Zero Gamma Line (ZGL) in NIFTY Options

1. How the Zero Gamma Line (ZGL) is Calculated

The Zero Gamma Line is calculated through a spot simulation search algorithm across all active NIFTY strike prices. By simulating how total Net GEX responds as hypothetical spot price moves up or down, the algorithm locates the exact crossover price level where net dealer gamma flips from positive to negative.

Because open interest shifts throughout the trading day as market participants write new calls and puts, ZGL updates dynamically in near-real-time alongside live market feed snapshots.

2. Strategy Selection Relative to ZGL

Quantitative traders use ZGL as an objective regime filter to decide between options buying and options selling strategies:

• Above ZGL (Positive Net GEX): Favors range-bound strategies (iron condors, short straddles, credit spreads). Market makers actively cushion price dips by buying futures and cap rallies by selling futures.
• Below ZGL (Negative Net GEX): Favors momentum & directional strategies (long options, debit spreads, breakout trades). Market makers sell into falling markets and buy into rising markets, expanding ATR and intraday candle range.