The fund offers exposure to equities that have low ESG risk ratings by tracking the Morningstar US Sustainability Extended Index. The index uses ESG risk rating scores from Sustainalytics to assess a companys ESG risk. From a universe of US large- and mid-cap stocks, the index eliminates those having a controversy rating of greater than three. Stocks covering the 67% of float market capitalization with the lowest ESG risk rating scores are selected, while enforcing weight constraints and buffer. The index also applies a screen that filters out those with certain involvement in any controversial products or services, such as tobacco, controversial weapons, firearms, gambling, and other controversial activities. Holdings are market-cap weighted and are rebalanced quarterly and reconstituted semi-annually.