GEX levels explained: gamma exposure, call walls, put walls and the gamma flip
Updated September 26, 2026 · Q-BITF
GEX levels are prices where options dealers' hedging is expected to push back on the market or speed it up. They come from gamma exposure (GEX): how much dealers must buy or sell in the underlying for every move in price, added up strike by strike across the option chain. Traders use them as support, resistance and regime markers on SPX, SPY, NDX, QQQ and the ES and NQ futures.
What gamma exposure (GEX) is
An option's gamma is how fast its delta changes as the underlying moves. A dealer who has sold or bought options hedges that delta, and gamma is how much the hedge has to change per point of movement. Multiply gamma by open interest and the contract size and you get the hedging that sits at each strike.
Q-BITF quotes it in dollars per 1% move, the convention SqueezeMetrics introduced for GEX:
- GEX at a strike = gamma × open interest × 100 × spot² × 0.01, counted positive for calls and negative for puts.
- Net GEX is the sum over every strike and expiry in the book.
The signs assume dealers are net long calls and net short puts, the usual position in index options (Gârleanu, Pedersen and Poteshman, 2009). For single stocks that assumption is weaker, and Q-BITF labels it as a convention there.
The GEX levels, one by one
| Level | What it marks | How it behaves |
|---|---|---|
| Call wall | The strike above price with the most call gamma | Acts as resistance: dealers sell into rallies toward it |
| Put wall | The strike below price with the most put gamma | Acts as support: dealers buy into declines toward it |
| Gamma flip | The price where net dealer gamma of the day-trade expiry crosses zero | Above it moves tend to be damped; below it they tend to extend |
| Max pain | The strike at which the expiring options would pay out the least in total | A pull on price into expiration, strongest on expiry day |
| HVL / vol trigger | The same zero-gamma crossing, for every expiry in the book | The slower regime line; between it and the flip, expect chop |
| Expected move (1σ) | Spot ± the move implied by at-the-money volatility | The day's likely range, narrowing into the close |
A useful detail about walls: Q-BITF measures each strike's gamma at that strike, not at the current price. Measured at the current price, the biggest wall is almost always the strike nearest to spot, so the "wall" moves with price and never holds. Measured at the strike, it stays put until the open interest behind it actually changes.
Reading a gamma exposure chart
Green bars are strikes where dealers are long gamma, red bars where they are short. In the example, price (6012) sits above the gamma flip (5985), so dealers are net long gamma: they sell strength and buy weakness, and moves tend to stall between the put wall (5930) and the call wall (6070). If price fell through 5985, dealers would switch to selling weakness and the same distance could be covered much faster.
Positive vs negative gamma
- Positive gamma (above the flip): dealer hedging trades against the move. Expect mean reversion, smaller ranges and walls that hold more often. Ni, Pearson, Poteshman and White (2021) find that net market-maker gamma lowers subsequent volatility.
- Negative gamma (below the flip): hedging trades with the move. Expect momentum, wider ranges and walls that break more easily. Baltussen, Da, Lammers and Martens (2021) link negative dealer gamma to intraday momentum across futures markets.
Large open interest at a single strike can also pin price near it into expiry (Avellaneda and Lipkin, 2003; Golez and Jackwerth, 2012, for S&P 500 futures).
GEX levels for ES and NQ futures
Futures have their own options, but most index gamma sits in SPX and NDX options (and in SPY and QQQ). To use those levels on ES or NQ, the strikes have to be moved into the futures' price: futures trade at a premium to the cash index that grows with interest rates and time to expiry. Q-BITF adds that cost-of-carry basis to every strike, so an SPX call wall lands on the matching ES price. The SPY and QQQ books are scaled onto the futures by the live price ratio instead.
0DTE and why levels move during the day
On many days more than half of the gamma in SPX expires the same session, in zero-days-to-expiry (0DTE) options. Their gamma grows as expiry approaches, so the levels can shift during the day even when open interest does not. Q-BITF blends the day's traded volume with the prior night's open interest, because open interest itself only updates once a day.
How to use GEX levels in trading
- Mark the walls and the flip before the open. They frame the session.
- Check the regime. Above the flip, fade moves into the walls. Below it, respect breakouts.
- Look for confluence. A wall that lines up with max pain, a high-volume node or the prior day's high carries more weight.
- Watch the levels change. A wall that migrates with price is weak; one that stays put while price tests it is being defended.
GEX levels describe dealer hedging pressure, not certainty. They are one input, and they work best with price action and risk management. Nothing here is financial advice; see the disclaimer.
Frequently asked questions
What are GEX levels?
Prices derived from options dealers' gamma exposure: the call wall, put wall, gamma flip, max pain and related levels, where dealer hedging tends to slow the market down or speed it up.
How is gamma exposure calculated?
For each strike, gamma × open interest × 100 × spot² × 0.01, with calls counted positive and puts negative, summed across expiries. The result is the dollar value dealers must trade for a 1% move.
What is the gamma flip?
The price where net dealer gamma changes sign. Above it dealers dampen moves; below it they amplify them.
Do GEX levels work for NQ and ES futures?
Yes, once SPX and NDX strikes are shifted into futures prices with the futures basis. Q-BITF does this automatically and can draw the levels on TradingView NQ and ES charts.
Are GEX levels accurate?
The arithmetic is exact, but two inputs are estimates: which side of each trade dealers hold, and how much of today's volume is new positioning. Treat the levels as zones rather than exact prices.
See live GEX levels
Q-BITF shows live GEX levels, ranked call and put walls, the gamma flip and the full greek exposure for SPX, NDX, SPY, QQQ, ES and NQ, and draws them on your TradingView chart. Open Q-BITF.
Sources
- SqueezeMetrics, "Gamma Exposure (GEX)" white paper.
- Gârleanu, Pedersen and Poteshman (2009), "Demand-Based Option Pricing", Review of Financial Studies.
- Ni, Pearson, Poteshman and White (2021), "Does Option Trading Have a Pervasive Impact on Underlying Stock Prices?", Review of Financial Studies.
- Baltussen, Da, Lammers and Martens (2021), "Hedging Demand and Market Intraday Momentum", Journal of Financial Economics.
- Avellaneda and Lipkin (2003), "A Market-Induced Mechanism for Stock Pinning", Quantitative Finance.
- Golez and Jackwerth (2012), "Pinning in the S&P 500 Futures", Journal of Financial Economics.