What is Gamma in Options? A Simple Guide for Indian Traders
Gamma measures how fast an option's delta changes as the underlying moves. It is the rate of change of delta. High gamma means delta shifts quickly, making the option more responsive and less predictable, especially for at-the-money options near expiry.
If delta tells you how much an option moves, gamma tells you how quickly that sensitivity itself changes. It is the Greek behind sudden swings in an option's behaviour.
Gamma matters most to option sellers, who can face fast-rising losses. What follows is a no-nonsense guide for Indian traders. You can view it on Stockk.
Key Takeaways
- Gamma measures how fast delta changes.
- High gamma means delta shifts quickly.
- Gamma peaks for at-the-money options near expiry.
- Sellers fear gamma because losses can accelerate.
- Buyers benefit from gamma on a fast move.
Where is gamma highest?
Picture this: an ATM NIFTY call has a delta of 0.5 and high gamma. A sharp move in NIFTY can push its delta to 0.7 quickly, accelerating gains. The same gamma works in reverse, so delta can drop just as fast if the index reverses.
Gamma peaks for at-the-money options near expiry, where a small move can flip the option between in and out of the money. Deep in or out-of-money options have low gamma because their delta is already stable.
Why gamma explodes on expiry day
On expiry day, an ATM option is balanced on a knife's edge. A tiny move can flip it from worthless to valuable, or back again. This means its delta can swing from near 0 to near 1 in moments, which is extreme gamma. For sellers of ATM options near expiry, this is dangerous, because a small, fast move can turn a calm position into a losing one almost instantly.
Why does gamma matter?
- Sellers: high gamma means losses accelerate as price moves against them
- Buyers: benefit when a move accelerates in their favour
- Near expiry: gamma rises sharply, making ATM options very reactive
Gamma across strikes
| Option | Gamma |
|---|---|
| At the money | Highest |
| Deep in the money | Low |
| Deep out of the money | Low |
Curious to try options yourself? Head to Stockk, open a quick demat account, and use the Knowledge Center whenever you need a refresher.
Futures and Options are leveraged products and carry a high risk of loss that can be more than the money you put in. This article is only for learning and is not a recommendation to trade in derivatives.
Frequently Asked Questions
What is the relationship between gamma and delta?
Gamma is the rate at which delta changes as the underlying moves. High gamma means delta shifts quickly, so it is delta's sensitivity.
Why is gamma highest at the money?
ATM options are most likely to flip between in and out of the money, so their delta is most sensitive. This concentrates gamma at the money.
Why do option sellers fear gamma?
High gamma means losses accelerate as the underlying moves against a short option, so the position can deteriorate rapidly. This is the main risk in selling.
Does gamma increase near expiry?
Yes. Gamma rises sharply for ATM options as expiry approaches, so small moves cause large delta swings, making expiry-day ATM options very volatile.
How do traders manage gamma risk?
Sellers hedge by adjusting positions or buying offsetting options to reduce net gamma.
Investments in securities market are subject to market risks. This article is for educational purposes only and does not constitute investment advice.
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