In: Finance
K = 30; S0 = 28; Su = 50; Sd = 25; r = 10%; t = 1; N = 100 call contracts = 100 x 100 = 10,000 options
Part (a)
Let the replicating portfolio comprise of borrowing an amount B at risk free rate for 1 year and buy C barrel today. Hence, the value of the replicating portfolio should be same as that of the call contracts.
In the up state:
Replicating portfolio value = Value of the call contracts
Hence, C x Su - B x (1 + r)t = Cu
Or, C x 50 - B x (1 + 10%)1 = max (Su - K, 0) x N = max (50 - 30, 0) x 10,000 = 200,000
Hence, 50C - 1.1B = 200,000 -----------Eqn (1)
In the down state:
Replicating portfolio value = Value of the call contracts
Hence, C x Sd - B x (1 + r)t = Cd
Or, C x 25 - B x (1 + 10%)1 = max (Su - K, 0) x N = max (25 - 30, 0) x 10,000 = 0
Hence, 25C - 1.1B = 0
Hence, 1.1B = 25C
From eqn (1): 50C - 1.1B = 50C - 25 C = 25C = 200,000
Hence, C = 200,000 / 25 = 8,000
and B = 25C/1.1 = 200,000 / 1.1 = 181,818.18
Hence, the replicating portfolio is to borrow $ 181,818.18 for a year and buy (long) 8,000 barrles of oil today.
Part (b)
The no arbitrage condition is:
the value of the call contracts today = Value of the replicating portfolio today
Part (c)
Value of the contracts = C x S0 - B = 8,000 x 28 - 181,818.18 = $ 42,181.82
Part (d)
If K = 20 then, we will have the following two equations:
In the up state:
Replicating portfolio value = Value of the call contracts
Hence, C x Su - B x (1 + r)t = Cu
Or, C x 50 - B x (1 + 10%)1 = max (Su - K, 0) x N = max (50 - 20, 0) x 10,000 = 300,000
Hence, 50C - 1.1B = 300,000 -----------Eqn (2)
In the down state:
Replicating portfolio value = Value of the call contracts
Hence, C x Sd - B x (1 + r)t = Cd
Or, C x 25 - B x (1 + 10%)1 = max (Su - K, 0) x N = max (25 - 20, 0) x 10,000 = 50,000
Hence, 25C - 1.1B = 50,000 ---------------- Eqn (3)
Hence, Eqn (2) - Eqn (3): 25C = 250,000
Hence, C = 250,000 / 25 = 10,000
and from eqn (3); B = (25C - 50,000)/1.1 = (25 x 10,000 - 50,000)/1.1 = 181,818.18
Hence, the replicating portfolio is to borrow $ 181,818.18 for a year and buy (long) 10,000 barrles of oil today.
And the value of the contracts = C x S0 - B = 10,000 x 28 - 181,818.18 = 98,181.82
Part (e)
Call options are safe ways to hedge. Call options bring unlimited upside with limited downside and hence is a very popular hedging tool. Shareholders sholuld react positively on disclosure of these contracts.