A stock currently sells for $69. The annual growth rate of the stock is 15%, and the stock’s annual volatility is 35%. The risk-free rate is currently 5%. You have bought a six-month European put option on this stock with an exercise price of $70.

a. Use @RISK to value this option.

b. Use @RISK to analyze the distribution of percentage returns (for a six-month horizon) for the following portfolios:

■ Portfolio 1: Own 100 shares of the stock.

■ Portfolio 2: Own 100 shares of the stock and buy the put described in part a.

Which portfolio has the larger expected return?

Explain why portfolio 2 is known as portfolio insurance.