NUSA provides broad exposure to short-term investment-grade bonds with 1-5 years to maturity. The fund invests in US government and corporate bonds that exhibit positive ESG characteristics. Bonds issued in the independent and integrated oil & gas producer and metals & mining sectors are excluded. Additionally, firms involved in alcohol production, tobacco production, nuclear power, gambling, and weapons and firearms production are excluded. For each industry, key ESG issues are identified that present costs or opportunities. Securities are then rated for each key ESG issue. Using a sector-specific key issue weighting model, entities are rated and ranked by industry peers. The index is market-value-weighted within each sector, with sector weights adjusted to match the sector exposure of the parent index. Prior to June 2023, the fund was Nuveen Enhanced Yield 1-5 Year U.S. Aggregate Bond ETF which follows a fundamentally-weighted index of broad market bonds.