NIKL provides pure-play exposure to nickel mining companies. The narrow portfolio typically holds 20 to 35 US and foreign firms that derive at least 50% of their revenue and/or assets from mining, exploration, development, and production of nickel. The fund also includes companies that invest all or a significant portion of their assets in nickel. The initial selection universe is determined using a proprietary selection methodology that may involve industry publications review and fundamental research. Eligible securities that meet the minimum market-cap and liquidity requirements are selected for index inclusion. Each constituent is assigned an intensity score depending on its revenue percentage attributable to nickel. While the index is market cap-weighted, several capping rules are implemented based on the securities initial weights for portfolio diversification. The index is reconstituted and rebalanced semi-annually in June and December.