Typically a successful entrepreneur who has built up a business, sold it and now brings not just money but experience, street-wisdom and credibility to a young management team starting up a new venture. Far-sighted investment institutions keep lists of potential angels whom they can introduce to young businesses that might not otherwise get off the ground.

Ambitious small companies can float on the Alternative Investment Market, after a vetting which is less rigorous than for a full listing (and generally less expensive). AIM, which was launched by the London Stock Exchange in 1995, can provide an exit for the original backers of the business. See listing.