Strategy. The Underlying Index, administered by NTI in its capacity as index provider (the Index Provider), is designed to reflect the performance of a selection of U.S.-dollar-denominated corporate bonds issued by companies that exhibit certain environmental, social and governance (ESG) characteristics in the aggregate, while also seeking to provide exposure to US dollar-denominated corporate bonds, i.e., the constituents in the Northern Trust Investment Grade U.S. Corporate Bond Index SM (the Eligible Universe). The Northern Trust Investment Grade U.S. Corporate Bond Index SM is a market-capitalization weighted index comprised of US dollar-denominated corporate bonds that (a) are publicly issued in the United States and registered with the SEC or eligible for resale under Rule 144A under the Securities Act of 1933, with … Show more… The Underlying Index, administered by NTI in its capacity as index provider (the Index Provider), is designed to reflect the performance of a selection of U.S.-dollar-denominated corporate bonds issued by companies that exhibit certain environmental, social and governance (ESG) characteristics in the aggregate, while also seeking to provide exposure to US dollar-denominated corporate bonds, i.e., the constituents in the Northern Trust Investment Grade U.S. Corporate Bond Index SM (the Eligible Universe). The Northern Trust Investment Grade U.S. Corporate Bond Index SM is a market-capitalization weighted index comprised of US dollar-denominated corporate bonds that (a) are publicly issued in the United States and registered with the SEC or eligible for resale under Rule 144A under the Securities Act of 1933, with or without registration rights, (b) are rated investment grade (i.e., rated at the time of inclusion in the Eligible Universe within the top four ratings categories by a Nationally Recognized Statistical Rating Organization (NRSRO)), and (c) have, at each rebalance, (i) a final time to stated maturity of at least one year and (ii) an outstanding principal balance of at least $250 million. The Fund does not have any portfolio maturity limitation and may invest its assets from time to time in instruments with varying maturities. The Underlying Index starts by excluding certain companies from the Eligible Universe that, based on third-party data, are determined to have certain levels of controversial business involvement or behavior, including in tobacco, weaponry, thermal coal, unconventional oil and gas, and for-profit prisons, or to have caused, contributed to or are linked to certain violations of international norms and standards. Such exclusions are based on percentage of revenue thresholds for certain categories (e.g., those that receive significant revenue from production, retail and distribution of civilian weapons) and categorical exclusions for others (e.g., tobacco producers). The above-described exclusionary screens are applied with each reconstitution of the Underlying Index. The Index Provider may modify this list of excluded companies at any time, at its own discretion. The Underlying Index next applies an optimization process to minimize variance to the Eligible Universe while also targeting certain ESG characteristics, which is designed to produce an index that, relative to the Eligible Universe: (a) has an aggregate higher scoring of certain ESG characteristics, as measured by the Northern Trust ESG Vector Score (ESG Vector Score) described below, (b) improves the carbon risk rating, as measured by certain carbon-related risk metrics, and (c) decreases the weighted average carbon intensity and potential emissions. The ESG Vector Score is designed to rank companies based on their management of and exposure to material ESG metrics as defined by the Sustainability Accounting Standards Board (SASB) Standards. In addition, the Index Provider uses available data from Institutional Shareholder Services ESG Solutions to assess carbon emissions intensity, carbon reserves and a carbon risk rating. Carbon emissions intensity measures (i) direct greenhouse gas emissions from sources controlled or owned by the company (e.g., emissions associated with fuel combustion in boilers, furnaces, or vehicles); and (ii) indirect greenhouse gas emissions associated with the purchase of electricity, steam, heat or cooling against the company. Carbon reserves measure the total estimated greenhouse gas emissions attributable to a companys fossil fuel reserve assets. The carbon risk rating provides an assessment of a companys ability to mitigate the risks of transition to a lower carbon economy based on its specific baseline carbon risk exposure. In the event that metrics or other data used to construct the ESG Vector Score as well as carbon emissions intensity, carbon reserves and/or the carbon risk rating are not available or otherwise deemed unreliable, NTI may make reasonable estimates or otherwise exercise its discretion to implement the optimization process. Notwithstanding the optimization process, it is possible that the Underlying Index will include (and therefore the Fund could invest in) securities that, individually, have a lower ESG Vector Score, lower carbon risk rating, or higher emissions relative to the weighted average of the Eligible Universe. The optimization process also includes sector, country, turnover, issuer and constituent constraints so that these characteristics in the Underlying Index vary within acceptable bands relative to the Eligible Universe. As of December 31, 2025 , there were 4,138 issues in the Underlying Index. The Underlying Index is reconstituted monthly under normal market conditions. The Fund generally reconstitutes its portfolio in accordance with the Underlying Index. NTI uses a passive or indexing approach to try to achieve the Funds investment objective. Unlike many investment companies, the Fund does not try to beat the index it tracks and does not seek temporary defensive positions when markets decline or appear overvalued. NTI uses a representative sampling strategy to manage the Fund. Representative sampling is investing in a representative sample of securities that collectively has an investment profile similar to the Underlying Index. The Fund may or may not hold all of the securities that are included in the Underlying Index. The Fund reserves the right to invest in substantially all of the securities in its Underlying Index in approximately the same proportions (i.e., replication) if NTI determines that it is in the best interest of the Fund. Under normal circumstances, the Fund will invest at least 80% of its total assets (exclusive of collateral held from securities lending) in the securities of the Underlying Index. The Fund may also invest up to 20% of its assets in cash and cash equivalents, including shares of money market funds advised by NTI or its affiliates, futures contracts and options on futures contracts, to-be-announced (TBA) transactions, as well as securities not included in the Underlying Index, but which NTI believes will help the Fund track its Underlying Index. The Underlying Index is created and sponsored by NTI, as the Index Provider. NTI also serves as the investment adviser to the Fund. The Index Provider determines the composition and relative weightings of the securities in the Underlying Index and publishes information regarding the market value of the Underlying Index. The Fund may lend securities representing up to one-third of the value of the Funds total assets (including the value of the collateral received). Industry Concentration Policy. The Fund will concentrate its investments (i.e., hold 25% or more of its total assets) in a particular industry or group of industries to approximately the same extent that the Underlying Index is concentrated. As of December 31, 2025 , the Underlying Index was concentrated in the Financial sector. The components of the Underlying Index, and the degree to which these components represent certain industries or sectors, may change over time. Show less