Anyone following SpaceX’s plans to sell shares to the public is likely to hear terms thrown around that describe steps and components of an initial public offering. Here’s a quick guide. Initial public offering, or IPO A company’s first offering of stock to the public. It is the first time a company’s value will be determined by a public market. Prospectus A formal offer to sell shares in the company. It also includes a business plan with details about the company’s finances and operations.