How Correlation Affects Quanto Option Valuation and Hedging
Summary
The document explores why correlation between a foreign underlying asset and the exchange rate matters for a quanto option, whose payoff is fixed in the holder’s currency. The questioner compares extreme positive and negative correlation cases in a simple two-outcome tree and concludes that the average payoff appears identical in both cases. This prompts a question about whether the option’s present value can therefore be independent of correlation.
The response locates the effect in replication and hedging rather than in the payoff formula alone. A quanto exposure combines the foreign security with currency conversion, so the hedge ratio depends on how the security and exchange rate move together. The example is an intuition prompt, not a complete pricing derivation: it does not specify a full probability model, discounting assumptions, or a calibrated valuation. It therefore highlights where correlation enters the valuation framework without quantifying its impact or establishing a general numerical result.
Key ideas
- A quanto option fixes its payoff in a currency different from the underlying asset’s currency.
- The option’s payoff formula does not explicitly contain the correlation between the asset and exchange rate.
- Correlation affects the replication and hedging of the quanto exposure.
- The appropriate hedge ratio depends on the joint behavior of the foreign security and exchange rate.
- The simple extreme-case example motivates the issue but does not provide a full pricing model.
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Full text
# Correlation effect in Quanto options # Correlation effect in Quanto options My question will probably be stupid but here it is. I try to understand the effect of the correlation between exchange rate and underlying in a quanto option. And to have a non-precise understanding of this effect, I will consider a simple binomial tree. Suppose I have one underlying valuing 100 \$ & current exchange rate 1€=1\$. The quanto option pays at maturity max(S-100,0) paid in €. I consider now two extreme cases (correlation=+/- 1): - At maturity, S=200\$, 1€=2\$ or S=50\$, 1€=0.5\$ - At maturity, S=50 \$, 1€=2\$ or S=200\$, 1€=0.5 \$ In both cases, the final payoff will be 50€=0.5 * 100€+0.5 * 0€ , whatever the correlation between underlying and exchange rate is. Therefore, the current value of the option would be the NPV in € of 100 € and is independent of the correlation between exchange rate and underlying. Where is the error in this simulation? PS: By the way, we can use multistep binomial trees. The evolution of the underlying does not depend on the exchange rate. ## Answer by river_rat (score 1) https://quant.stackexchange.com/a/64203 The correlation comes into the replication (and thus hedging) of a quanto and not explicitly in the final payoff. In a sense you are trying to hedge a linear payoff with a linear hedging instrument (exchange rate) and a non-linear hedging instrument (foreign security converted into local currency) and the correct hedge ratio depends on the correlation.
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