Index funds are increasingly embraced by investors seeking market-based returns at relatively lower costs than actively managed funds. Even within the specialized field of socially responsible and ESG-driven mutual funds, investors are turning to indexes for their consistent performance and as a platform for the integration of a full range of impact investing strategies. We anticipate this trend will continue, and even increase, as investors understand that they can responsibly integrate their values into their investment portfolios. SRI index funds use several different approaches – an optimized SRI index fund blends the benefits of market index funds with making a positive impact. Optimized index funds seek to track the returns of a public benchmark index within a narrow range, while not using all of the constituents of the index. For socially targeted funds, this is typically done by applying a set of exclusionary screens such as companies affiliated with gambling, tobacco, or weapons production. Fund managers may also exclude companies on the basis of environmental, social, and governance (ESG) factors.