Financial securities are broadly categorized into four primary asset classes: equities (which represent fractional ownership or shares in a corporation), debt instruments (such as bonds, notes, and debentures representing borrowed money that must be repaid with interest), derivatives (contracts whose value is derived from an underlying asset, index, or benchmark like options and futures), and hybrid instruments (which combine features of both debt and equity, such as convertible bonds or preferred stock). Each security type serves distinct capital-raising, hedging, and investment objectives within global financial markets.