交易型开放式指数基金或交易所交易基金（港澳称为交易所买卖基金，台湾称为指数股票型基金），由领航投资创办人约翰·柏格提倡问世，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。

其英文释义如下：

An exchange-traded fund (ETF) is a type of investment fund and exchange-traded product, i.e. they are traded on stock exchanges. ETFs are similar in many ways to mutual funds, except that ETFs are bought and sold throughout the day on stock exchanges while mutual funds are bought and sold based on their price at day's end. An ETF holds assets such as stocks, bonds, currencies, and/or commodities such as gold bars, and generally operates with an arbitrage mechanism designed to keep it trading close to its net asset value, although deviations can occasionally occur. Most ETFs are index funds, that is, they hold the same securities in the same proportions as a certain stock market index or bond market index.

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。

按资产管理规模划分，前五大ETF基金分别为：

Symbol         Name                     AUM              Avg Volume

SPY      SPDR S&P 500 ETF             $340,295,000.00       63,270,832

IVV   iShares Core S&P 500 ETF     $254,584,000.00       4,038,084

VTI  Vanguard Total Stock Market ETF   $219,219,000.00       4,104,894

VOO     Vanguard S&P 500 ETF       $199,296,000.00       3,019,069

QQQ   Invesco QQQ             $159,866,000.00       28,582,867

以下为相关双语示例：

The Investment Manager intends to implement a number of investment techniques in order to achieve the objectives of the Fund. Such techniques will include among others: purchasing global equities, ETFs and other securities that the Investment Manager believes will outperform the equity market indices, while short-selling the market indices or individual securities to hedge away macroeconomic and other specific risks.

投资经理打算采用众多投资技巧实现基金目标。这些技巧将包括：购买全球股份、交易所交易基金和投资经理认为将优于股市指数的其他证券，同时卖空市场指数或个别证券，以对冲宏观经济和其他特定风险。