HullOFOD8eSolutionsCh05.doc
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CHAPTER5
DeterminationofForwardandFuturesPrices
PracticeQuestions
Problem5.1.
Explainwhathappenswhenaninvestorshortsacertainshare.
Theinvestor’sbrokerborrowsthesharesfromanotherclient’saccountandsellsthemintheusualway.Tocloseouttheposition,theinvestormustpurchasetheshares.Thebrokerthenreplacesthemintheaccountoftheclientfromwhomtheywereborrowed.Thepartywiththeshortpositionmustremittothebrokerdividendsandotherincomepaidontheshares.Thebrokertransfersthesefundstotheaccountoftheclientfromwhomtheshareswereborrowed.Occasionallythebrokerrunsoutofplacesfromwhichtoborrowtheshares.Theinvestoristhenshortsqueezedandhastocloseoutthepositionimmediately.
Problem5.2.
Whatisthedifferencebetweentheforwardpriceandthevalueofaforwardcontract?
Theforwardpriceofanassettodayisthepriceatwhichyouwouldagreetobuyorselltheassetatafuturetime.Thevalueofaforwardcontractiszerowhenyoufirstenterintoit.Astimepassestheunderlyingassetpricechangesandthevalueofthecontractmaybecomepositiveornegative.
Problem5.3.
Supposethatyouenterintoasix-monthforwardcontractonanon-dividend-payingstockwhenthestockpriceis$30andtherisk-freeinterestrate(withcontinuouscompounding)is12%perannum.Whatistheforwardprice?
Theforwardpriceis
Problem5.4.
Astockindexcurrentlystandsat350.Therisk-freeinterestrateis8%perannum(withcontinuouscompounding)andthedividendyieldontheindexis4%perannum.Whatshouldthefuturespriceforafour-monthcontractbe?
Thefuturespriceis
Problem5.5.
Explaincarefullywhythefuturespriceofgoldcanbecalculatedfromitsspotpriceandotherobservablevariableswhereasthefuturespriceofcoppercannot.
Goldisaninvestmentasset.Ifthefuturespriceistoohigh,investorswillfinditprofitabletoincreasetheirholdingsofgoldandshortfuturescontracts.Ifthefuturespriceistoolow,theywillfinditprofitabletodecreasetheirholdingsofgoldandgolonginthefuturesmarket.Copperisaconsumptionasset.Ifthefuturespriceistoohigh,astrategyofbuycopperandshortfuturesworks.However,becauseinvestorsdonotingeneralholdtheasset,thestrategyofsellcopperandbuyfuturesisnotavailabletothem.Thereisthereforeanupperbound,butnolowerbound,tothefuturesprice.
Problem5.6.
Explaincarefullythemeaningofthetermsconvenienceyieldandcostofcarry.Whatistherelationshipbetweenfuturesprice,spotprice,convenienceyield,andcostofcarry?
Convenienceyieldmeasurestheextenttowhichtherearebenefitsobtainedfromownershipofthephysicalassetthatarenotobtainedbyownersoflongfuturescontracts.Thecostofcarryistheinterestcostplusstoragecostlesstheincomeearned.Thefuturesprice,,andspotprice,,arerelatedby
whereisthecostofcarry,istheconvenienceyield,andisthetimetomaturityofthefuturescontract.
Problem5.7.
Explainwhyaforeigncurrencycanbetreatedasanassetprovidingaknownyield.
Aforeigncurrencyprovidesaknowninterestrate,buttheinterestisreceivedintheforeigncurrency.Thevalueinthedomesticcurrencyoftheincomeprovidedbytheforeigncurrencyisthereforeknownasapercentageofthevalueoftheforeigncurrency.Thismeansthattheincomehasthepropertiesofaknownyield.
Problem5.8.
Isthefuturespriceofastockindexgreaterthanorlessthantheexpectedfuturevalueoftheindex?
Explainyouranswer.
Thefuturespriceofastockindexisalwayslessthantheexpectedfuturevalueoftheindex.ThisfollowsfromSection5.14andthefactthattheindexhaspositivesystematicrisk.Foranalternativeargument,letbetheexpectedreturnrequiredbyinvestorsontheindexsothat.Becauseand,itfollowsthat.
Problem5.9.
Aone-yearlongforwardcontractonanon-dividend-payingstockisenteredintowhenthestockpriceis$40andtherisk-freerateofinterestis10%perannumwithcontinuouscompounding.
a)Whataretheforwardpriceandtheinitialvalueoftheforwardcontract?
b)Sixmonthslater,thepriceofthestockis$45andtherisk-freeinterestrateisstill10%.Whataretheforwardpriceandthevalueoftheforwardcontract?
a)Theforwardprice,,isgivenbyequation(5.1)as:
or$44.21.Theinitialvalueoftheforwardcontractiszero.
b)Thedeliverypriceinthecontractis$44.21.Thevalueofthecontract,,aftersixmonthsisgivenbyequation(5.5)as:
i.e.,itis$2.95.Theforwardpriceis:
or$47.31.
Problem5.10.
Therisk-freerateofinterestis7%perannumwithcontinuouscompounding,andthedividendyieldonastockindexis3.2%perannum.Thecurrentvalueoftheindexis150.Whatisthesix-monthfuturesprice?
Usingequation(5.3)thesixmonthfuturespriceis
or$152.88.
Problem5.11.
Assumethattherisk-freeinterestrateis9%perannumwithcontinuouscompoundingandthatthedividendyieldonastockindexvariesthroughouttheyear.InFebruary,May,August,andNovember,dividendsarepaidatarateof5%perannum.Inothermonths,dividendsarepaidatarateof2%perannum.SupposethatthevalueoftheindexonJuly31is1,300.WhatisthefuturespriceforacontractdeliverableonDecember31ofthesameyear?
Thefuturescontractlastsforfivemonths.Thedividendyieldis2%forthreeofthemonthsand5%fortwoofthemonths.Theaveragedividendyieldistherefore
Thefuturespriceistherefore
or$1331.80.
Problem5.12.
Supposethattherisk-freeinterestrateis10%perannumwithcontinuouscompoundingandthatthedividendyieldonastockindexis4%perannum.Theindexisstandingat400,andthefuturespriceforacontractdeliverableinfourmonthsis405.Whatarbitrageopportunitiesdoesthiscreate?
Thetheoreticalfuturespriceis
Theactualfuturespriceisonly405.Thisshowsthattheindexfuturespriceistoolowrelativetotheindex.Thecorrectarbitragestrategyis
1.Buyfuturescontracts
2.Shortthesharesunderlyingtheindex.
Problem5.13.
Estimatethedifferencebetweenshort-terminterestratesinMexicoandtheUnitedStatesonMay26,2010fromtheinformationinTable5.4.
Thesettlementpricesforthefuturescontractsareto
Sept:
0.76375
Dec:
0.75625
TheDecember2009priceisabout0.98%belowtheSeptember2009price.Thissuggeststhattheshort-terminterestrateintheMexicoexceededshort-terminterestrateintheUnitedStatesbyabout0.98%perthreemonthsorabout3.92%peryear.
Problem5.14.
Thetwo-monthinterestratesinSwitzerlandandtheUnitedStatesare2%and5%perannum,respectively,withcontinuouscompounding.ThespotpriceoftheSwissfrancis$0.8000.Thefuturespriceforacontractdeliverableintwomonthsis$0.8100.Whatarbitrageopportunitiesdoesthiscreate?
Thetheoreticalfuturespriceis
Theactualfuturespriceistoohigh.ThissuggeststhatanarbitrageurshouldbuySwissfrancsandshortSwissfrancsfutures.
Problem5.15.
Thespotpriceofsilveris$15perounce.Thestoragecostsare$0.24perounceperyearpayablequarterlyinadvance.Assumingthatinterestratesare10%perannumforallmaturities,calculatethefuturespriceofsilverfordeliveryinninemonths.
Thepresentvalueofthestoragecostsforninemonthsare
or$0.176.Thefuturespriceisfromequation(5.11)givenbywhere
i.e.,itis$16.36perounce.
Problem5.16.
Supposethatandaretwofuturescontractsonthesamecommoditywithtimestomaturity,and,where.Provethat
whereistheinterestrate(assumedconstant)andtherearenostoragecosts.Forthepurposesofthisproblem,assumethatafuturescontractisthesameasaforwardcontract.
If
aninvestorcouldmakearisklessprofitby
1.Takingalongpositioninafuturescontractwhichmaturesattime
2.Takingashortpositioninafuturescontractwhichmaturesattime
Whenthefirstfuturescontractmatures,theassetispurchasedforusingfundsborrowedatrater.Itisthenhelduntiltimeatwhichpointitisexchangedforunderthesecondcontract.Thecostsofthefundsborrowedandaccumulatedinterestattimeis.Apositiveprofitof
isthenrealizedattime.Thistypeofarbitrageopportunitycannotexistforlong.Hence:
Problem5.17.
Whenaknownfuturecashoutflowinaforeigncurrencyishedgedbyacompanyusingaforwardcontract,thereisnoforeignexchangerisk.Whenitishedgedusingfuturescontracts,thedailysettlementprocessdoesleavethecompanyexposedtosomerisk.Explainthenatureofthisrisk.Inparticular,considerwhetherthecompanyisbetteroffusingafuturescontractoraforwardcontractwhen
a)Thevalueoftheforeigncurrencyfallsrapidlyduringthelifeofthecontract
b)Thevalueoftheforeigncurrencyrisesrapidlyduringthelifeofthecontract
c)Thevalueoftheforeigncurrencyfirstrisesandthenfallsbacktoitsinitialvalue
d)Thevalueoftheforeigncurrencyfirstfallsandthenrisesbacktoitsinitialvalue
Assumethattheforwardpriceequalsthefuturesprice.
Intotalthegainorlossunderafuturescontractisequaltothegainorlossunderthecorrespondingforwardcontract.Howeverthetimingofthecashflowsisdifferent.Whenthetimevalueofmoneyistakenintoaccountafuturescontractmayprovetobemorevaluableorlessvaluablethanaforwardcontract.Ofcoursethecompanydoesnotknowinadvancewhichwillworkoutbetter.Thelongforwardcontractprovidesaperfecthedge