Financial Instruments is a comprehensive reference manual of generally accepted accounting principles (U.S. GAAP) in the United States about financial instruments. A financial instrument is cash, an ownership interest in another entity (such as common stock), or a contract that conveys an obligation and a corresponding right to require delivery of (or exchange) a financial instrument(s). The right may be contingent (such as an option) or unconditional (such as a loan). A financial instrument is ultimately convertible to cash (or stock) and does not involve the delivery of goods or services.