An angel investor (also known as a business angel, informal investor, angel funder, private investor, or seed investor) is an individual who provides capital for a business or businesses start-up, usually in exchange for convertible debt or ownership equity. Angel investors usually give support to start-ups at the initial moments (where risks of the start-ups failing are relatively high) and when most investors are not prepared to back them. In a survey of 150 founders conducted by Wilbur Labs, about 70% of entrepreneurs will face potential business failure, and nearly 66% will face this potential failure within 25 months of launching their company. A small but increasing number of angel investors invest online through equity crowdfunding or organize themselves into angel groups or angel networks to share investment capital, as well as to provide advice to their portfolio companies. Over the last 50 years, the number of angel investors has greatly increased.