Green Century Equity Fund is a U.S. mutual fund managed by Green Century Capital Management, an investment adviser founded by nonprofit environmental advocacy organizations, that seeks long-term total return matching the performance of the MSCI KLD 400 Social ex Fossil Fuels Index. The fund invests substantially all of its assets in the common stocks comprising this index, which excludes companies that explore for, extract, produce, manufacture, or refine coal, oil, or gas, or that produce or transmit electricity or natural gas derived from fossil fuels, while favoring companies with strong environmental, social, and governance records.