The fund provides exposure to Canadian firms that have a higher standard of environmental and social performance. The underlying index models the S&P/TSX 60 and selects companies that pass its ESG criteria. The underlying index uses Sustainalytics ratings framework that examines a firms historical performance in areas such asaboriginal relations, community involvement, corporate governance, employee relations, the environment and human rights. It excludes companies that have significant involvement in nuclear power, tobacco and weapons-related contracting. The underlying index is usually rebalanced on an annual basis. XEN currently employs a replicating strategy wherein it invests in securities in considerably the same proportions as they are represented in the underlying index.