An initial public offering (IPO) or stock market launch is a type of public offering. A public offering is any tradable asset that is offered to the public. In an initial public offering, shares of stock in a company are sold to the general public, on a securities exchange, for the first time. Through this process, a private company transforms into a public company. Initial public offerings are used by companies to raise money for expansion and to become publicly traded enterprises. A company selling shares is never required to repay the money to the people who buy them.