The portfolio holds fixed-rate, taxable, investment-grade US bonds with at least one year until maturity. Qualifying bonds must have at least$ 300 million in outstanding face value, with higher minimums for some securitized fare. The index is market-value-weighted and rebalances each month. This results in a conservative portfolio that limits return and yield potential but also caps risk.
The portfolio's conservative complexion mimics that of the taxable, US investment-grade bond market. US Treasuries account for almost 45% of the portfolio, with the rest mostly in agency mortgage-backed securities (27%) and corporate bonds (26%). These figures differ from the category average, which places greater emphasis on mortgages and other securitized fare at the expense of Treasuries. The fund also excludes high-yield debt. Some peers allocate as much as 5% of their portfolios to below-investment-grade bonds, further accentuating the fund's conservative bend relative to category peers.
Average effective duration has fluctuated in recent years. As an index fund, this strategy is beholden to the issuing activity of bond types prevalent in its benchmark. This means the issuing activity of US Treasuries largely determines the makeup of the portfolio. As the Federal Reserve cut rates to zero following the initial coronavirus-driven shock in early 2020, this fund scooped up the low-coupon, longer-maturity debt that flooded the market. This led to higher duration and lower coupons than most active peers. As the Fed hiked rates in the years since, the fund’s average effective duration fell alongside long-dated issuances. These moves mimic those of the category norm, but their magnitude is more pronounced given the fund’s slightly higher interest-rate sensitivity.
With less credit risk comes less reward, and the fund leaves yield on the table by focusing on US Treasuries and other highly rated debt. Its average coupon and 12-month yield consistently lag the category average, falling 58 and 36 basis points short of the category norm, respectively, as of February 2024. However, the current rate environment gives even the safest portfolios an appetizing yield. The fund’s SEC yield of 4.4% as of February 2024 is more than double what it was in early 2022.
Note: The Process Pillar rating and analysis are indirectly assigned by an analyst. When an analyst covers a passively managed vehicle that tracks a particular index, Morningstar associates the Process Pillar rating assigned to that vehicle with the index concerned. Morningstar then maps the Process Pillar associated with a given index to any other uncovered passive strategies that track the same index. This ensures that the analyst’s view is leveraged whenever available and promotes consistency when analyzing passive vehicles associated with a given index.