A repo, or repurchase agreement, is a sale of a security (often a US Treasury obligation) that the seller promises to buy back later – often the day following the original sale – at a slightly higher price. The repo buyer thus lends to the seller, with the difference between the immediate “spot” price of the obligation and the “forward” repurchase price representing the interest on the loan.
回购协议即卖方卖出一种证券（通常是美国国债），并承诺在不久后以略高的价格买回（通常在卖出交易后一天）。因此，在回购交易中，买方是在向卖方贷款，即期的债券“现货”价格与“远期”回购价格之间的差额便是这笔贷款的利息。回购协议贷款给了公司（通常是金融公司）获得大笔廉价融资的机会（通常来自美国货币市场基金）。这是一个规模以万亿美元计的市场。