A buy-back is a situation in which a company buys shares back from its investors.
[business]
...a share buy-back scheme.
The company announced an extensive stock buy-back program.
buy-back in British English
(ˈbaɪˌbæk)
noun
business
the repurchase by a company of some or all of its shares from an investor, who acquired them by putting venture capital into the company when it was formed