IPOs technically have two prices, their offering price, and opening price. The offering price is the price at which shares are sold to institutional investors and brokers just before a company begins publicly trading. The process of figuring out an offering price is called book building, and involves underwriters gauging demand for the company’s stock by soliciting bids from institutional investors. The opening price is the price shares begin trading at on an exchange and is determined by compiling the bids of investors on the exchanges.