01
The math is the same
GEX is built the same way for any underlying with listed options: open interest times gamma times contract size times spot squared, summed across strikes. What changes between underlyings is the quality of the inputs.
02
Liquidity decides how much to trust it
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NIFTY and BANKNIFTY: deep open interest across many strikes, so the profile is smooth.
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FINNIFTY and MIDCPNIFTY: thinner chains, so a few strikes can dominate the total and the profile moves more between updates.
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SENSEX: a BSE index with options on BSE, with its own liquidity and expiry pattern.
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Single stocks: open interest is concentrated at few strikes and positions are more often driven by hedging of stock holdings, so dealer-sign assumptions are weaker.
Always read GEX for a thinner underlying against that underlying's own history, and check the open interest behind the number.
03
Assumptions that change by market
Settlement style, lot size, expiry cycle and the share of positions held by non-dealers all differ by contract. Confirm each from the current exchange circular instead of assuming the NIFTY values apply.
04
Coverage in the Arkenwell terminal
Arkenwell covers NSE index derivatives on NIFTY 50, BANKNIFTY, FINNIFTY and MIDCPNIFTY, and its dealer hedging flow desk covers NIFTY, BANKNIFTY, MIDCPNIFTY and SENSEX. Single-stock option chains are available for NSE F&O stocks, and chart overlays show call and put walls, max pain and the gamma flip on F&O symbols. Coverage can change, so check the terminal for the current list.
05
Frequently asked questions
Is there GEX for FINNIFTY and MIDCPNIFTY?
The calculation applies to any index with listed options. Their chains are thinner than NIFTY's, so read the result against its own history and the open interest behind it.
Does GEX work for single stocks?
The mechanics do, but stock options are concentrated at few strikes and the dealer-sign assumption is weaker, so treat stock-level GEX with more caution.
Is SENSEX GEX comparable to NIFTY GEX?
Not directly. They are different indices on different exchanges, so compare each with its own history.
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