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What are Option Greeks and how do they work — Delta, Gamma, Theta, Vega all understood in easy language. Hindi trading guide.
Published by The Retail Trader · AUG 12, 2026 · Features
What are Option Greeks and how do they work — Delta, Gamma, Theta, Vega all understood in easy language. Hindi trading guide.
Option Greeks are the 5 factors that determine how an option's price will change when market conditions change:
Keep these five points in mind:
• Delta (Δ) — effect of price
• Gamma (Γ) — change of Delta
• Theta (Θ) — effect (decay) of time
• Vega (ν) — effect of Volatility
• Rho (ρ) — effect of interest rate
In simple language: Greeks tell that if Nifty goes up by 100 points, or beats 1 day, or volatility increases – then how much will the price of your option rise or fall.
If the underlying (Nifty/stock) increases by ₹1 → how much will the option rise/fall.
Values:
• Deep ITM Call — Delta Range: 0.8-1.0, Meaning: Stock will move like
• ATM Call — Delta Range: 0.5, Meaning: Half move karega
• Deep OTM Call — Delta Range: 0.0-0.2, Meaning: Barely move karega
• ITM Put — Delta Range: -0.8 to -1.0, Meaning: full move in ultimate direction
• ATM Put — Delta Range: -0.5, Meaning: half move in ultimate direction
Practical Use:
• Nifty at 20,000, Delta of 20,200 CE = 0.6
• Nifty goes up by 100 points → Option price will increase by ~₹60
• Nifty goes down by 100 points → Option price will fall by ~₹60
Delta is approximately the probability that the option will expire ITM:
• Delta 0.5 = 50% chance ITM will expire
• Delta 0.3 = 30% chance
• Delta 0.8 = 80% chance
This is very useful - by looking at the delta, we understand how "in the money" the option is.
How much will Delta change when the underlying increases by ₹1?
Simple Example:
• Nifty 20,000 CE, Delta = 0.5, Gamma = 0.02
• Nifty rises by 100 points → Delta increases to 0.52
• Nifty falls by 100 points → Delta decreases to 0.48
ATM options have the highest gamma. Meaning the delta of ATM options changes the fastest.
Gamma risk: ATM options are very volatile near expiry — delta changes dramatically on small moves. This is a risk for sellers.
Advanced traders make profits using gamma:
• Buy ATM option (long gamma)
• When the price rises → delta is increasing → sell some of the underlying (hedge)
• When the price falls → delta is decreasing → buy some of the underlying
• This profit from repeated hedging
How much will the price of the option fall every day (if all factors remain the same).
The time value of options falls every day. This option is an enemy for BUYERS and a friend for option SELLERS.
Example:
• Nifty 20,200 CE, Price = ₹100, Theta = -5
• If Nifty remains same till tomorrow → Option will become ₹95
• After 5 days → Option will become ₹75 (only due to time decay)
Theta falls fastest in the last 7 days. Theta curve of ATM options:
Keep these five points in mind:
• 30 days — ~₹1-2/day
• 15 days — ~₹3-4/day
• 7 days — ~₹5-7/day
• 3 days — ~₹10-15/day
• Expiry day — ~₹20-30+/day
Meaning: Last week is very dangerous for option buyers. Option sellers make maximum profit in the last week.
Theta Strategy:
• Buy options early (20-30 days before expiry) — theta is slow
• Sell options near expiry (last 7 days) — theta is fast
• Avoid holding ATM options overnight near expiry — theta is very expensive
If implied volatility (IV) increases by 1% → how much will the option price increase?
Example:
• Nifty 20,200 CE, Price = ₹100, Vega = 8
• If IV increases by 2% → the option price becomes ₹116 (₹100 + 2×8)
• If IV falls by 2% → the option price becomes ₹84
IV increases a lot before earnings/results. IV drops suddenly after the results — whether the stock goes up or down.
Meaning: Buying options before results is EXPENSIVE (high IV). Following the results, IV crush causes the option price to fall even if the stock moves in your direction.
Best strategy: SELL options before results (high IV premium), BUY back after results (profit from IV crush).
India VIX is the implied volatility index of the Indian market:
• VIX high (>20): Options are expensive (high premium)
• VIX low (<12): Options are cheap (low premium)
• VIX rising: Buying options better
• VIX falling: Selling options better
Interest rate increases by 1% → How much will the option price change?
The impact of Rho is very small compared to delta, theta, and vega. Most traders ignore Rho.
Exception: Rho matters in long-term options (LEAPS) or high interest rate environments.
When RBI rate increases → Call options slightly expensive, Put options slightly cheap. But the effect is minimal (1-2% of option price).
Keep these points in mind:
• 📌 GREEKS FOR OPTION BUYERS
• DELTA (Δ):
• 📊 ITM option lo → Delta 0.7-0.8 (move higher)
• 📊 ATM option lo → Delta 0.5 (balanced)
• 📊 OTM option lo → Delta 0.2-0.3 (cheap, less likely)
• THETA (Θ):
• ⚠️ Time is your enemy
• ⚠️ Buy Options 20-30 days in advance (theta slow)
• ⚠️ Do not hold in last 7 days (theta fast)
• ⚠️ Theta of ATM options is highest
• VEGA (ν):
• ✅ Buy when IV is low (cheap premium)
• ✅ Sell when IV is high (expensive premium)
• ✅ VIX < 12 = Good time to BUY
• ✅ VIX > 20 = Good time to SELL
Keep these points in mind:
• 📌 GREEKS FOR OPTION SELLERS
• DELTA (Δ):
• 📊 Sell ATM → Delta 0.5 (balanced risk)
• 📊 Sell OTM → Delta 0.2-0.3 (high probability)
• 📊 Use Delta-neutral strategies
• THETA (Θ):
• ✅ Time is your friend
• ✅ Sell in last 7 days (theta fast decay)
• ✅ Highest theta is available on ATM options
• ✅ Create calendar spreads (sell near-term, buy far-term)
• VEGA (ν):
• ✅ Sell when IV is high (expensive premium)
• ✅ Profit from IV crush (after results/events)
• ✅ Iron condors, use credit spreads
• GAMMA (Γ):
• ⚠️ Gamma is very high on Near expiry ATM
• ⚠️ Delta will change dramatically in small moves
• ⚠️ Manage Gamma risk with position sizing
Setup: Nifty at 20,000. You buy 20,200 CE (14 days to expiry).
Keep these four points in mind:
• Delta — Value: 0.45, Meaning: Nifty rises by 100 → the option price increases by ~₹45
• Gamma — Value: 0.03, Meaning: Delta will change from 0.45 to 0.48
• Theta — Value: -6, Meaning: ₹6 will fall every day (time decay)
• Vega — Value: 10, Meaning: IV 1% badhe → Option ₹10 badhega
Scenario 1: Nifty goes up 100 points, after 1 day:
• Delta profit: +₹45
• Theta loss: -₹6
• Net: +₹39
Scenario 2: Nifty remains same, after 1 day:
• Delta profit: ₹0
• Theta loss: -₹6
• Net: -₹6
Scenario 3: Nifty goes down 100 points, after 1 day:
• Delta loss: -₹45
• Theta loss: -₹6
• Net: -₹51
Lesson: There is profit in option buying only when the move is more than theta. That's why buyers want BIG moves — small moves eat up theta profits.
"Delta is 0.5, if Nifty 100 goes up then ₹50 profit" — No! Theta eats ₹6 daily. If you held it for 5 days, you would have eaten ₹30 theta.
Time decay hurts option buyers a lot. Holding near expiry ATM options = slow bleeding.
Near expiry ATM sold, Nifty went up 200 points – delta from 0.3 to 0.7. Position size becomes 2x+. Margin call can be made.
Buying options before results = expensive premium. After the results IV crush the option price falls even if the stock moves in your direction.
Greeks change every second. Delta will change when the price changes (gamma). Theta will change when time changes. Greeks is a snapshot — update continuously.
Keep these five points in mind:
• How to Read an Option Chain?
• How Does F&O Expiry Work?
• What Is Implied Volatility?
• The Math Of Option Buyer Vs Seller
• A Basic Understanding Of Hedging
The Retail Trader — educational market analysis. Not investment advice.
This article is for educational purposes only. It is not a buy or sell recommendation, a claim of guaranteed returns, or advisory guidance. Exchanges, SEBI and RBI change rules, rates and procedures from time to time, so verify every figure with your broker or an official source.