Index Option

Index options are derivative contracts whose value depends on an underlying stock-market index. You can use a call when you expect the index to rise or a put when you expect it to fall.

• You pay a premium when you buy an option.
• A buyer can lose the entire premium paid.
• Calls and puts trade at different strike prices and expiry dates.
• Nifty 50 options currently have a market lot of 65 units.
• Bank Nifty has a market lot of 30 units.
• Nifty 50 has weekly and monthly option contracts.
• Index options on NSE are European-style and cash-settled.
• Option prices can fall even when your market direction is eventually correct because time and volatility also matter.
• Check premium, lot size, strike price, expiry, and maximum possible loss before trading.

You pay a premium to buy an option, and that premium changes as the index moves.

Suppose Ramesh earns ₹1,00,000 per month and wants to understand one Nifty option trade.

Assume:

Ramesh pays:

₹100 × 65 = ₹6,500

That ₹6,500 is the premium amount for one lot.

Now suppose the premium rises from ₹100 to ₹140.

The option value becomes:

₹140 × 65 = ₹9,100

Difference:

₹9,100 - ₹6,500 = ₹2,600

Before applicable charges, Ramesh has a ₹2,600 gain in this example.

But if the premium falls from ₹100 to ₹60:

₹60 × 65 = ₹3,900

Loss:

₹6,500 - ₹3,900 = ₹2,600

This is the basic money logic of index options.

The premium shown on the screen is only the price per unit. Always multiply it by the lot size.

A call and a put represent different market views.

When would someone buy a call option?

A call option is generally bought when the trader expects the index to rise.

Suppose Nifty is at 25,000.

Ramesh buys a 25,100 call.

If Nifty rises strongly before expiry, the call premium may increase.

But the price of the option also depends on time and volatility.

So, even if Nifty rises, the call does not automatically give a profit.

When would someone buy a put option?

A put option is generally bought when the trader expects the index to fall.

Suppose Nifty is at 25,000.

Ramesh buys a 24,900 put.

If Nifty falls strongly before expiry, the put premium may rise.

If Nifty does not fall enough, the premium can drop.

A put can also expire with no value.

If you buy an index option, you can lose the full premium paid.

Suppose the premium is ₹120 and the lot size is 65.

Total premium:

₹120 × 65 = ₹7,800

If that option expires with no value, the buyer can lose the full ₹7,800, plus applicable brokerage and statutory 

charges.

This is why the small premium number shown on the screen can be misleading.

₹120 may look small.

The actual money at risk for one lot is ₹7,800.

Option prices depend on more than direction.

Suppose Ramesh thinks Nifty will rise.

He buys a call at ₹100.

His premium cost is:

₹100 × 65 = ₹6,500

Over the next few days, Nifty rises slightly.

His market view was correct.

But the premium falls to ₹70 because expiry is getting closer and the move was not large enough.

The option is now worth:

₹70 × 65 = ₹4,550

Loss:

₹6,500 - ₹4,550 = ₹1,950

Ramesh correctly expected Nifty to rise, but he still lost ₹1,950 in this example.

This can happen because option prices depend on:

• Index movement
• Time left to expiry
• Volatility
• Strike price
• Interest rates
• Expected dividends

Direction alone is not enough.

These 3 details tell you what option contract you are trading.

What is the strike price?

The strike price is the index level linked to the option.

Suppose:

• Nifty level is 25,000
• Ramesh buys a 25,100 call

The 25,100 figure is the strike price.

What is the expiry date?

The expiry date is the final trading date of the contract.

Options have a limited life.

NSE currently uses Tuesday as the expiry day for its main equity-derivative contracts.

If Tuesday is a trading holiday, expiry moves to the previous trading day.

Nifty 50 currently has weekly and monthly option contracts, along with quarterly and longer-dated contracts.

What is the lot size?

Options trade in fixed lots.

Current market lots include:

Lot sizes can change.

Always check current exchange specifications before trading.

Start with the total money at risk.

Have you calculated the full premium?

Suppose the premium shown is ₹150.

For one Nifty 50 lot:

₹150 × 65 = ₹9,750

That is the premium amount for one lot.

Do not think the trade costs only ₹150.

Have you checked the expiry?

Short-expiry options can lose time value quickly.

A contract expiring tomorrow can behave very differently from one expiring after several weeks.

Have you checked the strike price?

Do not choose a strike only because the premium looks cheap.

A low-priced option may need a much larger market move before it gains enough value.

Have you checked liquidity?

Look at the buying price, selling price, and trading activity.

A wide gap between buyers and sellers can increase your trading cost.

Can you afford to lose the full premium?

Do not use:

• Emergency money
• Rent money
• School-fee money
• EMI money
• Household-expense money

Options use leverage. That means a small premium per unit can create a much larger total trade amount.

Suppose Suresh is an auto driver with ₹50,000 in savings.

He sees a Nifty call trading at ₹80.

He thinks:

“₹80 is cheap.”

But one lot costs:

₹80 × 65 = ₹5,200

If he buys 4 lots:

₹5,200 × 4 = ₹20,800

If all 4 lots expire with no value, he can lose the full ₹20,800, plus applicable charges.

That is more than 40% of his ₹50,000 savings.

The ₹80 number looked small.

The actual amount at risk was much bigger.

Index options can help you take a view on Nifty 50, Bank Nifty, and other indices, but they can also create quick losses. A call does not guarantee profit when the index rises, and a put does not guarantee profit when it falls. Check the premium, lot size, strike price, expiry, liquidity, and total money at risk before trading. Never treat a small-looking premium as a small-risk trade.