e price at time t the contract to exchange
for
at the future time
and at some exchange rate
.
We determine a fair forward exchange rate
by the following argument. We purchase
units of the
-bond,
short $-bond with maturity at
and enter into the exchange contract in question. The forward exchange rate
that makes such position of zero value is the correct exchange
rate.
where we used
by definition of the bond. We obtained two equations for two unknown variables
and
.
The solution
is
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(Forward exchange rate)
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