EMA 50SMA 20SMA 10
GEX by Strike
GEX Profile by Price
All expiriesEx next weekEx next monthly
Total net GEX if the underlying were at each price
This chart estimates options dealer gamma exposure for Nasdaq-100 index (NDX) options. NDX dealers hedge with Nasdaq-100 futures (NQ) and QQQ, so NDX GEX is a read on the hedging backdrop for large-cap technology stocks. The NDX options market is smaller than SPX, so open interest clusters at fewer strikes and the walls can be sharper. QQQ options, which carry a large share of Nasdaq-100 options activity, are not included, so treat NDX GEX as a partial picture.
Strike-level GEX uses delayed Cboe option chains and Cboe's gamma for each contract, assuming dealers are long calls and short puts. The GEX profile reprices gamma with Black-Scholes at 60 prices within ±20% of spot (±30% for VIX), using each expiry's implied interest rate and dividend yield solved from put-call parity and measuring volatility time in trading days (business days ÷ 262, with same-day expiries counted as one day). The implied rates and dividends by expiry are listed on the volatility surface page.
Gamma exposure estimates how much options dealers would need to buy or sell in the underlying to stay delta-hedged when the price moves. For each strike it multiplies option gamma by open interest, the contract multiplier and the squared index level, and expresses the result in dollars per 1% move. Summing across strikes gives total net GEX.
Positive GEX means dealers are estimated to be long gamma: they sell into rallies and buy into dips to stay hedged, which tends to dampen moves and lower realized volatility. Negative GEX means dealers are short gamma and hedge in the same direction as the move, buying strength and selling weakness, which can amplify moves and raise volatility.
The gamma flip is the price at which total net GEX changes sign. Above it the market is estimated to be in a positive gamma regime, below it in a negative gamma regime. On this site it is the lowest price at which the all-expiries GEX profile crosses zero.
The call wall is the strike with the largest call gamma and the put wall is the strike with the largest put gamma. Heavy dealer hedging around these strikes often makes them act as resistance (call wall) and support (put wall), especially as expiration approaches, although they move as positions change and are not guaranteed levels.
The chart uses Cboe delayed quotes, which lag the market by about 15 minutes. Turn on Refresh every minute to keep it current during the session. Before the open, at night and on weekends it shows the last session's chain. Open interest is published once a day, so switch to Volume GEX to see positioning built up today, such as 0DTE trading.
GEX depends on assumptions: which side dealers are on, whether open interest or volume is used, which expirations are included, how gamma is computed and with what rates, dividends and time to expiry. This site assumes dealers are long calls and short puts, uses Cboe gamma for the strike chart, and reprices gamma with implied rates and dividends for the profile. Different choices shift totals and levels, so compare levels within one source over time.
No. GEX describes a likely hedging backdrop, not a forecast. The dealer-positioning assumption can be wrong, for example when customers sell puts or buy calls in size, and macro news can overwhelm hedging flows. Use it as context alongside price, volatility and the VIX term structure. Nothing on this site is investment advice.
Data is delayed and may be incomplete. Nothing here is investment advice.