Writing an option means creating and selling an options contract. As the option writer (seller) you collect a premium immediately in exchange for taking on the obligation to either sell (for a written call) or buy (for a written put) the underlying shares at a pre‑specified price (the strike) if the option buyer chooses to exercise before or at expiration.
Key points at a glance
– You receive a premium up front.
– You take on an obligation: to deliver shares for a call, or to buy shares for a put, at the strike price.
– The premium depends on the underlying price, strike, time to expiration, volatility and other market variables.
– Time decay (theta) works in the writer’s favor: options lose value as expiration approaches, all else equal.
– Risk varies by how the option is written: covered vs. naked writing have very different risk profiles.
How writing an option works (plain language)
– Selling a call: You sell someone the right to buy 100 shares per contract at the strike price. If the option is exercised you must deliver those shares at that strike. If you don’t already own the shares, you are “naked” and risk potentially unlimited losses if the stock rallies sharply. If you already own the shares, your position is a “covered call.”
– Selling a put: You sell someone the right to sell you 100 shares per contract at the strike price. If exercised you must buy the shares at the strike. If you set aside cash to buy those shares if assigned, the put is “cash‑secured.” A naked put exposes you to large downside risk (limited to the strike down to zero).
Why traders write options (benefits)
– Immediate income: You collect the premium on sale.
– Potential to keep entire premium: If the option expires worthless (out‑of‑the‑money), you keep the premium and the obligation ends.
– Time decay advantage: With each day, option extrinsic value typically declines, which benefits the seller.
– Flexibility to close: You can buy back the option to remove the obligation before expiration.
– Use in defined strategies: Writing can be combined with stock positions (covered calls), cash allocation (cash‑secured puts), or other options (spreads) to implement income or entry strategies.
Risks to be aware of
– Naked call risk: Theoretically unlimited loss if the underlying moves far above the strike.
– Put risk: Losses can be large (strike price minus zero, per share), reduced only by the premium received.
– Assignment risk: Short option positions can be assigned at any time for American‑style options, potentially before your plan anticipated.
– Margin requirements and forced liquidation: Naked positions often require margin; sudden moves can trigger margin calls.
– Opportunity cost: With covered calls, large upside in the stock is foregone if shares are called away.
Practical examples (numbers you can follow)
1) Covered call example
– You own 100 shares of XYZ bought at $100.
– You write 1 XYZ 110 call for a $3.00 premium ($300 total).
– If stock is above $110 at assignment: you sell shares for $110. Net per‑share outcome = (110 − 100) + 3 = $13 gain.
– If stock stays below $110 and option expires worthless: you keep the $3 premium and still own the stock (unrealized stock gain/loss continues to apply).
– Break‑even on your stock position considering the premium = $100 − $3 = $97.
2) Cash‑secured put example
– You write 1 ABC 50 put for $2.00 ($200 premium) and set aside $5,000 cash to cover assignment.
– If ABC is below $50 at expiration and you are assigned, your effective purchase price = 50 − 2 = $48 per share.
– Maximum loss if ABC goes to zero = (50 − 0) − 2 = $48 per share (less the premium).
3) Naked call example (risk illustration)
– You write 1 LMN 40 call for $1 premium and do not own the underlying.
– If LMN spikes to $200, you must purchase stock at the market to deliver at $40 or buy back the call at a huge price—losses can be very large and technically unlimited as price rises.
How option premiums are determined (main drivers)
– Underlying price relative to strike (moneyness).
– Time to expiration: longer time generally = more premium.
– Implied volatility: higher volatility → higher premium.
– Interest rates and dividends (minor effects).
– Supply/demand and liquidity in the options market.
Practical, step‑by‑step guide to writing an option
1. Get approval and understand margin/requirements
• Ensure your brokerage account is approved for option writing strategies (often requires a higher trading level). Review margin rules and required collateral for naked vs. covered positions.
2. Choose the underlying and position type
• Decide whether you will write covered calls, cash‑secured puts, or sell naked options (the latter generally for experienced traders only).
3. Select strike and expiration
• Pick a strike and expiration consistent with your outlook, risk tolerance and desired premium. Shorter expirations have faster time decay but lower absolute premiums; further out options pay more but take longer to decay.
4. Calculate outcomes and break‑evens
• Compute your break‑even and best/worst‑case outcomes (see examples above). For covered calls, break‑even = cost basis − premium. For cash‑secured puts, break‑even = strike − premium.
5. Place the order (and specify order type)
• Enter a sell‑to‑open order, choose limit price (recommended to control premium received) and set appropriate size. Confirm margin requirements and capital reserved.
6. Monitor the trade
• Track underlying price, implied volatility and time remaining. Be aware of dividend dates and earnings that can spike moves or lead to early assignment.
7. Manage risk and exit strategy
• Decide in advance: will you buy to close if the option reaches a loss threshold, roll the option to a later date/strike, or allow assignment? For covered calls you may be willing to be called away; for cash‑secured puts you should be ready to accept assignment and buy the stock.
8. If assigned, follow through
• For a short call assignment you must deliver shares (sell existing shares or buy in the market). For a short put assignment you must buy shares at the strike; ensure you have funds or margin available.
Risk management techniques
– Favor covered calls or cash‑secured puts over naked writing if you want limited and defined risk.
– Limit position sizes to a small percent of total portfolio.
– Use vertical spreads (sell one option and buy another) to cap risk for a net credit while still earning premium.
– Consider buying a small long call to limit upside risk on a sold call (creating a covered call converted into a collar or buying a protective call on a naked short call).
– Roll positions before large events (earnings, dividends) if you want to avoid assignment risk.
– Set alerts for large price moves and monitor margin.
Tax and record‑keeping considerations
– Premiums received are typically treated as short‑term capital for the seller unless carrier positions change and specific rules apply. Assignment and closing trades change tax basis of the underlying. Keep detailed records and consult a tax advisor for your country’s tax rules.
Sample checklist before writing an option
– Account approval and margin reviewed.
– Underlying security and strategy chosen.
– Strike and expiry set with clearly calculated break‑even and scenarios.
– Risk limits and maximum acceptable loss determined.
– Exit/roll/assignment rules planned.
– Size limited appropriately within portfolio.
When writing options makes sense
– You want to generate income on a stock you already own (covered calls).
– You want to try to buy a stock you like at a lower effective price (sell cash‑secured puts).
– You are comfortable with margin requirements and assignment risk, and you understand volatility and timing.
When to be careful or avoid writing options
– You cannot meet margin calls or the capital to accept assignment.
– You lack experience managing early assignment risk or rolling positions.
– Your view is that the underlying could have a large directional move against your sold option (especially for naked calls).
Further reading and source
This article is based on basic option principles and practical examples. For a formal overview of writing options and examples, see Investopedia’s “Writing an Option”
Editor’s note: The following topics are reserved for upcoming updates and will be expanded with detailed examples and datasets.