Under convention B every strike on the 30 Jun 2026 chain adds negative exposure, so there is no zero gamma level

Under convention B every strike on the 30 Jun 2026 chain adds negative exposure, so there is no zero gamma levelNet gamma exposure by strike under convention B (hedgers short both calls and puts), in ₹ crore per 1% move of spot. 0 bars positive, 37 negative; the largest bar is −2,327 at 24,025. Each bar adds up 2 neighbouring strikes. Spot 23,215.Convention B: hedgers short both calls andputs₹ crore per 1% move of spotPositive net gammaNegative net gamma−2,500−2,000−1,500−1,000−500022,00023,00024,000Strike priceSpot 23,215Call wall 24,000Put wall 23,000
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