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OptionsMath

Protective Put Calculator

Protective put profit or loss equals stock price at expiration minus stock cost basis, plus the maximum of put strike minus stock price or zero, minus put premium, times 100 shares times number of contracts.

Expiration scenarios

Solution

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Protective Put Formula

Break-even equals stock cost plus put premium. The downside floor is the put strike minus stock cost minus premium, multiplied by shares.

Worked Examples

Load these protective put examples to compare downside insurance, upside retention, and break-even behavior.

HEDGE FLOOR

How much does a protective put limit a stock drawdown?

An investor owns 2 contracts worth of shares at $80 and buys $75 puts for $2.40. The stock falls to $70 by expiration.

  • Stock P/L = ($70 - $80) x 200 = -$2,000.
  • Put value = ($75 - $70) x 200 = $1,000.
  • Put cost = $2.40 x 200 = $480.
  • Net loss = -$2,000 + $1,000 - $480 = -$1,480.

Result: the hedge loses $1,480.00 instead of the full stock drawdown.

A higher strike would protect more downside, but it usually costs more premium.

UPSIDE KEPT

What happens when the stock rallies?

A trader owns 100 shares at $120 and buys a $110 put for $4. The stock finishes at $136.

  • Stock P/L = ($136 - $120) x 100 = $1,600.
  • The put expires worthless because the stock is above $110.
  • Put cost = $4 x 100 = $400.
  • Net profit = $1,600 - $400 = $1,200.

Result: the position earns $1,200.00 while keeping upside exposure.

The premium reduces profit compared with owning unhedged stock.

AT BREAK-EVEN

Where does the hedge break even?

An investor buys stock at $48 and a $45 put for $1.50. The stock finishes at $49.50.

  • Break-even = $48 + $1.50 = $49.50.
  • Stock gain = $1.50 x 100 = $150.
  • Put expires worthless.
  • Net P/L = $150 - $150 premium = $0.

Result: the protective put lands exactly at break-even.

The put still had value as insurance even though it expired worthless.

How It Works

A protective put combines long stock with a long put option. The stock keeps upside exposure, while the put creates a floor below the strike price. At expiration, the calculator adds the stock gain or loss, adds any put intrinsic value, and subtracts the put premium paid.

Example Problem

You own 100 shares bought at $100 and buy 1 $95 put for $3. The stock finishes at $90. What are the hedge profit or loss, break-even price, and maximum loss?

  1. Identify the inputs: stock cost = $100, put strike = $95, put premium = $3, stock price at expiration = $90, contracts = 1.
  2. Stock P/L = ($90 - $100) x 100 = -$1,000.
  3. Put value = max($95 - $90, 0) x 100 = $500.
  4. Put cost = $3 x 100 = $300.
  5. Net P/L = -$1,000 + $500 - $300 = -$800.
  6. Break-even equals stock cost plus put premium: $100 + $3 = $103.

The put does not prevent every loss. It limits the downside below the strike after accounting for the premium.

Key Concepts

The protective put is often compared with insurance. The premium raises break-even, but the put limits downside if the stock falls below the strike. Upside remains open because the stock is still owned.

Applications

  • Estimating hedge cost for an existing stock position.
  • Comparing different put strikes and premiums.
  • Sizing how many contracts are needed to protect round lots of stock.
  • Understanding the tradeoff between downside protection and higher break-even.

Common Mistakes

  • Forgetting to subtract the put premium from the final payoff.
  • Assuming the put strike is the break-even price.
  • Using this expiration payoff as a live option quote before expiration.
  • Buying fewer contracts than needed to hedge the share position.

Frequently Asked Questions

What is a protective put?

A protective put is a long stock position paired with a long put option. The put gives the investor the right to sell at the strike price, which limits downside below that strike at expiration.

How do I calculate protective put break-even?

Break-even equals the stock purchase price plus the put premium per share. If stock was bought at $100 and the put cost $3, break-even is $103.

What is the maximum loss on a protective put?

Maximum loss is the stock cost plus put premium minus the put strike, multiplied by shares, unless the put strike is high enough to lock in a gain.

Does a protective put cap upside?

No. The stock can still rise without a short call cap. The tradeoff is that the premium paid reduces net profit and raises break-even.

Does this calculator include early exercise or dividends?

No. It models expiration payoff only and does not include dividends, assignment timing, commissions, taxes, or changing option value before expiration.

Reference: Options Industry Council, Protective Put strategy description and expiration payoff definitions.

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