Final answer:
Convertible bonds are usually converted into common stock when the bondholder exercises the conversion option.
Step-by-step explanation:
Convertible bonds are usually converted into common stock when the bondholder chooses to exercise the conversion option. Convertible bonds give the bondholder the right to convert the bond into a specified number of shares of common stock at a predetermined conversion price. This allows the bondholder to participate in the potential upside of the company's stock.