VI. Options 23. Warrants and
investors became disenchanted with dot.com companies and Amazon’s stock price
fell by 75 percent to $15. This was well below the conversion price of $78.03. Con-
vertible bondholders might have hoped that the bond value would provide a secure
floor to the value of their investment. Unfortunately, by early 2001 Amazon’s bonds
no longer looked as safe as they once had, and Moody’s placed its convertible in the
junk bond category Caa. By the spring of that year the price of the convertible had
fallen to about $400 and offered a promised yield to maturity of 20 percent.
Figure 23.2(b) shows the possible conversion values at maturity of Kojak’s convert-
ible. We assume that Kojak already has one million shares of common stock out-
standing, so the convertible holders will be entitled to half the value of the firm. For
example, if the firm is worth $2 million,
11
the one million shares obtained by conver-
sion would be worth $1 each. Each convertible bond can be exchanged for 1,000 shares
of stock and therefore would have a conversion value of 1,000 ⫻ 1 ⫽ $1,000.
Kojak’s convertible also cannot sell for less than its conversion value. If it did,
smart investors would buy the convertible, exchange it rapidly for stock, and sell
the stock. Their profit would be equal to the difference between the conversion
value and the price of the convertible.
Therefore, there are two lower bounds to the price of the convertible: its bond
value and its conversion value. Investors will not convert if bond value exceeds
conversion value; they will do so if conversion value exceeds bond value. In other
words, the price of the convertible at maturity is represented by the higher of the
two lines in Figure 23.2(a) and (b). This is shown in Figure 23.2(c).
Value before Maturity We can also draw a picture similar to Figure 23.2 when the
convertible is not about to mature. Because even healthy companies may subse-
quently fall sick and default on their bonds, other things equal, the bond value will
be lower when the bond has some time to run. Thus bond value before maturity is
represented by the curved line in Figure 23.3(a).
12
Figure 23.3(b) shows that the lower bound to the price of a convertible before
maturity is again the higher of the bond value and conversion value. However,
before maturity the convertible bondholders do not have to make a now-or-never
choice for or against conversion. They can wait and then, with the benefit of hind-
sight, take whatever course turns out to give them the highest payoff. Thus be-
fore maturity a convertible is always worth more than its lower-bound value. Its
actual selling price will behave as shown by the top line in Figure 23.3(c). The dif-
ference between the top line and the lower bound is the value of a call option on
the firm. Remember, however, that this option can be exercised only by giving up
the bond. In other words, the option to convert is a call option with an exercise
price equal to the bond value.
Dilution and Dividends Revisited
If you want to value a convertible, it is easiest to break the problem down into two
parts. First estimate bond value; then add the value of the conversion option.
When you value the conversion option, you need to look out for the same
things that make warrants more tricky to value than traded options. For example,
CHAPTER 23
Warrants and Convertibles 651
11
Firm value is equal to the value of Kojak’s common stock plus the value of its convertible bonds.
12
Remember, the value of a risky bond is the value of a safe bond less the value of a put option on the
firm’s assets. The value of this option increases with maturity.