Binomial option pricing replicating port...
Binomial_option_pricing_replicating_portfolio_answer_key.doc-Binomial option pricing – valuing Amgen
Showing 1-2 out of 2
Binomial option pricing replicating portfolio answ...
Binomial_option_pricing_replicating_portfolio_answer_key.doc-Binomial option pricing – valuing Amgen
Binomial option pricing replicating...
Binomial_option_pricing_replicating_portfolio_answer_key.doc-Binomial option pricing – valuing Amgen
Page 1
Binomial option pricing – valuing Amgen call option
Suppose that Amgen’s current stock price is $60, and every four-month period it can
either go up or down. The standard deviation of Amgen’s stock return is 0.3523. If the
risk-free rate is 0.5% per four months, what is the value of an eight-month call option on
Amgen’s stock with an exercise price of $60?
Solution:
Our goal is to find C
0
. We first need to figure out how the price of Amgen would change
in each four-month period. In this case h = 120/360. In Period 1 it could go up to
60*e
(0.3523*sqrt(120/360))
= $73.54,
or go down to
60/( e
(0.3523*sqrt(120/360))
) = $48.9
In the same way we can find the stock price at the end of the eight-month period.
Stock price=90.12
Option payoff=30.12
Stock price=60
Option payoff=0
Stock price=39.94
Option payoff=0
Stock price=60
C
0
=?
Stock
price=73.53
Cu=?
Stock
price=48.96
Cd=?


Page 2
1) To calculate Cu, we need to form a replicating portfolio in month 4 by investing M in
the stock and borrowing B dollars at 0.5% for four months in such a way that this
portfolio has the exact same payoffs as the option in month 8. Then, the value of the
portfolio in Month 4 should be exactly equal to the value of the option, Cu.
M*(90.12) – B*1.005 = 30.12
M*(60) – B*1.005 = 0
If you solve for M and B you get M=1 and B=59.70. The value of the portfolio at the end
of month 4 is:
M*(73.53) – B = 73.53 – 59.7 = 13.84 = Cu
2) To calculate Cd, we need to form a replicating portfolio in month 4 by investing M in
the stock and borrowing B dollars at 0.5% for four months in such a way that this
portfolio has the exact same payoffs as the option in month 8. Then, the value of the
portfolio in Month 4 should be exactly equal to the value of the option, Cd. However,
since both option payoffs in month 8 are 0, Cd=0
3) To calculate C
0
, we need to form a replicating portfolio in month 0 (right now) by
investing M in the stock and borrowing B dollars at 0.5% for four months in such a way
that this portfolio has the exact same payoffs as the option in month 4. Then, the value of
the portfolio in Month 0 should be exactly equal to the value of the option, C
0
.
M*(73.53) – B*1.005 = 13.83
M*(48.96) – B*1.005 = 0
If you solve for M and B you get M=0.563 and B=27.44. The value of the portfolio in
month 0 is:
M*(60) – B = 0.563*(60) – 27.44 = 6.34 = C
0


Ace your assessments! Get Better Grades
Browse thousands of Study Materials & Solutions from your Favorite Schools
George Washington Univers...
George_Washington_University
School:
Cases_in_Fin_Management_and_Inv_Banking
Course:
Great resource for chem class. Had all the past labs and assignments
Leland P.
Santa Clara University
Introducing Study Plan
Using AI Tools to Help you understand and remember your course concepts better and faster than any other resource.
Find the best videos to learn every concept in that course from Youtube and Tiktok without searching.
Save All Relavent Videos & Materials and access anytime and anywhere
Prepare Smart and Guarantee better grades

Students also viewed documents