Key takeaways
– A put option is a contract that gives the buyer the right, but not the obligation, to sell a specified amount of an underlying asset at a fixed price (the strike) on or before a specified date (expiration).
– Buyers of puts profit when the underlying price falls below the strike (minus the premium paid). Sellers (writers) of puts collect the premium but face the obligation to buy the asset if assigned.
– Puts are used for hedging (protective puts) and speculation on downside moves. Time decay and implied volatility are major drivers of option prices.
1 — Basic terms and mechanics
– Underlying: the asset the option is based on (stock, ETF, index, commodity, currency).
– Strike (exercise price): the price at which the put holder can sell the underlying.
– Expiration: the date the option contract expires.
– Premium: the price paid to buy the option.
– Exercise: using the right to sell the underlying at the strike.
– In the money (ITM), at the money (ATM), out of the money (OTM):
• Put is ITM when strike > underlying price.
• ATM when strike ≈ underlying price.
• OTM when strike < underlying price.
– Intrinsic value = max(strike − underlying price, 0). Extrinsic (time) value = premium − intrinsic value.
– American vs European: American options can be exercised anytime before expiration; European only at expiration.
2 — How a put option works (simple example)
Example (numbers):
– Buy 1 put contract on ABC (each contract = 100 shares).
– Strike = $10, premium = $1.00 per share ($100 per contract).
– Current stock price = $12.
If at expiration the stock is $8:
– Option intrinsic value = $10 − $8 = $2 per share = $200.
– Buyer profit = intrinsic − premium = $200 − $100 = $100.
Breakeven stock price at expiration = strike − premium = $10 − $1 = $9. If the stock finishes above $9, buyer loses some or all premium.
3 — Payoff formulas (per share)
– Put buyer profit at expiration = max(K − S_T, 0) − premium
– Put seller profit at expiration = premium − max(K − S_T, 0)
Where K = strike, S_T = underlying price at expiration.
4 — Uses of puts
– Hedging (protective put or “married put”): buy a put while owning the underlying to limit downside to (strike − premium) per share.
– Speculation: buying puts to profit from an expected decline without shorting the stock.
– Income generation via selling (writing) puts:
• Cash-secured put: seller holds cash equal to the purchase obligation and collects premium.
• Unsecured put writing is riskier and may require margin.
5 — Puts vs. calls — difference in one line
– Put: right to sell (bearish view).
– Call: right to buy (bullish view).
6 — Is a put bullish or bearish?
– Buying a put is a bearish trade (you profit if the underlying declines).
– Writing a put reflects a neutral to mildly bullish view (you expect the price to stay above the strike).
7 — Downsides and risks
For put buyers:
– Maximum loss = premium paid (option can expire worthless).
– Time decay (theta) erodes extrinsic value as expiration nears.
– Premiums can be high when implied volatility is elevated.
For put sellers (writers):
– Potentially large loss if the underlying plunges. Maximum loss for a short put (per share) is strike − 0 − premium (if underlying goes to zero); per contract that’s 100×(strike − premium).
– Assignment risk (especially on American options) and margin requirements.
8 — Greeks and price drivers (brief)
– Delta: sensitivity to underlying price (put delta is negative).
– Theta: time decay (hurts buyers).
– Vega: sensitivity to volatility (higher vol raises premiums).
– Rho: sensitivity to interest rates (minor for most equity options).
9 — Practical steps — how to buy a put (step-by-step)
1. Get options approval from your broker and understand required trading level.
2. Identify the underlying asset and timeframe for your view (short-term vs longer-term).
3. Choose a strike price:
• In-the-money: more intrinsic value, higher premium, less leverage.
• Out-of-the-money: cheaper, higher leverage, needs a bigger move.
4. Choose expiration date: longer expirations cost more but have slower time decay.
5. Calculate breakeven = strike − premium (per share).
6. Size the position to match risk tolerance (remember max loss = premium).
7. Place the order (market or limit). Confirm contract multiplier (usually 100 shares per stock option).
8. Monitor Greeks and underlying price; consider closing or rolling the position before expiration if needed.
9. If in-the-money at/near expiration, decide to sell the option, exercise (if you want to deliver shares), or let assignment happen (if you’re short the put).
10 — Practical steps — how to sell (write) a put safely
1. Ensure you have sufficient margin or cash (cash-secured = recommend for covered risk).
2. Select strike and expiration consistent with the price you’d be willing to buy the underlying.
3. Collect premium but understand obligation: you may be assigned and must buy at strike.
4. Monitor for assignment risk, especially if option is ITM near ex-dividend dates or expiration.
5. Manage position by closing (buying back) or rolling (sell a later-dated put) if needed.
11 — Hedging example: protective put
– Suppose you own 100 shares of XYZ at $50 and buy a 3-month $45 put for $2 (per share).
– Downside is limited: if stock falls below $45, put offsets losses below $45. Net cost of protection = $2 per share.
– If stock rises, you still profit on the stock minus the premium paid.
12 — Tax and settlement notes (brief)
– Option exercise and assignment have tax and settlement consequences. Tax treatment depends on jurisdiction and holding periods. Consult a tax advisor.
13 — Common strategies involving puts
– Protective put (hedge).
– Long put (speculation).
– Married put (owner hedging their shares).
– Cash-secured put (generate income or buy at desired price).
– Spreads (bear put spread, calendar spreads) to limit cost and risk.
14 — Quick examples and calculations
Example 1 — Long put:
– Strike 30, premium 2 → breakeven = 28. If underlying = 20 at expiration, payoff = (30 − 20) − 2 = $8 per share profit.
Example 2 — Short cash‑secured put:
– Strike 25, premium 1.50, you’re assigned when price = 20.
– Effective purchase price = strike − premium = 23.50. If you were willing to buy at ~23.50, this may be acceptable.
15 — Final notes and best practices
– Understand all option mechanics and margin rules before trading.
– For beginners, paper trade or use small sizes; consider protective puts to hedge existing long positions.
– Monitor implied volatility: rising IV increases put premiums (can benefit sellers), falling IV hurts sellers and benefits buyers.
– Always calculate breakeven and worst-case scenarios before entering a trade.
Further reading / source
– Investopedia: Put Option —
Editor’s note: The following topics are reserved for upcoming updates and will be expanded with detailed examples and datasets.