ICLN invests in global clean energy companies, which is defined as those involved in the biofuels, ethanol, geothermal, hydroelectric, solar, and wind industries. Aside from holding companies that produce energy through these means, ICLN also includes companies that develop technology and equipment used in the process. Selected by the index committee, the fund is weighted by market-cap and exposure score subject to several constraints and reconstituted semi-annually. Prior to April 19, 2021, the index followed a more narrow methodology.