Determination of Forward and Futures Prices Chapter 5 Options, Futures, and Other Derivatives 6th Edition, Copyright © John C. Hull 2005 5.1 Consumption vs Investment Assets Investment assets are assets held by significant numbers of people purely for investment purposes (Examples: stock, bonds, gold, silver) Consumption assets are assets held primarily for consumption (Examples: copper, crude oil, corn, etc.) Use arbitrage argument to determine forward and futures prices of investment asset. Options, Futures, and Other Derivatives 6th Edition, Copyright © John C. Hull 2005 5.2 Short Selling Short selling involves selling securities you do not own Your broker borrows the securities from another client and sells them in the market in the usual way Options, Futures, and Other Derivatives 6th Edition, Copyright © John C. Hull 2005 5.3 Short Selling (continued) At some stage you must buy the securities back so they can be replaced in the account of the client You must pay dividends and other benefits the owner of the securities receives Options, Futures, and Other Derivatives 6th Edition, Copyright © John C. Hull 2005 5.4 Example Consider the position of an investor who shorts 500 IBM shares in April, when the price is $120 per share He closes out the position by buying them back in July when the price per share is $100 A dividend of $1 per share is paid in May The net gain of the investor is? Options, Futures, and Other Derivatives 6th Edition, Copyright © John C. Hull 2005 5.5 Example The net gain of the investor is 500*$120-500*$1500*$100=$9,500 The investor is required to maintain a margin account with the broker. Note: Net gain of the trader with long position: 500*100-500*120+500 = ($9500) Options, Futures, and Other Derivatives 6th Edition, Copyright © John C. Hull 2005 5.6 Assumptions 1 The market participants are subject to no transaction costs when they trade 2 The market participants are subject to the same tax rate on all net trading profits (for simplicity we assume tax rate to be zero) 3 The market participants can borrow and lend at the same risk-free rate of interest 4 The market participants take advantage of arbitrage opportunities as they occur . No restrictions on short-selling. Options, Futures, and Other Derivatives 6th Edition, Copyright © John C. Hull 2005 5.7 Notation for Valuing Futures and Forward Contracts S0: Spot price today F0: Futures or forward price today T: Time until delivery date r: Risk-free interest rate for maturity T (assume continuous compounding) Options, Futures, and Other Derivatives 6th Edition, Copyright © John C. Hull 2005 5.8 Valuation of forward/futures contracts: Basic Principles Forwards and futures have net zero value at the time of inception. Both long position and short position should have ZERO value at the time contract is struck. Forwards and futures are zero-sum game i.e. gain on long contract = loss on short contract and vice versa 5.9 Valuation of forward/futures contracts: Basic Principles Imp: There should be no arbitrage opportunity during the life of the contract Explain Arbitrage Hence, forwards and futures are valued under the assumption of NO-ARBITRAGE 5.10 Valuation of forward/futures contracts: Basic Principles contd.. At the time contract is struck the future cash flows are known with certainty! Example: A trader is considering purchasing a stock and hedge it using a forward contract. 5.11 Valuation of forward/futures contracts: Basic Principles contd.. The trader borrows the spot price and buys 1 share of ABC Ltd and shorts 1 forward contract (lot size is 1 share). Other Information: Spot price = Rs 100/share; risk-free interest rate = 4.88%; expiry of forward/futures contract = 1 year 5.12 Valuation of forward/futures contracts: Basic Principles contd.. Trader’s Strategy: To hedge the risk of this portfolio (i.e. long 1 share) the trader shorts 1 futures contract at price F0. F0 is the price at which shares will be delivered at time T. Assume a non-dividend paying stock. Question: What should be the no-arbitrage price of the forward contract? 5.13 Valuation of forward/futures contracts: Basic Principles contd.. What are the cash flows at time T? From hedging => cash inflow = F0 From borrowing => cash outflow = 100*e(4.88%*1) 5.14 Valuation of forward/futures contracts: Basic Principles contd.. Under no-arbitrage argument these two cash flows should be equal i.e. F0 = 100*e(4.88%*1) F0 = Rs 105 What if F0=Rs 95? Options, Futures, and Other Derivatives 6th Edition, Copyright © John C. Hull 2005 5.15 Valuation of forward/futures contracts: Basic Principles contd.. What if F0=Rs 95? Trader will: long forward contract to buy 1 share at Rs 95 on expiry. will short 1 share for Rs 100 will lend Rs 100 for 1 year at 4.88% 5.16 Valuation of forward/futures contracts: Basic Principles contd.. Pay-off on expiry: Cash inflow = 100*e(4.88%*1) = Rs 105 Cash outflow = Buy share at the pre-determined forward price of Rs 95 and cover the short position. Risk-less gain = Rs 10 5.17 Valuation of forward/futures contracts: Basic Principles contd.. To summarize: Under no-arbitrage the present value of the future cash flows discounted at the risk-free rate should be the Spot Price of the asset. i.e. S0=F0e-(r*t) And, F0=S0e(r*t) Since, future cash flows are known with certainty the future cash flows are risk-less and hence must be discounted using the risk-free rate. 5.18 1. Gold: An Arbitrage Opportunity? Suppose that: The spot price of gold is US$390 The quoted 1-year forward price of gold is US$425 The 1-year US$ interest rate is 5% per annum No income or storage costs for gold Is there an arbitrage opportunity? Options, Futures, and Other Derivatives 6th Edition, Copyright © John C. Hull 2005 5.19 2. Gold: Another Arbitrage Opportunity? Suppose that: The spot price of gold is US$390 The quoted 1-year forward price of gold is US$390 The 1-year US$ interest rate is 5% per annum No income or storage costs for gold Is there an arbitrage opportunity? Options, Futures, and Other Derivatives 6th Edition, Copyright © John C. Hull 2005 5.20 The Forward Price of Gold If the spot price of gold is S and the futures price for a contract deliverable in T years is F, then F = S0erT where r is the 1-year risk-free rate of interest. In our examples, S=390, T=1, and r=0.05 so that F = $410 This is the theoretical forward price of gold. Options, Futures, and Other Derivatives 6th Edition, Copyright © John C. Hull 2005 5.21 Another Example Consider a stock that is currently selling for $30 The quoted 2-years forward price of the stock is $35 The 2-years US$ interest rate is 5% per annum This means that the stock can be bought or sold for 35 with delivery in two years Is there an arbitrage opportunity? Options, Futures, and Other Derivatives 6th Edition, Copyright © John C. Hull 2005 5.22 Arbitrage Positions: 1. 2. 3. Arbitrageurs can adopt the following strategy: Borrow $30 at 5% for two years Buy 1 share of the stock Enter into a short forward contract to sell 1 share for $35 in two years In two-years $30e0.05*2=33.16 is required to repay the loan. The arbitrageur can sell the shares for $35. The result is a riskless profit of $1.84. It is easy to see that any forward price above $33.16 gives rise to this type of riskless arbitrage profit Options, Futures, and Other Derivatives 6th Edition, Copyright © John C. Hull 2005 5.23 Continued.. Consider a stock that is currently selling for $30 The quoted 2-years forward price of the stock is $31 The 2-years US$ interest rate is 5% per annum This means that the stock can be bought or sold for $31 with delivery in two years Is there an arbitrage opportunity? Options, Futures, and Other Derivatives 6th Edition, Copyright © John C. Hull 2005 5.24 Arbitrage Positions: 1. 2. 3. Arbitrageurs can adopt the following strategy: Short 100 shares of the stock Invest the proceeds (3000) at 5% for two-years Enter into a long forward contract to repurchase 100 shares for 3100 in two-years In two-years the 3000 investment grows to 3000e0.05*2=3316. 100 shares are purchased for 3100 and the short position is closed out. The result is a riskless profit of 216. This riskless arbitrage opportunity is available whenever the forward price is below 33.16 Options, Futures, and Other Derivatives 6th Edition, Copyright © John C. Hull 2005 5.25 Arbitrage Riskless arbitrage opportunities, if they are observed at all, rarely last for long As traders take advantage of these arbitrage opportunities, the forward price will be driven up or down and the arbitrage opportunity will disappear. Options, Futures, and Other Derivatives 6th Edition, Copyright © John C. Hull 2005 5.26 Generalization: The relationship between F0 and S0 is: F0 = S0erT When F0 > S0erT an arbitrageur can buy the asset and short forward (futures) contacts on the asset When F0 < S0erT an arbitrageur can short the asset and buy forward (futures) contracts on it Options, Futures, and Other Derivatives 6th Edition, Copyright © John C. Hull 2005 5.27 Example Consider a four-month forward contract to buy a zero-coupon bond that will mature one year from today The current price of the bond is $930 The 4-months interest rate is 6% per annum Estimate the theoretical forward price? Options, Futures, and Other Derivatives 6th Edition, Copyright © John C. Hull 2005 5.28 Example The forward price is obtained by F0= P0er*T = 930e0.06*4/12 =$948.79 Options, Futures, and Other Derivatives 6th Edition, Copyright © John C. Hull 2005 5.29 When an Investment Asset Provides a Known Dollar Income F0 = (S0 – I )erT where I is the present value of the income during life of forward contract Examples are stocks paying dividends and coupon bearing bonds. Options, Futures, and Other Derivatives 6th Edition, Copyright © John C. Hull 2005 5.30 Example Consider a one-year forward contract to purchase a coupon-bearing bond whose current price is 900, that will mature in five years Coupon payments of 40 are expected after 6 and 12 months Six-month and one-year riskless rates are 9% and 10% respectively So, S0=900, I=40e-0.09*0.5 + 40e-0.1*1 =74.433, and F0 = (S0-I)er*T=(900-74.433)e0.1*1 =912.39 Options, Futures, and Other Derivatives 6th Edition, Copyright © John C. Hull 2005 5.31 Arbitrage If F0>(S0-I)er*T, an arbitrageur can lock in a profit by buying the asset and shorting a forward contract on the asset. If F0<(S0-I)er*T, an arbitrageur can lock in a profit by shorting the asset and taking a long position in a forward contract Options, Futures, and Other Derivatives 6th Edition, Copyright © John C. Hull 2005 5.32 Example Consider a 10-month forward contract on a stock with price of 50 The riskless rate is 8% per annum for all maturities Dividends of 0.75 per share are expected after three, six and nine months The present value of the dividends, I, is given by I=0.75e-0.08*3/12+0.75e-0.08*6/12+0.75e-0.08*9/12 =2.162 The forward price is given by F0 = (S0-I)er*T=(50-2.162)e0.08*10/12 =51.14 Options, Futures, and Other Derivatives 6th Edition, Copyright © John C. Hull 2005 5.33 When an Investment Asset Provides a Known Yield F0 = S0 e(r–q )T where q is the average yield during the life of the contract (expressed with continuous compounding) Options, Futures, and Other Derivatives 6th Edition, Copyright © John C. Hull 2005 5.34 Example Consider a 6-month forward contract on a stock with price of 25 The riskless rate is 10% per annum The stock is expected to provide income equal to 2% of the stock price in 6 months. The yield is 3.96% per annum with continuous compounding. The forward price is given by F0 = S0e(r-q)*T=25e(0.10-0.0396)*0.5 =25.77 Options, Futures, and Other Derivatives 6th Edition, Copyright © John C. Hull 2005 5.35 Valuing a Forward Contract Suppose that K is delivery price in a forward contract and F0 is forward price that would apply to the contract today The value of a long forward contract, ƒ, is ƒ = (F0 – K )e–rT Similarly, the value of a short forward contract is (K – F0 )e–rT Options, Futures, and Other Derivatives 6th Edition, Copyright © John C. Hull 2005 5.36 Example Consider a six-month long forward contract on a non-dividend paying stock, that was entered into some time ago The stock price is 25, and the delivery price is 24 The risk-free rate of interest is 10% per annum Then, the forward price, F0, is given by F0 = S0er*T= 25e0.1*0.5=26.28 The value of the forward contract is f = (F0-K)e-r*T = S0-Ke-r*T=25-24e-0.1*0.5=2.17 Options, Futures, and Other Derivatives 6th Edition, Copyright © John C. Hull 2005 5.37 Example Consider A Forward Contract That Has A Term Of 2 Years. The Price Of The Asset Underlying The Contract Is Currently $200 And The Risk-Free Rate Is 9%. Given The Forward Price Of $220, The Value Of The Forward Contract At Initiation Is Closest To ? Options, Futures, and Other Derivatives 6th Edition, Copyright © John C. Hull 2005 5.38 Example Consider A Forward Contract That Has A Term Of 2 Years. The Price Of The Asset Underlying The Contract Is Currently $200 And The Risk-Free Rate Is 9%. Given The Forward Price Of $220, The Value Of The Forward Contract At Initiation Is Closest To ? 200-220*exp(-9%*2) = 16.24 Options, Futures, and Other Derivatives 6th Edition, Copyright © John C. Hull 2005 5.39 Stock Index Can be viewed as an investment asset paying a dividend yield The futures price and spot price relationship is therefore F0 = S0 e(r–q )T where q is the average dividend yield on the portfolio represented by the index during life of contract Options, Futures, and Other Derivatives 6th Edition, Copyright © John C. Hull 2005 5.40 Example Consider a 3-month futures contract on the S&P 500 The riskless rate is 6% per annum The stocks underlying the index provide a dividend yield of 1% per annum. The current value of the index is 800 The futures price is given by F0 = S0e(r-q)*T=800e(0.06-0.01)*0.25 =810.06 Options, Futures, and Other Derivatives 6th Edition, Copyright © John C. Hull 2005 5.41 Index Arbitrage When F0 > S0e(r-q)T an arbitrageur buys the stocks underlying the index and sells futures When F0 < S0e(r-q)T an arbitrageur buys futures and shorts or sells the stocks underlying the index Options, Futures, and Other Derivatives 6th Edition, Copyright © John C. Hull 2005 5.42 Futures and Forwards on Currencies A foreign currency is analogous to a security providing a dividend yield The continuous dividend yield is the foreign risk-free interest rate It follows that if rf is the foreign risk-free interest rate F0 S0e ( r rf ) T Options, Futures, and Other Derivatives 6th Edition, Copyright © John C. Hull 2005 5.43 Why the Relation Must Be True Figure 5.1, page 113 1000 units of foreign currency at time zero 1000 e rf T units of foreign currency at time T 1000 F0 e rf T dollars at time T 1000S0 dollars at time zero 1000 S 0 e rT dollars at time T Options, Futures, and Other Derivatives 6th Edition, Copyright © John C. Hull 2005 5.44 Example Suppose the 2-year interest rate in Australia and the US are 5% and 7% respectively The spot exchange rate is 0.62 USD for 1 AUD The 2-year forward exchange rate should be F0 = S0e(r-rf)*T= 0.62e(0.07-0.05)*2 =0.6453 Options, Futures, and Other Derivatives 6th Edition, Copyright © John C. Hull 2005 5.45 Arbitrage Position 1: 1. 2. Suppose the 2-year forward exchange rate is less than this, say 0.63. An arbitrageur can: Borrow 1000 AUD at 5% per annum for 2-years, convert to 620 USD and invest the USD at 7% Enter into a forward contract to buy 1,105.17 AUD for 1,105,17*0.63=696.26 USD The 620 USD grow to 620e0.07*2=713.17 USD. 696.26 USD are used to purchase 1,105,17 AUD under the terms of the forward Repay the principal and interest on the 1000 AUD that are borrowed (1000e0.05*2=1,105.17) This riskless profit is 713.17-696.26=16.91 USD Options, Futures, and Other Derivatives 6th Edition, Copyright © John C. Hull 2005 5.46 Arbitrage Position 2: 1. 2. Suppose the 2-year forward exchange rate is greater than this, say 0.6600. An arbitrageur can: Borrow 1000 USD at 7% per annum for 2-years, convert to 1000/0.62=1,612.90 AUD and invest the AUD at 5% Enter into a forward contract to sell 1,782.53 AUD for 1,782.53*0.66=1,176.47 USD The 1,612.90 AUD grow to 1,612.90e0.05*2=1,782.53 AUD. The forward contract has the effect of converting this to 1,176.47 USD Repay the principal and interest on the 1000 USD that are borrowed (1000e0.07*2=1,150.27) This riskless profit is 1,176.47-1,150.27=26.20 USD Options, Futures, and Other Derivatives 6th Edition, Copyright © John C. Hull 2005 5.47