交易所交易基金、交易所买卖基金（英语：Exchange Traded Funds，常常缩写为 ETF，台译指数型证券投资信托基金），是一种在证券交易所交易，提供投资人参与指数表现的指数基金。ETF将指数证券化，投资人不以传统方式直接进行一篮子证券之投资，而是透过持有表彰指数标的证券权益的受益凭证来间接投资。

ETF基金以持有与指数相同之证券为主，分割成众多单价较低之投资单位，进而发行受益凭证。ETF商品将指数的价值由传统的证券市场涨跌指标，转变成具有流动性的资本证券，指数成分股票的管理由专业机构来进行，指数变动的损益直接反映在凭证价值的涨跌中。因此，只会因为连动指数成分股内容及权重改变而调整投资组合之内容或比重以符合「被动式管理」之目的。

An exchange-traded fund (ETF) is an investment fund traded on stock exchanges, much like stocks. An ETF holds assets such as stocks, commodities, or bonds, and trades close to its net asset value over the course of the trading day. Most ETFs track an index, such as a stock index or bond index. ETFs may be attractive as investments because of their low costs, tax efficiency, and stock-like features. By 2013, ETFs were the most popular type of exchange-traded product.