Gamma: When Delta Moves Fast
Gamma explains delta acceleration near ATM strikes — critical for expiry-day Nifty options and gamma squeeze dynamics.
Definition
Gamma measures how much delta changes when the underlying moves one point. High gamma means delta shifts rapidly — small spot moves create large premium swings. Gamma peaks at ATM options near expiry.
Long option positions are long gamma — they benefit from choppy large moves. Short positions are short gamma — painful on trend days.
Expiry Week Impact
Wednesday through expiry, ATM gamma explodes. Hedgers must adjust futures frequently, sometimes amplifying intraday moves — the mechanics behind gamma squeeze episodes.
Buying cheap OTM on expiry morning is often short gamma relative to move needed — theta and low delta dominate.
Reading Gamma on the Chain
Strikes with massive open interest become gamma hotspots. Price may whip around these levels as dealers rebalance.
On quiet expiry afternoons, high gamma can pin spot near defended strikes.
Frequently Asked Questions
- Is high gamma good?
- For long options in volatile markets, yes. For sellers, high gamma increases hedge cost and loss speed.
- When is gamma highest?
- ATM options in the final days before expiry.
Key Takeaways
- Gamma drives delta changes — peaks ATM near expiry.
- Long gamma loves movement; short gamma fears trends.
- Heavy OI strikes are gamma battlegrounds.
Related Articles
- Greeks Explained: Delta, Gamma, Theta, and Vega for OptionsA practical introduction to option Greeks — how delta, gamma, theta, and vega affect Nifty and Bank Nifty positions in intraday trading.
- Gamma Squeeze: Feedback Loops in Index OptionsHow dealer hedging and concentrated gamma can amplify Nifty and Bank Nifty moves — and why squeezes end abruptly.
- Expiry Day Strategies for Weekly Nifty & Bank Nifty OptionsPractical expiry-day tactics — pin risk, gamma scalping, when to stay flat, and how max pain and OI shape the final session.