Option Greeks sound technical, but each one answers a simple, practical question about your trade: How much will I gain if NIFTY moves? How much am I losing every day to time? What happens if volatility drops?

This guide explains Delta, Theta, Vega and Gamma in plain language, with examples, and shows how to watch them on a real position.

Delta: sensitivity to the index

Delta runs from 0 to 1 for calls and 0 to –1 for puts.

• ATM options have a delta around 0.5 (or –0.5 for puts).
• Deep ITM options move almost one-for-one with the index (delta near 1).
• Far OTM options barely react (delta near 0).

Example: A call with delta 0.4 gains about ₹40 if NIFTY rises 100 points.

Many traders also use delta as a rough guide to the chance of the option expiring in the money.

Theta: the cost of time

Theta is usually shown as a negative number for option buyers. A theta of –12 means the option loses about ₹12 a day if nothing else changes.

• Theta is highest for ATM options.
• It speeds up as expiry gets closer.
• Buyers pay theta; sellers collect it.

Vega: sensitivity to volatility

Vega shows how much the premium changes when implied volatility (IV) changes by 1 point. If vega is 8 and IV falls by 2 points, the option loses about ₹16.

• Vega is highest for ATM options with more time to expiry.
• It shrinks as expiry approaches.

Gamma: how fast delta changes

Gamma tells you how much delta changes when the index moves 1 point. High gamma means your position's sensitivity changes quickly.

• Gamma is highest for ATM options close to expiry.
• That's why ATM premiums can explode or collapse on expiry day.
• High gamma helps buyers in big moves and hurts sellers.

All four together: a quick example

Illustrative numbers. Real Greeks change with strike, time and market conditions, and gamma will also change delta during the move.

See the Greeks on a real position

Reading about Greeks only takes you so far. Watching them change on your own position is what makes them click.

1. Open the Options Simulator and buy an ATM option on NIFTY.
2. Watch the position's Greeks as the market moves.
3. Note how delta changes when NIFTY moves away from your strike.
4. Watch how theta grows on expiry week.

Other places to see Greeks on OPIFY

• Live option chain: switch to the Greeks view to see Delta, Theta, Vega and IV for every strike.
• Strategy Builder: see current and projected Greeks for a multi-leg strategy.

Frequently asked questions

Which Greek matters most?

For short-term buyers, delta and theta. For trades held through events, vega. For expiry-day trades, gamma.

Do I need to calculate Greeks myself?

No. OPIFY shows them for you in the option chain, strategy builder and simulator.

This article is for education only and is not investment advice. Options trading involves risk.