Option Writer

By purchasing an option, you have to pay a premium in order to obtain the right to buy or sell the underlying asset at a particular price. When you write an option, you are taking the opposite position to that trade. The option writer sells the contract and gets the premium, at the same time assuming the obligation if the option is exercised.

Option writing is different from option buying since the maximum loss for the buyer is usually no more than the premium paid, whereas the option writer's potential loss can be large, especially in the case of an uncovered position.

This article explains how the strategy may generate income and how the potential losses can be significantly greater than the premium received.

Key Takeaways

• A person who writes options is the one who sells a call or a put option and receives a premium from the buyer.
• When a call writer agrees that the underlying asset will be sold to him at the strike price if the contract is exercised.
• A writer might have to purchase the underlying asset at the strike price should the option be exercised.
• The effect of time decay benefits the person who writes an option since an option usually loses some of its time value as the expiry date nears.
• Since writing options entails margin requirements, traders may suffer substantial losses, particularly in the case of uncovered positions.

What is Option Writing?

Option writing (selling) in India involves specific margin mechanisms, volatility impacts, and settlement rules mandated by exchanges like NSE and BSE.

SPAN, Exposure Margins, and Volatility Fluctuations

When you write options in India, your broker requires you to maintain adequate margins to cover potential losses. This margin requirement is divided into two main components:

• SPAN Margin (Standard Portfolio Analysis of Risk): Calculated by the exchange using portfolio-based risk models. It evaluates how your position would perform under various simulated market stress scenarios and extreme price movements.
• Exposure Margin: An additional buffer charged by the exchange (over and above SPAN) to cover risks not captured by SPAN, such as sudden market gaps or extreme intraday volatility.

How Does the Process of Writing Options Work?

Option writing begins when a trader decides to sell a call or a put option rather than purchase one. The basic process is:

1. The writer chooses an option contract.
2. The writer enters into the contract and takes the premium.
3. The value of the option varies as the price of the underlying asset, the time until expiry, and other factors change.
4. The writer has the option of closing the position before it expires or of letting the contract continue until the expiry date.
5. If the option finishes without being of any value to the buyer, the writer keeps the premium, provided that trading costs and the relevant rules are taken into account.
6. An option seller can also settle their position before expiry by purchasing back the same option contract. This eliminates the obligation connected with the original short position.

What Does it Mean to Write a Call and to Write a Put?

Option writing can take the form of calls or puts, and the risk profile varies depending on the type.

Factor	Call writing	Put writing
What the writer sells	Call option	Put option
Buyer's right	Right to buy	Right to sell
Writer's obligation	Sell the underlying at the strike price if exercised	Buy the underlying at the strike price if exercised
Writer earns	Premium	Premium
Main risk	Underlying price rises sharply	Underlying price falls sharply
Ideal market view	Neutral to bearish	Neutral to bullish

What a call writer usually expects is for the underlying asset to stay below the strike price or for it not to increase greatly before expiry. A writer generally assumes that the underlying asset will stay above the strike price or at least not decrease greatly.

What Does the Covered and Uncovered Option Writing Involve?

Writing options can generally be divided into covered and uncovered positions.

1. Covered Option Writing

A position is said to be covered when the writer of the option holds the underlying security against it. For instance, a trader who owns shares and writes a call option against those shares has a covered call position.

The asset underneath offers a certain level of protection against the liability resulting from the call.

2. Uncovered Option Writing

A naked position is one in which the writer does not hold a contrary position in the underlying asset. The trader could thus suffer much larger losses if the market moves sharply in the wrong direction.

Although the possible loss is considerable, the maximum gain is still only equal to the premium received.

How Does an Option Writer Make Money?

The main source of return for an option writer is the premium received from the option buyer.

Consider this example:

• Strike price: ₹1,000
• Option premium received: ₹30
• Underlying price at expiry: ₹950

The call option becomes worthless since the price of the underlying asset is lower than the strike price.

Premium received = ₹30

If the option has no value when it expires, the writer retains the premium, before any brokerage fees, taxes, or other applicable charges. The highest profit that the writer can obtain in this simple example is ₹30 per share. When the contract covers 100 shares, the total premium received will be:

₹30 × 100 = ₹3,000

The true profit may vary once transaction costs and other charges are taken into account.

What Does the Decay of Time Have to do With Option Writers?

Time decay is the term used for the decrease in the time value of an option as the expiry date nears. This is an advantage for those who write options.

An option which has more time left available has greater scope of moving into the money. As the expiry date nears, however, this time element decreases.

With an option that is out of the money, the writer can benefit from the decline in time value since the option may then cost less to buy back.

Market risk is not eliminated by time decay. If there is a sudden change in the price of the underlying asset, the value of the option can increase rapidly, which may result in losses for the writer.

How Volatility and MTM Movements Affect Margins

Volatility Impact (IV Spikes): Option prices are heavily driven by Implied Volatility (IV). When market volatility spikes (often due to earnings, geopolitical events, or macroeconomic data), the value of written options increases. Because short options represent a liability, higher IV inflates the SPAN margin requirement significantly. You may experience a margin shortfall even if the underlying asset's price hasn't moved much.

Mark-to-Market (MTM) Movements: MTM is settled daily (and intraday during high volatility). If the market moves against your short position, your MTM loss is debited from your cash balance. If these losses reduce your available cash below the required margin threshold, your broker will issue a margin call, requiring you to bring in additional funds immediately or face square-off.

Physical vs Cash Settlement at Expiry: Key Differences

At expiry, the settlement mechanism in the Indian derivatives market differs fundamentally depending on the underlying contract type:

Stock Options (Physical Settlement)

All single-stock options that expire In-The-Money (ITM) result in physical delivery. If you are a short option writer and your stock option expires ITM, you are legally obligated to either deliver the underlying shares (for short calls) or take delivery and pay for the shares (for short puts). This requires substantial capital or underlying stock holdings; failing to meet physical delivery obligations invites hefty penalties from the clearing corporation.

Index Options (Cash Settlement)

Index options such as NIFTY, BANKNIFTY, and FINNIFTY are cash-settled. If they expire ITM, no underlying shares change hands. Instead, the intrinsic value of the option is debited from or credited to your trading account in cash based on the final settlement price (usually the volume-weighted average price during the last 30 minutes of expiry day).

What are the Advantages of Writing Options?

Option writing can offer several potential benefits:

• For premium income, the writer gets the premium at the time the position is opened.
• The time value decreasing is an advantage for a seller if all the other factors are favorable.
• If the option expires and has no value, the writer might keep the whole of the premium before deducting costs.
• The writer has the opportunity to buy back the option and close the position before the expiry date.
• When a trader anticipates only a small amount of movement or has a particular view on prices, they can use writing calls and puts.

With these advantages, there is a great deal of risk involved, and the premium must not be regarded as guaranteed income.

What Risks are There in Being an Option Writer?

The greatest risk is the underlying asset moving abruptly in a direction opposite to that of the writer. For example, a call writer receives ₹30 as premium.

If the underlying asset rises significantly above the strike price, the option can become much more valuable. The writer may then have to buy it back at a much higher price or meet the obligation.

The margin required is generally the case with option writing since the writer assumes an obligation. The exposure under the mark-to-market method can lead to a rise in margin requirements and losses if there are adverse price movements.

Also, sudden changes in price can cause a short option position to become expensive to close. The highest possible profit is limited since the premium received determines the maximum gross gain in the case of a basic short-option position.

There is a high level of risk when positions are not covered: if an option is written without coverage, it can lead to large losses.

Difference Between an Option Buyer and an Option Writer?

Factor	Call writing	Put writing
What the writer sells	Call option	Put option
Buyer's right	Right to buy	Right to sell
Writer's obligation	Sell the underlying at the strike price if exercised	Buy the underlying at the strike price if exercised
Writer earns	Premium	Premium
Main risk	Underlying price rises sharply	Underlying price falls sharply
Ideal market view	Neutral to bearish	Neutral to bullish

The difference is essentially about rights and obligations. The buyer pays for a right. The writer receives the premium for taking on the corresponding obligation.

How can Option Writers Manage Risk?

Risk management is important because option writing can create losses that are much larger than the initial premium. Some commonly used measures include:

• Set a stop-loss: A predetermined exit level can limit losses when the option moves against the position.
• Monitor margin requirements: Additional funds may be required when the market moves sharply.
• Understand the underlying asset: Price movements in the underlying directly affect the option position.
• Avoid excessive position sizes: A large short-option position can magnify losses.
• Understand expiry behavior: Options can behave differently as they approach expiry, particularly when they are near the strike price.

Conclusion

An option writer sells a call or put option and receives a premium from the buyer. The strategy can benefit from premium income and time decay, particularly when the underlying asset does not move sharply against the position. The trade-off is important. The writer's potential gain is generally limited to the premium received, while losses can be much larger, especially with uncovered positions. Margin requirements and mark-to-market exposure also need to be considered.

Understanding the option contract, strike price, expiry, premium, and underlying asset is essential before entering an option-writing position.