Normally investing at least 80% of assets in bonds included in the Bloomberg MSCI U.S. Aggregate ESG Choice Bond Index. The Bloomberg MSCI U.S. Aggregate ESG Choice Bond Index is composed of U.S. dollar denominated, investment-grade fixed-rate debt issues, including government, corporate, asset-backed, and mortgage-backed securities, and follows the rules of the Bloomberg U.S. Aggregate Bond Index. MSCI ESG Research applies additional sector and ESG criteria for security eligibility in the index and adjusts the sector weights of the index to match the exposures of the Bloomberg U.S. Aggregate Bond Index. Companies showing involvement above certain thresholds in adult entertainment, alcohol, gambling, tobacco, military weapons, civilian firearms, nuclear power, and genetically modified organisms are excluded. The index is rebalanced monthly. Effective December 11, 2025, derivative instruments that provide investment exposure to the investments above or exposure to one or more market risk factors associated with such investments are included in the fund's 80% policy, consistent with the fund's investment policies and limitations with respect to investments in derivatives.   Using statistical sampling techniques based on duration, maturity, interest rate sensitivity, security structure, and credit quality to attempt to replicate the returns of the Bloomberg MSCI U.S. Aggregate ESG Choice Bond Index using a smaller number of securities. Engaging in transactions that have a leveraging effect on the fund, including investments in derivatives - such as swaps (interest rate, total return, and credit default), options, and futures contracts - and forward-settling securities, to adjust the fund's risk exposure.