We have seen earlier that there are callable bonds. This is a valuable feature for the issuers who consider that their stock is undervalued enough so that selling the stock directly would dilute the equity of current stockholders. The company will set the conversion ratio based on a stock price it regards as acceptable. When the market price reaches the conversion point, the issuer will want to see the conversion happen in view of the risk that the price may drop in future. This motivates the company to go for conversion even though this is not in the interest of the owners of the security whose price is likely to be adversely affected by the call.