1 hedging strategies using futures chapter 3. 2 long & short hedges a long futures hedge is...
TRANSCRIPT
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Hedging Strategies Using Futures
Chapter 3
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Long & Short Hedges
• A long futures hedge is appropriate when you know you will purchase an asset in the future and want to lock in the price
• A short futures hedge is appropriate when you know you will sell an asset in the future & want to lock in the price
• A short hedge is also appropriate if you currently own the asset and want to be protected against price fluctuations
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Arguments in Favor of Hedging
• Companies should focus on the main business they are in and take steps to minimize risks arising from interest rates, exchange rates, and other market variables
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Arguments against Hedging
• Shareholders are usually well diversified and can make their own hedging decisions
• It may increase risk to hedge when competitors do not
• Explaining a situation where there is a loss on the hedge and a gain on the underlying can be difficult
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Convergence of Futures to Spot
Time Time
(a) (b)
FuturesPrice
FuturesPrice
Spot Price
Spot Price
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Basis Risk
• Basis is the difference between spot & futures
• Basis risk arises because of the uncertainty about the basis when the hedge is closed out
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Long Hedge • Suppose that
F1 : Initial Futures Price
F2 : Final Futures Price
S2 : Final Asset Price• You hedge the future purchase of an asset
by entering into a long futures contract• Exposed to basis risk if hedging period
does not match maturity date of futures
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Long Hedge • Cost of Asset = Future Spot Price - Gain on Futures
• Gain on Futures = F2 - F1
• Future Spot Price = S2
• Cost of Asset= S2 - (F2 - F1)• Cost of Asset = F1 + Basis2
• Basis2 = S2 - F2
• Future basis is uncertain• Therefore, effective cost of asset hedged is
uncertain
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Short Hedge
• Suppose that
F1 : Initial Futures Price
F2 : Final Futures Price
S2 : Final Asset Price
• You hedge the future sale of an asset by entering into a short futures contract
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Short Hedge
• Price Realized = Gain on Futures + Future Spot Price
• Gain = F1 - F2
• Future Spot Price = S2
• Price Realized = S2 + F1 - F2
• Price Realized = F1 + Basis2
• Basis2 = S2 - F2
• Price Realized = Cost of Asset
• Same Formula
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Example
• Hedging period 3 months• Futures contract expires in 4 months• We’re exposed to basis risk
• Suppose F1 = $105 and S1 =100
• Current basis = 100 - 105 = -5• Basis in 3 months is uncertain• What is basis in 4 months?
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Example
• If F2 = 110 and S2 = $102• Long Hedge
– Gain = 110 - 105 = $5– Effective cost = 102 - 5 = $97
• Short Hedge– Gain = 105 - 110 = $ -5– Realized (effective) price = 102 + (-5) = $97
• Future basis = 102 - 110 = -8
• Formula: Realized Price = F1 + basis2
• Realized Price = 105 + (-8) = $97
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Choice of Contract
• Choose a delivery month that is as close as possible to, but later than, the end of the life of the hedge
• When there is no futures contract on the asset being hedged, choose the contract whose futures price is most highly correlated with the asset price.
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Minimum Variance Hedge Ratio
• Hedge ratio is the ratio of the futures to underlying asset position
• A perfect hedge requires that futures and underlying spot asset price changes are perfectly correlated
• For imperfect hedge, set hedge ratio to minimize variance of hedging error
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Minimum Variance Hedge Ratio
Proportion of the exposure that should optimally be hedged is
where
S is the standard deviation of S, the change in the spot price during the hedging period,
F is the standard deviation of F, the change in the futures price during the hedging period
is the coefficient of correlation between S and F.
h S
F
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• Error =S - hF
• Perfect hedge: Error = 0 at all timesS = hF + Error
• Choose h to minimize var(Error)
• Therefore, h = slope of regression
• Or h = cov(S, F)/var(F)
Minimum Variance Hedge Ratio Continued
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Hedging Using Index Futures
• P: Current portfolio value• A: Current value of futures contract on index• F: Current futures price of index• S: Current value of underlying index• A = F x multiplier• For S&P 500 futures, multiplier = $250• If F=1000, A = 250,000
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Hedging Using Index Futures
• Naive hedge: N = - P/A
• Match dollar value of futures to dollar value of portfolio
• Suppose you wish to hedge $1M portfolio with S&P 500 hundred futures
• Sell 1,000,000/250,000 = 4 contracts
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Hedging Using Index Futures
• Remember total risk can divided up into systematic and unsystematic risk
• Systematic risk is measured by the portfolio beta
• Hedging with futures allows us to change the systematic risk
• But not the unsystematic risk
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Hedging Using Index Futures
• To hedge the risk in a portfolio the number of contracts that should be shorted is
• where P is the value of the portfolio, is its beta, and A is the value of the assets underlying one futures contract
P
A
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Hedging Stock Portfolios
• Hedge reduces systematic -- not unsystematic risk
is computed with respect to the index underlying the futures contract
• Futures should be chosen on underlying index that most closely matches the investor’s portfolio
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Changing Beta
• Let * = desired beta
• Let = portfolio beta
• Then N = (* - )(P/A) (N < 0: sell)
• N > 0: buy
• If we adopt the above convention, this formula textbook generalizes
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Reasons for Hedging an Equity Portfolio
• Desire to be out of the market for a short period of time. (Hedging may be cheaper than selling the portfolio and buying it back.)
• Desire to hedge systematic risk (Appropriate when you feel that you have picked stocks that will outperform the market.)
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Example
Value of S&P 500 is 1,000
Value of Portfolio is $5 million
Beta of portfolio is 1.5
What position in futures contracts on the S&P 500 is necessary to hedge the portfolio?
A = 1000x250 = $.25 M
N = (0 – 1.5)(5)/.25 = - 30 contracts (sell)
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Changing Beta
• What position is necessary to reduce the beta of the portfolio to 0.75?
N = (.75 – 1.5)(5)/.25 = -15 contracts (sell)
• What position is necessary to increase the beta of the portfolio to 2.0?
N = (2 – 1.5)(5)/.25 = 10 contracts (buy)
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Rolling The Hedge Forward
• We can use a series of futures contracts to increase the life of a hedge
• Each time we switch from 1 futures contract to another we incur a type of basis risk