IFRA provides a different approach to infrastructure exposure. By design, the fund tracks an index focused on US companies that could benefit from domestic infrastructure activities. Index selection begins with all US-listed stocks in infrastructure-related industries. Companies must also derive at least half of their revenue from the US. Each company is further classified into one of two categories: infrastructure enablers (construction companies, engineering services, machineries and materials) or infrastructure asset owners and operators (utilities, energy transportation and storage, railroad transportation). Each category gets 50% weight in the index, and individual holdings are equal weighted within the categories. IFRA is reconstituted annually and rebalanced quarterly.