iShares Core Universal USD Bond ETF
U.S. bond index ETF · tracks Bloomberg U.S. Universal Index
As of its 2026 Q2 report, iShares Core Universal USD Bond ETF held 17,790 positions with $36.54B in net assets. Its ten largest holdings made up 6.7% of the fund. The IUSB share class costs 0.06% a year. Over the 12 months to May 2026, IUSB returned 5.5%, with dividends reinvested. In 2026 Q3 it added 990 new positions and exited 723.
The iShares Core Universal USD Bond ETF (the Fund ) seeks to track the investment results of an index composed of U.S. dollar-denominated bonds that are rated either investment-grade or high yield.
The fund tracks the Bloomberg U.S. Universal Index using representative sampling, holding a sample of U.S. dollar-denominated investment-grade and high-yield bonds across Treasuries, government-related debt, corporate bonds, mortgage-backed securities, asset-backed securities, and emerging market bonds. Because the fund does not hold all index constituents, its returns may diverge from the index it seeks to track.
What you own
| Company | Weight | Value | Shares |
|---|---|---|---|
Blackrock Liquidity Tempcash | 2.88% | $1.05B | — |
BlackRock Funds III | 0.93% | $341.25M | — |
United States of America 4.25% · due 2034-11-15 | 0.37% | $135.63M | — |
United States of America 4.38% · due 2034-05-15 | 0.37% | $133.98M | — |
United States of America 3.88% · due 2034-08-15 | 0.37% | $133.74M | — |
United States of America 4.00% · due 2030-02-28 | 0.37% | $133.77M | — |
United States of America 4.25% · due 2035-05-15 | 0.36% | $131.36M | — |
United States of America 4.00% · due 2034-02-15 | 0.36% | $131.29M | — |
United States of America 4.63% · due 2035-02-15 | 0.36% | $130.26M | — |
United States of America 4.50% · due 2033-11-15 | 0.35% | $126.35M | — |
The 200 largest of 17,790 holdings, with the share counts as filed, open with a free account.
What the fund is made of
Percentages are of fund net assets. Rounding, liabilities and short positions can make totals differ from 100%.
| Bonds | 76.84% |
| Securitized | 21.60% |
| Cash & short-term | 3.82% |
By sector
- Government
- 44.2%
- Securitized
- 20.5%
- Other
- 7.0%
- International
- 6.2%
- 12 other sectors
- 22.1%
- Government
- 44.2%
- Securitized
- 20.5%
- Other
- 7.0%
- International
- 6.2%
- Cash
- 5.0%
- Financials
- 4.8%
- Utilities
- 2.3%
- Health Care
- 1.9%
- Information Technology
- 1.5%
- Industrials
- 1.4%
- Communication Services
- 1.3%
- Consumer Staples
- 1.0%
- Consumer Discretionary
- 1.0%
- Energy
- 0.8%
- Real Estate
- 0.6%
- Materials
- 0.4%
How it has done
IUSB share class · total returns with dividends reinvested
Volatility over the last 12 months: 3.14%. Past returns are a record, not a forecast.
Jun 2026 and Jul 2026 have been filed since the trailing figures were struck, so they are not in the table above or the curve — every figure here shares one cut-off, which is what makes them comparable with other funds.
Fees & fund details
iShares Core Universal USD Bond ETF is a U.S. bond index ETF that tracks the Bloomberg U.S. Universal Index.
- Asset class
- Bonds
- Region
- United States
- Management
- Index (passive)
- Fund type
- ETF
- Credit quality
- Investment grade
- Rate sensitivity
- Intermediate duration
- Expense ratio, by class
- 0.06%· IUSB 0.06%
- Portfolio turnover
- 65.00% a year · as of 2026 Q1
Turnover is how much of the portfolio was replaced in a year.
Classified from what the fund holds, not from its name · 2026 Q2. The summary is a paraphrase of the prospectus; the objective is verbatim.
What changed this quarter
Positions that entered or left the fund since its previous filing. Positions that were only resized are not listed.
990 new· the largest 2
723 exited· the largest 3
Debt profile
What this fund holds — value-weighted across its bond and securitized long positions · as of 2026-04-30
Share of the fund's debt by how its coupon behaves — the fact that decides whether a rate move reaches this portfolio at all.
| Fixed rate | 94.2% |
| Floating rate | 5.8% |
Share of the fund's debt value in each maturity band, shortest first.
| <1y | 1.0% |
| 1-3y | 21.1% |
| 3-5y | 18.9% |
| 5-10y | 20.0% |
| 10y+ | 38.9% |
These three overlap — one holding can be in arrears and paying in kind at once — so they are shown separately and never summed.
Risk profile
Interest-rate and credit-spread sensitivity, both in years · as of 2026Q2
Most of this fund’s sensitivity is to interest rates, with credit spreads carrying about half as much.
Where the loss would come from. The two shocks are the same size, so this is the balance of the fund's two sensitivities rather than a bet on one moving more.
| Interest rates | 62% |
| Credit spreads | 38% |
Filers report the impact of a 0.01% move only, so the total is our own scaling of that one number and overstates the loss on most bonds — read it as approximate, never as precise. The two sensitivities overlap rather than add up: they measure the same positions against different shocks, which is why the durations above are shown side by side and never summed.
Share of the fund's spread duration carried by each credit tier.
| Investment grade | +3.15 yr |
| High yield | +0.24 yr |
Share of duration at each point, shortest first. A positive figure loses value when spreads widen; a negative one offsets — a credit hedge.
| 3 mo | 0.01 yr | 0% |
| 1 yr | 0.44 yr | 8% |
| 5 yr | 2.17 yr | 39% |
| 10 yr | 1.52 yr | 28% |
| 30 yr | 1.38 yr | 25% |
| 3 mo | 0.01 yr | 0% |
| 1 yr | 0.12 yr | 4% |
| 5 yr | 1.62 yr | 48% |
| 10 yr | 0.78 yr | 23% |
| 30 yr | 0.87 yr | 26% |
The two bands measure the same positions against different shocks and do not add — a Treasury carries rate duration and no spread duration, a floating-rate credit the reverse. Rate tenors are also summed across every currency the fund discloses.
Show the numbers
| Tenor | Rate yrs | IG yrs | HY yrs | IG $/bp | HY $/bp |
|---|---|---|---|---|---|
| 3 mo | +0.01 | +0.01 | +0.00 | $18.6k | $2.0k |
| 1 yr | +0.44 | +0.10 | +0.02 | $375.5k | $74.5k |
| 5 yr | +2.17 | +1.47 | +0.15 | $5.36m | $541.7k |
| 10 yr | +1.52 | +0.74 | +0.03 | $2.72m | $127.7k |
| 30 yr | +1.38 | +0.83 | +0.04 | $3.05m | $138.3k |
Dollar change per 1bp of spread movement, as filed and sign-anchored. A blank cell was not filed; a zero was.
Duration contribution in years, summing to the fund's 5.50 yr.
This is where the fund's rate exposure sits, not its currency risk — most international bond funds hedge the currency back to dollars, and the size of those hedges is not in the filing. Tenors are also summed across curves, so a 5-year JPY point and a 5-year USD point are added together.
A newer credit-spread reading (2026Q3) is on file. This page holds one quarter across every figure on it, so that one appears here next quarter.
Understand how this fund fits with the rest.
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