SCHH is passively managed to invest in US equity REITS which primarily own and operate income-producing real estate. The fund excludes mortgage REITS or those involved in real estate finance, and hybrid REITs involved in both equity and mortgage. The index selects its constituents based on market cap and liquidity screens, subject to certain constraints. First, no single companys weight can exceed 10% and second, aggregate weight of all companies weighing above 4.5% cannot exceed 22.5%. The Index is market-cap weighted and undergoes a quarterly review. Prior to June 22, 2020, SCHH follows the Dow Jones U.S. Select REIT Index which has the same methodology but without the additional cap constraints.