Forward Contract
Forward Contract
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Summaries
1. Long
position – agree to buy the financial or physical asset at the forward
price (FP) at expiration (T).
2. Short
position – agree to sell
3. For long
position, at time t, if the spot price is more than the PV of FP, there is +ve value for the contract. Because you may short the asset
at spot price and buy at expiration to earn:
V(t,
long) = S(t) – FP/ (1+r)^(T-t)
Similarly,
V(t,
short) = FP/(1+r)^(T-t) – S(t)
4. To
prevent arbitrage, V(0) = 0, So S(0) = FP/(1+r)^T
This can be
proved by cost-of-carry model.
5. This is
based on frictionless market assumption:
1) transaction cost is 0
2) no restriction on short sales
3) borrowing and lending can be done
unlimited with risk-free rate
6. Equity
forward price
V(t,
long) = S(t) – PVD – FP/(1+r)^(T-t)
PVD is the PV
of dividend. Since the stock has to be short at t, so the one who longs the
contract receive no dividend. So have to subtract PVD. **** Make sure only dividend before the contract expires (T) is
included.
Use 365
days or 12 months.
7. Equity
forward contracts with continuous dividend (Useful for equity index)
d_c =
continuous compounded yield of the index dividend
r_c =
continuous compounded risk free rate
(r = exp(r_c) –
1 ***r_c<r)
Therefore,
FP = S(0)exp(-d_c*T)*exp(r_c*T)
(??Approximation
by exp(-d_c*T) ~ 1 –
exp(d_c*T))
V(t,long) = S(t)/exp(d_c*(T-t)) –
FP/exp(r_c*(T-t))
General
strategy: Calculate the FP with the assumption of V(0) =0. And then calculate the V(t).
[...] G. When there is cash flow for the stocks (dividend), the call option value will decrease and put option value increase. This is similar to what we have learnt from binomial model. We can substitute S0 => S0 exp(-d_c*T) [...]