Call Option
A call is the right to buy at a fixed price. Pay the premium, and the most you can lose is known on day one; what you can make depends only on how far the market runs.
In short: a call option is a contract that gives the buyer the right, but not the obligation, to buy the underlying at a fixed strike price on the expiry date, in exchange for a premium paid to the seller (writer). The buyer profits if the underlying rises enough above the strike to cover the premium; the maximum loss is the premium. The writer receives the premium and takes on the obligation to deliver, with a loss that grows without limit as the underlying rises. On NSE, index calls are European and cash-settled; stock calls are European and physically settled.
The intuition
Suppose you expect a flat to pay ₹1.2 crore in three months but it is on the market today at ₹1 crore. You could buy it now, or you could pay the owner ₹2 lakh for the right to buy it at ₹1 crore any time in the next three months. If prices rise you exercise and keep the difference; if they fall you walk away, out only the ₹2 lakh. That fee is the premium, ₹1 crore is the strike, three months is the expiry, and the arrangement is a call option. The owner who took your ₹2 lakh is the writer: paid up front, obliged to sell at ₹1 crore however high the market goes.
An index call works the same way with one difference: there is nothing to deliver, so NSE settles the difference in cash.
Formula (per unit; multiply by lot size)
Value at expiry = max(S − K, 0), where S is the underlying’s settlement price and K the strike
Buyer’s profit = max(S − K, 0) − premium paid
Break-even = K + premium
Writer’s profit = premium received − max(S − K, 0)
Before expiry the premium has two parts: intrinsic value, max(S − K, 0) using today’s price, and time value, everything above that, which reflects the chance of a bigger move before expiry and decays as expiry approaches.
Worked example (illustrative prices)
Suppose NIFTY is at 24,000 with 30 days to the monthly expiry and the 24,400 call trades at ₹266 (a Black-Scholes value at an illustrative 14% implied volatility). A trader buys one lot of 65 units, paying ₹17,290.
| NIFTY at expiry | Call value | Buyer’s P&L per lot | Writer’s P&L per lot |
|---|---|---|---|
| 23,700 | 0 | −₹17,290 | +₹17,290 |
| 24,400 | 0 | −₹17,290 | +₹17,290 |
| 24,666 | 266 | ₹0 (break-even) | ₹0 |
| 25,000 | 600 | +₹21,710 | −₹21,710 |
| 25,500 | 1,100 | +₹54,210 | −₹54,210 |
The index must rise 666 points, about 2.8%, before the buyer makes anything at expiry. Below the strike the entire premium is lost, whether the index finishes at 24,399 or at 22,000. Above break-even the buyer earns 65 rupees per index point with no ceiling, and the writer loses the same. Had the trader bought the at-the-money 24,000 call instead, the premium would have been about ₹451 (₹29,300 a lot), the break-even 24,451, and the probability of finishing in the money higher: closer strikes cost more and need a smaller move.
Why it matters
- Defined risk for a directional view. A call expresses a bullish view with the loss capped at the premium, unlike a futures long that loses 65 rupees per point without limit.
- Leverage with a time cost. ₹17,290 controls ₹15.6 lakh of index exposure, but the premium decays every day; the view must play out before expiry. See theta.
- It is the building block. Spreads, straddles, condors and covered calls are all combinations of calls and puts; see payoff diagram for how they add up.
- The chain shows the market’s view. Call open interest by strike shows where writers are concentrated and where the market expects resistance; see how to read an option chain.
Common mistakes
- Buying far out-of-the-money calls because they are cheap. They are cheap because the move required is unlikely; most expire worthless.
- Being right on direction and still losing. A slow rise that does not reach break-even by expiry loses money to time decay and falling implied volatility.
- Holding a barely in-the-money call into expiry. Exercise is automatic, and the exercise STT (0.15% of intrinsic value from 1 April 2026) plus the loss of any remaining time value can make selling before close the better exit.
- Forgetting the lot. A premium of ₹266 is ₹17,290 per NIFTY lot, and stock option lots differ by stock.
Indian specifics
NSE index and stock options are European: exercise happens only at expiry, and all in-the-money options are exercised automatically. Index calls (NIFTY, Bank Nifty, FinNifty) settle in cash at the final settlement price, the index’s closing value as NSE computes it (closing-auction based since August 2026; last-30-minute VWAP of continuous trading from 7 December 2026); NIFTY weekly contracts expire on Tuesdays and monthlies on the last Tuesday. Stock calls settle physically since October 2019: an in-the-money long call at expiry results in delivery of the shares, and the account must have the funds. Lot sizes in November 2026 are NIFTY 65, Bank Nifty 30, FinNifty 60 and SENSEX 20 (BSE, Thursday expiry). The buyer pays no STT on entry; the writer pays 0.15% of the premium; see STT.
FAQ
What is a call option in simple terms?
The right, not the obligation, to buy at a fixed price by expiry, bought for a premium; maximum loss is the premium.
How do you calculate the break-even of a call option?
Strike plus premium: a 24,400 call bought at 266 breaks even at 24,666.
What happens if a call option expires out of the money?
It expires worthless; the buyer loses the premium and the writer keeps it.
What is the maximum loss on buying a call option?
The premium paid times the lot size, for example 266 times 65 = 17,290 rupees.
Are Nifty call options cash settled?
Yes, index calls settle in cash; stock calls settle by physical delivery.
Pick the strike with the numbers in front of you
TradePulse’s option chain shows LTP, IV, open interest and the Greeks for every call strike, so the premium, break-even and probability can be compared before buying.
Related terms
- Put option, the right to sell
- Premium, what the buyer pays
- Strike price, the fixed price
- Intrinsic value, the part that survives expiry
- Option writer, the other side
- Long call strategy, the strategy page