Chapter Twenty Five
Options, Caps, Floors, and Collars
Chapter Outline
Introduction
Basic Features of Options
Buying a Call Option on a Bond
Writing a Call Option on a Bond
Buying a Put Option on a Bond
Writing a Put Option on a Bond
Writing versus Buying Options
Economic Reasons for Not Writing Options
Regulatory Reasons
Futures versus Options Hedging
The Mechanics of Hedging a Bond or Bond Portfolio
Hedging with Bond Options Using the Binomial Model
Actual Bond Options
Using Options to Hedge Interest Rate Risk on the Balance Sheet
Using Options to Hedge Foreign Exchange Risk
Hedging Credit Risk with Options
Hedging Catastrophe Risk with Call Spread Options
Caps, Floors, and Collars
Caps
Floors
Collars
Caps, Floors, Collars, and Credit Risk
Summary
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Solutions to End-of-Chapter Questions and Problems: Chapter Twenty Five
1. How does using options differ from using forward or futures contracts?
Both options and futures contracts are useful in managing risk. Other than the pure mechanics,
the primary difference between these contracts lies in the requirement of what must be done on
or before maturity. Futures and forward contracts require that the buyer or seller of the contracts
must execute some transaction. The buyer of an option has the choice to execute the option or to
let it expire without execution. The writer of an option must perform a transaction only if the
buyer chooses to execute the option.
2. What is a call option?
A call option is an instrument that allows the owner to buy some underlying asset at a
prespecified price on or before a specified maturity date.
3. What must happen to interest rates for the purchaser of a call option on a bond to make
money? How does the writer of the call option make money?
The call option on a bond allows the owner to buy a bond at a specific price. For the owner of
the option to make money, he should be able to immediately sell the bond at a higher price.
Thus, for the bond price to increase, interest rates must decrease between the time the option is
purchased and the time it is executed. The writer of the call option makes a premium from the
sale of the option. If the option is not exercised, the writer maximizes profit in the amount of the
premium. If the option is exercised, the writer stands to lose a portion or the entire premium, and
may lose additional money if the price on the underlying asset moves sufficiently far.
4. What is a put option?
A put option is an instrument that allows the owner to sell some underlying asset at a
prespecified price on or before a specified maturity date.
5. What must happen to interest rates for the purchaser of a put option on a bond to make
money? How does the writer of the put option make money?
The put option on a bond allows the owner to sell a bond at a specific price. For the owner of the
option to make money, he should be able to buy the bond at a lower price immediately prior to
exercising the option. Thus, for the bond price to decrease, interest rates must increase between
the time the option is purchased and the time it is executed. The writer of the put option makes a
premium from the sale of the option. If the option is not exercised, the writer maximizes profit
in the amount of the premium. If the option is exercised, the writer stands to lose a portion or the
entire premium, and may lose additional money if the price on the underlying asset moves
sufficiently far.
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6. Consider the following:
a. What are the two ways to use call and put options on T-bonds to generate positive cash
flows when interest rates decline? Verify your answer with a diagram.
The FI can either (a) buy a call option, or (b) sell a put option on interest rate instruments,
such as T-bonds, to generate positive cash flows in the event that interest rates decline. In
the case of a call option, positive cash flows will increase as long as interest rates continue
to decrease. See Figure 25-1 in the text as an example of positive cash flows minus the
premium paid for the option. Although not labeled in this diagram, interest rates are
assumed to be decreasing as you move from left to right on the x-axis. Thus bond prices
are increasing.
The sale of a put option generates positive cash flows from the premium received. Figure
25-4 shows that the payoff will decrease as the price of the bond falls. Of course this can
only happen if interest rates are increasing. Again, although not labeled in this diagram,
interest rates are assumed to be increasing as you move from right to left on the x-axis.
b. Under what balance sheet conditions can an FI use options on T-bonds to hedge its
assets and/or liabilities against interest rate declines?
An FI can use call options on T-bonds to hedge an underlying cash position that decreases
in value as interest rates decline. This would be true if, in the case of a macrohedge, the
FI’s duration gap is negative and the repricing gap is positive. In the case of a microhedge,
the FI can hedge a single fixed-rate liability against interest rate declines.
c. Is it more appropriate for FIs to hedge against a decline in interest rates with long calls
or short puts?
An FI is better off purchasing calls as opposed to writing puts for two reasons. First,
regulatory restrictions limit an FI’s ability to write naked short options. Second, since the
potential positive cash inflow on the short put option is limited to the size of the put
premium, there may be insufficient cash inflow in the event of interest rate declines to
offset the losses in the underlying cash position.
7. In each of the following cases, identify what risk the manager of an FI faces and whether
the risk should be hedged by buying a put or a call option.
a. A commercial bank plans to issue CDs in three months.
The bank faces the risk that interest rates will increase. The FI should buy a put option. If
rates rise, the CDs can be purchased at a lower price and sold immediately by exercising
the option. The gain will offset the higher interest rate the FI must pay in the spot market.
b. An insurance company plans to buy bonds in two months.
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The insurance company (IC) is concerned that interest rates will fall, and thus the price of
the bonds will rise. The IC should buy call options that allow the bond purchase at the
lower price. The bonds purchased with the options can be sold immediately for a gain that
can be applied against the lower yield realized in the market. Or the bonds can be kept and
placed in the IC’s portfolio if they are the desired type of asset.
c. A thrift plans to sell Treasury securities next month.
The thrift is afraid that rates will rise and the value of the bonds will fall. The thrift should
buy a put option that allows the sale of the bonds at or near the current price.
d. A U.S. bank lends to a French company with a loan payable in francs.
The U.S. bank is afraid that the dollar will appreciate (francs will depreciate). Thus the
bank should buy a put to sell francs at or near the current exchange rate.
e. A mutual fund plans to sell its holding of stock in a British company.
The fund is afraid that the dollar will appreciate (£ will depreciate). Thus the fund should
buy a put to sell £ at or near the current exchange rate.
f. A finance company has assets with a duration of six years and liabilities with a duration
of 13 years.
The FI is concerned that interest rates will fall, causing the value of the liabilities to rise
more than the value of the assets which would cause the value of the equity to decrease.
Thus the bond should buy a call option on interest rates (bonds).
8. Consider an FI that wishes to use bond options to hedge the interest rate risk in the bond
portfolio.
a. How does writing call options hedge the risk when interest rates decrease?
In the case where the FI is long the bond, writing a call option will provide extra cash flow
in the form of a premium. But falling interest rates will cause the value of the bond to
increase, and eventually the option will be exercised at a loss to the writer. But the loss is
offset by the increase in value of the long bond. Thus the initial goal of maintaining the
interest rate return on the long bond can be realized.
b. Will writing call options fully hedge the risk when interest rates increase? Explain.
Writing call options provides a premium that can be used to offset the losses in the bond
portfolio caused by rising rates up to the amount of the premium. Further losses are not
protected.
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c. How does buying a put option reduce the losses on the bond portfolio when interest
rates rise?
When interest rates increase, the value of the bond falls, but the put allows the sale of the