BND vs IUSB

The Bloomberg U.S. Aggregate Bond Index is the standard measure of U.S. dollar investment-grade bonds with fixed rates. It covers Treasuries, government-related securities, corporate bonds, agency mortgage pass-throughs, commercial mortgage-backed securities and asset-backed securities, and it leaves out inflation-protected bonds, tax-exempt municipal bonds and high-yield corporate bonds.

BND tracks the Bloomberg U.S. Aggregate Float Adjusted Index, which counts only bonds actually available to investors. It owns a sample of 11,434 bonds from an index of 14,254, as of Sep 30, 2026.

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. The Universal index is a superset of the Aggregate, so most of the two portfolios is the same kind of bond; the extra layer is what separates them.

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 BND is 0.47% of the fund (Jun 30, 2026) and the largest in IUSB is 0.50% (Nov 6, 2026). The BND top ten is all U.S. Treasury notes, while the IUSB top ten is not (see the table). The top ten total 4.11% of BND and 3.84% of IUSB.

The two lists are dated differently on purpose, because each issuer publishes holdings on its own schedule: BND Jun 30, 2026 (SEC Form N-PORT, filed Aug 28, 2026 (fund-level, all share classes)); IUSB Nov 6, 2026 (iShares holdings file). 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.

8,822 individual bonds appear in both funds, out of 17,396 distinct bonds in BND and 16,434 in IUSB. Adding up the smaller of the two weights for every shared bond gives a portfolio overlap of 41.7%.

That is a floor, not a ceiling, for three reasons: the files are dated Jun 30, 2026 and Nov 6, 2026, so bonds that matured or were bought in between show as unshared; some weight carries no bond identifier (99% of BND and 77% of IUSB 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. BND: Jun 30, 2026. IUSB: Nov 6, 2026. Weights are percent of each fund’s net assets.

Corporate bonds split three ways

Each issuer uses its own labels (BND: Distribution by issuer (Vanguard label), Sep 30, 2026; IUSB: Sector (iShares label), Nov 6, 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.

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

79% of BND and 81% of IUSB sits between one and ten years, and 10.6% of BND and 9.5% of IUSB runs past 20 years. Average effective maturity is 8.3 years for BND and 7.96 years for IUSB. Both funds are intermediate in profile, and the gaps between the bands are small.

Duration estimates how much a bond fund’s price moves when yields change. A duration of 5.7 years means a rise of one percentage point in yields would lower the price by about 5.7%, and a fall of one point would raise it by about the same. BND reports average duration of 5.7 years (Sep 30, 2026); IUSB reports effective duration of 5.54 years (Nov 6, 2026). That is a difference of 0.16 years, which is too small to matter.

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. BND showed 5.02% and IUSB showed 5.21%, a gap of 0.19 points.

The two figures are dated Nov 5, 2026 and Nov 6, 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: 4.12% for BND and 4.33% for IUSB.

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 $72 against $45), 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 Vanguard fact sheet (Sep 30, 2026) and fund page for BND and iShares fund page and holdings file (Nov 6, 2026) for IUSB. Past performance does not guarantee future results. The funds launched in different years (BND Apr 3, 2007, IUSB Jun 10, 2014), so since-inception figures (2.86% and 1.93%) 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 ($167.76B and $50.47B), and large funds usually trade with tight spreads. BND’s assets above are the ETF share class only; Vanguard reports $389.3B (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.

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, BND · StockAnalysis, IUSB.

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.

BND vs IUSB, which is better?

Neither is better in general, because they do different jobs. BND holds the U.S. investment-grade bond market through the float adjusted Bloomberg U.S. Aggregate index, while 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. 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.

BND vs IUSB, what is the difference in fees?

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

BND vs IUSB, which has the higher yield?

BND showed a 30-day SEC yield of 5.02% on Nov 5, 2026 and IUSB showed 5.21% on Nov 6, 2026. The gap is 0.19 points; the dates differ, so the comparison is approximate.

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

By duration, about 5.7% for BND and 5.54% for IUSB for each one-point rise in yields, before counting the interest each fund earns. This is an estimate, not a forecast.

BND vs IUSB, do they hold the same bonds?

Partly. The files compared here show 8,822 bonds in both funds, a portfolio overlap of 42%. BND holds 11,434 bonds and IUSB holds 18,359. The sector overlap on this page is about 92%.

IUSB vs BND, does the order change the comparison?

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

BND vs IUSB, can I own both?

You can, but because the two funds hold nearly the same market, owning both adds little diversification beyond owning one.

BND vs IUSB, 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.