This exchange-traded fund primarily allocates capital to a diverse collection of high-quality fixed income instruments. These securities, which encompass mortgage-backed bonds, originate from both domestic and international corporate and governmental entities. To be considered 'investment grade,' they must possess a credit rating of at least BBB- from S&P or Fitch, or Baa3 from Moody's. A core principle of this portfolio is its sustainable investment strategy, which leads to the exclusion or reduced weighting of debt issued by certain corporations and non-sovereign governmental bodies, based on their environmental, social, and governance impact.