The fund provides core exposure to long-term bonds issued by the government of Canada. It tracks an index that consists of investment grade, semi-annual pay fixed rate bonds denominated in CAD, with remaining maturities of 15 years and above. Conversely, the index excludes agency and real return bonds. Holdings are weighted by market value. XFLB uses a sampling strategy to track its index, which rebalances monthly. In addition, the fund may also replicate the index by investing in one or more iShares ETFs, or through the use of derivatives.