Convertibles

Securities, usually bonds or preferred shares, that can be converted into common stock.

Investopedia Says:
Convertibles are ideal for investors demanding greater potential for appreciation than bonds give and higher income than common stocks offer.

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Find out about the nuts and bolts, pros and cons of investing in bonds. Convertible Bonds: An Introduction
These securities offer an answer for investors who want the profit potential of stocks but not the risk. Introduction To Convertible Preferred Shares

Corporate securities (usually preferred shares or bonds) that are exchangeable for a set number of another form (usually common shares) at a prestated price. Convertibles are appropriate for investors who want higher income than is available from common stock, together with greater appreciation potential than regular bonds offer. From the issuer's standpoint, the convertible feature is usually designed as a sweetener, to enhance the marketability of the stock or preferred. Also called Deferred Equity.