Fidelity MSCI Materials Index ETF (FMAT US) – Portfolio Construction MethodologyThe underlying MSCI USA IMI Materials 25/50 Index targets comprehensive US materials exposure across large, mid, and small caps from the MSCI US Investable Market universe and then applies a 25/50 diversification overlay. An optimizer minimizes tracking error to the pro forma parent sector while enforcing: no single group entity >25% and the aggregate of >5% group entities ≤50%, implemented with 10% buffers at rebalance (22.5%/4 ...