Strategy. Under normal circumstances, the Fund seeks to achieve its investment objective by investing at least 80% of its net assets (plus any borrowings for investment purposes) in equity securities of U.S. and non-U.S. infrastructure-related companies and in derivatives and other instruments that have economic characteristics similar to such securities. The Fund will concentrate its investments in the Infrastructure Industry. The Fund considers a company to be an infrastructure-related company if it derives at least 50% of its revenue or profits from the ownership or operation of infrastructure assets, which include, among other types of assets, the physical structures, networks and systems of transportation, energy, water and sewage, and communication. Examples of infrastructure assets include transportation assets (such as toll roads, … Show more… Under normal circumstances, the Fund seeks to achieve its investment objective by investing at least 80% of its net assets (plus any borrowings for investment purposes) in equity securities of U.S. and non-U.S. infrastructure-related companies and in derivatives and other instruments that have economic characteristics similar to such securities. The Fund will concentrate its investments in the Infrastructure Industry. The Fund considers a company to be an infrastructure-related company if it derives at least 50% of its revenue or profits from the ownership or operation of infrastructure assets, which include, among other types of assets, the physical structures, networks and systems of transportation, energy, water and sewage, and communication. Examples of infrastructure assets include transportation assets (such as toll roads, bridges, airports and seaports), utility assets (such as generating stations, gas and electric lines, water and sewer facilities, and communications networks) and social assets (such as hospitals, schools, and subsidized housing). The principal type of equity security in which the Fund invests is common stock. The Fund may also invest in infrastructure-related companies organized as master limited partnerships (MLPs), including up to 20% of its net assets in MLPs that are not taxed as regular corporations for U.S. federal income tax purposes. The MLPs in which the Fund invests are publicly traded partnerships or limited liability companies engaged, among other things, in the transportation, storage, processing, refining, marketing, exploration, production and mining of minerals and natural resources. Under normal circumstances, the Fund will provide exposure to investments that are economically tied to at least three different countries, including the U.S. Under normal circumstances, at least 40%, unless market conditions are not deemed favorable, in which case at least 30%, of the Funds net assets will provide exposure to investments that are economically tied to countries other than the U.S, including depositary receipts. The Fund may invest up to 25% of its net assets in securities of issuers located in emerging market countries, i.e., those that are generally in the early stages of their industrial cycles. The Fund may invest in securities of issuers of all capitalization sizes. The Fund can invest in derivative instruments including forward foreign currency contracts and futures contracts. The Fund can use forward foreign currency contracts to hedge against adverse movements in the foreign currencies in which portfolio securities are denominated; though the Fund has not historically used these instruments. The Fund can use futures contracts, including currency futures, to hedge against adverse movements in the foreign currencies in which portfolio securities are denominated. The Fund is non-diversified, which means that it can invest a greater percentage of its assets in a small group of issuers or in any one issuer than a diversified fund can. The portfolio managers investment process incorporates both fundamental and securities analysis. The investment process includes a bottom-up stock selection methodology that evaluates and ranks potential investments according to relative value using earnings data and other fundamental variables. This analysis generally favors those companies with characteristics such as more consistent cash flow growth, positive earnings revisions, relatively attractive multiples to cash flow and assets to price, sustainable dividends, and favorable investor reception relative to peers. The investment process also incorporates macro level risk control and attempts to predict the potential effects that variables such as country/currency exposure, regional economic expectations, population growth, and demand trends have on the asset holdings of each individual company. This macro component seeks to identify infrastructure-related companies offering the best expected relative fundamentals. Individual stocks are then selected based upon expected excess return within defined risk constraints that include beta, tracking error to the benchmark, geographic region, asset type and liquidity. The portfolio managers seek to limit risk through various controls, such as diversifying the portfolio sectors and geographic areas as well as by considering the relative liquidity of each security and limiting the size of any one holding. The portfolio managers will consider selling a security if, among other things, (1) relative valuation falls below the desired levels; (2) a change in fundamentals occurs, either company specific or industry wide; (3) the risk-return relationship changes significantly; or (4) a more attractive investment opportunity is identified. In attempting to meet its investment objective or to manage subscription and redemption requests, the Fund may engage in active and frequent trading of portfolio securities. As part of the Funds investment process to implement its investment strategy in pursuit of its investment objective, the Funds portfolio managers may also consider both qualitative and quantitative environmental, social and governance (ESG) factors they believe to be material to understand an issuers fundamentals, assess whether any ESG factors pose a material financial risk or opportunity to the issuer and determine whether such risks are appropriately reflected in the issuers valuation. This analysis may involve the use of third-party research as well as proprietary research. Consideration of ESG factors is just one component of the portfolio managers' assessment of issuers eligible for investment and not necessarily determinative to an investment decision. Therefore, the Funds portfolio managers may still invest in securities of issuers that may be viewed as having a high ESG risk profile. The ESG factors considered by the Funds portfolio managers may change over time, one or more factors may not be relevant with respect to all issuers eligible for investment and ESG considerations may not be applied to each issuer or Fund investment. Show less