Short Strangle Calculator

Short Strangle at a glance

How a short strangle works

Selling a strangle means you take in two premiums at once. The put strike sits below the current price and the call strike sits above it, so the stock has room to drift in either direction before either option gains intrinsic value. Your credit is the most you can earn. In exchange, you accept the obligation to buy 100 shares at the put strike or sell 100 shares at the call strike if assigned. Neither leg is hedged by a long option, so brokers treat the position as naked and require substantial margin.

At expiration the payoff looks like a flat plateau with two cliffs. Anywhere between the put strike and the call strike, both options expire worthless and you keep the full credit. Below the put strike the position loses one dollar per share for each dollar the stock falls, offset by the credit, all the way down to zero. Above the call strike the loss grows dollar for dollar with no ceiling. The wider you set the strikes, the wider the plateau and the smaller the credit.

Before expiration the short strangle is a bet on time decay and falling implied volatility. Each day the stock stays inside the range erodes the value of both options, and a drop in implied volatility, such as the decline that typically follows an earnings release, can shrink them quickly. The danger is gamma. As expiration approaches, a move toward either strike changes delta fast, so losses can build sharply in the final weeks even if the stock travels only a moderate distance.

Short Strangle example with real numbers

With the stock at $100, implied volatility at 30%, a 4.1% risk free rate and no dividend, you would sell 1 95 put (32 days) at $1.43, sell 1 105 call (32 days) at $1.78. That is a net credit of $321. At expiration a maximum profit of $321 and a maximum loss of unlimited, with breakevens at $91.79 and $108.21. The lognormal chance of profit is 64%.

These are theoretical American option prices from the Bjerksund and Stensland model, not live quotes. Load any ticker in the short strangle calculator above to run the same math on real market prices.

When to use a short strangle

• You expect the stock to trade in a range through expiration and want to be paid for that view without picking a direction.
• Implied volatility is high relative to its own history, so the premiums you sell are rich.
• You have the margin capacity and the discipline to manage a position with unlimited risk on one side.
• You want a wider profit zone than a short straddle offers and accept a smaller credit for it.

Max profit, max loss and breakeven

Maximum profit

Net credit received × 100. You keep all of it only if the stock finishes between the put strike and the call strike at expiration, so both options expire worthless.

Maximum loss

Unlimited on the upside, where the loss is stock price minus call strike minus net credit, times 100, with no cap. On the downside the loss is put strike minus net credit, times 100, if the stock falls to zero, which is large but finite.

Breakeven

Lower breakeven = put strike minus net credit. Upper breakeven = call strike plus net credit. The position is profitable at expiration anywhere between these two prices.

Short Strangle Greeks

• Delta: Close to zero at entry because the short put's positive delta roughly offsets the short call's negative delta. It turns negative as the stock rises toward the call and positive as it falls toward the put, so the position always leans against the move.
• Gamma: Negative, and it grows as expiration nears or as the stock approaches either short strike. Negative gamma is why a quiet position can turn into a fast loss.
• Theta: Positive. Both short options lose time value every day, which is the main source of profit.
• Vega: Negative. A rise in implied volatility increases the value of both short options and creates an open loss even if the stock has not moved.

See the live numbers for your position in the Greeks tab of the calculator, or explore a single option in the options Greeks calculator.

Early exercise and assignment risk

Because US equity options are American style, either short leg can be assigned before expiration once it moves in the money. The call is the bigger concern around dividends: if the stock rallies above the call strike and the call's remaining time value is smaller than an upcoming dividend, call holders have a reason to exercise the day before the ex dividend date. You would then be short 100 shares, owe the dividend, and still hold the short put. Short stock plus a short put is a covered put, which keeps unlimited risk if the stock keeps rising.

On the downside, a short put that goes deep in the money can be assigned early once its time value shrinks to almost nothing, which tends to happen sooner when interest rates are high. Assignment leaves you long 100 shares bought at the put strike, and together with the still open short call you now hold a covered call. That is not a disaster, but it ties up far more buying power than the strangle did. Rolling a tested leg out in time restores extrinsic value, and closing both legs before expiration avoids surprise assignment near either strike.

The calculator's Early exercise risk tab flags short legs that are likely to be assigned. For a single option, use the early exercise calculator or read how early exercise and assignment work.

Pros and cons

How to manage a short strangle

• Set a profit target and buy the strangle back once most of the credit has been earned rather than holding for the last few cents.
• When one side is tested, roll the untested side closer to collect more credit, or roll the whole strangle out in time for a net credit.
• Define a maximum loss in advance, for example a multiple of the credit received, and exit when it is reached.
• Close or roll before expiration week if the stock is near either strike, since gamma and assignment risk peak at the end.

Short Strangle FAQ

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Educational tool, not financial advice. Calculations are theoretical and depend on your inputs; real fills, fees, early assignment and dividends can change results. Options involve risk and are not suitable for every investor.