exist. This is rare at major structural levels (call wall, put wall) but more common at minor strikes.
BSM Greeks
We use Black-Scholes to compute greeks. BSM assumes log-normal returns, constant volatility, and continuous hedging — none of which are true in practice. The greeks we display are the model's best estimate, not exact measurements of dealer exposure. Every OPRA-based GEX platform shares this limitation.
OI Is Yesterday's
Open interest is published once daily by OPRA at approximately 6:30 AM ET, reflecting the previous day's close. When you see OI values on the platform, they're from yesterday. We estimate intraday OI changes using our Adaptive Trade Monitor — a self-improving classification engine that tracks every options trade and learns to distinguish new positions from closing trades. But the base OI is always 24 hours old.
This means the first hour of trading can reshape the actual OI significantly without our base data reflecting it. The Adaptive Trade Monitor calibrates itself each morning against the previous day's actual OI to improve its classification accuracy over time, but it's still an estimate — not a certainty.
GEX ≠ Certainty
Structural levels describe where mechanical hedging flows concentrate. They don't determine outcomes. A call wall can be breached by strong institutional buying. A support zone can collapse during a macro shock. GEX gives you the terrain map — it doesn't guarantee the terrain will hold.
When to Ignore the Tools
- Major macro events: FOMC days, CPI releases, unexpected geopolitical events. External forces dwarf structural hedging flows. The map still exists, but the forces driving price are too large for structural levels to contain.
- Earnings: Single-stock GEX around earnings is dominated by the binary event. The structural levels you see were built from pre-earnings positioning — they may not reflect post-announcement reality.
- Flash crashes / circuit breakers: When markets gap, greeks change discontinuously. The model can't predict behavior in discontinuous markets.
- Low liquidity sessions: Holiday-shortened days, summer Fridays. Thin participation means structural levels are less meaningful — there are fewer dealers enforcing them.
Our Commitment
We're building accuracy tracking into the platform. Once we have 90 days of live SSS and regime data, we'll publish real accuracy statistics — not fabricated ones. When our signals are wrong, we'll show that too. Transparency about our limitations is a feature, not a bug.
This is a data platform, not a trading service. We show you the structural landscape. The trading decisions are yours. We believe that honest tools, honestly presented, make better traders than overconfident tools that hide their failures.