Primary markets, or primary financial markets, are where new financial assets are issued. There are two main types of primary-market issues. The first type of issue is known as an initial public offering, or IPO. These issues are the very first shares a company offers to the public. Investment bankers serve as underwriters for these issues: they facilitate the process of selling these initial public offerings.

The second type of issue is known as a seasoned new issue. These issues are new shares that are being issued by a company that already has publicly traded shares on existing stock exchanges. A seasoned new issue is the way a company sells more shares to the investing public.