Option Greeks, explained for Indian traders
The Greeks measure how an option's price reacts to movement, time, volatility and interest rates. Master them and you stop guessing why a position made or lost money. Each guide below has a plain-English explanation, an original diagram, the formula, a Nifty worked example and an FAQ.
What are the option Greeks? The option Greeks are a set of risk measures showing how an option's price changes with the underlying price (Delta), the rate of that change (Gamma), the passage of time (Theta), implied volatility (Vega) and interest rates (Rho), plus second-order cross-effects (Vanna, Charm, Vomma).
Delta Δ
First-orderDelta measures how much an option's price is expected to change when the underlying moves by ₹1 — and doubles as a rough probability of the option finishing in-the-money.
Gamma Γ
Second-orderGamma measures how fast Delta changes when the underlying moves — it is the acceleration behind an option's directional exposure, and it peaks for at-the-money options close to expiry.
Theta Θ
First-orderTheta measures how much value an option loses each day purely from the passage of time — the daily 'rent' an option buyer pays and an option seller collects.
Vega ν
First-orderVega measures how much an option's price changes when implied volatility moves by one percentage point — it is your exposure to the market's expectation of future movement, not to the movement itself.
Rho ρ
First-orderRho measures how much an option's price changes when interest rates move by one percentage point — the least influential Greek for short-dated Indian options, but meaningful for long-dated positions.
Vanna —
Second-orderVanna measures how an option's Delta shifts when implied volatility changes — equivalently, how Vega shifts when the underlying moves — a cross-Greek that matters most for skew-sensitive and Delta-hedged positions.
Charm —
Second-orderCharm measures how much an option's Delta changes as one day passes — the 'Delta decay' that quietly re-shapes your directional exposure over time, especially near expiry.
Vomma —
Second-orderVomma measures how much an option's Vega changes when implied volatility moves — the convexity of your volatility exposure, which makes long-Vega positions gain Vega as volatility rises.
How the Greeks fit together
Think of Delta as speed and Gamma as acceleration; Theta as the clock draining value; Vega as your exposure to the market's fear gauge (India VIX); and Rho as the quiet background rate effect. The second-order Greeks — Vanna, Charm and Vomma — describe how the first-order Greeks themselves shift as volatility and time change. Together they turn options from a black box into a set of measurable, manageable risks.