IUSB vs VGIT

IUSB tracks the Bloomberg U.S. Universal Index, which holds everything in the Aggregate and adds high-yield corporate bonds, emerging-market debt and other securities. It held 18,359 lines on Nov 6, 2026.

VGIT tracks the Bloomberg U.S. Treasury 3-10 Year Bond Index: U.S. Treasury securities with three to ten years remaining. It held 102 bonds on Sep 30, 2026, all of them Treasuries. The Treasury fund owns a small, concentrated list, while the Universal fund owns thousands of bonds across several sectors.

Holdings counts are not directly comparable: some are a count of bonds, others a count of lines in a holdings file, which can include cash and futures.

The largest bond line in IUSB is 0.50% of the fund (Nov 6, 2026) and the largest in VGIT is 1.92% (Aug 31, 2026). The VGIT top ten is all U.S. Treasury notes, while the IUSB top ten is not (see the table). The top ten total 3.84% of IUSB and 18.51% of VGIT. VGIT owns only 102 bonds, so each position is large and its top ten make up 18.5% of the fund.

The two lists are dated differently on purpose, because each issuer publishes holdings on its own schedule: IUSB Nov 6, 2026 (iShares holdings file); VGIT Aug 31, 2026 (SEC Form N-PORT, filed Oct 29, 2026 (fund-level, all share classes)). IUSB’s list includes a mortgage security sold on a to-be-announced basis (TBA), which is a forward purchase of a pool of mortgages rather than a single named bond.

97 individual bonds appear in both funds, out of 16,434 distinct bonds in IUSB and 103 in VGIT. Adding up the smaller of the two weights for every shared bond gives a portfolio overlap of 17.4%. The shared bonds are 17% of IUSB but 97% of VGIT, because VGIT is a short list of Treasuries that IUSB also owns among its many other holdings.

That is a floor, not a ceiling, for three reasons: the files are dated Nov 6, 2026 and Aug 31, 2026, so bonds that matured or were bought in between show as unshared; some weight carries no bond identifier (77% of IUSB and 99% of VGIT is matched to an identifier), mostly mortgage securities and cash; and the funds may identify the same mortgage pools differently.

Shared bonds are ranked by the smaller of the two weights. IUSB: Nov 6, 2026. VGIT: Aug 31, 2026. Weights are percent of each fund’s net assets.

Corporate bonds split three ways

Each issuer uses its own labels (IUSB: Sector (iShares label), Nov 6, 2026; VGIT: Distribution by issuer (Vanguard label), Sep 30, 2026). This page groups them into common categories: “Treasury and agency” adds Treasury, agency and government lines; corporate adds industrial, financial and utility bonds; “Other and cash” holds the remainder.

IUSB: Maturity (iShares label), Nov 6, 2026. VGIT: Distribution by effective maturity (Vanguard label), Sep 30, 2026. Where an issuer reports narrower bands, they are added together to match the common bands shown.

81% of IUSB and 100% of VGIT sits between one and ten years, and 9.5% of IUSB and 0.0% of VGIT runs past 20 years. Average effective maturity is 7.96 years for IUSB and 5.6 years for VGIT. The gap in the one-to-ten-year share is large enough to show up in how the funds react to rate changes.

Duration estimates how much a bond fund’s price moves when yields change. A duration of 5.54 years means a rise of one percentage point in yields would lower the price by about 5.54%, and a fall of one point would raise it by about the same.

IUSB reports effective duration of 5.54 years (Nov 6, 2026); VGIT reports average duration of 4.8 years (Sep 30, 2026). That is a difference of 0.74 years, which is large enough to matter: the fund with the higher duration will move more when yields change.

Estimate: price change ≈ −duration × change in yield, applied to $10,000. It ignores interest income, convexity, spread changes and trading costs, so real results will differ. IUSB reports convexity of 0.45 and an option-adjusted spread of 53.92 basis points (Nov 6, 2026); the other fund’s fact sheet does not list either figure.

The 30-day SEC yield is the standard way to compare bond funds because every fund calculates it the same way, after expenses. IUSB showed 5.21% and VGIT showed 4.90%, a gap of 0.31 points.

The two figures are dated Nov 6, 2026 and Nov 5, 2026, and market yields can change in between, so the comparison is approximate. Yield to maturity is shown with its date where the issuer publishes it. Trailing 12-month yield is a record of what was paid, not a forecast: 4.33% for IUSB and 3.98% for VGIT.

Monthly payouts per share, newest first

Third-party payout history (StockAnalysis, Nov 9, 2026), the 12 most recent payouts listed, which include two in December 2025 and none dated January 2026. Per-share amounts differ because the funds have different share prices (about $45 against $58), so compare yields, not dollars per share. Bond fund payouts change from month to month with the income the fund earns.

Average annual returns to September 30, 2026

Calendar-year returns

Net asset value (NAV) total returns, with distributions reinvested, from iShares fund page and holdings file (Nov 6, 2026) for IUSB and Vanguard fact sheet (Sep 30, 2026) and fund page for VGIT. Past performance does not guarantee future results. The funds launched in different years (IUSB Jun 10, 2014, VGIT Nov 19, 2009), so since-inception figures (1.93% and 1.99%) cover different periods and are not compared here.

IUSB charges 0.03 percentage points more, which is $3 a year more on $10,000. Both funds are large ($50.47B and $41.51B), and large funds usually trade with tight spreads. VGIT’s assets above are the ETF share class only; Vanguard reports $47.8B (Sep 30, 2026) across all share classes of the fund.

Neither fund’s fee is likely to be the largest cost of owning it: the choice of how much to hold in bonds, and for how long, matters far more than a few hundredths of a percent.

Interest from bond funds is generally taxed as ordinary income rather than at the lower rates that apply to qualified dividends, and the monthly distributions of these funds are mostly interest. For that reason many investors hold taxable bond funds in tax-advantaged accounts, such as retirement accounts, when they have the choice.

Some interest from U.S. Treasuries can be exempt from state income tax; how much of each fund’s income qualifies is reported by the issuer after year-end and varies by fund and year. VGIT holds only Treasuries, so more of its income may qualify for the state-tax exemption than the income of a fund that also holds corporate and mortgage bonds; the issuer reports the exact share after year-end.

Canadian and other non-U.S. investors face their own rules, including currency conversion and withholding considerations, and should check them before buying a U.S.-listed fund.

Every figure on this page, with its source, date and evidence grade. Open the issuer documents before relying on any number.

Third-party sources

StockAnalysis, IUSB · StockAnalysis, VGIT.

Methodology and limits

• Issuer figures are shown with their own dates. Where the two funds report on different dates the page says so and does not mix them silently.
• Sector and maturity overlap are this page’s sums of the smaller weight in each common category, and are approximate because issuers use different labels.
• Holdings overlap matches bonds by CUSIP or ISIN between the two holdings files named above; bonds without an identifier cannot be matched.
• Figures that were unavailable are marked as such, and nothing was filled from memory or from another fund.
• Rate-sensitivity figures are estimates from reported duration only.

IUSB vs VGIT, which is better?

Neither is better in general, because they do different jobs. IUSB holds the U.S. bond market through the wider Bloomberg U.S. Universal index, which adds high-yield and other lower-rated debt to the Aggregate, while VGIT holds only U.S. Treasury notes and bonds with 3 to 10 years left to run. The right one depends on the role bonds play in a portfolio, the investor’s tolerance for interest-rate and credit risk, and the account used.

IUSB vs VGIT, what is the difference in fees?

IUSB charges 0.06% and VGIT charges 0.03%, a difference of 0.03 percentage points, or $3 a year on $10,000.

IUSB vs VGIT, which has the higher yield?

IUSB showed a 30-day SEC yield of 5.21% on Nov 6, 2026 and VGIT showed 4.90% on Nov 5, 2026. The gap is 0.31 points; the dates differ, so the comparison is approximate.

IUSB vs VGIT, how much do they fall if rates rise?

By duration, about 5.54% for IUSB and 4.8% for VGIT for each one-point rise in yields, before counting the interest each fund earns. This is an estimate, not a forecast.

IUSB vs VGIT, do they hold the same bonds?

Partly. The files compared here show 97 bonds in both funds, a portfolio overlap of 17%. IUSB holds 18,359 bonds and VGIT holds 102. The sector overlap on this page is about 42%.

VGIT vs IUSB, does the order change the comparison?

No. VGIT vs IUSB and IUSB vs VGIT describe the same pair of funds, and every figure on this page applies either way. The order only decides which fund is listed first.

IUSB vs VGIT, can I own both?

You can. The two funds hold different exposures, with an overlap of 17%, so owning both gives a different mix from owning either alone.

IUSB vs VGIT, are they suitable for Canadian investors?

Both are U.S.-listed and trade in U.S. dollars, so Canadians face currency conversion costs and should check how interest income is taxed in their account type before buying.

Pathways, not rankings or recommendations.