期货与期权9习题解答
- 格式:doc
- 大小:249.00 KB
- 文档页数:9
CHAPTER 31Interest Rate Derivatives: Models of the Short Rate Practice QuestionsProblem 31.1.What is the difference between an equilibrium model and a no-arbitrage model?Equilibrium models usually start with assumptions about economic variables and derive the behavior of interest rates. The initial term structure is an output from the model. In ano-arbitrage model the initial term structure is an input. The behavior of interest rates in ano-arbitrage model is designed to be consistent with the initial term structure.Problem 31.2.Suppose that the short rate is currently 4% and its standard deviation is 1% per annum. What happens to the standard deviation when the short rate increases to 8% in (a) Vasicek’s model;(b) Rendleman and Bartter’s mod el; and (c) the Cox, Ingersoll, and Ross model?In Vasicek’s model the standard deviation stays at 1%. In the Rendleman and Bartter model the standard deviation is proportional to the level of the short rate. When the short rate increases from 4% to 8% the standard deviation increases from 1% to 2%. In the Cox, Ingersoll, and Ross model the standard deviation of the short rate is proportional to the square root of the short rate. When the short rate increases from 4% to 8% the standard deviation increases from 1% to 1.414%.Problem 31.3.If a stock price were mean reverting or followed a path-dependent process there would be market inefficiency. Why is there not market inefficiency when the short-term interest rate does so?If the price of a traded security followed a mean-reverting or path-dependent process there would be market inefficiency. The short-term interest rate is not the price of a traded security. In other words we cannot trade something whose price is always the short-term interest rate. There is therefore no market inefficiency when the short-term interest rate follows amean-reverting or path-dependent process. We can trade bonds and other instruments whose prices do depend on the short rate. The prices of these instruments do not followmean-reverting or path-dependent processes.Problem 31.4.Explain the difference between a one-factor and a two-factor interest rate model.In a one-factor model there is one source of uncertainty driving all rates. This usually means that in any short period of time all rates move in the same direction (but not necessarily by the same amount). In a two-factor model, there are two sources of uncertainty driving all rates. The first source of uncertainty usually gives rise to a roughly parallel shift in rates. The second gives rise to a twist where long and short rates moves in opposite directions.Problem 31.5.Can the approach described in Section 31.4 for decomposing an option on a coupon-bearing bond into a portfolio of options on zero-coupon bonds be used in conjunction with a two-factor model? Explain your answer.No. The approach in Section 31.4 relies on the argument that, at any given time, all bond prices are moving in the same direction. This is not true when there is more than one factor.Problem 31.6.Suppose that 01a =. and 01b =. in both the Vasicek and the Cox, Ingersoll, Ross model. In both models, the initial short rate is 10% and the initial standard deviation of the short rate change in a short time t ∆is 0.zero-coupon bond that matures in year 10.In Vasicek’s model, 01a =., 01b =., and 002σ=. so that01101(10)(1)63212101B t t e -.⨯,+=-=..22(63212110)(010100002)00004632121(10)exp 00104A t t ⎡⎤.-.⨯.-..⨯.,+=-⎢⎥..⎣⎦071587=. The bond price is therefore 63212101071587038046e -.⨯..=.In the Cox, Ingersoll, and Ross model, 01a =., 01b =.and 00200632σ=.=.. Also013416γ==. Define10()(1)2092992a e γβγγ=+-+=.102(1)(10)607650e B t t γβ-,+==.225()2(10)069746ab a e A t t σγγβ/+⎛⎫,+==. ⎪⎝⎭The bond price is therefore 60765001069746037986e -.⨯..=.Problem 31.7.Suppose that 01a =., 008b =., and 0015σ=. in Vasicek’s model with the initial value of the short rate being 5%. Calculate the price of a one-year European call option on azero-coupon bond with a principal of $100 that matures in three years when the strike price is $87.Using the notation in the text, 3s =, 1T =, 100L =, 87K =, and2010015(1002588601P e σ-⨯..=-=.. From equation (31.6), (01)094988P ,=., (03)085092P ,=., and 114277h =. so thatequation (31.20) gives the call price as call price is 100085092(114277)87094988(111688)259N N ⨯.⨯.-⨯.⨯.=. or $2.59.Problem 31.8.Repeat Problem 31.7 valuing a European put option with a strike of $87. What is the put –call parity relationship between the prices of European call and put options? Show that the put and call option prices satisfy put –call parity in this case.As mentioned in the text, equation (31.20) for a call option is essentially the same as Bl ack’s model. By analogy with Black’s formulas corresponding expression for a put option is (0)()(0)()P KP T N h LP s N h σ,-+-,- In this case the put price is 87094988(111688)100085092(114277)014N N ⨯.⨯-.-⨯.⨯-.=.Since the underlying bond pays no coupon, put –call parity states that the put price plus the bond price should equal the call price plus the present value of the strike price. The bond price is 85.09 and the present value of the strike price is 870949888264⨯.=.. Put –call parity is therefore satisfied:82642598509014.+.=.+.Problem 31.9.Suppose that 005a =., 008b =., and 0015σ=. in Vasicek’s model with the initialshort-term interest rate being 6%. Calculate the price of a 2.1-year European call option on a bond that will mature in three years. Suppose that the bond pays a coupon of 5% semiannually. The principal of the bond is 100 and the strike price of the option is 99. The strike price is the cash price (not the quoted price) that will be paid for the bond.As explained in Section 31.4, the first stage is to calculate the value of r at time 2.1 years which is such that the value of the bond at that time is 99. Denoting this value of r by r *, we must solve(2125)(2130)25(2125)1025(2130)99B r B r A e A e **-.,.-.,...,.+..,.=where the A and B functions are given by equations (31.7) and (31.8). In this case A (2.1, 2.5)=0.999685, A (2.1,3.0)=0.998432, B(2.1,2.5)=0.396027, and B (2.1, 3.0)= 0.88005. and Solver shows that 065989.0*=r . Since434745.2)5.2,1.2(5.2*)5.2,1.2(=⨯-r B e Aand56535.96)0.3,1.2(5.102*)0.3,1.2(=⨯-r B e Athe call option on the coupon-bearing bond can be decomposed into a call option with a strike price of 2.434745 on a bond that pays off 2.5 at time 2.5 years and a call option with a strike price of 96.56535 on a bond that pays off 102.5 at time 3.0 years. The options are valued using equation (31.20).For the first option L =2.5, K = 2.434745, T = 2.1, and s =2.5. Also, A (0,T )=0.991836, B (0,T ) = 1.99351, P (0,T )=0.880022 while A (0,s )=0.988604, B (0,s )=2.350062, andP (0,s )=0.858589. Furthermore σP = 0.008176 and h = 0.223351. so that the option price is 0.009084.For the second option L =102.5, K = 96.56535, T = 2.1, and s =3.0. Also, A (0,T )=0.991836, B (0,T ) = 1.99351, P (0,T )=0.880022 while A (0,s )=0.983904, B (0,s )=2.78584, andP (0,s )=0.832454. Furthermore σP = 0.018168 and h = 0.233343. so that the option price is0.806105.The total value of the option is therefore 0.0090084+0.806105=0.815189.Problem 31.10.Use the answer to Problem 31.9 and put –call parity arguments to calculate the price of a put option that has the same terms as the call option in Problem 31.9.Put-call parity shows that: 0()c I PV K p B ++=+ or 0()()p c PV K B I =+--where c is the call price, K is the strike price, I is the present value of the coupons, and 0B is the bond price. In this case 08152c =., ()99(021)871222PV K P =⨯,.=., 025(025)1025(03)874730B I P P -=.⨯,.+.⨯,=. so that the put price is0815287122287473004644.+.-.=.Problem 31.11.In the Hull –White model, 008a =. and 001σ=.. Calculate the price of a one-year European call option on a zero-coupon bond that will mature in five years when the term structure is flat at 10%, the principal of the bond is $100, and the strike price is $68.Using the notation in the text 011(0)09048P T e -.⨯,==. and 015(0)06065P s e -.⨯,==.. Also4008001(100329008P e σ-⨯..=-=.. and 04192h =-. so that the call price is10006065()6809048()0439P N h N h σ⨯.-⨯.-=.Problem 31.12.Suppose that 005a =. and 0015σ=. in the Hull –White model with the initial term structure being flat at 6% with semiannual compounding. Calculate the price of a 2.1-year European call option on a bond that will mature in three years. Suppose that the bond pays a coupon of 5% per annum semiannually. The principal of the bond is 100 and the strike price of the option is 99. The strike price is the cash price (not the quoted price) that will be paid for the bond.This problem is similar to Problem 31.9. The difference is that the Hull –White model, which fits an initial term structure, is used instead of Vasicek’s model where the initial term structure is determined by the model.The yield curve is flat with a continuously compounded rate of 5.9118%.As explained in Section 31.4, the first stage is to calculate the value of r at time 2.1 years which is such that the value of the bond at that time is 99. Denoting this value of r by r *, we must solve(2125)(2130)25(2125)1025(2130)99B r B r A e A e **-.,.-.,...,.+..,.=where the A and B functions are given by equations (31.16) and (31.17). In this case A (2.1, 2.5)=0.999732, A (2.1,3.0)=0.998656, B(2.1,2.5)=0.396027, and B (2.1, 3.0)= 0.88005. and Solver shows that 066244.0*=r . Since434614.2)5.2,1.2(5.2*)5.2,1.2(=⨯-r B e Aand56539.96)0.3,1.2(5.102*)0.3,1.2(=⨯-r B e Athe call option on the coupon-bearing bond can be decomposed into a call option with a strike price of 2.434614 on a bond that pays off 2.5 at time 2.5 years and a call option with a strike price of 96.56539 on a bond that pays off 102.5 at time 3.0 years. The options are valued using equation (31.20).For the first option L =2.5, K = 2.434614, T = 2.1, and s =2.5. Also, P (0,T )=exp(-0.059118×2.1)=0.88325 and P (0,s )= exp(-0.059118×2.5)=0.862609. Furthermore σP = 0.008176 and h = 0.353374. so that the option price is 0.010523. For the second option L =102.5, K = 96.56539, T = 2.1, and s =3.0. Also, P (0,T )=exp(-0.059118×2.1)=0.88325 and P (0,s )= exp(-0.059118×3.0)=0.837484. Furthermore σP = 0.018168 and h = 0.363366. so that the option price is 0.934074.The total value of the option is therefore 0.010523+0.934074=0.944596.Problem 31.13.Observations spaced at intervals ∆t are taken on the short rate. The ith observation is r i (1 ≤ i ≤ m). Show that the maximum likelihood estimates of a, b, and σ in Vasicek’s model are given by maximizing[]∑=--⎪⎪⎭⎫ ⎝⎛∆σ∆----∆σ-m i i i i t t r b a r r t 122112)()ln(What is the corresponding result for the CIR model?The change r i –r i -1 is normally distributed with mean a (b − r i -1) and variance σ2∆t. The probability density of the observation is⎪⎭⎫⎝⎛∆σ---∆πσ--t r b a r r ti i i 21122)(exp 21We wish to maximize∏=--⎪⎭⎫⎝⎛∆σ---∆πσmi i i i t r b a r r t121122)(exp 21Taking logarithms, this is the same as maximizing[]∑=--⎪⎪⎭⎫ ⎝⎛∆σ∆----∆σ-m i i i i t t r b a r r t 122112)()ln(In the case of the CIR model, the change r i –r i -1 is normally distributed with mean a (b − r i -1) and variance t r i ∆σ-12and the maximum likelihood function becomes[]∑=----⎪⎪⎭⎫ ⎝⎛∆σ∆----∆σ-mi i i i i i t r t r b a r r t r 11221112)()ln(Problem 31.14.Suppose 005a =., 0015σ=., and the term structure is flat at 10%. Construct a trinomial tree for the Hull –White model where there are two time steps, each one year in length.The time step, t ∆, is 1 so that 0002598r ∆=.=.. Also max 4j = showing that the branching method should change four steps from the center of the tree. With only three steps we never reach the point where the branching changes. The tree is shown in Figure S31.1.Figure S31.1: Tree for Problem 31.14Problem 31.15.Calculate the price of a two-year zero-coupon bond from the tree in Figure 31.6.A two-year zero-coupon bond pays off $100 at the ends of the final branches. At nodeB it is worth 01211008869e -.⨯=.. At nodeC it is worth 010********e -.⨯=.. At nodeD it is worth 00811009231e -.⨯=.. It follows that at node A the bond is worth 011(88690259048059231025)8188e -.⨯.⨯.+.⨯.+.⨯.=. or $81.88Problem 31.16.Calculate the price of a two-year zero-coupon bond from the tree in Figure 31.9 and verify that it agrees with the initial term structure.A two-year zero-coupon bond pays off $100 at time two years. At nodeB it is worth 0069311009330e -.⨯=.. At nodeC it is worth 0052011009493e -.⨯=.. At nodeD it is worth 0034711009659e -.⨯=.. It follows that at node A the bond is worth 003821(933001679493066696590167)9137e -.⨯.⨯.+.⨯.+.⨯.=.or $91.37. Because 00451229137100e -.⨯.=, the price of the two-year bond agrees with the initial term structure.Problem 31.17.Calculate the price of an 18-month zero-coupon bond from the tree in Figure 31.10 and verify that it agrees with the initial term structure.An 18-month zero-coupon bond pays off $100 at the final nodes of the tree. At node E it is worth 0088051009570e -.⨯.=.. At node F it is worth 00648051009681e -.⨯.=.. At node G it is worth 00477051009764e -.⨯.=.. At node H it is worth 00351051009826e -.⨯.=.. At node I it is worth 00259051009871e .⨯.=.. At node B it is worth 0056405(011895700654968102289764)9417e -.⨯..⨯.+.⨯.+.⨯.=.Similarly at nodes C and D it is worth 95.60 and 96.68. The value at node A is therefore 0034305(016794170666956001679668)9392e -.⨯..⨯.+.⨯.+.⨯.=.The 18-month zero rate is 0181500800500418e -.⨯..-.=.. This gives the price of the 18-month zero-coupon bond as 00418151009392e -.⨯.=. showing that the tree agrees with the initial term structure.Problem 31.18.What does the calibration of a one-factor term structure model involve?The calibration of a one-factor interest rate model involves determining its volatility parameters so that it matches the market prices of actively traded interest rate options as closely as possible.Problem 31.19.Use the DerivaGem software to value 14⨯, 23⨯, 32⨯, and 41⨯ European swap options to receive fixed and pay floating. Assume that the one, two, three, four, and five year interest rates are 6%, 5.5%, 6%, 6.5%, and 7%, respectively. The payment frequency on the swap is semiannual and the fixed rate is 6% per annum with semiannual compounding. Use the Hull –White model with 3a %= and 1%σ=. Calcula te the volatility implied by Black’s model for each option.The option prices are 0.1302, 0.0814, 0.0580, and 0.0274. The implied Black volatilities are 14.28%, 13.64%, 13.24%, and 12.81%Problem 31.20.Prove equations (31.25), (31.26), and (31.27).From equation (31.15) ()()()()r t B t t t P t t t A t t t e -,+∆,+∆=,+∆ Also ()()R t t P t t t e -∆,+∆= so that()()()()R t t r t B t t t e A t t t e -∆-,+∆=,+∆or()()()()()()()()R t B t T t B t t t r t B t T B t T B t t t e eA t t t -,∆/,+∆-,,/,+∆=,+∆ Hence equation (31.25) is true with()ˆ()(B t T t Bt T B t t t ,∆,=,+∆ and()()()ˆ()()B t T B t t t A t T At T A t t t ,/,+∆,,=,+∆ or()ˆln ()ln ()ln ()()B t T At T A t T A t t t B t t t ,,=,-,+∆,+∆Problem 31.21.(a) What is the second partial derivative of P(t,T) with respect to r in the Vasicek and CIR models?(b) In Section 31.2, ˆDis presented as an alternative to the standard duration measure D. What is a similar alternative ˆCto the convexity measure in Section 4.9? (c) What is ˆCfor P(t,T)? How would you calculate ˆC for a coupon-bearing bond? (d) Give a Taylor Series expansion for ∆P(t,T) in terms of ∆r and (∆r)2 for Vasicek and CIR.(a) ),(),(),(),(),(2),(222T t P T t B e T t A T t B rT t P r T t B ==∂∂- (b) A corresponding definition for Cˆis 221r QQ ∂∂(c) When Q =P (t ,T ), 2),(ˆT t B C=For a coupon-bearing bond C ˆis a weighted average of the Cˆ’s for the constituent zero -coupon bonds where weights are proportional to bond prices. (d)+∆+∆-=+∆∂∂+∆∂∂=∆22222),(),(21),(),(),(21),(),(r T t P T t B r T t P T t B r rT t P r r T t P T t PProblem 31.22.Suppose that the short rate r is 4% and its real-world process is0.1[0.05]0.01dr r dt dz =-+while the risk-neutral process is0.1[0.11]0.01dr r dt dz =-+(a) What is the market price of interest rate risk?(b) What is the expected return and volatility for a 5-year zero-coupon bond in the risk-neutral world?(c) What is the expected return and volatility for a 5-year zero-coupon bond in the real world?(a) The risk neutral process for r has a drift rate which is 0.006/r higher than the real world process. The volatility is 0.01/r . This means that the market price of interest rate risk is −0.006/0.01 or −0.6.(b) The expected return on the bond in the risk-neutral world is the risk free rate of 4%. The volatility is 0.01×B (0,5) where935.31.01)5,0(51.0=-=⨯-e Bi.e., the volatility is 3.935%.(c) The process followed by the bond price in a risk-neutral world isPdz Pdt dP 03935.004.0-=Note that the coefficient of dz is negative because bond prices are negatively correlated with interest rates. When we move to the real world the return increases by the product of the market price of dz risk and −0.03935. The bond price process becomes:Pdz Pdt dP 03935.0)]03935.06.0(04.0[--⨯-+=orPdz Pdt dP 03935.006361.0-=The expected return on the bond increases from 4% to 6.361% as we move from the risk-neutral world to the real world.Further QuestionsProblem 31.23.Construct a trinomial tree for the Ho and Lee model where 002σ=.. Suppose that the initial zero-coupon interest rate for a maturities of 0.5, 1.0, and 1.5 years are 7.5%, 8%, and 8.5%. Use two time steps, each six months long. Calculate the value of a zero-coupon bond with a face value of $100 and a remaining life of six months at the ends of the final nodes of the tree. Use the tree to value a one-year European put option with a strike price of 95 on the bond. Compare the price given by your tree with the analytic price given by DerivaGem.The tree is shown in Figure S31.2. The probability on each upper branch is 1/6; the probability on each middle branch is 2/3; the probability on each lower branch is 1/6. The six month bond prices nodes E, F, G, H, I are 0144205100e -.⨯., 0119705100e -.⨯., 0095205100e -.⨯., 0070705100e -.⨯., and 0046205100e -.⨯., respectively. These are 93.04, 94.19, 95.35, 96.53, and 97.72. The payoffs from the option at nodes E, F, G, H, and I are therefore 1.96, 0.81, 0, 0, and 0. The value at node B is 0109505(0166719606667081)08192e -.⨯..⨯.+.⨯.=.. The value at node C is00851050166708101292e -.⨯..⨯.⨯=.. The value at node D is zero. The value at node A is 0075005(01667081920666701292)0215e -.⨯..⨯.+.⨯.=. The answer given by DerivaGem using the analytic approach is 0.209.Figure S31.2: Tree for Problem 31.23Problem 31.24.A trader wishes to compute the price of a one-year American call option on a five-year bond with a face value of 100. The bond pays a coupon of 6% semiannually and the (quoted) strike price of the option is $100. The continuously compounded zero rates for maturities of sixmonths, one year, two years, three years, four years, and five years are 4.5%, 5%, 5.5%, 5.8%, 6.1%, and 6.3%. The best fit reversion rate for either the normal or the lognormal model has been estimated as 5%.A one year European call option with a (quoted) strike price of 100 on the bond is actively traded. Its market price is $0.50. The trader decides to use this option for calibration. Use the DerivaGem software with ten time steps to answer the following questions.(a) Assuming a normal model, imply the σ parameter from the price of the European option.(b) Use the σ parameter to calculate the price of the option when it is American. (c) Repeat (a) and (b) for the lognormal model. Show that the model used does notsignificantly affect the price obtained providing it is calibrated to the known European price.(d) Display the tree for the normal model and calculate the probability of a negative interest rate occurring.(e) Display the tree for the lognormal model and verify that the option price is correctly calculated at the node where, with the notation of Section 31.7, 9i = and 1j =-.Using 10 time steps:(a) The implied value of σ is 1.12%.(b) The value of the American option is 0.595(c) The implied value of σ is 18.45% and the value of the American option is 0.595. Thetwo models give the same answer providing they are both calibrated to the same European price.(d) We get a negative interest rate if there are 10 down moves. The probability of this is0.16667×0.16418×0.16172×0.15928×0.15687×0.15448×0.15212×0.14978×0.14747 ×0.14518=8.3×10-9 (e) The calculation is0052880101641791707502789e -.⨯..⨯.⨯=.Problem 31.25.Use the DerivaGem software to value 14⨯, 23⨯, 32⨯, and 41⨯ European swap options to receive floating and pay fixed. Assume that the one, two, three, four, and five year interest rates are 3%, 3.5%, 3.8%, 4.0%, and 4.1%, respectively. The payment frequency on the swap is semiannual and the fixed rate is 4% per annum with semiannual compounding. Use thelognormal model with 5a %=, 15%σ=, and 50 time steps. Calculate the volatility implied by Black’s model for each option.The values of the four European swap options are 1.72, 1.73, 1.30, and 0.65, respectively. The implied Black volatilities are 13.37%, 13.41%, 13.43%, and 13.42%, respectively.Problem 31.26.Verify that the DerivaGem software gives Figure 31.11 for the example considered. Use the software to calculate the price of the American bond option for the lognormal and normalmodels when the strike price is 95, 100, and 105. In the case of the normal model, assume that a = 5% and σ = 1%. Discuss the results in the context of the heavy-tails arguments of Chapter 20.With 100 time steps the lognormal model gives prices of 5.585, 2.443, and 0.703 for strike prices of 95, 100, and 105. With 100 time steps the normal model gives prices of 5.508, 2.522, and 0.895 for the three strike prices respectively. The normal model gives a heavier left tail and a less heavy right tail than the lognormal model for interest rates. This translates into a less heavy left tail and a heavier right tail for bond prices. The arguments in Chapter 20 show that we expect the normal model to give higher option prices for high strike prices and lower option prices for low strike. This is indeed what we find.Problem 31.27.Modify Sample Application G in the DerivaGem Application Builder software to test theconvergence of the price of the trinomial tree when it is used to price a two-year call option on a five-year bond with a face value of 100. Suppose that the strike price (quoted) is 100, the coupon rate is 7% with coupons being paid twice a year. Assume that the zero curve is as in Table 31.2. Compare results for the following cases:(a) Option is European; normal model with 001σ=. and 005a =..(b) Option is European; lognormal model with 015σ=. and 005a =..(c) Option is American; normal model with 001σ=. and 005a =..(d) Option is American; lognormal model with 015σ=. and 005a =..The results are shown in Figure S31.3.Figure S31.3: Tree for Problem 31.27Problem 31.28.Suppose that the (CIR) process for short-rate movements in the (traditional) risk-neutral world is()dr a b r dt =-+and the market price of interest rate risk is λ(a) What is the real world process for r?(b) What is the expected return and volatility for a 10-year bond in the risk-neutral world? (c) What is the expected return and volatility for a 10-year bond in the real world?(a) The volatility of r (i.e., the coefficient of rdz in the process for r ) is real world process for r is therefore increased by r r λσ⨯ so that the process isdz r dt r r b a dr σ+λσ+-=])([(b) The expected return is r and the volatility is (,B t T σin the risk-neutral world.(c) The expected return is r T t B r ),(λσ+ and the volatility is as in (b) in the real world.。
cHAPTra KI betUrM M«4duxn«x<^ ar ••••• f«g ・t plM OM<a to MB ll ・—TL —▼rMdV — ■ M 9•&・ Mtw«aH 叩■厂 1—、M»A-l S*2*0«M ■■ ^7521 1*4SeM 0|«tc4WB* ap*w ^«K « <* o az «•«!io •e ・fOMHVu ・w« Aft. xW*・9«v MBMk t» W*»|w «WM !•«•••— %-V> K ・9. ■・•( •*©> T-»» ■.空竺J 马A 空兰.…计•A SK<•4 «>A7・・1・•・R ・08*・5ZE 11*.F<<O<MI4WV ■❷•waw JttM <«•<«■■ J ・I9H74・ MrtMyiiPH—W ・(VAlw«・・,•■■■>•・" M «M 4 MI « E f R —W •字•字)vfViurutMjnr^vMtai 111 A —i"・^«hW —WI4»••一 y wt 卯 v >•*♦ *» <wr* 戸 x« tv•I Mt «wM ■*■<> «W ■・vfl !• mtvwvF k» VKM »> t»l • p< c» IW Mk vtt»•••• MM• tl»>■斗・4r.•丄防| n*kw !•*J M **vWatAM)' H MB*・朴・卜:卞”・ 4tJJ• Mm K -W ・ r ・Q.・ 9-QS.M > T-«» ・4CMP»c»to« A ■a0>■!«<•(■・•《 Mkwtaa 血”•>« «WE>y«»«vP • IF —・••—■—■科M4_ <tl ・oaMalWMi .11创n 11MM ■— 一A""・v«r■n«^»a w'«•!•<.•..»■ •> i- a-k>―初|・(« _F0R »*i!<■<■« i ・9” ■*!•«••«・》MM E ・》*k>e« —«E.r ■MIC ■一* »» ■•• ”・$«s» •• ts. no ¥ wr ■5— wK ・・«■•*・•••■•••・•••• *♦"■・••••・”•・•・~•l*« f*ASK"*""b QU ,,•・"♦(■* rI・・t ・K •WR XVIM •一刪・0|«・・・<||"• 8K kfk •■>•••<• ■…m»«*w<WH ” IK* lMW«IM iewr mu ■・—A« 巧 ki j«"U >• >^*10* t••<!•.»<»• ••••(■a * 、・r R if 。
期货从业:期权试题及答案(题库版)1、判断题欧式期权是在欧洲普遍采用的一种期权。
O正确答案:错参考解析:美式期权与欧式期权的划分并无地域上的区别。
近年来,无论在欧洲还是在美国,或是其他地区,美式期权已占据主流,欧式期权(江南博哥)虽然仍存在,但其交易量已比不上美式期权。
2、判断题在期权交易中,期权的买方有权在其认为合造的时候行使权力,但并不负有必须买入或卖出的义务。
期权合约的卖方却没有任何权力,而只有义务满足期权买方要求履行合约时买入或卖出一定数量的期货合约。
O正确答案:对3、判断题期权交易的绝大部分均是通过履约平仓的方式进行的。
O正确答案:错4、判断题看涨期权的买方要想对冲了结在手的合约头寸,其应当买入同样内容、同等数量的看跌期权合约。
O正确答案:错参考解析:看涨期权的买方要想对冲了结在手的合约部位,只需卖出同样内容、同等数量的看涨期权合约即可。
5、单选芝加哥期货交易所大豆期货期权合约报价14.3,14.3表示的是O美分/蒲式耳。
A.14.125B.14.25C.14.375D.14.75正确答案:C参考后析:在期货期权合约中,报价以1/8美分或1/8美分的整数倍出现。
14.3表示的是14+1/8x3=14.375(美分/蒲式耳)。
6、多选下列哪些场合可以进行卖出看跌期权?()A.预期后市下跌或见顶B.预期后市看涨C.认为市场已经见底D.标的物市场处于牛市正确答案:B,C,D参考解析:本题考查卖出看跌期权的运用。
7、多选执行价格又称OoA.履约价格B.敲定价格C.交付价格D.行权价格正确答案:A,B,D参考解析:加行⅛r格是进行履约时的价格,也称敲定价格和行权价格。
C项交付价格是商品交割时的价格,与执行价格不同。
8、单选只能在合约到期日被执行的期权,是OOA.看跌期权B.美式期权C.看涨期权D.欧式期权正确答案:D参考解析:欧式期权在规定的合约到期日方可行使权利,期权买方在期权合约到期日之前不•熊行使权利;美式期权可在期权到期日行权,也可在期权到期前任一交易日行权;看涨期权是约定将来以一定价格买入标的资产的期权;看跌期权是约定将来以一定价格卖出标的资产的期权。
1.在我国,批准设立期货的机构是A期货交易所2.期货合约是在D现货合同和现货远期合约的基础上发展起来的合约3.期货交易有实物交易和B对冲平仓两种履约方式4.在今年十月时,CBOT小麦市场的基差为-2美分/蒲式耳,到了8月,基差变为5美分/蒲式耳,表明市场状态从正向转变为市场,这种变化基差为A走强5.某投资者买入一份看涨期权,在某一时点,该期权的资产市场大雨执行价格,则在此时该期权是一份A实值期权6.期货交易者在期货交易所买卖期货合约的目的是B转移价格风险,获取风险收益7.某投资者购买了一份看跌期权,若期权费为C,执行价格为X,则当标的资产价格为B (X-C),该投资者不赚不赔.8.某投资者若在3个月后将获得一笔资金,并希望用该笔资金进行股票投资,但是担心股市整体上涨从而影响其投资成本,这种情况下可采取B股指期货的多头套期保值9.在期权交易中,买入看涨期权最大的损失是A期权费10.在反向市场中,当客户在做买入套期保值时,如果基差缩小,在不考虑交易手续费的情况下,则客户将会A盈利11.在形态理论中,属于持续整理形态的有C旗形12.当合约到期时,以B标的物所有权转移进行的交割为实物交割13.下为实值期权的是B执行价格为300,市场价格为350的买入看涨期权14.短期国库券期属于C利率期货15.B期货价格能反映多种生产要素在在未来一定时期的变化趋势,具有超前性16.套期保值的基本原理是B建立对冲组合17.客户保证金不足时应B及时追加保证金或自行平仓18.当期货合约临近到期时,现货价格与期货价格之间的基差接近于B零19.加工商和农场主通常所采用的套期保值方式是D多头套期保值,空头套期保值20.期货交易和交割的时间顺序是B通常在交易前,交割在后多选题1早期期货市场具有以下特点A起源于远期合约市场B投机者少,市场流动性小D实物交割比重大2对基差的理解正确的是A基差是衡量期货价格与现货价格关系的重要指标C在正向市场上基差的负债D理论上基差最终在交割同趋于零3在期货市场中,套期保值能够实现的原理是A现货市场和期货市场的价格具有趋同性D当期货合约临近交割时,现货价格与期货价格趋于一致。
赫尔《期权、期货及其他衍生产品》(第9版)笔记和课后习题详解目录第1章引言1.1复习笔记1.2课后习题详解第2章期货市场的运作机制2.1复习笔记2.2课后习题详解第3章利用期货的对冲策略3.1复习笔记3.2课后习题详解第4章利率4.1复习笔记4.2课后习题详解第5章如何确定远期和期货价格5.1复习笔记5.2课后习题详解第6章利率期货6.1复习笔记6.2课后习题详解第7章互换7.1复习笔记7.2课后习题详解第8章证券化与2007年信用危机8.1复习笔记8.2课后习题详解第9章OIS贴现、信用以及资金费用9.1复习笔记9.2课后习题详解第10章期权市场机制10.1复习笔记10.2课后习题详解第11章股票期权的性质11.1复习笔记11.2课后习题详解第12章期权交易策略12.1复习笔记12.2课后习题详解第13章二叉树13.1复习笔记13.2课后习题详解第14章维纳过程和伊藤引理14.1复习笔记14.2课后习题详解第15章布莱克-斯科尔斯-默顿模型15.1复习笔记15.2课后习题详解第16章雇员股票期权16.1复习笔记16.2课后习题详解第17章股指期权与货币期权17.1复习笔记17.2课后习题详解第18章期货期权18.1复习笔记18.2课后习题详解第19章希腊值19.1复习笔记19.2课后习题详解第20章波动率微笑20.1复习笔记20.2课后习题详解第21章基本数值方法21.1复习笔记21.2课后习题详解第22章风险价值度22.1复习笔记22.2课后习题详解第23章估计波动率和相关系数23.1复习笔记23.2课后习题详解第24章信用风险24.1复习笔记24.2课后习题详解第25章信用衍生产品25.1复习笔记25.2课后习题详解第26章特种期权26.1复习笔记26.2课后习题详解第27章再谈模型和数值算法27.1复习笔记27.2课后习题详解第28章鞅与测度28.1复习笔记28.2课后习题详解第29章利率衍生产品:标准市场模型29.1复习笔记29.2课后习题详解第30章曲率、时间与Quanto调整30.1复习笔记30.2课后习题详解第31章利率衍生产品:短期利率模型31.1复习笔记31.2课后习题详解第32章HJM,LMM模型以及多种零息曲线32.1复习笔记32.2课后习题详解第33章再谈互换33.1复习笔记33.2课后习题详解第34章能源与商品衍生产品34.1复习笔记34.2课后习题详解第35章章实物期权35.1复习笔记35.2课后习题详解第36章重大金融损失与借鉴36.1复习笔记36.2课后习题详解赫尔的《期权、期货及其他衍生产品》是世界上流行的证券学教材之一。
第1章引言1.3远期合约多头与远期合约空头的区别是什么?答:持有远期合约多头的交易者同意在未来某一确定的时间以某一确定的价格购买一定数量的标的资产;而持有远期合约空头的交易者则同意在未来某一确定的时间以某一确定的价格出售一定数量的标的资产。
1.6某交易员进入期货价格每磅50美分的棉花远期合约空头方。
合约的规模是50000磅棉花。
当合约结束时棉花的价格分别为(a)每磅48.20美分,(b)每磅51.30美分,对应以上价格交易员的盈亏为多少?答:(a)此时交易员将价值48.20美分/磅的棉花以50美分/磅的价格出售,收益=(0.50 00-0.482)×50000=900(美元)。
(b)此时交易员将价值51.30美分/磅的棉花以50美分/磅的价格出售,损失=(0.513 -0.500)×50000=650(美元)。
1.9你认为某股票价格将要上升,股票的当前价格为29美元,而3个月期限,执行价格为30美元的看涨期权价格为2.90美元,你总共有5800美元的资金。
说明两种投资方式:一种是利用股票,另一种是利用期权。
每种方式的潜在盈亏是什么?答:在目前的资金规模条件下,一种方式为买入200只股票,另一种方式是买入2000个期权(即20份合约)。
如果股票价格走势良好,第二种方式将带来更多收益。
例如,如果股票价格上升到40美元,将从第二种方式获得2000×(40-30)-5800=14200(美元),而从第一种方式中仅能获得200×(40-29)=2200(美元)。
然而,当股票价格下跌时,第二种方式将导致更大的损失。
例如,如果股票价格下跌至25美元,第一种方式的损失为200×(29-25)=800(美元),而第二种方式的损失为全部5800美元的投资。
这个例子说明了期权交易的杠杆作用。
1.12解释为什么期货合约既可以用于投机也可以用于对冲。
答:如果一个交易员对一资产的价格变动有风险敞口,他可以用一个期货合约来进行对冲。
第1章引言1.3远期合约多头与远期合约空头的区别是什么?答:持有远期合约多头的交易者同意在未来某一确定的时间以某一确定的价格购买一定数量的标的资产;而持有远期合约空头的交易者则同意在未来某一确定的时间以某一确定的价格出售一定数量的标的资产。
1.6某交易员进入期货价格每磅50美分的棉花远期合约空头方。
合约的规模是50000磅棉花。
当合约结束时棉花的价格分别为(a)每磅48.20美分,(b)每磅51.30美分,对应以上价格交易员的盈亏为多少?答:(a)此时交易员将价值48.20美分/磅的棉花以50美分/磅的价格出售,收益=(0.50 00-0.482)×50000=900(美元)。
(b)此时交易员将价值51.30美分/磅的棉花以50美分/磅的价格出售,损失=(0.513 -0.500)×50000=650(美元)。
1.9你认为某股票价格将要上升,股票的当前价格为29美元,而3个月期限,执行价格为30美元的看涨期权价格为2.90美元,你总共有5800美元的资金。
说明两种投资方式:一种是利用股票,另一种是利用期权。
每种方式的潜在盈亏是什么?答:在目前的资金规模条件下,一种方式为买入200只股票,另一种方式是买入2000个期权(即20份合约)。
如果股票价格走势良好,第二种方式将带来更多收益。
例如,如果股票价格上升到40美元,将从第二种方式获得2000×(40-30)-5800=14200(美元),而从第一种方式中仅能获得200×(40-29)=2200(美元)。
然而,当股票价格下跌时,第二种方式将导致更大的损失。
例如,如果股票价格下跌至25美元,第一种方式的损失为200×(29-25)=800(美元),而第二种方式的损失为全部5800美元的投资。
这个例子说明了期权交易的杠杆作用。
1.12解释为什么期货合约既可以用于投机也可以用于对冲。
答:如果一个交易员对一资产的价格变动有风险敞口,他可以用一个期货合约来进行对冲。
期货期权练习题答案期货期权是金融衍生品市场中的重要组成部分,它们允许投资者对未来的资产价格进行投机或对冲风险。
以下是一些期货期权练习题的答案,供学习者参考:1. 期货合约的定义是什么?答案:期货合约是一种标准化的合约,买卖双方同意在未来的某个日期以约定的价格买卖某种资产。
2. 期权合约的基本类型有哪些?答案:期权合约主要有两类,即看涨期权(Call Option)和看跌期权(Put Option)。
看涨期权赋予持有者在未来以特定价格购买资产的权利,而看跌期权则赋予持有者以特定价格出售资产的权利。
3. 什么是内在价值和时间价值?答案:内在价值是指期权的执行价格与标的资产当前市场价格之间的差额。
时间价值是指期权合约除了内在价值之外,由于到期时间的存在而具有的价值。
4. 期权的时间价值如何随着到期日的临近而变化?答案:随着期权到期日的临近,时间价值通常会逐渐减少,直至到期时变为零。
这种现象被称为时间衰减(Time Decay)。
5. 什么是Delta值?答案:Delta值是衡量期权价格相对于标的资产价格变动的敏感度的指标。
对于看涨期权,Delta值的范围通常在0到1之间;对于看跌期权,Delta值的范围在-1到0之间。
6. 如何计算期权的内在价值?答案:对于看涨期权,如果执行价格低于标的资产的市场价格,内在价值等于市场价格减去执行价格。
如果执行价格高于市场价格,则内在价值为零。
对于看跌期权,如果执行价格高于标的资产的市场价格,内在价值等于执行价格减去市场价格。
如果执行价格低于市场价格,则内在价值为零。
7. 期权的希腊字母有哪些,它们分别代表什么?答案:期权的希腊字母包括Delta、Gamma、Theta、Vega和Rho。
Delta衡量期权价格对标的资产价格变动的敏感度;Gamma衡量Delta 值对标的资产价格变动的敏感度;Theta衡量期权价格对时间流逝的敏感度;Vega衡量期权价格对标的资产波动率变动的敏感度;Rho衡量期权价格对无风险利率变动的敏感度。
赫尔《期权、期货及其他衍生产品》(第9版)笔记和课后习题详解答案赫尔《期权、期货及其他衍生产品》(第9版)笔记和课后习题详解完整版>精研学习?>无偿试用20%资料全国547所院校视频及题库全收集考研全套>视频资料>课后答案>往年真题>职称考试第1章引言1.1复习笔记1.2课后习题详解第2章期货市场的运作机制2.1复习笔记2.2课后习题详解第3章利用期货的对冲策略3.1复习笔记3.2课后习题详解第4章利率4.1复习笔记4.2课后习题详解第5章如何确定远期和期货价格5.1复习笔记5.2课后习题详解第6章利率期货6.1复习笔记6.2课后习题详解第7章互换7.1复习笔记7.2课后习题详解第8章证券化与2007年信用危机8.1复习笔记第9章OIS贴现、信用以及资金费用9.1复习笔记9.2课后习题详解第10章期权市场机制10.1复习笔记10.2课后习题详解第11章股票期权的性质11.1复习笔记11.2课后习题详解第12章期权交易策略12.1复习笔记12.2课后习题详解第13章二叉树13.1复习笔记13.2课后习题详解第14章维纳过程和伊藤引理14.1复习笔记14.2课后习题详解第15章布莱克-斯科尔斯-默顿模型15.1复习笔记15.2课后习题详解第16章雇员股票期权16.1复习笔记16.2课后习题详解第17章股指期权与货币期权17.1复习笔记17.2课后习题详解第18章期货期权18.1复习笔记18.2课后习题详解第19章希腊值19.1复习笔记第20章波动率微笑20.1复习笔记20.2课后习题详解第21章基本数值方法21.1复习笔记21.2课后习题详解第22章风险价值度22.1复习笔记22.2课后习题详解第23章估计波动率和相关系数23.1复习笔记23.2课后习题详解第24章信用风险24.1复习笔记24.2课后习题详解第25章信用衍生产品25.1复习笔记25.2课后习题详解第26章特种期权26.1复习笔记26.2课后习题详解第27章再谈模型和数值算法27.1复习笔记27.2课后习题详解第28章鞅与测度28.1复习笔记28.2课后习题详解第29章利率衍生产品:标准市场模型29.1复习笔记29.2课后习题详解第30章曲率、时间与Quanto调整30.1复习笔记30.2课后习题详解第31章利率衍生产品:短期利率模型31.1复习笔记31.2课后习题详解第32章HJM,LMM模型以及多种零息曲线32.1复习笔记32.2课后习题详解第33章再谈互换33.1复习笔记33.2课后习题详解第34章能源与商品衍生产品34.1复习笔记34.2课后习题详解第35章章实物期权35.1复习笔记35.2课后习题详解第36章重大金融损失与借鉴36.1复习笔记36.2课后习题详解。
CH99.1 股票现价为$40。
已知在一个月后股价为$42或$38。
无风险年利率为8%(连续复利)。
执行价格为$39的1个月期欧式看涨期权的价值为多少?解:考虑一资产组合:卖空1份看涨期权;买入Δ份股票。
若股价为$42,组合价值则为42Δ-3;若股价为$38,组合价值则为38Δ当42Δ-3=38Δ,即Δ=0.75时,组合价值在任何情况下均为$28.5,其现值为:0.08*0.08333e-=,28.528.31即:-f+40Δ=28.31 其中f为看涨期权价格。
所以,f=40×0.75-28.31=$1.69另解:(计算风险中性概率p)40e,p=0.566942p-38(1-p)=0.08*0.08333期权价值是其期望收益以无风险利率贴现的现值,即:f=(3×0.5669+0×0.4331)0.08*0.08333e-=$1.699.2 用单步二叉树图说明无套利和风险中性估值方法如何为欧式期权估值。
解:在无套利方法中,我们通过期权及股票建立无风险资产组合,使组合收益率等价于无风险利率,从而对期权估值。
在风险中性估值方法中,我们选取二叉树概率,以使股票的期望收益率等价于无风险利率,而后通过计算期权的期望收益并以无风险利率贴现得到期权价值。
9.3什么是股票期权的Delta?解:股票期权的Delta是度量期权价格对股价的小幅度变化的敏感度。
即是股票期权价格变化与其标的股票价格变化的比率。
9.4某个股票现价为$50。
已知6个月后将为$45或$55。
无风险年利率为10%(连续复利)。
执行价格为$50,6个月后到期的欧式看跌期权的价值为多少?解:考虑如下资产组合,卖1份看跌期权,买Δ份股票。
若股价上升为$55,则组合价值为55Δ;若股价下降为$45,则组合价值为:45Δ-5当55Δ=45Δ-5,即Δ=-0.50时,6个月后组合价值在两种情况下将相等,均为$-27.5,其现值为:0.10*0.50e--=-,即:27.5$26.16-P+50Δ=-26.16所以,P=-50×0.5+26.16=$1.16另解:求风险中性概率p0.10*0+-=p p e5545(1)50所以,p=0.7564看跌期权的价值P=0.10*0.50+=e-(0*0.75645*0.2436)$1.169.5 某个股票现价为$100。
有连续2个时间步,每个时间步的步长为6个月,每个单步二叉树预期上涨10%,或下降10%。
无风险年利率为8%(连续复利)。
执行价格为$100的一年期欧式看涨期权的价值为多少? 解:由题意得,u =1.10,d =0.90,r =0.08所以,0.08*0.500.900.70411.100.90rT e d e p u d --===--图9.1 则看涨期权价值为:2*0.08*0.5022*(0.7041*212*0.7041*0.2959*00.2959*0)9.61e -++=9.6 考虑习题9.5中的情况,执行价格为$100的一年期欧式看跌期权的价值为多少?证明欧式看涨期权和欧式看跌期权满足看涨看跌期权的平价关系。
解:如上题,计算二叉树图的结果如下则看跌期权的价值为:2*0.08*0.502*(0.7041*02*0.7041*0.2959*10.29591.92e -++=100 1.92101S P +=+=,0.08*1.001009.61101.92rT Xe C e --+=+=所以有:rT S P Xe C -+=+即:期权平价公式成立。
9.7 考虑这样一种情况,在某个欧式期权的有效期内,股票价格的运动符合两步二叉树运动模式。
请解释为什么用股票和期权组合的头寸在期权的整个有效期内不可能一直是无风险的。
解:无风险组合可由卖空1份期权及买入Δ份股票构成。
但由于Δ在期权的有效期内是会变化的,因而,无风险组合总是会变化。
所以,用股票和期权组合的头寸不可能是一直无风险的。
9.8 某个股票现价为$50。
已知在两个月后,股票价格为$53或$48。
无风险年利率为10%(连续复利)。
请用无套利原理说明,执行价格为$49的两个月后到期的欧式看涨期权的价值为多少?解:两个月后欧式看涨期权的价值将为$4(当股价为$53)或$0(当股价为$48)。
考虑如下资产组合:+Δ份股票 -1份看涨期权则两个月后组合价值将为53Δ-4或48Δ,当53Δ-4=48Δ,即Δ=0.8时,则两个月后无论股价如何,组合价值将均为38.4。
该组合现值为: 0.8×50-f 其中f 是期权价值。
因为该资产组合是无风险利率投资,所以有:0.10*0.16667(0.8*50-f )38.4e= 即: f =2.23因此,期权的价值为$2.23。
此外,此题也可直接根据公式(9.2)和(9.3)计算,由题意可得:1.06,0.96u d ==,则:.10*0.166670.960.56811.060.96e p -==- 且0.10*0.16667*0.5681*4 2.23f e-==9.9 某个股票现价为$50。
已知在4个月后,股票价格为$75或$85。
无风险年利率为5%(连续复利)。
请用无套利原理说明,执行价格为$80的4个月后到期的欧式看跌期权的价值为多少?解:4个月后欧式看涨期权的价值将为$5(当股价为$75)或$0(当股价为$85)。
考虑如下资产组合:-Δ份股票 +1份看跌期权(注:看跌期权的套期保值率Δ是负值)。
则两个月后组合价值将为-75Δ+5或-85Δ,当-75Δ+5=-85Δ,即Δ=-0.5时,则两个月后无论股价如何,组合价值将均为42.5。
该组合现值为: 0.5×80+f 其中f 是期权价值。
因为该资产组合是无风险的,所以有:0.05*0.3333(0.5*80)42.5f e +=即: 1.80f = 因此,看跌期权的价值为$1.80此外,此题也可直接利用公式(9.2)和(9.3)计算。
由题意可得: 1.0625,0.9u d == 则: 0.05*0.33330.93750.63451.06250.9375e p -==-, 1-p =0.3655 且 0.05*0.33333*0.3655*5 1.80f e-==9.10某个股票现价为$50。
已知在6个月后,股价将变为$60或$42。
无风险年利率为12%(连续复利)。
计算执行价格为$48,有效期为6个月的欧式看涨期权的价值为多少。
证明无套利原理和风险中性估价原理得出相同的答案。
解:6个月后期权的价值为$12(当股价为$60时)或$0(当股价为$42时)。
考虑如下资产组合:+Δ份股票 -1份看涨期权 则资产组合价值为60Δ-12或42Δ。
当60Δ-12=42Δ,即Δ=0.67时,6个月后,无论股价如何变化,该资产组合的价值将均为$28;此时组合的Δ 值是无风险的。
组合的现值为: 50Δ-f 其中f 为期权的价值。
(1)根据无套利原理,该资产组合必须是无风险的,因而有:0.12*0.50(50*0.67)*28f e -=则有: f =6.96(2)根据风险中性估价定理,设p 为风险中性条件下股价上升的概率,有: 0.12*06042(1)50p pe +-=即: 0.6162p = 在风险中性世界,期权的期望价值为:12×0.6162+0×0.3838=7.3944 其现值为:0.12*0.257.39446.96e= 所以,无套利原理与风险中性估价定理的计算结果一致。
9.11某个股票现价为$40。
已知在3个月后,股价将变为$45或$35。
无风险年利率为8%(连续复利)。
计算执行价格为$40,有效期为3个月的欧式看跌期权的价值。
证明无套利原理和风险中性估价原理得出相同的答案。
解:3个月后期权的价值为$5(当股价为$35时)或$0(当股价为$45时)。
考虑如下资产组合:-Δ份股票 +1份看跌期权 则资产组合价值为-35Δ+5或-45Δ 当-35Δ+5=-45Δ,即Δ=-0.5时,无论股价如何变化,该资产组合价值均将为$22.5;此时组合的Δ值是无风险的。
组合的现值为:-40Δ+f 其中f 为期权的价值。
(1)根据无套利理论,该资产组合必须是无风险的,因而有:0.08*0.25(40*0.5)*22.5f e +=则有: 2.06f = 即看跌期权的价值为$2.06。
(2)根据风险中性估价定理,设p 为风险中性条件下股价上升的概率,有:0.08*04535(1)40*p p e +-=即: 0.58p = 在风险中性世界,期权的期望价值为:0×0.58+5×0.42=2.10 其现值为:0.08*0.252.102.06e= 所以,无套利原理与风险中性估价定理的计算结果一致。
9.12某个股票现价为$50。
有连续2个时间步,每个时间步的步长为3个月,每个单步二叉树的股价或者上涨6%或者下跌5%。
无风险年利率为5%(连续复利)。
执行价格为$51,有效期为6个月的欧式看涨期权的价值为多少? 解:由题意可得, 1.06,0.95u d ==则风险中性概率 0.25*0.050.950.56891.060.95rT e d e p u d --===--在最高的终节点,期权的价值为56.18-61=5.18;在其他情形期权价值均为0。
因而,该期权的价值为:20.05*0.55.18*0.5689*1.635e -=9.13考虑习题9.12中的情况,执行价格为$51,有效期为6个月的欧式看跌期权的价值为多少?证明欧式看涨期权和看跌期权满足看涨看跌期权平价关系。
如果看跌期权是美式期权,在树图上的任何节点,提前执行期权是否会更优呢? 解:(1)如上题, 1.06,0.95u d ==,0.5689p =计算二叉树图的结果如下如上图,当到达中间的终节点时,期权的损益为51-50.35=0.65;当到达最低的终节点时,期权的损益为51-45.125=5.875。
因此,期权的价值为:20.05*0.50.65*2*0.5689*0.43115.875*0.4311)1.37e -+= (2)因为, 1.3765051.P S +=+= 且有, 0.05*0.51.6355151.376rT C Xe e --+=+=因而, rT P S C Xe -+=+即欧式看涨期权和欧式看跌期权满足期权平价公式。
(3)为确定提前执行是否会更优,我们要计算比较每一节点处立即执行期权的损益。
在C 节点处,立即执行期权的损益为51-47.5=3.5,大于2.8664。
因此,期权必须在此节点处被执行,在A 、B 节点处均不执行。