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Gamma Exposure (GEX)

Gamma exposure is a single number that tells you how much stock (or futures) dealers need to buy or sell as the market moves. It determines whether dealer hedging flows stabilize or destabilize the market.

One sentence

Positive GEX = dealers dampen moves (low vol). Negative GEX = dealers amplify moves (high vol).

How to read GEX​

Deep Negative
Negative
Neutral
Positive
Deep Positive
Amplifies movesTap a zone to learn moreDampens moves

Why does GEX exist?​

When you buy an option, a dealer takes the other side. The dealer doesn't want directional risk, so they hedge by buying or selling the underlying asset. How much they need to hedge changes as the market moves. That rate of change is gamma.

The total gamma across all dealer positions in a market is the gamma exposure (GEX).

Positive GEX

Dealers are long gamma

  • Market drops → dealers buy the dip
  • Market rallies → dealers sell the rip
  • Both actions push price back to where it was
Like a rubber band: the more you stretch it, the harder it pulls back.

Negative GEX

Dealers are short gamma

  • Market drops → dealers sell into it
  • Market rallies → dealers buy into it
  • Both actions push price further in the same direction
Like a ball on a hill: any push sends it rolling faster.

GEX by strike​

GEX is not evenly distributed. It concentrates at specific strike prices where large open interest sits. Knowing where GEX clusters tells you which price levels will act as magnets or breakout triggers.

GEX by strike (illustrative)
Hover/tap a labeled bar for details
+GEX
-GEX
Put wall
Pin strike
Call wall
92
94
96
98
100
102
104
106
108
110
112
114

How to read a GEX chart​

A typical GEX chart shows gamma by strike price, with bars going up (positive) or down (negative).

What you see
What it means
Trading implication
Large positive bar at a strike
Dealers will defend this level (buy dips, sell rips near it)
Price tends to "pin" near this strike. Expect low vol around it.
Large negative bar at a strike
Dealers will amplify moves through this level
Fast breakout if price reaches it. High vol zone.
Net positive across all strikes
Overall stabilizing environment
Range-bound strategies work well (iron condors, butterflies).
Net negative across all strikes
Overall destabilizing environment
Directional or vol-buying strategies. Expect outsized moves.
Cluster of bars near one strike
Massive OI concentration, usually from a known position
This strike will act as a magnet. Watch for pin risk near expiry.

The gamma flip​

The gamma flip is the price level where total GEX crosses from positive to negative. Above it, dealers stabilize. Below it, dealers destabilize.

The gamma flip: where dealer behavior changes
+ GEX
Dealers stabilize
- GEX
Dealers amplify
Gamma Flip
Lower pricesHigher prices
Below the flip: dealer hedging adds fuel to sell-offs. Expect trending, volatile days.
Above the flip: dealer hedging absorbs moves. Expect mean-reverting, quiet days.

SpotGamma publishes this level daily for the S&P 500. It is one of the most-watched numbers in institutional options trading. Laevitas shows equivalent data for crypto markets.

Where to track GEX​

S&P 500 / Equities​

  • SpotGamma - Real-time SPX GEX, gamma flip level, strike-level data, 0DTE tracking. Free basic dashboard, paid for full data.
  • Unusual Whales - GEX heatmaps, flow alerts, historical GEX
  • GammaLab - Daily GEX readings, backtests, gamma flip history
  • CBOE - Raw open interest data (calculate GEX yourself)

Crypto (BTC / ETH / SOL)​

  • Laevitas - GEX by strike, by expiry, by exchange. BTC, ETH, SOL, XRP on Deribit, Binance, OKX, Bybit
  • Amberdata - GEX heatmaps, open interest, dealer positioning estimates
  • Glassnode - Taker-flow-based GEX model (novel methodology)
  • Greeks.live - Real-time gamma by strike for BTC/ETH on Deribit

GEX and expiration​

GEX is not static. It changes throughout the day and spikes near expiration.

Why does gamma increase near expiry?

Drag the slider to see how the gamma curve changes as expiration approaches:

Days to expiry30 days
1 day (expiry)90 days (quarterly)
-10%
-8%
-6%
-4%
-2%
ATM
+2%
+4%
+6%
+8%
+10%
At 30 days, gamma is spread out and low. Dealer hedging has minimal impact. This is why a fresh quarterly collar does not move the market.

The key insight: an ATM option with 1 day left has far more gamma than the same option with 90 days. This is because near expiry, the option is either going to be worth something or nothing, and small price moves tip the balance. Dealers must rebalance aggressively.

This is why quarterly expirations (like the JPM collar roll) have such outsized market impact, and why 0DTE options (60-70% of S&P volume) create massive intraday gamma swings.

After expiration, that gamma vanishes. A market that was pinned to a strike can suddenly move freely. This is why the days immediately after large expirations often see increased volatility.

Crypto vs equities GEX​

S&P 500 GEX

Largest options complex in the world

  • Dominated by institutional hedgers and market makers
  • 0DTE options create massive intraday gamma
  • Quarterly events (JPM collar) can dominate
  • GEX data widely available and well-understood
More mature, higher impact on price. SpotGamma is the go-to source.

Crypto GEX

Growing rapidly, Deribit-dominated

  • Smaller notional but growing fast
  • Concentrated on Deribit (80%+ of volume)
  • Quarterly and monthly expirations matter
  • Fewer market makers, so GEX effects can be outsized
Less liquid, but GEX effects can be proportionally larger. Laevitas is the go-to.

Related:

  • Gamma - The Greek that GEX measures across all dealers
  • Delta - The hedge ratio that dealers adjust based on gamma
  • Vol Indices - VIX, BVIV, EVIV and how they relate to GEX regimes