The Option Buyer vs. The Option Seller

The buyer pays a premium to own the option. That is a long position. A seller who opens a position by selling is going short, and is called the writer. The writer receives the premium and accepts the obligation. On a call, the buyer has the right to buy at the strike, and the writer must sell if the buyer exercises. On a put, the buyer has the right to sell, and the writer must buy. Index options settle the difference in cash, so no index changes hands.

₹100 is the price per unit, so our lot costs ₹100 × 65 = ₹6,500. It is one payment, made once, at entry: it leaves the buyer’s account and is credited to the writer. Brokers and the clearing corporation handle it, so the two traders never pay each other directly. The writer must also keep margin, which is security held against the obligation. A premium credit is not necessarily money you can withdraw, and receiving ₹6,500 is not earning ₹6,500.

Long and short describe your holding, not whether the market must rise or fall. NSE labels calls CE (Call European) and puts PE (Put European). European describes exercise timing: these options are exercised at expiry, but can still be traded earlier. A bought call generally benefits from a rise in the underlying; a bought put generally benefits from a fall. Writing reverses that directional exposure, other pricing inputs unchanged.

A call writer faces increasing expiry losses if the index rises far above the strike. A put writer faces increasing losses as it falls far below the strike. Both receive premium, but their risks are different. Blue identifies Call and beige identifies Put throughout this series. Either contract can produce a profit or a loss.

At expiry, a call’s exercise value per unit is the amount by which the final settlement level exceeds the strike, or zero if it does not. At 25,050, it is worth 50 points per unit: ₹3,250 for 65 units. The buyer paid ₹6,500, so loses ₹3,250. The writer received ₹6,500 and owes ₹3,250 of exercise value, leaving a ₹3,250 gain before costs. Having exercise value does not mean the buyer made a profit.

At or below 25,000, this call expires worthless: its exercise value is zero. The buyer loses the full ₹6,500 premium, while the writer retains ₹6,500 before costs. This is why a buyer can lose the whole amount paid even without borrowing money.

Both sides break even at 25,100 before costs: strike 25,000 plus premium 100. At 25,300, exercise value is ₹19,500. The buyer gains ₹13,000 and the writer loses ₹13,000. Read the chart at one expiry level: solid is the buyer’s result; dashed is the writer’s. Both include premium. Zero means neither profit nor loss before costs.

Keep the strike, assumed premium and quantity, but change to a put. Its expiry value is the amount by which strike exceeds the final settlement level, or zero. At 24,950 it is worth ₹3,250, so the buyer still loses ₹3,250 after premium. At 24,900 both sides break even before costs. At 24,700 the buyer gains ₹13,000 and the writer loses ₹13,000.

At or above 25,000, this put expires worthless. The buyer loses the ₹6,500 premium and the writer retains ₹6,500 before costs. A fall below strike gives the put exercise value, but the buyer still needs to recover the premium before making a profit.

The Sell button has two meanings. If you own a lot, an executed sale of the identical contract and quantity closes your long position. If you own nothing, selling a lot opens a short position. Selling more than you own makes the extra part short. Check the position you end up with, not just the button you pressed.

A writer closes by buying back the same underlying, expiry, strike, type and quantity. Placing an order is not the same as getting a fill. Buying a put does not close a short call: it creates another position. Your closing counterparty need not be the trader from the original entry.

Before expiry, calculate using executed premiums. Buying for ₹100 and selling at ₹70 loses ₹1,950. Writing at ₹100 and buying back at ₹70 gains ₹1,950. At a ₹160 closing premium, the buyer gains ₹3,900 and the writer loses ₹3,900. An early profitable exit does not require the index to cross the expiry breakeven.

Premium buys the option; it is not a refundable deposit. Margin is security held against the writer’s obligations, not a loss ceiling. Requirements depend on the contract, market conditions, other positions and applicable rules. Brokers may require more than exchange minimums. Approved assets pledged as collateral can contribute towards margin, but only part of their value may count. That reduction is called a haircut. Collateral is not automatically spendable cash for settlement payments.

Consider a separate funding illustration: assume margin for our short call is ₹1,80,000. This is invented for teaching, not today’s broker or exchange quote. At a NIFTY settlement level of 28,000, the call has ₹1,95,000 of exercise value. Less the ₹6,500 premium received, the writer’s loss before costs is ₹1,88,500. That exceeds the assumed margin. Margin was security, not a loss cap.

Neither side has a universal win rate. Strike, premium, time remaining, market path, hedges, costs and exits all matter. A profitable expiry does not reveal how much adverse movement came first, whether funds ran out or whether a desired exit was available.

Imagine ten separate copies of our call with the same assumed entry terms. Nine expire worthless, each earning the writer ₹6,500. One expires at 26,100 and loses the writer ₹65,000. Nine gains total ₹58,500, leaving a ₹6,500 overall loss before costs. We chose these outcomes to show arithmetic. They are not historical data, forecast probabilities or a typical win rate.

NIFTY index options settle in cash using the official final settlement reference. In-the-money means the option has positive exercise value: a call above strike or a put below strike. An open in-the-money long option is automatically exercised at expiry; the corresponding short position is assigned its settlement obligation. Exercise puts the buyer’s right into effect. Assignment makes the writer fulfil the corresponding obligation through clearing. You do not receive a basket of NIFTY shares. Cash received on exercise is not profit by itself: entry premium and costs still count.

NSE individual-stock options are physically settled. An open in-the-money call buyer receives shares and pays the strike-based delivery amount; the call writer delivers shares and receives payment. A put buyer delivers shares and receives payment; the put writer receives shares and pays. These are electronic demat holdings, not paper certificates. Delivery margins and deadlines can apply before the final exchange of shares and cash.