The Optica Rare Earths & Critical Materials ETF primarily invests in the securities that constitute its underlying benchmark. This index specifically identifies companies that either already generate a minimum of half their income from rare earth elements and critical materials, or are actively developing ventures anticipated to achieve this 50% revenue milestone once fully operational. A substantial portion—at least 80% of the fund's total assets—will be committed to holdings in businesses operating within the rare earths and critical materials sector.