对冲（又称避险、套期保值，英语：Hedge），是指对于国际间从事商品买卖的洋行、进出口贸易商，以及在国际间从事投资的人士，若预期未来将收付一定金额的外汇，为避免因变动产生的损失（参见交易风险），可利用远期外汇交易以规避风险，这种避险的操作方式，称为远期避险或远期对冲。它是一种在减低商业风险的同时仍然能在投资中获利的手法。

对冲在外汇市场中最为常见，着意避开单线买卖的风险。所谓单线买卖，就是看好某一种货币就做买空（或称揸仓），看淡某一种货币，就做沽空（空仓）。如果判断正确，所获利润自然多；但如果判断错误，损失亦不会较没有进行对冲大。

A hedge is an investment position intended to offset potential losses/gains that may be incurred by a companion investment. In simple language, a hedge is used to reduce any substantial losses/gains suffered by an individual or an organization.

A hedge can be constructed from many types of financial instruments, including stocks, exchange-traded funds, insurance, forward contracts, swaps, options, many types of over-the-counter and derivative products, and futures contracts.