Fundamentals7 min read

How to Read the Option Greeks on Your Broker Screen

A practical walkthrough of what the Delta, Gamma, Theta, Vega and IV numbers on your option chain actually mean — and how to turn them into rupees per lot.

By Bulan Sarkar · 27 June 2026

In short: The Greeks column on your broker screen shows per-share sensitivities: Delta (rupees gained per 1-point index move), Theta (rupees lost per day), Vega (rupees per 1% change in implied volatility) and Gamma (how fast Delta itself moves). To convert any Greek into rupees per lot, multiply it by the lot size — for Nifty that means multiplying by the current lot quantity (75 in our examples). Signs flip when you sell: a buyer's negative Theta becomes the seller's positive Theta.

The single most common confusion for new Indian traders is scale. Your broker's option chain — whether Zerodha Kite, Angel One, Dhan or Upstox — quotes Greeks per unit of the underlying, exactly the way the premium itself is quoted per share. A Nifty option premium of ₹120 is really ₹120 × lot size per contract. The Greeks follow the same rule. So when the screen shows Delta 0.50 and Theta −18, you must multiply by the lot size to see your real exposure. With a 75-unit lot, that Delta means ₹37.5 of P&L per index point, and that Theta means about ₹1,350 of decay per day for one lot. Read the Greeks in 'per share' language, then translate to rupees per lot before you size the trade.

Delta: your directional exposure in one number

Delta is usually the first Greek column. For a call it runs 0 to +1; for a put, 0 to −1. An at-the-money Nifty option sits near ±0.50, deep in-the-money strikes approach ±1, and far out-of-the-money strikes approach 0. To read it in rupees, multiply Delta × lot size × the index move. If you hold a 0.40-Delta call and Nifty rises 50 points, that is roughly 0.40 × 50 × 75 = ₹1,500 of gain before other Greeks adjust it. Delta also doubles as a rough probability the option finishes in-the-money, so a 0.30-Delta strike loosely implies a 30% chance of expiring ITM. Sum the Delta of every leg (times lots and lot size) to see your true net directional bet.

Theta: the daily rent ticking against you

Theta is shown as a negative number for a long option because the position loses that much value each calendar day if nothing else changes. A Theta of −18 on a Nifty weekly call means about ₹18 per share, or ₹18 × 75 = ₹1,350 per lot, evaporates every day you hold it flat. This decay is not linear — it accelerates sharply in the final sessions before expiry, so a weekly option's Theta reading today understates what it will be two days from now. When you sell that same option, the sign flips: the seller's screen effectively shows Theta as income. Always check Theta before holding a long option over a weekend or an NSE holiday, because two or three days of decay are booked with no chance of a move.

Vega and IV: reading the volatility column

Most option chains show two related numbers: implied volatility (IV), quoted as a percentage per strike, and Vega, the rupee sensitivity to a 1% change in that IV. A Vega of 12 means the option gains or loses ₹12 per share — ₹900 per lot — for each one-point move in IV, even if Nifty stands perfectly still. The IV column is where you spot rich versus cheap premium: if the IV on this week's Nifty options is far above the India VIX level or above where it usually sits, you are paying up for volatility. This is the setup for IV crush — buying inflated IV before results or the Union Budget and watching Vega bleed the moment the event passes, even when your direction was right.

Gamma: why your Delta reading won't stay put

Gamma tells you how fast the Delta column will change as the index moves. It is highest for at-the-money options and rises dramatically as expiry approaches. A Gamma of 0.006 means each 1-point Nifty move adds 0.006 to your Delta, so a 50-point move lifts a 0.50-Delta call to roughly 0.80. On expiry day, ATM Gamma is so large that a 30-40 point Bank Nifty swing can flip an option's Delta from 0.4 to 0.6 in minutes. Practically, Gamma is a warning label on the Delta number: the exposure you read now is only a snapshot, and it will accelerate — in your favour if you are long options, against you if you are short.

Signs flip when you sell — read your position, not the option

The Greeks on the option chain describe the option itself, which is the buyer's perspective. The instant you sell, invert every sign. A long call's +Delta, −Theta, +Vega and +Gamma become the short seller's −Delta, +Theta, −Vega and −Gamma. This is why a premium seller earns Theta but carries dangerous short Gamma, and why a straddle seller profits from falling IV (short Vega) but is exposed to a volatility spike. Good broker platforms show a consolidated 'position Greeks' or 'basket Greeks' view that already applies the signs and lot multiples for your open trades — learn to read that screen, because it tells you your real, net exposure rather than the theoretical exposure of a single contract.

A worked example: reading one line end to end

Suppose Nifty is at 24,500 and the chain shows the 24,500 CE at ₹120, IV 15%, Delta 0.52, Gamma 0.006, Theta −18, Vega 12. Buying one lot costs ₹120 × 75 = ₹9,000. If Nifty rises 100 points and nothing else changes, Delta earns about 0.52 × 100 × 75 = ₹3,900, plus a little extra as Gamma lifts the Delta during the move. Hold it flat for a day and Theta costs ₹18 × 75 = ₹1,350. If IV drops 2 points to 13%, Vega costs 12 × 2 × 75 = ₹1,800. Read that way, a single option-chain row tells you exactly how price, time and volatility will each hit your rupees — before you commit a single lot.

Key takeaways

Greeks are quoted per share; multiply by the lot size (75 in our Nifty examples) to get rupees per lot.
Delta = P&L per index point and a rough ITM probability; Theta = daily decay; Vega = P&L per 1% IV move; Gamma = how fast Delta changes.
Selling flips every sign — read your consolidated position Greeks, not the single-option Greeks.
The IV column reveals rich vs cheap premium and warns of IV crush around known events.
Gamma is a warning on the Delta number: near expiry, today's Delta reading changes fast.

Frequently asked questions

Are the Greeks on my broker screen per lot or per share?

Per share, just like the premium. Multiply any Greek by the lot size to get your real rupees-per-lot exposure — for example, Theta −18 on a 75-unit Nifty lot is about ₹1,350 of decay per day.

Why is my Theta shown as a negative number?

Because you are long the option and lose that value each day from time decay. If you sold the option instead, that same Theta works in your favour as income.

What does the IV column tell me?

Implied volatility is the market's forecast of future movement priced into that strike. High IV means expensive premium; comparing it to India VIX or its own history helps you judge whether options are rich or cheap.

My Delta keeps changing even when I refresh — why?

Delta moves as the index moves and as time passes; Gamma is the Greek that measures how fast. Near expiry and near the strike, Gamma is large, so Delta shifts quickly.

Where do I see the Greeks for my whole position, not one option?

Most platforms have a positions or basket-Greeks view that sums each leg's Greeks with the correct signs and lot multiples. That net figure is your true exposure and is what you should manage.

Sources & references

Published 27 June 2026. Educational content only — not investment advice.