Most of the estimated $120 billion that’s injected into new and early stage businesses each year comes from friends and family of the entrepreneurs, but as much as $20 billion comes out of the pockets of individuals known as angel investors. Often, they are people who have accumulated wealth through their own enterprises and now wish to participate in the growth of others.

More than 170 angel groups involving some 8,000 accredited investors operate throughout the United States, according to the Angel Capital Association.

To meet accreditation requirements of the Securities and Exchange Commission, an investor must have a net worth, or joint net worth with a spouse, that exceeds $1 million and annual income exceeding $200,000 or joint income above $300,000.

Individual investments into an angel fund or client company typically range from $15,000 into the millions.

The median size of an angel investment nationally increased 30 percent last year to $980,000, according to the Halo Report published by the Angel Resource Institute and Silicon Valley Bank.