QCLN holds a broad portfolio of US-listed firms in the clean energy industry. Eligible companies must be manufacturers, developers, distributors, or installers of one of the following four sub-sectors: advanced materials (that enable clean-energy or reduce the need for petroleum products), energy intelligence (smart grid), energy storage and conversion (hybrid batteries), or renewable electricity generation (solar, wind, geothermal, etc). Because there is subjectivity in classifying companies as clean energy, potential investors would be well-served by reviewing the funds portfolio to make sure your definition of clean energy matches QCLNs.