NIFTY · SESSION …SOURCE: NSE F&O BHAVCOPY · END OF DAY · ₹ CRORE
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GEX in one sentence
GEX, short for gamma exposure, is an estimate of how option dealers' hedging trades change as the market moves: whether they will tend to lean against a move (dampening it) or add to it (amplifying it), and by how much in rupees or dollars.
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Why dealers hedge, and why it matters
When a dealer sells options to a client, the dealer takes on directional risk. To remove it, they trade the underlying (futures or shares) in the opposite direction. That hedge has to be adjusted as the price moves, because an option's sensitivity to price (its delta) is not constant. The rate at which delta changes is called gamma.
Add up gamma across every strike and expiry, weighted by open interest, and you get an estimate of how large and in which direction the hedge adjustments will be. That total is gamma exposure.
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The three things to read on a GEX chart
1. Sign: positive GEX means dealer hedging tends to lean against moves, so ranges are tighter. Negative GEX means hedging tends to add to moves, so ranges are wider.
2. Size: how large the figure is relative to that market's own recent range. A GEX number is only meaningful against its own history.
3. Flip level: the price where the total changes sign. Spot above it implies the positive regime, below it the negative one.
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What GEX does not tell you
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It is not a price forecast. A positive reading is not bullish and a negative reading is not bearish.
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Exchanges publish open interest but not who holds each side, so every GEX figure rests on an assumption about dealer positioning.
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It changes during the day as price, volatility and open interest change.
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Other participants' flows can outweigh hedging effects, especially around news.
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Where GEX applies
GEX can be computed for any underlying with a liquid options market. Index options carry the largest effect because their open interest is deep. Arkenwell computes GEX for NSE index options from live option chain data; the Nifty GEX and Bank Nifty GEX guides cover the specifics.
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Frequently asked questions
What does GEX mean?
GEX stands for gamma exposure. It estimates how option dealers' hedging flow responds to price moves, expressed as a currency amount per 1% move in the underlying.
What is a good or bad GEX?
There is no good or bad value. Positive GEX describes dampened, range-bound conditions; negative GEX describes larger, more directional moves. Compare any reading with the same market's own history.
Is GEX the same as gamma?
No. Gamma is the sensitivity of a single option's delta. GEX adds up gamma across all open positions, weighted by open interest and contract size, to estimate total hedging pressure.
Can GEX predict the market?
No. GEX describes how hedging flow is likely to behave, not where price will go. It is context for risk and range, not a trading signal, and this is analysis rather than investment advice.
How is GEX different from DEX?
GEX is how quickly dealer exposure changes as the market moves. DEX is how much directional exposure dealers carry right now.
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