Abstract
Business angels (BAs), also called angel investors (entry “Angel Investors,” this encyclopedia), are “high net worth individuals” (Wetzel 1983) typically investing their own money in young entrepreneurial ventures. Over the past two decades, BAs have increasingly joined forces in informal networks (BANs) or in more structured groups (BAGs). Angel groups collectively carry out certain tasks that alleviate and help professionalize the individual investors’ workload in activities, such as deal sourcing and due diligence, to name only a few relevant examples. To organize and carry out collective activities, angel groups, although they also hire some permanent staff, rely heavily on group members who volunteer to get involved in various angel-group activities. Hence, we call involvement in BA groups the voluntary activities into which business angels invest part of their time to run the BAG and accomplish certain investment-related activities (Bonnet et al. 2022).