17 Best Sustainable Investment Funds Worth Looking at in 2026

7. Fidelity U.S. Sustainability Index Fund - Mainstream ESG Adoption

The Fidelity U.S. Sustainability Index Fund demonstrates how ESG investing has moved into the mainstream, offering investors a low-cost way to access U.S. companies with strong sustainability practices while maintaining broad market exposure. This fund tracks an index that selects and weights companies based on their ESG scores relative to sector peers, ensuring representation across all major industries while emphasizing those companies leading their sectors in sustainability practices. The fund's approach recognizes that sustainability leadership looks different across industries, allowing for inclusion of the best-in-class companies from each sector rather than excluding entire industries. This methodology provides investors with exposure to companies that are driving sustainability improvements within their respective industries, from oil companies investing heavily in renewable energy to technology companies reducing their carbon footprints. In 2026, the fund has captured the value created by companies that have successfully integrated sustainability into their core business strategies, demonstrating that sustainable practices can drive competitive advantage and financial outperformance. The fund's low expense ratio and tax efficiency make it particularly attractive for long-term investors seeking to align their portfolios with their values without sacrificing returns or paying excessive fees.