金融衍生工具（Derivative）是一种特殊类别买卖的金融工具统称。这种买卖的回报率是根据一些其他金融要素的表现情况衍生出来的。比如资产（商品，股票或债券），利率，汇率，或者各种指数（股票指数，消费者物价指数，以及天气指数）等。这些要素的表现将会决定一个衍生工具的回报率和回报时间。衍生工具的主要类型有期货，期权，权证，远期合约，互换等，这些期货，期权合约都能在市场上买卖。

对此类金融工具进行买卖投资者需要十分谨慎，因为由其引起的损失有可能大于投资者最初投放于其中的资金。同时由于其本身并不代表任何资产，其买卖也不应该被视作投资。

In finance, a derivative is a contract that derives its value from the performance of an underlying entity. This underlying entity can be an asset, index, or interest rate, and is often simply called the "underlying". Derivatives can be used for a number of purposes, including insuring against price movements (hedging), increasing exposure to price movements for speculation or getting access to otherwise hard-to-trade assets or markets. Some of the more common derivatives include forwards, futures, options, swaps, and variations of these such as synthetic collateralized debt obligations and credit default swaps. Most derivatives are traded over-the-counter (off-exchange) or on an exchange such as the Bombay Stock Exchange, while most insurance contracts have developed into a separate industry. Derivatives are one of the three main categories of financial instruments, the other two being stocks (i.e., equities or shares) and debt (i.e., bonds and mortgages).