Financial instruments used in the money markets and capital markets. A more accurate and descriptive term is Sale and Repurchase Agreement, since what occurs is that the cash receiver (or repo seller) sells securities to the cash provider (or repo buyer) now in return for cash, and agrees to repurchase those securities from the cash provider for a greater sum of cash at some later date. That greater sum is all of the money lent and some extra money (constituting the implicit interest rate, known as the repo rate). Treasury or Government bills, corporate and Treasury or Government bonds, and stocks, may all be used as securities involved in a repo. A reverse repo is simply a repurchase agreement as described from the cash provider's point of view.