Developing return-oriented green revolving funds (GRFs) is a rapidly growing trend at colleges and universities. A green revolving fund (GRF) is a special account designated for investment in on-campus projects that improve energy efficiency or decrease material use. GRFs invest in a variety of cost-saving initiatives, resulting in significant financial and environmental benefits. This "Investment Primer" is designed for key decision makers, such as senior financial officers or boards of trustees' investment committees, who want to learn more about developing a GRF. It discusses critical financial and fund-structuring issues that institutions should consider when developing a GRF. Recommendations are based on research conducted by the Sustainable Endowments Institute for its report "Greening the Bottom Line," and on interviews with experts in higher education finance, operations and sustainability. (Contains 1 figure.) [Mark Orlowski was a contributing author for this paper.]