Title: Options on Stock Indices, Currencies, and Futures Chapter 13
1Options onStock Indices, Currencies, and
FuturesChapter 13
2STOCK INDEX OPTIONS ONE CONTRACT VALUE
(INDEX VALUE)(MULTIPLIER) One contract
(I)(m) ACCOUNTS ARE SETTLED BY CASH
3- STOCK INDEX OPTIONS FOR
- PORTFOLIO INSURANCE
- Problems
- How many puts to buy?
- Which exercise price will guarantee the desired
level of protection? - The answers are not easy because the
- index underlying the puts is not the
- portfolio to be protected.
4The protective put with a single stock
5The protective put consists of holding the
portfolio and purchasing n puts.
6 WE USE THE CAPITAL ASSET PRICING MODEL. For
any security i,the expected excess return on the
security and the expected excess return on the
market portfolio are linearly related by their
beta
7THE INDEX TO BE USED IN THE STRATEGY, IS TAKEN
TO BE A PROXY FOR THE MARKET PORTFOLIO, M.
FIRST, REWRITE THE ABOVE EQUATION FOR THE INDEX I
AND ANY PORTFOLIO P
8Second, rewrite the CAPM result, with actual
returns
In a more refined way, using V and I for the
portfolio and index market values, respectively
9NEXT, use the ratio Dp/V0 as the portfolios
annual dividend payout ratio qP and DI/I0 the
index annual dividend payout ratio, qI.
The ratio V1/ V0 indicates the portfolio required
protection ratio.
10 For example
The manager wants V1, to be down to no more than
90 of the initial portfolio market value, V0
V1 V0(.9). We denote this desired level by
(V1/ V0). This is the decision variable.
111. The number of puts is
122. The exercise price, K, is determined by
substituting I1 K and the required level, (V1/
V0) into the equation
and solving for K
13We rewrite the Profit/Loss table for the
protective put strategy
We are now ready to calculate the floor level of
the portfolio V1n(m)(K- I1)
14We are now ready to calculate the floor level of
the portfolio Min portfolio value V1n(m)(K-
I1) This is the lowest level that the portfolio
value can attain. If the index falls below the
exercise price and the portfolio value declines
too, the protective puts will be exercised and
the money gained may be invested in the portfolio
and bring it to the value of V1n(m)K- n(m)I1
15Substitute for n
16To substitute for V1 we solve the equation
173. Substitution V1 into the equation for the Min
portfolio value
The desired level of protection is made at time
0. This determines the exercise price and
management can also calculate the minimum
portfolio value.
18EXAMPLE A portfolio manager expects the market
to fall by 25 in the next six months. The
current portfolio value is 25M. The manager
decides on a 90 hedge by purchasing 6-month puts
on the SP500 index. The portfolios beta with
the SP500 index is 2.4. The SP500 index stands
at a level of 1,250 points and its dollar
multiplier is 100. The annual risk-free rate is
10, while the portfolio and the index annual
dividend payout ratios are 5 and 6,
respectively. The data is summarized below
19Solution Purchase
20The exercise price of the puts is
Solution Purchase n 480 six-months puts with
exercise price K 1,210.
21(No Transcript)
22CONCLUSION Holding the portfolio and purchasing
480, 6-months protective puts on the SP500
index, with the exercise price K 1210,
guarantees that the portfolio value, currently
25M, will not fall below 22,505,000 in six
months.
23Example (page 274) protection for 3 months
Solution Purchase
24The exercise price of the puts is
Solution Purchase n 10 six-months puts with
exercise price K 960.
25(No Transcript)
26CONCLUSION Holding the portfolio and purchasing
10, 3-months protective puts on the SP500 index,
with the exercise price K 960, guarantees that
the portfolio value, currently 500,000 will not
fall below 450,000 in three months.
27- A SPECIAL CASE In the case that
- ß 1 and 2. qP qI, the portfolio is
- statistically similar to the index.
- In this case
28Assume that in the above example, ßp 1 and qP
qI, then
29Example (page 273) ßp 1 and qP qI, then
30FOREIGN CURRENCY FUTURES Standardized Options
Currencies Traded The PHLX lists six
dollar-based standardized currency option
contracts, which settle in the actual physical
currency. These are the most heavily traded
currencies in the global inter bank
market. Contract Size The amounts of currency
controlled by the various currency options
contracts are geared to the needs of the widest
possible range of participants.
31- Currency options Units
- USD/AUD 50,000AUD
- USD/GBP 31,250GBP
- USD/CD 50,000CD
- USD/EUR 62,500EUR
- USD/JPY 6,250,000JPY
- USD/CHF 62,500CHF
- Exercise Style American- or European
- options available for physically settled
- contracts Long-term options are
- European-style only.
32- Expiration/Last Trading Day The PHLX offers a
variety of expirations in its physically settled
currency options contracts, including Mid-month,
Month-end and Long-term expirations. Expiration,
which is also the last day of trading, occurs on
both a quarterly and consecutive monthly cycle.
That is, currency options are available for
trading with fixed quarterly months of March,
June, September and December and two additional
near-term months. For example, after December
expiration, trading is available in options which
expire in January, February, March, June,
September, and December. Month-end option
expirations are available in the three nearest
months.
33Standardized Options
With the Canadian dollar spot price currently at
a level of USD.6556/CD, strike prices would be
listed in half-cent intervals ranging from 60 to
70. i.e., 60, 60.5, 61, , 69, 69.5, 70. If the
Canadian dollar spot rate should move to say
USD.7060/CD, additional strikes would be listed.
E.G, 70, 70.5, 71, , 75.
- Exercise PricesExercise prices are expressed in
terms of U.S. cents per unit of foreign currency.
Thus, a call option on EUR with an exercise price
of 82 would give the option buyer the right to
buy Euros at 82 cents per EUR.
34- It is important that available exercise prices
relate closely to prevailing currency values.
Therefore, exercise prices are set at certain
intervals surrounding the current spot or market
price for a particular currency. When significant
price changes take place, additional options with
new exercise prices are listed and commence
trading. - Strike price intervals vary for the different
expiration time frames. They are narrower for the
near-term and wider for the long-term options.
35- Premium Quotation premiums for dollar-based
options are quoted in U.S. cents per unit of the
underlying currency with the exception of
Japanese yen which are quoted in hundredths of a
cent. - Example
- A premium of 1.00 for a given EUR option is one
cent (USD.01) per EUR. - Since each option is for 62,500 EURs, the total
option premium would be - 62,500DMUSD.01/EUR USD625.
36Customized Currency Options
- Currencies Traded
- Customized currency options can be traded on any
combination of the currencies currently available
for trading. Currently, AUD must be denominated
in U.S. dollars. AUD premiums must be denominated
in USD.
In the case of an option on the USD in CD, the
underlying currency is U.S. dollars. The strike
prices and premiums are quoted in Canadian
dollars. E.G, a call option on the USD with a
strike price of 1.542 gives the buyer the right
to purchase 50,000 USD at CD1.542/USD.
37- Underlying CurrencyThe underlying currency is
that currency which is purchased (in the case of
a call) or sold (in the case of a put) upon
exercise of the contract. - Base CurrencyThe base currency is that currency
in which terms the underlying is being quoted,
i.e. strike price. - Expiration/Last Trading DayExpirations can be
established for any business day up to two years
from the trade date. Customized option contracts
expire at 1015 a.m., Eastern Time on the
expiration day in contrast with standardized
options which expire at 1159 p.m., Eastern Time
on the expiration day.
38- In addition, the exercise and assignment process
for customized options is more akin to the OTC
market in terms of expiration timeframe. Unlike
the process utilized for standardized options,
exercise notices must be received by 1000 a.m.,
Eastern Time and the writer is then notified of
the number of contracts assigned. If necessary,
contact the PHLX for more details. - The contract size for customized currency options
is
39Underlying currency Contract size Australian
dollar 50,000AUD British Pound 31,250GBP Canadi
an dollar 50,000CD Euro 62,500EUR Japanese
Yen 6,250,000JPY Mexican
Peso 250,000MXP Spanish Peseta
5,000,000ESP Swiss Frank 62,500CHF USD 50,0
00USD.
40- Exercise PricesExercise or strike prices may be
expressed in any increment out to four
characters. For example, a USD/GBP option could
have an exercise price of 1.543. - Exercise-style European-style only.
- Minimum Transaction SizeSince customized
currency options were designed for the
institutional market, there is a minimum opening
transaction size which equals or exceeds 50
contracts.
41A call option on the EUR quoted in American terms
would have a strike price expressed in USD. For
example, USD.8484 per EUR. A similar option
expressed in European terms would be a put option
on USD with a strike price expressed in EUR. For
example, 1.1787 EUR per USD.
42- Contract TermsAn option may be expressed in
either American terms or European terms (inverse
terms). For example, an option in American terms
would have exercise prices quoted in terms of
U.S. dollar per unit of foreign currency. An
option in European or inverse terms would have
exercise prices quoted in terms of units of
foreign currency per U.S. dollar.
43- Trading ProcessTrading is conducted in an open
outcry auction market, just as in standardized
option contracts. When initial interest in a
customized option series is expressed, a floor
member must first present a Request For Quote
(RFQ) to an Exchange staff member for
dissemination. Subsequently, responsive quotes
are generated by competing market makers and
floor brokers representing off floor interest.
44- PremiumsPremiums may be expressed either in
terms of the base currency per unit of the
underlying currency or in percent of the
underlying currency (based on contract size). For
example, the premium for an option on the USD/EUR
(USD being the base currency and EURO being the
underlying currency) could be expressed in U.S.
cents per EUR or as a percentage of 62,500 EUROS.
45- Price and Quote DisseminationRequest For Quotes
(RFQs), responsive quotes and trades will be
disseminated to the Option Price Reporting
Authority (OPRA) for availability to quote
vendors
The premium for an option on the EUR with a
strike price in USD (EUR is the underlying
currency and the USD is the base currency) quoted
in cents per EUR(premium of 2.50) would be
calculated as follows the aggregate premium for
each contract USD1562.50(USD.025 x 62,500EUR
per contract ).Similarly, if this option were
quoted in percentage of underlying and the
premium was 2.5, the premium amount for each
contract 1562.5 EUR (.025 x 62,500 EUR per
contract).
46- Position LimitsPosition limits are the maximum
number of contracts in an underlying currency
which can be controlled by a single entity or
individual. Currently, position limits are set at
200,000 contracts on each side of the market
(long calls and short puts or short calls and
long puts) for each currency except the Mexican
peso, and the Spanish peseta which are 100,000
contracts. For purposes of computing position
limits, all options involving the U.S. dollar
against another currency will be aggregated with
each other for each currency (i.e., USD/EUR and
EUR/USD on the same side of the market will be
aggregated - USD/EUR long calls and short puts
with EUR/USD short calls and long puts).
47- FX Options As InsuranceOptions on spot
represent insurance bought or written on the spot
rate. (options on futures represent insurance
bought or written on the futures price.) An
individual with foreign currency to sell can use
put options on spot to establish a floor price on
the domestic currency value of the foreign
currency. For example, a put option on EUR with
an exercise price of USD.80/EUR ensures that, if
the value of the EUR falls below USD.80/EUR, the
EUR can be sold for USD.80/EUR.
48If the put option costs USD.01/EUR, the floor
price can be roughly approximated as USD.80/EUR
- USD.O1/EUR USD.79/EUR. That is, if the
option is used, the put holder will be able to
sell the EUR for the USD.80/EUR strike price, but
in the meantime, have paid a premium of
USD.01/EUR. Deducting the cost of the premium
leaves USD.79/EUR as the floor price established
by the purchase of the put. This calculation
ignores fees and interest rate adjustments.
49- Similarly, an individual who has to buy foreign
currency at some point in the future can use call
options on spot to establish a ceiling price on
the domestic currency amount that will have to be
paid to purchase the foreign exchange.
50- For example, a call option on EUR with an
exercise price of USD.80/EUR will ensure that, in
the event the value of the EURO rises above
USD.80/EUR, the EUR can be bought for USD.80/EUR
anyway. If the call option costs USD.02/EUR,
this ceiling price can be approximated - USD.80/EUR USD.02/EUR USD.82/EUR
- or the strike price plus the premium.
51- To summarize these two important points involving
FX puts and calls - 1- Foreign currency put options on spot can be
used as insurance to establish a floor price on
the domestic currency value of foreign exchange.
This floor price is approximately - Floor price exercise price of put
- - put premiumÂ
- 2- Foreign currency call options on spot can be
used as insurance to establish a ceiling price on
the domestic currency cost of foreign exchange.
This ceiling price is approximately  - Ceiling price exercise price of call
- call premium.
52- These calculations are only approximate for
essentially two reasons. First, the exercise
price and the premium of the option on spot
cannot be added directly without an interest rate
adjustment. The premium will be paid now, up
front, but the exercise price (if the option is
eventually exercised) will be paid later. The
time difference involved in the two payment
amounts implies that one of the two should be
adjusted by an interest rate factor. Second,
there may be brokerage or other expenses
associated with the purchase of an option, and
there may be an additional fee if the option is
exercised. The following two examples illustrate
the insurance feature of FX options on spot and
show how to calculate floor and ceiling values
when some additional transactions costs are
included.
53- Example 1Â A U.S. importer will have a net cash
out flow of 250,000 in payment for goods bought
in Great Britain. The payment date is not known
with certainty, but should occur in late
November. On September 16 the importer locks in a
ceiling purchase for pounds by buying 8 PHLX
calls 250,000/31,250 8 on the pound, a
strike price K USD1.50/GBP and a December
expiration. The option premium on September 16 is
USD.0220/GBP. With a brokerage commission of
4/option, the total cost of the eight contracts
is - 8(3l,250)(.0220/) 8(4) 5,532.
54- Measured from today's viewpoint, the importer has
essentially assured that the purchase price for
pounds will not be greater than - 5,532/250,000 1.50/ .02213/ 1.50/
USD1.52213/GBP. - Notice here that the add factor USD.02213/GBP
is larger than the option premium of USD.0220/GBP
by USD.00013/GBP, which represents the dollar
brokerage cost per pound. The number
USD1.52213/GBP is the importer's ceiling price.
The importer is assured he will not pay more than
this, but he could pay less. The price the
importer will actually pay will depend on the
spot price on the November payment date. To
illustrate this, we can consider two scenarios
for the spot rate.
55- Case A. The spot rate on the November payment
date is USD1.46/GBP. The importer would not
exercise the call but would buy pounds spot at
the rate of USD1.46/GBP. The importer then sell
the eight calls for whatever market value they
had remaining. Assuming, a brokerage fee of 4
per contract for the sale, the options would be
sold as long as their remaining market value was
greater than 4 per option. The total cost will
have turned out to be - USD1.46/GBPUSD.02213/GBP
- - (sale value of options- 32)/250,000.
56- If the resale value is not greater than 32, then
the total cost per pound is 1.46 .02213
1.48213. - The USD.02213/GBP that was the original cost of
the premium and brokerage fee turned out in this
case to be an unnecessary expense. - Now, to be strictly correct, a further
adjustment to the calculation should be made.
Namely, the 1.46 and .02213 represent cash
flows at two different times. Thus, if R is the
amount of interest paid per dollar over the
September 16 to November time period, the proper
calculation is - 1.46.02213(lR)
- - (sale value of options-32)/250,000.
57- Case B. The spot rate on the November payment
date is USD1.55/GBP. The importer can either
exercise his options or sell them for their
market value. Assume the importer sells them at
a current market value of .055 and pays 32
total in brokerage commissions on the sale of
eight option contracts. The importer then buys
the pounds in the spot market for USD1.55/GBP.
The total cost is, before adding the premium and
commission costs paid in September - (USD1.55/GBP)(250,000)
- (USD.055/GBP))( 250,000) 8(4)
- 373,782.
- This amount is
- 373,782/250,000 USD1.49513/GBP.
- Â
58- Adding in the premium and commission costs paid
back in September, the total cost is - USD1.49513/GBP USD.02213(l R)/GBP
- Â
- If the importer chooses instead to exercise the
option, the calculations will be similar except
that the brokerage fee will be replaced by an
exercise fee. - This concludes Example 1.
59- Example 2 Â A Japanese company wants to lock in a
minimum yen value of USD50M, this amount to be
sold between July1 and December 31. Since the
company wishes to sell USD and receive JPY, the
company will buy a put option on USD, with an
exercise price stated in terms of JPY. - Suppose the company buys from its bank an
American put on USD50M with a strike price of
JPY130/USD.
60- This call is purchased directly from the bank
thus, there is no resale value to the option. The
company pays a premium of JPY4/USD. In this
case, assume there are no additional fees. Then,
the Japanese company has established a floor
value for its USD, approximately at - JPY130/USD - JPY4/USD JPY126/USD.
- Again, we can consider two scenarios, one in
which the yen falls in value to JPY145/USD and
the other in which the yen rises in value to
JPY115/USD.
61- Case A.
- The yen falls to JPY145/USD. In this case the
company will not exercise the option to sell
dollars for yen at JPY13O/USD, since the company
can do better than this in the exchange market.
The company will have obtained a net value of - JPY145/USD - JPY4/USD JPY141/USD.
62- Case B.
- The JPY rises to JPY115/USD. The company will
exercise the put and sell each U.S. dollar for
JPY130/USD. The company will obtain, net, - JPY130/USD - JPY4/USD JPY126/USD.
- This is JPY11 better than would have been
available in the FX market and reflects a case
where the insurance paid off. This concludes
Example 2.
63- Writing Foreign Currency Options
- General considerations. The writer of a foreign
currency option on spot or futures is in a
different position from the buyer of these
options. The buyer pays the premium up front and
then can choose to exercise the option or not.
The buyer is not a source of credit risk once the
premium has been paid. The writer is a source of
credit risk, however, because the writer has
promised either to sell or to buy foreign
currency if the buyer exercises his option. The
writer could default on the promise to sell
foreign currency if the writer did not have
sufficient foreign currency available, or could
default on the promise to buy foreign currency if
the writer did not have sufficient domestic
currency available.
64- If the option is written by a bank, this risk of
default may be small. But if the option is
written by a company, the bank may require the
company to post margin or other security as a
hedge against default risk. For exchange-traded
options, as noted previously, the relevant
clearinghouse guarantees fulfillment of both
sides of the option contract. The clearinghouse
covers its own risk, however, by requiring- the
writer of an option to post margin. At the PHLX,
for example, the Options Clearing Corporation
will allow a writer to meet margin requirements
by having the actual foreign currency or U.S.
dollars on deposit, by obtaining an irrevocable
letter of credit from a suitable bank, or by
posting cash margin.
65- If cash margin is posted, the required deposit is
the current market value of the option plus 4
percent of the value of the underlying foreign
currency. This requirement is reduced by any
amount the option is out of the money, to a
minimum requirement of the premium plus .75
percent of the value of the underlying foreign
currency. These percentages can be changed by the
exchanges based on currency volatility. Thus, as
the market value of the option changes, the
margin requirement will change. So an option
writer faces daily cash flows associated with
changing margin requirements.
66- Other exchanges have similar requirements for
option writers. The CME allows margins to be
calculated on a net basis for accounts holding
both CME FX futures options and IMM FX futures.
That is, the amount of margin is based on one's
total futures and futures options portfolio. The
risk of an option writer at the CME is the risk
of being exercised and consequently the risk of
acquiring a short position (for call writers) or
a long position (for put writers) in IMM futures.
Hence the amount of margin the writer is
required to post is related to the amount of
margin required on an IMM FX futures contract.
The exact calculation of margins at the CME
relies on the concept of an option delta.
67- From the point of view of a company or
individual, writing options is a form of
risk-exposure management of importance equal to
that of buying options. It may make perfectly
good sense for a company to sell foreign currency
insurance in the form of writing FX calls or
puts. The choice of strike price on a written
option reflects a straightforward trade-off. FX
call options with a lower strike price will be
more valuable than those with a higher strike
price. Hence the premiums the option writer will
receive are correspondingly larger. However, the
probability that the written calls will be
exercised by the buyer is also higher for calls
with a lower strike price than for those with a
higher strike. Hence the larger premiums
received reflect greater risk taking on the part
of the insurance seller, ie., the option writer. -
68- Writing Foreign Currency Options
- an example.
- The following example will illustrate
- the risk/return trade-off for the case of an oil
company with an exchange rate risk, that chooses
to become an option writer.
69- Example 3 Iris Oil Inc., a Houston-based energy
company, has a large foreign currency exposure in
the form of a CD cash flow from its Canadian
operations. The exchange rate risk to Iris is
that the CD may depreciate against the USD. In
this case, Iris CD revenues, transferred to its
USD account will diminish and its total USD
revenues will fall. Iris chooses to reduce its
long position in CD by writing CD calls with a
USD strike price. The strategy chosen is one of
hedge ratio 11.
70- By writing options, Iris will receive an
immediate USD cash flow representing the
premiums. This cash flow will increase Iris'
total USD return in the event the CD depreciates
against the USD or, remains unchanged against the
USD, or appreciates only slightly against the
USD. - Clearly, the options might expire worthless or
they might be exercised. In either case, however,
Iris walks away with the full amount of the
options premium
71- If the USD value of the CD remains unchanged, the
option premium received is simply additional
profit. - If the value of the CD falls, the premium
received on the written option will offset part
or all of the opportunity loss on the underlying
CD position. - If the value of the CD rises sharply, Iris will
only participate in this increased value up to a
ceiling level, where the ceiling level is a
function of the exercise price of the option
written.
72- In short, the payoff to Iris' strategy will
depend both on exchange rate movements and on the
selection of the strike price of the written
options. - To illustrate Iris' strategy, consider an
anticipated cash flow of CD300M over the next 180
days. With hedge ratio of 11, Iris sells
CD300,000,000/CD50,000 6,000 PHLX calls.
73- Assume Iris writes 6,000 PHLX calls with a
6-month expiration the current spot rate is S
USD.75/CD and the 6-month forward rate is - F USD.7447/CD.
- For the current level of spot rate, logical
strike price choices for the calls might be X
USD.74, or USD.75, or USD.76. - For the illustration, assume that Iris
brokerage fee is USD4 per written call and let
the hypothetical market values of the options be
those listed in the following
74c(K USD.74/CD) USD.01379 c(K SUD.75/CD)
USD.00650 c(K USD.76/CD) USD.00313.
75- The payoff to the total position depends on the
choice of exercise price, K, and the spot
exchange rate, S(USD/CD), at the calls
expiration. We now introduce an additional cost,
that is associated with the exercise fee, which
exists in the real markets. If the options are
exercised, an additional Options Clearing
Corporation fee of USD35 per option is assumed.
In our example then, an exercise of the calls
requires a total OCC fee of USD35(6,000)
USD210,000 for the 6,000 written calls. The
total value of the long CD position of Iris, plus
short option position will be
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77Actually, the above table consolidates three
profit profile tables, each corresponding to one
of the three strike prices under
consideration. The three tables are as follows
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81As illustrated by the consolidated table and the
three separate profit profile tables, the lower
the strike price chosen, the better the
protection against a depreciating CD. On the
other hand, a lower strike price limits the
corresponding profitability of the strategy if
the CD happens to appreciate against the USD in
six months. The optimal decision of which
strategy to take is a function of the spot
exchange rate at expiration. One possible
comparison is to evaluate the options strategy
vis-Ã -vis the immediate forward exchange.
82- Recall that when Iris enters the
- options strategy the forward
- exchange rate is
- F USD.7447/CD.
- Thus, a future break-even spot
- rate can be calculated for every
- corresponding exercise price
- chosen
83- F .7447. Iris may exchange today, CD300M
forward for - CD300,000,000(USD.7447/CD)
- USD223,410,000.
- IF K .74,
- S(CD300M) 4,113,000 USD223,410,000
- ? SBE USD.7310/CD.
- IF K .75,
- S(CD300M) 1,926,000 USD223,410,000
- ? SBE USD.7383/CD.
- IF K .76,
- S(CD300M) 915,000 USD223,410,000
- ? SBE USD.7416/CD.
84- CONCLUSION
- Writing the calls will protect Iris flow
- in USD six months from now better
- than an immediate forward exchange,
- for all spot rates (in six months) that
- are above the corresponding break-
- even exchange rates.
85- A second possible analysis of the optimal
decision depends on all possible values of the
spot exchange rate, given our assumptions. Recall
that the assumptions are - Iris either maintains an open long position of
CD300M un hedged. Alternatively, Iris writes
6,000 PHLX calls with 180-day expiration period.
Possible strike prices are USD.76/CD, USD.75/CD,
USD.74/CD. Current spot and forward exchange
rates are USD.75/CD and USD.7447/CD, respectively.
86- The terminal spot rate is the market exchange
rate when the calls expire. It is assumed Iris
pays a brokerage-fee of USD4 per option contract
and an additional fee of USD35 per option to the
Options Clearing Corporation if the options are
exercised.
87- Optimal Decision Under Iris' Strategy as a
Function Of The (Unknown) Terminal Spot Rate - Terminal Spot rate Optimal Decision
- S .76235 Hold long currency only
- .75267 .76
- .74477 .75
- S
88- Final comments on Example 3.
- Because of the large OCC fee of USD35 per
exercised call assumed in the example, it might
be less expensive for Iris to buy back the calls
and pay the brokerage fee of USD4 per call in the
event the options were in dancer of being
exercised. In addition, it is assumed that Iris
will have the CD300M on hand if the options are
exercised. This would not be the case if actual
Canadian dollar revenues were less than
anticipated. In that event, the options would
need to be repurchased prior to expiration.
89- Each of the three choices of strike price
- will have a different payoff, depending on
- the movement in the exchange rate. But
- Iris' expectation regarding the exchange
- rate is not the only relevant criterion for
- choosing a risk-management strategy.
- The possible variation in the underlying
- position should also be considered.
90- Here are the maximal and minimal
- payoffs for each of the call-writing
- choices, compared to the un hedged
- position and a forward market hedge
91- Strategy Max Value Min Value
- Unhedged
- Long
- Position None. Zero.
- Sell
- forward USD223,410,000 USD223,410,000
- .76 call USD228,705,000 Unhedged minimum
USD915,000. - .75 call USD226,716,000 Unhedged minimum
USD1,926,000. - .74 call USD225,903,000 Unhedged minimum
USD4,113,000.
92Mechanics of Call Futures Options
- When a call futures option is exercised the
holder acquires - 1. A long position in the futures
- 2. A cash amount equal to the excess of
- the most recent settlement futures price over
the strike price
93Mechanics of Put Futures Option
- When a put futures option is exercised the
holder acquires - 1. A short position in the futures
- 2. A cash amount equal to the excess of
- the strike price over the most recent
settlement futures price
94The Payoffs
- If the futures position is closed out
immediately - Payoff from call F0 K
- Payoff from put K F0
- where F0 is futures price at time of exercise
95Put-Call Parity for Futures Options (Equation
13.13, page 284)
- Consider the following two portfolios
- 1. European call plus Ke-rT of cash
- 2. European put plus long futures plus cash
equal to F0e-rT - They must be worth the same at time T so that
- cKe-rTpF0 e-rT
96Valuing European Futures Options
- We can use the formula for an option on a stock
paying a dividend yield - Set S0 current futures price (F0)
- Set q domestic risk-free rate (r )
- Setting q r ensures that the expected growth
of F in a risk-neutral world is zero
97Blacks Formula (Equations 13.17 and 13.18,
page 287)
- The formulas for European options on futures are
known as Blacks formulas