FPO stands for Follow-on Public Offer, which is a process by which a company that is already listed on the stock exchange issues new shares to the existing shareholders or to new investors. This is done to raise capital for the company, expand its equity base, diversify its shareholder base, or pay off debt. FPOs are usually conducted after a company has gone through the process of an IPO.

There are two main types of FPOs: dilutive and non-dilutive. In a dilutive FPO, new shares are added, which can decrease the share price and earnings per share. In a non-dilutive FPO, existing private shares are sold publicly, which does not affect the number of shares in circulation or the earnings per share.

Investors can participate in FPOs by purchasing additional shares or selling some of their existing ones. The share price issued in an FPO is usually lower than the prevailing market price to attract more subscribers to the issue. FPOs are generally considered less risky than IPOs because investors have access to historical data about the companys management, business practices, and potential growth.