Anatomy of option features in convertible bonds

Several earlier theoretical studies on the optimal issuer's calling policy of a convertible bond suggest that the issuer should call the bond as soon as the conversion value exceeds the call price. However, empirical studies on actual cases of calling by convertible bond issuers reveal that firms “delayed” calling their convertible bonds until the conversion value well exceeded the call price. In this paper, we construct valuation algorithms that price risky convertible bonds with embedded option features. In particular, we examine the impact of the soft call and hard call constraints, notice period requirement and other factors on the optimal issuer's calling policy. Our results show that the critical stock price at which the issuer should optimally call the convertible bond depends quite sensibly on these constraints and requirements. The so‐called “delayed call phenomena” may be largely attributed to the underestimation of the critical call price due to inaccurate modeling of the contractual provisions. © 2004 Wiley Periodicals, Inc. Jrl Fut Mark 24:513–532, 2004