The GEX Percentile Screener: A Trader’s Guide to Historical Gamma Context

What is GEX Percentile?

GEX (Gamma Exposure) tells you whether dealers are long or short gamma. A positive GEX means dealers are long gamma, they stabilize prices by selling rallies and buying dips (pinning effect). A negative GEX means dealers are short gamma, price trends amplify as dealers hedge along with the market.

But raw GEX alone is incomplete. A GEX of -$500K tells you dealers are short gamma right now, but is that extreme historically, or normal for this stock?

Enter GEX Percentile (1-Year). This tells you where today’s GEX ranks against all readings from the past year (0–100%).

• High percentile (70–100%): Today’s GEX is exceptionally positive/bullish historically
• Low percentile (0–30%): Today’s GEX is exceptionally negative/bearish historically
• Mid-range (40–60%): Today’s GEX is neutral — no historical extreme

How Traders Should Use GEX Percentile

Identify Pinning Conditions (Positive GEX + High Percentile)

When GEX > 0 and GEX Percentile (1-Year) > 70%, dealers are in an unusually strong long-gamma state. This is ideal for:

• Iron condors & credit spreads: price gravitates toward dealer short strikes, limiting downside risk
• Short strangles: gamma clustering creates a “sticky” price zone
• Earnings adjustments: less expected gamma shock if dealers can absorb moves

Action: Look for stocks with GEX Percentile (1-Year) > 75% as prime candidates for premium-selling strategies. Pair with IV Rank > 0.5 for maximum edge.

Spot Volatility Regime Changes (Negative GEX + Low Percentile)

When GEX < 0 and GEX Percentile (1-Year) < 30%, dealers are in an exceptionally short-gamma state. This signals:

• Price trends amplify: dealers hedge into the move, adding momentum
• Wide breakouts possible: tight stops fail; trends persist longer than normal
• Mean reversion fades: don’t expect a quick snap-back

Action: Shift from range-bound strategies to directional plays. Use wider stops, add long-dated hedges, or scale into breakouts rather than fade them.

Use 1-Year vs 3-Month for Regime Confirmation

Compare GEX Percentile (1-Year) and GEX Percentile (3-Month):

• If both are high (>70%): strong, sustained pinning environment
• If 1-Year is high but 3-Month is mid-range: positive GEX is returning to normal after a recent spike
• If 1-Year is low but 3-Month is high: recent shift toward long gamma (possible reversal brewing)

This reveals regime momentum — not just today’s snapshot.

Screen for Extremes (Anomalies)

Stocks with GEX Percentile (1-Year) in the top 5% or bottom 5% are statistical outliers:

• Top 5%: rare, powerful pinning — ideal for defined-risk sellers if IV Rank is also high
• Bottom 5%: extreme short-gamma — breakout conditions, trend-following setups win

Use these as starting points for deeper analysis, not standalone signals.

Combine with Q-Scores for Confirmation

Don’t rely on GEX percentile alone. Align with other factors:

Ask QUIN to generate the Screener.

Practical Screening Workflow

For Premium Sellers (Iron Condors)

Filter: GEX Percentile (1-Year) > 70% and GEX > 0

Filter: Volatility Score ≤ 2 (calm market)

Filter: IV30 Rank > 0.5 (expensive options)

Sort: By GEX Percentile (1-Year) descending

Result: Stocks with maximum pinning potential and high IV environment

For Trend Traders (Directional)

Filter: GEX Percentile (1-Year) < 30% and GEX < 0

Filter: Momentum Score ≥ 4 (strong uptrend or downtrend)

Filter: Volatility Score ≥ 4 (swinging market)

Sort: By GEX Percentile (1-Year) ascending

Result: Stocks with dealer-amplified trends and strong momentum

For Breakout Hunters

Filter: GEX Percentile (1-Year) < 25%

Filter: VRP < 0 (IV cheap vs realized volatility)

Filter: Monitor Expiring GEX (1-Week) and Expiring GEX (1-Month) for weekly and monthly expirations

Result: Gamma shocks possible; wide moves rewarded

Use the Q-Scores like a Fund Manager.

Cheatsheet: GEX Percentile Quick Reference:

Key Takeaways

• GEX Percentile contextualizes raw gamma: High percentile = strong pinning historically; low percentile = strong amplification historically
• Combine with volatility and IV: Positive GEX + low volatility + high IV = premium-selling environment
• Watch for regime shifts: When percentiles cross key thresholds (30%, 70%), strategy effectiveness changes
• Use 1-Year and 3-Month together: Reveals both current state and recent momentum
• Pair with Q-Scores: GEX Percentile is a filter, not a standalone signal
  

Ask QUIN to generate this Cheatsheet.

Conclusion

GEX Percentile transforms gamma exposure from a binary (positive/negative) observation into a contextual edge tool. By screening for historical extremes and pairing with volatility regime and IV rank, traders can systematically identify high-probability setups: premium-selling in pinning environments, or trend-following in breakout conditions.

Use the cheatsheet above as your daily reference when scanning the MenthorQ screener.