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Optionsintermediate

Short Straddle

A short straddle is created by writing a call and writing a put at the same strike KK and same expiry TT. The writer collects both premia upfront and profits if the underlying stays close to KK. Maximum profit equals C+PC + P, achieved when ST=KS_T = K. Maximum loss is unlimited to the upside via the short call and bounded but large to the downside via the short put. The strategy is a short-volatility play, often called a short-vega income trade.

Why it matters

A short straddle is a bet on stillness. The writer collects two premia and hopes the underlying drifts within a narrow band around KK through expiry. Time decay (theta) works steadily in the writer's favour, since both legs lose value if the underlying stands still. The downside is brutal. A single surprise move on either side wipes out months of accumulated premium. Many funds learnt this lesson during the 2018 Volmageddon episode, when a sharp VIX spike inflicted catastrophic losses on short-vol strategies.

Formulas

Profit at expiry
Profit=(C+P)−∣ST−K∣\text{Profit} = (C + P) - |S_T - K|
Maximum at ST=KS_T = K, equal to the combined premium. Falls one-for-one as ∣ST−K∣|S_T - K| grows.
Break-evens
ST∗=K±(C+P)S_T^* = K \pm (C + P)
Same break-evens as the long straddle, viewed from the opposite side.

Worked examples

Scenario

Sell a straddle on the S&P/ASX 200 at K=7000K = 7000 index points, collecting call C=C = 40$ and put P=P = 35$ in dollar terms per index unit. At expiry the index closes at 7000.

Solution

Both legs expire worthless. Profit =40+35−0== 40 + 35 - 0 = 75$ per index unit, the maximum possible. The writer keeps the entire combined premium because realised volatility was zero relative to the strike.

Scenario

Same straddle, but the index closes at ST=6800S_T = 6800 after a sharp risk-off move.

Solution

Call payoff =−max⁡(6800−7000,0)== -\max(6800 - 7000, 0) = 0$. Put payoff =−max⁡(7000−6800,0)=−= -\max(7000 - 6800, 0) = -200$. Total payoff =−= -200$. Profit =75−200=−= 75 - 200 = -125$ per index unit. One adverse move dwarfs the combined premium, illustrating the negative skew of short straddles. The same loss size could occur on the upside, where the short call has no cap.

Common mistakes

  • ✗Short straddles have limited risk. The short call leg has unlimited loss potential as ST→∞S_T \to \infty. Many retail platforms restrict naked short straddles to higher option approval tiers because of this.
  • ✗Selling premium is a free lunch. Short straddles concentrate losses into rare but large events. Premia look like steady income most of the time, but a single tail move can erase years of returns, as the LJM Preserved Capital Fund discovered in February 2018.
  • ✗Short straddles always benefit from time decay. Theta and vega act together. A spike in implied volatility can hurt the position even with no underlying move and no time passing, by lifting the mark-to-market value of both legs.

Revision bullets

  • •Sell call ++ put, same KK and same TT
  • •Max gain =C+P= C + P at ST=KS_T = K
  • •Max loss is unlimited above KK
  • •Short vega, profits from low realised volatility
  • •Earns theta day by day if spot stays put

Quick check

A short straddle reaches maximum profit when:

Sell straddle at K=K = 100,call, call C = $4,put, put P = $3$. The stock closes at ST=S_T = 115$. Profit per share is:

Connected topics

Short CallShort PutLong Straddle

In learning paths

Options Path

Sources

  1. Hull (2022), §12.3
    Hull, John C. Options, Futures, and Other Derivatives. 11th ed. Pearson, 2022. ISBN 978-0-13-693997-9.
    Develops short-straddle payoff diagrams and connects them to a view of low realised volatility around the strike.
  2. McMillan (2012), Ch. 16
    McMillan, Lawrence G. Options as a Strategic Investment. 5th ed. Prentice Hall Press, 2012. ISBN 978-0-7352-0466-2.
    Practitioner treatment of short straddles including risk management techniques, defensive adjustments, and historical pitfalls.
  3. OIC Short Straddle Strategy
    Options Industry Council. Strategy Guide: Short Straddle. Options Education, accessed 2026.
    Industry guide with payoff diagram, break-even formula, and explicit unlimited-loss warning for naked short straddles.
  4. SEC Staff Report on February 2018 Volatility Event
    US Securities and Exchange Commission, Office of the Investor Advocate. Risks of Short Volatility Strategies. SEC, 2018.
    Regulator alert documenting the catastrophic losses experienced by short-volatility strategies, including short straddles, during the February 2018 VIX spike.
How to cite this page
Dr. Phil's Quant Lab. (2026). Short Straddle. Derivatives Atlas. https://phucnguyenvan.com/concept/short-straddle
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