The investment objective of the iShares US Infrastructure ETF seeks to track the NYSE FactSet US Infrastructure Index. The index divides infrastructure companies into two types: enablers, and owners/operators. Each group gets 50% of the index. Enablers are “potential beneficiaries of infrastructure investment,” the prospectus says. And will mostly be companies in construction and engineering services, machineries and materials. Owners and operators will mostly be companies in energy transportation and storage, railroad transportation, and utilities.