FIN 3506 Lecture Notes - Lecture 9: Rational Pricing, Risk-Free Interest Rate, Put Option
Document Summary
The following is a little different approach than that of you text but results in the same answers. The equations present in the text solve the general condition. Let us assume that a portfolio consisting of going long the stock and shorting the risk free bond can be made to replicate the pay out of the option that we are trying to price. To show this let us assume that we are trying to price an option that has a strike price of. 50 and expiration at the end of one period. The current price of the underlying asset is. 50 and we have determined at the end of the next period the stock price will either rise to 60 or fall to 40. Let us further assume that the price of a risk free bond is currently b and currently has an interest rate of 3% for the period in question.