期权期货与其他衍生产品第九版课后习题与答案Chapter.docx
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期权期货与其他衍生产品第九版课后习题与答案Chapter
期权期货与其他衍生产品第九版课后习题与答案Chapter
CHAPTER29
InterestRateDerivatives:
TheStandardMarketModels
PracticeQuestions
Problem29.1.
Acompanycapsthree-monthLIBORat10%perannum.Theprincipalamountis$20million.Onaresetdate,three-monthLIBORis12%perannum.Whatpaymentwouldthisleadtounderthecap?
Whenwouldthepaymentbemade?
Anamount
20000000002025100000$$,,?
.?
.=,
wouldbepaidout3monthslater.
Problem29.2.
Explainwhyaswapoptioncanberegardedasatypeofbondoption.
Aswapoption(orswaption)isanoptiontoenterintoaninterestrateswapatacertaintimeinthefuturewithacertainfixedratebeingused.Aninterestrateswapcanberegardedastheexchangeofafixed-ratebondforafloating-ratebond.Aswaptionisthereforetheoptiontoexchangeafixed-ratebondforafloating-ratebond.Thefloating-ratebondwillbeworthitsfacevalueatthebeginningofthelifeoftheswap.Theswaptionisthereforeanoptiononafixed-ratebondwiththestrikepriceequaltothefacevalueofthebond.
Problem29.3.
UsetheBlack’smodeltovalueaone-yearEuropeanputoptionona10-yearbond.Assumethatthecurrentvalueofthebondis$125,thestrikepriceis$110,theone-yearrisk-freeinterestrateis10%perannum,thebond’sforwardpricevolatilityis8%perannum,andthepresentvalueofthecouponstobepaidduringthelifeoftheoptionis$10.
Inthiscase,0110(12510)12709Fe.?
=-=.,110K=,011(0)PTe-.?
=,008Bσ=.,and10T=..2121ln(12709110)(0082)18456008
00817656
ddd./+./==..=-.=.Fromequation(29.2)th
evalueo
ftheputoptionis
011011110(17656)12709(18456)012eNeN-.?
-.?
-.-.-.=.
or$0.12.
Problem29.4.
Explaincarefullyhowyouwoulduse(a)spotvolatilitiesand(b)flatvolatilitiestovalueafive-yearcap.
Whenspotvolatilitiesareusedtovalueacap,adifferentvolatilityisusedtovalueeach
caplet.Whenflatvolatilitiesareused,thesamevolatilityisusedtovalueeachcapletwithinagivencap.Spotvolatilitiesareafunctionofthematurityofthecaplet.Flatvolatilitiesarea
functionofthematurityofthecap.
Problem29.5.
Calculatethepriceofanoptionthatcapsthethree-monthrate,startingin15months’time,at13%(quotedwithquarterlycompounding)onaprincipalamountof$1,000.Theforwardinterestratefortheperiodinquestionis12%perannum(quotedwithquarterly
compounding),the18-monthrisk-freeinterestrate(continuouslycompounded)is11.5%perannum,andthevolatilityoftheforwardrateis12%perannum.
Inthiscase1000L=,025kδ=.,012kF=.,013KR=.,0115r=.,012kσ=.,125kt=.,1(0)08416kPt+,=..
250kLδ=
212052*********6637
dd==-.=-.-.=-.Th
evalueo
ftheoptionis
25008416[012(05295)013(06637)]NN?
.?
.-.-.-.
059=.or$0.59.
Problem29.6.
AbankusesBlack’smodeltopriceEuropeanbondoptions.Supposethatanimpliedpricevolatilityfora5-yearoptiononabondmaturingin10yearsisusedtopricea9-yearoptiononthebond.Wouldyouexpecttheresultantpricetobetoohighortoolow?
Explain.
Theimpliedvolatilitymeasuresthestandarddeviationofthelogarithmofthebondpriceatthematurityoftheoptiondividedbythesquarerootofthetimetomaturity.Inthecaseofafiveyearoptiononatenyearbond,thebondhasfiveyearsleftatoptionmaturity.Inthecaseofanineyearoptiononatenyearbondithasoneyearleft.Thestandarddeviationofaoneyearbondpriceobservedinnineyearscanbenormallybeexpectedtobeconsiderablylessthanthatofafiveyearbondpriceobservedinfiveyears.(SeeFigure29.1.)Wewouldthereforeexpectthepricetobetoohigh.
Problem29.7.
Calculatethevalueofafour-yearEuropeancalloptiononbondthatwillmaturefiveyearsfromtodayusingBlack’smodel.Thefive-yearcashbondpriceis$105,thecashpriceofafour-yearbondwiththesamecouponis$102,thestrikepriceis$100,thefour-yearrisk-freeinterestrateis10%perannumwithcontinuouscompounding,andthevolatilityforthebondpriceinfouryearsis2%perannum.
Thepresentvalueoftheprincipalinthefouryearbondis40110067032e-?
.=..Thepresentvalueofthecouponsis,therefore,1026703234968-.=..Thismeansthattheforwardpriceofthefive-yearbondis
401(10534968)104475e?
.-.=.TheparametersinBlack’smodelaretherefore104475BF=.,100K=,01r=.,4T=,
and002B=.σ.
212111144010744
ddd==.=-.=.Th
epriceo
ftheEuropeancallis
014[104475(11144)100(10744)]319eNN-.?
..-.=.
or$3.19.
Problem29.8.
Iftheyieldvolatilityforafive-yearputoptiononabondmaturingin10yearstimeis
specifiedas22%,howshouldtheoptionbevalued?
Assumethat,basedontoday’sinterestratesthemodifieddurationofthebondatthematurityoftheoptionwillbe4.2yearsandtheforwardyieldonthebondis7%.
TheoptionshouldbevaluedusingBlack’smodelinequation(29.2)withthebondpricevolatilitybeing
4200702200647.?
.?
.=.or6.47%.
Problem29.9.
Whatotherinstrumentisthesameasafive-yearzero-costcollarwherethestrikepriceofthecapequalsthestrikepriceofthefloor?
Whatdoesthecommonstrikepriceequal?
A5-yearzero-costcollarwherethestrikepriceofthecapequalsthestrikepriceoftheflooristhesameasaninterestrateswapagreementtoreceivefloatingandpayafixedrateequaltothestrikeprice.Thecommonstrikepriceistheswaprate.Notethattheswapisactuallyaforwardswapthatexcludesthefirstexchange.(SeeBusinessSnapshot29.1)
Problem29.10.
Deriveaput–callparityrelationshipforEuropeanbondoptions.
Therearetwowayofexpressingtheput–callparityrelationshipforbondoptions.Thefirstisintermsofbondprices:
0RTcIKepB-++=+
wherecisthepriceofaEuropeancalloption,pisthepriceofthecorrespondingEuropeanputoption,Iisthepresentvalueofthebondcouponpaymentsduringthelifeoftheoption,Kisthestrikeprice,Tisthetimetomaturity,0Bisthebondprice,andR
istherisk-freeinterestrateforamaturityequaltothelifeoftheoptions.Toprovethiswecanconsidertwoportfolios.ThefirstconsistsofaEuropeanputoptionplusthebond;thesecondconsistsoftheEuropeancalloption,andanamountofcashequaltothepresentvalueofthecouponsplusthepresentvalueofthestrikeprice.Bothcanbeseentobeworththesameatthematurityoftheoptions.
Thesecondwayofexpressingtheput–callparityrelationshipis
RTRTBcKepFe--+=+
whereBFistheforwardbondprice.Thiscanalsobeprovedbyconsideringtwoportfolios.ThefirstconsistsofaEuropeanputoptionplusaforwardcontractonthebondplusthepresentvalueoftheforwardprice;thesecondconsistsofaEuropeancalloptionplusthe
presentvalueofthestrikeprice.Bothcanbeseentobeworththesameatthematurityoftheoptions.
Problem29.11.
Deriveaput–callparityrelationshipforEuropeanswapoptions.
Theput–callparityrelationshipforEuropeanswapoptionsis
+=
cVp
wherecisthevalueofacalloptiontopayafixedrateof
sandreceivefloating,pis
K
thevalueofaputoptiontoreceiveafixedrateof
sandpayfloating,andVisthevalue
K
oftheforwardswapunderlyingtheswapoptionwhere
sisreceivedandfloatingispaid.
K
Thiscanbeprovedbyconsideringtwoportfolios.Thefirstconsistsoftheputoption;thesecondconsistsofthecalloptionandtheswap.Supposethattheactualswaprateatthe
s.Thecallwillbeexercisedandtheputwillnotbematurityoftheoptionsisgreaterthan
K
exercised.Bothportfoliosarethenworthzero.Supposenextthattheactualswaprateatthe
s.Theputoptionisexercisedandthecalloptionisnotmaturityoftheoptionsislessthan
K
sisreceivedandfloatingispaid.exercised.Bothportfoliosareequivalenttoaswapwhere
K
InallstatesoftheworldthetwoportfoliosareworththesameattimeT.Theymustthereforebeworththesametoday.Thisprovestheresult.
Problem29.12.
ExplainwhythereisanarbitrageopportunityiftheimpliedBlack(flat)volatilityofacapisdifferentfromthatofafloor.DothebrokerquotesinTable29.1presentanarbitrageopportunity?
Supposethatthecapandfloorhavethesamestrikepriceandthesametimetomaturity.Thefollowingput–callparityrelationshipmusthold:
+=
capswapfloor
wheretheswapisanagreementtoreceivethecaprateandpayfloatingoverthewholelifeofthecap/floor.IftheimpliedBlackvolatilitiesforthecapequalthoseforthefloor,theBlackformulasshowthatthisrelationshipholds.Inothercircumstancesitdoesnotholdandthereisanarbitrageopportunity.ThebrokerquotesinTable29.1donotpresentanarbitrageopportunitybecausethecapofferisalwayshigherthanthefloorbidandthefloorofferisalwayshigherthanthecapbid.
Problem29.13.
Whenabond’spriceislognormalcanthebond’syieldbenegative?
Explainyouranswer.
Yes.Ifazero-couponbondpriceatsomefuturetimeislognormal,thereissomechancethatthepricewillbeabovepar.Thisinturnimpliesthattheyieldtomaturityonthebondisnegative.
Problem29.14.
WhatisthevalueofaEuropeanswapoptionthatgivestheholdertherighttoenterintoa
3-yearannual-payswapinfouryearswhereafixedrateof5%ispaidandLIBORisreceived?
Theswapprincipalis$10million.AssumethattheLIBOR/swapyieldcurveisusedfordiscountingandisflatat5%perannumwithannualcompoundingandthevolatilityoftheswaprateis20%.CompareyouranswertothatgivenbyDerivaGem.Nowsupposethatall
swapratesare5%andallOISratesare4.7%.UseDerivaGemtocalculatetheLIBORzerocurveandtheswapoptionvalue?