LIGB focuses on investment-grade corporate debt with long remaining maturities of ten years or more. Eligible bonds must be US dollar-denominated, issued in the US market, and meet minimum outstanding issuance requirements. The index uses market-value weighting and is rebalanced monthly, with credit ratings determined using specified rules for ratings. The Fund may use representative sampling to approximate the indexs duration, maturity, credit quality, yield, and issuer and sector exposures. It may also hold cash, money market instruments, and other fixed-income securities to support index tracking and manage cash flows. The Fund is non-diversified and may have greater exposure to individual issuers.