Equity derivative is a class of derivatives whose value is at least partly derived from one or more underlying equity securities. Options and futures are by far the most common equity derivatives; however there are many other types of equity derivatives that are actively traded.
A derivative is a contract between two or more parties whose value is based on an agreed-upon underlying financial asset (like a security) or set of assets (like an index). Common underlying instruments include bonds, commodities, currencies, interest rates, market indexes and stocks.
The risk-reward equation is often thought to be the basis for investment philosophy and derivatives can be used to either mitigate risk (hedging) or assume risk with the expectation of commensurate reward (speculation).