--- title: "What is GEX (gamma exposure) | RupeeCase" description: "Gamma exposure, or GEX, adds up the gamma of every option strike, scaled by open interest and the index level." source_url: "https://www.rupeecase.com/learn/questions/what-is-gex" --- Under convention B every strike on the 30 Jun 2026 chain adds negative exposure, so there is no zero gamma level Net gamma exposure by strike, in Rs crore per one percent move of the index, from the NIFTY chain of 10 Jun 2026 for the 30 Jun 2026 expiry. Convention B: writers are short both calls and puts. A model, not a measurement. Source: NSE end of day data, computed by RupeeCase. As of 10 Jun 2026. Gamma is how fast an option's delta changes as the index moves. A writer who has sold options and hedges with the index has to adjust that hedge as the index moves, and gamma says how much. GEX adds this across the chain: for each strike, gamma times open interest times the index level squared, with a sign that says whether the hedge buys or sells the index as the market rises. The sign is the whole argument. The version popular in the US assumes dealers are long calls and short puts. The chart uses convention B instead, where the writers are short both calls and puts, so every bar is negative. The same chain gives a different picture under each rule, and the GEX lab lets you switch between conventions on the same chain. Read the bars as a model, not a measurement. NSE publishes open interest by strike and expiry, and it publishes participant totals across index derivatives at the end of the day, but it does not publish who holds each side of each strike. The bars also depend on the implied volatility used for each strike and on which expiries are included. What the bars cannot tell you is which way the index will go. A large total under one rule is a statement about that rule. The next page, on the walls and the zero gamma level, shows how the levels people quote move when the inputs do. **Before you trade.** Derivatives trading carries a high risk of loss. SEBI's study "Profitability of Individual Traders in the Equity Derivatives Segment (FY25 to FY26)" (August 2026) found that 87.7% of individual traders in equity F&O made net losses in FY26, with aggregate net losses of Rs 91,685 crore. [Read the SEBI study](https://www.sebi.gov.in/reports-and-statistics/research/aug-2026/study-profitability-of-individual-traders-in-the-equity-derivatives-segment-fy25-fy26-_103835.html) What is GEX (gamma exposure)?Gamma exposure, or GEX, adds up the gamma of every option strike, scaled by open interest and the index level, to estimate how much hedging the option writers would need to do as the index moves. It is a model built on an assumption about which side each party holds, because no exchange in India publishes that by strike, so the sign of each bar depends on the convention chosen. LGo deeper ## Where Learn teaches this. [Go deeperGamma exposure: the computation and its assumptions10 min, Advanced](/learn/path-15/module-15-9-gamma-exposure-gex)[Go deeperGamma: why it grows so fast near expiry8 min, Intermediate](/learn/path-14/module-14-11-gamma)[Try itGEX labGamma exposure under three sign conventions, switched on screen.](/learn/tools/gex-lab) SSources ## Go to the source. 2 sources, NISM the most cited The publisher of each source listed below. Source: Module undefined source list. 1. [NSE, equity derivatives contract specifications (expiry, settlement, exercise and lot size rules)](https://www.nseindia.com/static/products-services/equity-derivatives-contract-specifications) NSE 2. [NISM, Series VIII equity derivatives test objectives](https://www.nism.ac.in/revamp-nism/test-objectives-revised-nism-series-viii-equity-derivatives-certification-examination/) NISM ?Questions people ask ## Related questions. [QuestionWhat is gamma, and what is a "gamma blast"?Intermediate, trap check](/learn/questions/what-is-gamma)[QuestionWhat are open interest, change in OI and cumulative OI?Beginner](/learn/questions/what-is-open-interest)[QuestionIs the highest call OI strike resistance and the highest put OI strike support?Intermediate, trap check](/learn/questions/highest-oi-support-resistance)[QuestionWhat is implied volatility?Beginner](/learn/questions/what-is-implied-volatility)[QuestionWhat is a delta neutral strategy or delta hedging?Intermediate](/learn/questions/delta-neutral-and-delta-hedging) [All 130 questions](/learn/questions/) Explore next ## Go deeper on this question. * [QuestionIs Nifty GEX reliable in India?A short answer with a dated chart](/learn/questions/is-nifty-gex-reliable) * [QuestionWhat are vanna and charm flows?A short answer with a dated chart](/learn/questions/vanna-and-charm-flows) * [ToolOption payoff builderLegs on a dated Nifty chain, breakevens and charges](/learn/tools/payoff-builder) * [GlossaryInvesting glossary, 230 termsPlain word definitions, and the app’s own](/learn/glossary) Community ## Join my WhatsApp group. 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