Chapter 10 Derivatives: Risk Management with Speculation, Hedging, and Risk Transfer 155
46. Digital options: Digital (or binary) options can only have two payoffs at maturity. If the strike
condition set in the option is met, the buyer will receive the full prespecified payoff. If not, the buyer
receives no payoff. This is different from a traditional option where there exists an infinite number of
payoffs. For example, we could have a digital option on the French CAC index, stating that the option
buyer will get €200 if the CAC index is above 4,000 at expiration and zero otherwise. On this digital
option, the buyer will get exactly 200 as soon as the CAC index is above the 4,000 level at expiration,
whether it be 4,001, 4,100, or 5,000.
a. Draw the profit and loss curve at expiration as a function of the CAC index for these two options:
• Traditional call on the CAC index: Exercise price: 4,000; premium: 40.
• Digital call on the CAC index: Exercise price: 4,000; payoff if exercised: 200; premium: 40.
b. What are the relative advantages of the two options?
c. Assume that the volatility of the French stock market increases suddenly. Should the premium on
the digital call increase more (or less) than the premium on the traditional call?
47. Guaranteed note.
You are a young banker offering a client to issue a guaranteed note. The yield curve is flat at 9% for
each maturity. Options on the stock index are offered by banks. A at-the-money call with a two-year
maturity trades at 12% of the index value, whereas a three-year call is worth 15% of the index.
You wonder about the characteristics of the bond. If you offer a high coupon, the indexation will be
low. Therefore, you decide to compute the indexation levels in accordance to the current market
conditions for maturities of two and three years and coupon levels of 0%, 2%, and 5%.