Option Buyer vs Option Seller: Understanding the Risk on Each Side

Published 2026-10-26 · Aadarna Stock Broking Pvt. Ltd.

Every option trade has two people: a buyer and a seller. They take on very different kinds of risk. Many new traders look only at how much they might gain. They do not look closely at how much they could lose, or how quickly.

This article explains what each side pays, receives and risks. It also covers margin and time decay, so you can understand the trade-off before you decide anything for yourself. It explains concepts only and does not suggest any strategy.

What is an option, and what is the premium?

An option is a contract linked to an underlying asset, such as a stock or an index. It is traded on exchanges like NSE and BSE. It has a strike price (the agreed price) and an expiry date (the last day the contract is valid).

There are two types:

• Call option: gives the buyer the right, but not the duty, to buy at the strike price.
• Put option: gives the buyer the right, but not the duty, to sell at the strike price.

The premium is the price of the option. The buyer pays it and the seller receives it. Options trade in lots, which are fixed quantities set by the exchange, so you pay the premium per unit multiplied by the lot size.

What does the option buyer risk?

The buyer pays the full premium when the trade is placed. This is the buyer's maximum loss, plus brokerage and other charges.

For example, say a hypothetical call option has a strike price of ₹500 and a premium of ₹10 per unit, and the lot has 100 units. The buyer pays ₹1,000. If the underlying stays below ₹500 at expiry, the option expires worthless and the buyer loses the full ₹1,000. If the underlying ends at ₹530, the option is worth ₹30 per unit, and the buyer gains ₹20 per unit, or ₹2,000, before costs.

"Limited loss" does not mean small or unlikely loss. Buyers often lose the entire premium. For the buyer to profit, the price usually has to move far enough, in the right direction, before expiry.

What does the option seller risk?

The seller, also called the writer, receives the premium. It is the most the seller can ever earn from that trade. In return, the seller takes on the duty to honour the contract if the buyer gains.

Using the same example, the seller receives ₹1,000. If the underlying stays below ₹500, the seller keeps it, less costs. But if the underlying jumps to ₹600, the option is worth ₹100 per unit. The seller loses ₹90 per unit, or ₹9,000, which is nine times the premium received.

• Call seller: there is no upper limit on how high a price can go, so the potential loss is, in theory, unlimited.
• Put seller: the loss can be very large if the underlying falls sharply, up to the strike price minus the premium per unit.

This is the key difference. The buyer's loss is capped at the premium. The seller's gain is capped at the premium, while the loss can be far larger.

Why do option sellers need margin?

Because a seller's loss can be large, the exchange and clearing corporation require sellers to keep margin. Margin is money or collateral kept with the broker as security against possible losses. Buyers usually do not need margin because they pay the full premium upfront.

Points to understand about margin:

• The required margin is calculated by the clearing corporation and can increase suddenly when prices move or volatility rises.
• Profits and losses are settled daily through mark-to-market. If losses reduce your margin, you have to add money quickly.
• If you cannot meet a margin shortfall, the broker may close your positions, possibly at a loss, and penalties may apply.
• Since September 1, 2020, stock brokers can accept securities as margin from clients only by way of pledge in the depository system. Pledged shares remain exposed to market risk, and pledging does not reduce the risk of the option position itself.

You can check the margin needed for a trade on Angel One before placing it.

What is time decay, and who does it affect?

An option's premium has two parts. Intrinsic value is what the option would be worth if exercised right now. Time value is the extra amount people pay for the chance that the price moves favourably before expiry.

Time decay means time value shrinks as expiry gets closer, if other things stay the same. On the expiry date, the remaining time value goes to zero.

• For the buyer, time decay works against you. Each day the price does not move enough, the option tends to lose value.
• For the seller, time decay works in your favour, but only slowly. A sharp price move or a rise in volatility can cause losses far bigger than what time decay adds.

Time decay is only one force acting on the premium. It does not make either side's outcome predictable.

What risks and costs do both sides share?

• Transaction costs: brokerage as per Angel One's prevailing tariff, plus statutory charges and taxes, apply on both buying and selling.
• Liquidity risk: some options trade rarely, so you may not get a fair price when you want to exit.
• Settlement rules: stock options that are in-the-money at expiry may be physically settled. This can mean taking or giving delivery of shares. Check the exchange rules before expiry.
• Leverage: a small price move in the underlying can mean a large percentage change in the option's value.

A SEBI study dated January 25, 2023, using FY 2021-22 data, found that 9 out of 10 individual traders in equity F&O incurred net losses. Loss makers spent an additional 28% of net trading losses as transaction costs.

What should you check before trading options?

1. Read the risk disclosure document and the SEBI material on SEBI's investor website.
2. Work out your maximum possible loss on paper before every trade, for the buyer side and the seller side.
3. Check the lot size, expiry date and settlement type on the NSE or BSE website.
4. Ask how much margin is needed and how much more you could be asked to add if prices move.
5. Add up all charges using Angel One's tariff, so you know your costs before you place the trade.

Frequently asked questions

Is buying options safer than selling options?

No. Neither side is safe. A buyer's loss is limited to the premium paid plus costs, but buyers often lose the whole premium. A seller's gain is limited to the premium, while losses can be much larger.

Why does the seller get the premium upfront if they could lose more?

The premium is payment for taking on the obligation and the risk of the contract. The seller is effectively being paid to accept possible large losses. That is why sellers must keep margin with the broker.

Can I lose more than my margin as an option seller?

Yes. Margin is a security deposit, not a cap on losses. If losses exceed your margin, you have to pay the difference, and the broker may close your positions if you cannot add funds in time.

Does time decay mean option sellers always make money?

No. Time decay slowly reduces an option's time value, but a sharp price move or a rise in volatility can quickly create losses much bigger than the premium. Time decay does not remove risk for the seller.

Sources

• SEBI – study on individual traders in equity F&O and margin pledge rules
• SEBI – investor education website
• NSE – equity derivatives contract and settlement information
• Angel One – tariff and margin information

Risk disclosures on derivatives

• 9 out of 10 individual traders in equity Futures and Options Segment, incurred net losses.
• On an average, loss makers registered net trading loss close to ₹50,000.
• Over and above the net trading losses incurred, loss makers expended an additional 28% of net trading losses as transaction costs.
• Those making net trading profits, incurred between 15% to 50% of such profits as transaction cost.

Source: SEBI study dated January 25, 2023 on "Analysis of Profit and Loss of Individual Traders dealing in equity Futures and Options (F&O) Segment", wherein Aggregate Level findings are based on annual Profit/Loss incurred by individual traders in equity F&O during FY 2021-22.