An angel investor (also known as a business angel, informal investor, angel funder, private investor, or seed investor) is an affluent individual who provides capital for a business start-up, usually in exchange for convertible debt or ownership equity. A small but increasing number of angel investors invest online through equity crowdfunding or organize themselves into angel groups or angel networks to share research and pool their investment capital, as well as to provide advice to their portfolio companies.
The application of the term "angel" to a kind of investor originally comes from Broadway theater, where it was used to describe wealthy individuals who provided money for theatrical productions that would otherwise have had to shut down. In 1978, William Wetzel, then a professor at the University of New Hampshire and founder of its Center for Venture Research, completed a pioneering study on how entrepreneurs raised seed capital in the USA, and he began using the term "angel" to describe the investors that supported them. A similar term is patron, commonly used in arts.
Angel investors are often retired entrepreneurs or executives, who may be interested in angel investing for reasons that go beyond pure monetary return. These include wanting to keep abreast of current developments in a particular business arena, mentoring another generation of entrepreneurs, and making use of their experience and networks on a less than full-time basis. Thus, in addition to funds, angel investors can often provide valuable management advice and important contacts. Because there are no public exchanges listing their securities, private companies meet angel investors in several ways, including referrals from the investors' trusted sources and other business contacts; at investor conferences and symposia; and at meetings organized by groups of angels where companies pitch directly to investor in face-to-face meetings.
According to the Center for Venture Research, there were 258,000 active angel investors in the U.S. in 2007. According to literature reviewed by the US Small Business Administration, the number of individuals in the US who made an angel investment between 2001 and 2003 is between 300,000 and 600,000. Beginning in the late 1980s, angels started to coalesce into informal groups with the goal of sharing deal flow and due diligence work, and pooling their funds to make larger investments. Angel groups are generally local organizations made up of 10 to 150 accredited investors interested in early-stage investing. In 1996 there were about 10 angel groups in the United States. There were over 200 as of 2006.