Delta: sensitivity to the underlying
Delta estimates the premium change for a small one-point move in the underlying, holding other inputs constant. Hypothetically, delta 0.50 and a +10-point index move suggest about +₹5 per unit from delta alone. A bought put usually has negative delta.
Gamma: how delta changes
Gamma estimates how much delta changes for a one-point underlying move. Delta is therefore not a fixed multiplier for a large move.
Theta: sensitivity to passing time
Theta describes time sensitivity. Providers often express it per day; verify the convention. A displayed theta of −2 suggests about ₹2 per unit of modelled decay for that time increment, with other inputs held constant.
Vega: sensitivity to implied volatility
Vega commonly describes premium sensitivity to a one-percentage-point IV change. An IV move from 15% to 16% is one percentage point, not a 1% relative increase. Verify the provider’s units.
Apply the numbers to one consistent contract
In TradeLab, use the same underlying, strike, expiry and option type in the option chain and Greeks view. Check the timestamp and data status. Missing Greeks are not zero. The examples here are synthetic and are not estimates for a current contract.
Keep the practice question specific
Before a replay or paper session, write one observation to examine: what happens to the premium as time passes, or how it responds when the underlying changes? Record the contract and timestamp, then compare what the available data actually shows. Several inputs can move together, so a single Greek cannot explain every change.
Common questions
Can Greeks predict the exact next premium?+
No. They are model sensitivities. Inputs, spreads, liquidity and the model itself affect the observed price.
Should I multiply by quantity?+
A per-unit sensitivity scales with the number of units for a position estimate. Check whether the displayed value is per unit, lot or position first.
Try the numbers yourself
Explore a hypothetical scenario in our free calculator.
Option break-even →Further reading
References explain general concepts. They do not endorse TradeLab or its simulations.