The State Street SPDR Portfolio Aggregate Bond ETF (SPAB) aims to closely match the price appreciation and income generation of the Bloomberg U.S. Aggregate Bond Index, before accounting for its own management fees and expenses. This ETF is a cost-effective member of the core SPDR Portfolio suite, designed to serve as a foundational component for diversified investment portfolios. It provides broad, economical access to a comprehensive range of US dollar-denominated, investment-grade fixed income securities. This includes government debt, corporate bonds, mortgage pass-through securities, commercial mortgage-backed securities, and asset-backed securities. The underlying index utilizes a market capitalization weighting scheme and is rebalanced on the final business day of each month.