Chapter 26: Exotic Options
6 min readWhat Makes an Option "Exotic"?
Exotic options have more complex payoff structures than standard (vanilla) calls and puts. They are mostly traded OTC and are tailored to specific hedging or investment needs.
Packages
A package is a portfolio of standard vanilla options. Examples: bull spreads, butterfly spreads, straddles, strangles. Some packages have standard names in certain markets (e.g., "risk reversal" = long OTM call + short OTM put).
Perpetual American Options
Options with no expiration date (T→∞T \to \infty). Closed-form solutions exist for perpetual American calls and puts. For a perpetual American call on a non-dividend stock:
C(S)=(SH)γ⋅(H−K)C(S) = \left(\frac{S}{H}\right)^{\gamma} \cdot (H - K)
where HH is the critical exercise boundary and γ\gamma depends on rr, σ\sigma.
Nonstandard American Options
Variations on the American exercise feature:
- Bermudan options: Exercisable on specific dates (between European and American)
- Canary options: Exercisable on certain dates before a period of "lock-out" after which they become Bermudan
- Early exercise restricted to specific windows
Gap Options
A gap call pays ST−GS_T - G when ST>KS_T > K (gap between payoff trigger KK and payoff calculation ST−GS_T - G). A gap put pays G−STG - S_T when ST<KS_T < K.
The price is:
c=S0N(d1)−Ge−rTN(d2)c = S_0 N(d_1) - G e^{-rT} N(d_2)
where d1d_1 and d2d_2 use KK as the strike for the exercise criterion, but GG for the payoff.
Forward Start Options
Options that are paid for now but start at a future date. At the start date, the strike is typically set at-the-money. Used in employee stock option plans with staggered vesting. Valuation: the option is worth the same as an at-the-money option starting immediately, discounted for the forward start period.
Cliquet Options
A cliquet (ratchet) option is a series of forward start options where the strike for each period is reset to the asset price at the start of that period. The payoff accumulates over sub-periods with a cap and floor applied to each period's return.
Compound Options
An option on an option — gives the right to buy/sell another option. Four types:
- Call on a call
- Call on a put
- Put on a call
- Put on a put
Uses: bidding on projects (option to acquire a follow-on option), hedging future option positions.
Chooser Options
The holder can decide at a future date whether the option is a call or a put with the same strike and remaining maturity. This has the same value as:
Chooser=c(S0,K,T)+p(S0,Ke−r(T−tc),tc)\text{Chooser} = c(S_0, K, T) + p(S_0, K e^{-r(T-t_c)}, t_c)
where tct_c is the choice date (via put–call parity).
Barrier Options
The payoff depends on whether the underlying reaches a certain barrier level during the option's life.
| Type | Description |
|---|---|
| Knock-out | Option ceases to exist if barrier is hit |
| Knock-in | Option comes into existence only if barrier is hit |
| Down-and-out call | Regular call unless SS falls below HH |
| Up-and-out put | Regular put unless SS rises above HH |
| Down-and-in | Becomes a vanilla option if SS falls below HH |
Barrier options are cheaper than vanilla options (because of the knock-out risk) and provide continuous monitoring (or discrete monitoring at fixing times).
Key relationship: Knock-in+Knock-out=Vanilla\text{Knock-in} + \text{Knock-out} = \text{Vanilla}
Binary (Digital) Options
Pay a fixed amount if a condition is met:
- Cash-or-nothing call: Pays QQ if ST>KS_T > K
- Asset-or-nothing call: Pays STS_T if ST>KS_T > K
Price for cash-or-nothing call: Q⋅e−rT⋅N(d2)Q \cdot e^{-rT} \cdot N(d_2)
Lookback Options
Payoff depends on the minimum or maximum asset price during the option's life:
- Floating lookback call: Payoff = ST−SminS_T - S_{\min}
- Floating lookback put: Payoff = Smax−STS_{\max} - S_T
- Fixed lookback call: Payoff = max(Smax−K,0)\max(S_{\max} - K, 0)
Lookback options are expensive because they guarantee a holder-optimal exercise price.
Asian Options
Payoff depends on the average price over a period, not the spot price at a single point:
- Average price call: max(Savg−K,0)\max(S_{\text{avg}} - K, 0)
- Average strike call: max(ST−Savg,0)\max(S_T - S_{\text{avg}}, 0)
Asian options are cheaper than vanilla because averaging reduces volatility. They reduce manipulation risk at expiration (harder to manipulate an average than a spot price).
Pricing is complex because the average of lognormal variables is not lognormal. A common approximation treats the average as lognormal with adjusted mean and variance (Turnbull–Wakeman approximation).
Exchange Options
An option to exchange one asset for another. Margrabe's formula (1978):
c=S0(1)N(d1)−S0(2)N(d2)c = S_0^{(1)} N(d_1) - S_0^{(2)} N(d_2)
d1=ln(S0(1)/S0(2))+σ2T/2σT,d2=d1−σTd_1 = \frac{\ln(S_0^{(1)} / S_0^{(2)}) + \sigma^2 T/2}{\sigma \sqrt{T}}, \quad d_2 = d_1 - \sigma \sqrt{T}
where σ2=σ12+σ22−2ρσ1σ2\sigma^2 = \sigma_1^2 + \sigma_2^2 - 2\rho\sigma_1\sigma_2.
Volatility and Variance Swaps
- Variance swap: Pays realized variance minus the strike variance
- Volatility swap: Pays realized volatility minus the strike volatility
Variance swaps can be statically replicated using a portfolio of European options — no dynamic hedging needed. The fair strike for a variance swap is:
Kvar=2T[∫0F0P(K)K2dK+∫F0∞C(K)K2dK]K_{\text{var}} = \frac{2}{T}\left[\int_0^{F_0} \frac{P(K)}{K^2} dK + \int_{F_0}^{\infty} \frac{C(K)}{K^2} dK\right]
where P(K)P(K) and C(K)C(K) are OTM put and call prices, and F0F_0 is the forward price.