Short Straddle Calculator

Short Straddle at a glance

How a short straddle works

Selling both at the money options collects a large credit, because at the money strikes carry the most time value in the chain. In return you have no protection in either direction. A rally turns the short call into a growing liability, and a decline does the same to the short put. You are betting the stock will move less than the market expects by expiration. Margin requirements are substantial, and brokers reserve naked straddles for their highest approval level.

At expiration the payoff is an inverted V peaking at the strike. If the stock closes exactly at the strike, both options expire worthless and you keep the entire credit. Profit shrinks as the stock moves away, reaching zero at the two breakevens, the strike plus and minus the total credit. Beyond the upper breakeven, losses grow without limit; beyond the lower one, they grow until the stock reaches zero.

Before expiration, the position earns heavy time decay and benefits from falling implied volatility, which is why short straddles are often opened after a volatility spike or ahead of an event that traders expect to deflate volatility. The cost is negative gamma: every move pushes the position's delta against you, and the effect intensifies near expiration. A small move early in the trade may be absorbed by decay, but a fast move late in the cycle can wipe out the credit in a day.

Short Straddle 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 1 100 call (32 days) at $3.73, sell 1 100 put (32 days) at $3.39. That is a net credit of $712. At expiration a maximum profit of $712 and a maximum loss of unlimited, with breakevens at $92.88 and $107.12. The lognormal chance of profit is 58%.

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

When to use a short straddle

• You expect the stock to stay very close to its current price through expiration.
• Implied volatility is high and you expect it to fall, often once an event has passed.
• You have the highest options approval level, ample margin, and a plan for sharp moves.
• You want maximum time decay and accept undefined risk in exchange.

Max profit, max loss and breakeven

Maximum profit

Total premium received for both options, times 100. You keep all of it only if the stock closes exactly at the strike at expiration.

Maximum loss

Unlimited on the upside, where loss equals stock price minus strike minus total credit, times 100. On the downside, loss reaches strike minus total credit, times 100, if the stock goes to zero.

Breakeven

Upper breakeven equals strike plus total credit. Lower breakeven equals strike minus total credit.

Short Straddle Greeks

• Delta: Delta starts near zero but moves against you as the stock moves: negative on a rally and positive on a decline.
• Gamma: Gamma is strongly negative and peaks near the strike close to expiration, so small moves in the final days have outsized effects.
• Theta: Theta is strongly positive. You collect decay from two at the money options, the fastest decaying strikes in the chain.
• Vega: Vega is strongly negative. A volatility rise hurts both legs at once, while a volatility crush helps.

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 both legs start at the money, one of them will almost always finish in the money, so assignment is a question of when, not if, unless you close the trade. Early assignment of the call is most likely on the day before an ex dividend date if the stock has rallied and the dividend exceeds the call's remaining time value. Early assignment of the put is most likely after a sharp decline, once the put is deep in the money with little time value left.

If the call is assigned, you are short 100 shares plus the short put, a combination that behaves like a short call, so the risk profile is similar but now includes borrow costs and any dividend owed. If the put is assigned, you are long 100 shares plus the short call, which is a covered call and behaves like a short put. Pin risk is acute because the stock often finishes near the strike, leaving you unsure which leg was assigned. Close or roll before the final session.

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 straddle

• Set a stop based on the stock reaching a breakeven or the position losing a set multiple of the credit.
• Buy a call above and a put below to convert the trade into an iron butterfly and define the risk.
• Close early once a large share of the credit has decayed, since gamma risk rises as expiration approaches.
• If the stock trends, rebalance delta by rolling the untested leg toward the stock, knowing each adjustment narrows your margin for error.

Short Straddle 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.