The term "buyback" in the context of the financial markets refers to a situation where a company is buying back its own shares which results in a reduction in the number of the company's outstanding shares. A buyback is undertaken typically because a company believes its shares are undervalued in the stock market. Buybacks usually occur in the open market over an extended period of time, although they can be also be accomplished through an issuer tender offer. The amount of the buyback program is typically announced in advance by a company.