Selling membership into society has taken on new life with the recent proliferation globally of Immigrant Investor Programs (IIPs). IIPs involve the sale of national membership privileges to wealthy foreigners, justified by their purported ability to stimulate economic development and attract engaged investor-migrants. This paper surveys IIP objectives, activities and performance. We argue that IIP success may depend upon the coming-together of expertise from two domains – migration policy and investment management, and that the latter may offer a means of legitimizing the former. Drawing some insights from the emerging community of Sovereign Development Funds (SDFs), we propose a set of principles that could guide the emergence of a new type of SDF: Immigrant Investment Funds (IIFs).