At a glance
IUSB charges 0.06% a year, below the 0.19% average of the 7 funds most like it (the 4th cheapest of 8). It has $43.00B in assets, the 4th largest of that group; it paid 4.31% of its price in distributions over the past 12 months, monthly. Over the past year it returned −0.3% with distributions reinvested, 3rd of those 8 funds; over three years it returned +5.1% a year. At its worst it fell 9.9% in the 2020 crash (S&P 500: 33.7%) and 14.9% in the 2022 bear market (S&P 500: 24.5%), and was back at its earlier high 3 months and 35 months after the lows. Its ten largest positions make up 3.5% of the fund, out of 18,106 in all.
The short version
iShares Core Total USD Bond Market ETF (IUSB) is a BlackRock index fund that tracks the Bloomberg U.S. Universal Index, which spans Treasuries, mortgage bonds and corporate debt. Unlike investment-grade-only funds, the index also includes high-yield (“junk”) and emerging-market bonds. It pays monthly, with a 12-month yield of 4.31% as of October 27, 2026. It costs 0.06% a year, double the fee of BND and AGG but below the 0.22% average of similar funds.
Price history
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IUSB -0.3% over the year to Nov 2, 2026, total return with distributions reinvested.
How it has behaved
| YTD | 1 yr | 3 yr | 5 yr | 10 yr | Since start | |
|---|---|---|---|---|---|---|
| IUSB official prospectus, to Dec 31, 2025 | — | +7.47% | — | +0.02% | +2.39% | — |
| Bloomberg US Universal Index index, same period | — | +7.58% | — | +0.06% | +2.44% | — |
| IUSB price data to Nov 2, 2026 | -0.7% | -0.3% | +5.1% | +0.1% | +1.7% | +2.0% |
- Over the year to Nov 2, 2026, IUSB returned -0.3%, 3rd of 8 among similar funds.
- Its 5-year annualized return was +0.1% and its 10-year +1.7%.
- In the 2020 COVID crash it fell 9.9% and regained its old high 2.7 months after the low.
- Its worst full calendar year was 2022 (-13.1%); its best was 2019 (+9.1%).
- The deepest fall in its price history was 17.9% (Dec 31, 2020 to Oct 20, 2022), recovered by Oct 20, 2025.
Show as a table
| Year | Price data | Prospectus (official) |
|---|---|---|
| 2026 (to date) | -0.7% | — |
| 2025 | +7.4% | +7.47% |
| 2024 | +2.1% | +2.13% |
| 2023 | +6.2% | +6.20% |
| 2022 | -13.1% | -13.01% |
| 2021 | -1.3% | -1.28% |
| 2020 | +7.7% | +7.59% |
| 2019 | +9.1% | +9.26% |
| 2018 | -0.3% | -0.38% |
| 2017 | +3.8% | +4.06% |
| 2016 | +4.0% | +3.78% |
| 2015 | +0.4% | — |
| 2008 financial crisis stocks fell Oct 9, 2007 – Mar 9, 2009 | Before this security existed |
|---|---|
| 2020 COVID crash stocks fell Feb 19, 2020 – Mar 23, 2020 | Lost 4.8% over that stretch · deepest drop along the way 9.9%, back to its old high 2.7 months after the low |
| 2022 bear market stocks fell Jan 3, 2022 – Oct 12, 2022 | Lost 14.7% over that stretch · deepest drop along the way 14.9%, back to its old high 35.2 months after the low |
Dividends and income
Show as a table
| Year | Per share | Change |
|---|---|---|
| 2026 (to date) | $1.4511 | |
| 2025 | $1.9400 | +6.0% |
| 2024 | $1.8300 | +15.1% |
| 2023 | $1.5900 | +40.7% |
| 2022 | $1.1300 | +21.5% |
| 2021 | $0.9300 | -37.2% |
| 2020 | $1.4800 | -5.7% |
| 2019 | $1.5700 | +6.1% |
| 2018 | $1.4800 | +13.8% |
| 2017 | $1.3000 | -0.8% |
| 2016 | $1.3100 | +35.1% |
| 2015 | $0.9700 |
What's inside
As of Jul 31, 2026, the fund held 18,106 securities; the ten largest made up 3.54% of assets, and 5.16% sat in cash and money-market holdings.
| Holding | Weight | |
|---|---|---|
| Federal National Mortgage Association or Federal Home Loan Mortgage Corp. Mortgage-backed securities | 0.41% | |
| United States of America Bonds and notes | 0.37% | |
| United States of America Bonds and notes | 0.37% | |
| United States of America Bonds and notes | 0.36% | |
| United States of America Bonds and notes | 0.35% | |
| United States of America Bonds and notes | 0.34% | |
| United States of America Bonds and notes | 0.34% | |
| United States of America Bonds and notes | 0.34% | |
| United States of America Bonds and notes | 0.33% | |
| United States of America Bonds and notes | 0.33% | |
| United States of America Bonds and notes | 0.33% | |
| United States of America Bonds and notes | 0.33% | |
| United States of America Bonds and notes | 0.32% | |
| Federal National Mortgage Association or Federal Home Loan Mortgage Corp. Mortgage-backed securities | 0.31% | |
| United States of America Bonds and notes | 0.31% |
By country
United States 85.92%Canada 1.21%United Kingdom 1.01%Cayman Islands 0.83%Japan 0.65%By issuer
US Treasury 39.5%Companies 32.24%US government-sponsored enterprises 15.72%Foreign governments 5.9%US government agencies 4.55%The bonds mature in 11.8 years on average (weighted by size), with an average coupon of 4.11%.
Source: N-PORT holdings report as of Jul 31, 2026. Cash, money-market funds and derivatives are shown separately from the securities list.What changed recently
- Over the three months to Jul 31, 2026, investors added a net $7.17B (creations minus redemptions, per the N-PORT report).
- Monthly total returns reported for that quarter: +0.33%, +0.27%, -1.23%.
How it works
IUSB tracks the Bloomberg U.S. Universal Index, which covers taxable bonds priced in U.S. dollars. Bloomberg, not BlackRock, picks the index's bonds and sets their weights. The index mixes Treasuries, government-related debt, corporate bonds, mortgage-backed securities (pools of home loans), asset-backed bonds and emerging-market dollar bonds. It includes investment-grade bonds and also high-yield (“junk”) bonds. Junk bonds are rated below investment grade and are more likely to default. The fund's prospectus, filed February 23, 2026, calls it the iShares Core Universal USD Bond ETF.
BlackRock doesn't hold every bond in the index. It uses representative sampling, which means holding a smaller set of bonds chosen to match the index's interest-rate sensitivity (duration), maturity, credit ratings, yield and sector mix. As of July 31, 2026, that meant 18,106 holdings. The largest, a Fannie Mae or Freddie Mac mortgage security, was 0.41% of assets. At least 80% of assets must be in index bonds or to-be-announced (TBA) trades, which are agreements to purchase mortgage pools at a later date. Up to 10% can go into futures, options, swaps or other bonds.
The fund does not try to beat the index or turn defensive when markets fall. Portfolio turnover, the share of holdings traded over a year, was 65%. Trading costs are not included in the expense ratio. The fund may also lend up to one-third of its assets to earn extra income.
What it really costs
- IUSB charges 0.06% a year, versus an average of 0.19% for the similar funds below (4th of 8, cheapest first).
- Using the prospectus's standard example, $10,000 invested would cost about $6 in the first year and $77 over 10 years (assuming a 5% annual return).
| Cost of $10,000 (SEC example) | 1 yr | 3 yrs | 5 yrs | 10 yrs |
|---|---|---|---|---|
| IUSB | $6 | $19 | $34 | $77 |
Structure and tax notes
- Bond prices move opposite to interest rates; the longer the maturities it holds, the more its price reacts to rate changes.
In a retirement portfolio
It tracks the Bloomberg U.S. Universal Index, which mixes Treasuries, mortgage-backed securities, investment-grade bonds and high-yield (junk) bonds, so it can serve as a portfolio's main bond holding at low cost.
Launched in 2014, it has no 2008 crisis record. In the 2020 COVID crash it fell 9.9%, recovering in about 2.7 months. The 2022 bear market was harder: as rates rose, it dropped 14.9%, offering little shelter from falling stocks. Its worst calendar year was 2022 (−13.01%), and its deepest drop, 17.9% from December 2020 to October 2022, took 36 months to recover. Selling in late 2022 meant locking in losses. Its yield over the prior year was 4.31% as of October 27, 2026, paid monthly, which may cover spending without selling.
Its expense ratio (annual fee) is 0.06%, or $6 in the first year and $77 over 10 years per $10,000 in the SEC's standard example. That is below the 0.22% average for similar funds but above BND and AGG's 0.03%. Past results don't predict the future; a plan should weigh the whole portfolio, not one fund.
Who it may suit — and who should look elsewhere
May suit
- Investors wanting one fund spanning Treasuries, mortgage bonds, corporates, high-yield and emerging-market debt: 18,106 holdings as of July 31, 2026.
- Retirees who value monthly income; the fund's trailing 12-month yield was 4.31% as of October 27, 2026.
- Cost-conscious investors who want a broad bond index for 0.06% a year, well under the 0.22% average of similar funds.
Look elsewhere if
- Investors seeking the lowest fee: BND and AGG have similar average maturities and charge 0.03% a year, half IUSB's 0.06%.
- Savers who may need the money within a few years: IUSB lost 13.0% in 2022 and took 36 months to recover from its deepest drop.
- Investors wanting only investment-grade bonds: IUSB's index includes high-yield (“junk”) and emerging-market bonds, which can carry more default risk.
Close alternatives
Matched by bond funds with the closest average maturity and issuer mix (N-PORT).
| Fund | Avg. maturity | Cost | Net assets | 1 yr | 3 yr |
|---|---|---|---|---|---|
| IUSB this fund | 11.8 yrs | 0.06% | $43.00B | -0.3% | +5.1% |
| EUSB iShares ESG Advanced Total USD Bond Market … | 11.4 yrs | 0.12% | $710.3M | -1.0% | +5.4% |
| BND Vanguard Total Bond Market ETF | 11.7 yrs | 0.03% | $397.11B | -0.4% | +4.7% |
| AGG iShares Core U.S. Aggregate Bond ETF | 12.4 yrs | 0.03% | $138.32B | -0.4% | +4.7% |
| FBND Fidelity Total Bond ETF | 14.4 yrs | 0.36% | $28.16B | -0.2% | +5.4% |
| STOT SPDR DoubleLine Short Duration Total Return… | 13.2 yrs | 0.45% | $473.3M | +2.1% | +4.8% |
| TOTR T. Rowe Price Total Return ETF | 16.1 yrs | 0.32% | $572.6M | -1.2% | +5.6% |
| BIV Vanguard Intermediate-Term Bond ETF | 7.5 yrs | 0.03% | $52.45B | -0.7% | +5.1% |
Questions investors ask
What's the difference between IUSB and BND?
The main differences are breadth and cost. IUSB's index, the Bloomberg U.S. Universal Index, includes high-yield (“junk”) corporate bonds and dollar-denominated emerging-market debt alongside Treasuries, mortgage bonds and investment-grade corporates. Vanguard's BND and iShares' own AGG each charge 0.03% a year, versus IUSB's 0.06%. Returns have been close. As of October 27, 2026, IUSB lost 0.9% over one year and gained 5.6% a year over three years. BND lost 1.1% and gained 5.2% a year over the same periods.
Does IUSB pay monthly dividends?
Yes. IUSB makes distributions every month. Over the 12 months to October 27, 2026, it paid about $1.93 per share, a trailing yield of 4.31%. As a bond fund, its payouts come mostly from interest on the bonds it holds rather than from company dividends. Payments vary. The prospectus warns that income can decline when interest rates fall, because maturing, called or prepaid bonds may be replaced with lower-yielding ones.
Is IUSB a good bond fund for retirement?
It may suit retirees looking for one broad, low-cost bond fund, but it is not risk-free. As of July 31, 2026, IUSB had 18,106 holdings with an average maturity of 11.8 years. It charges 0.06% a year. Its price can swing with interest rates, and it has fallen hard before. It lost 13.0% in 2022, and its deepest drop, 17.9%, took 36 months from the low to recover, ending in October 2025. That matters for anyone who may need to cash out within a few years.
Does IUSB hold junk bonds?
Yes, its index includes them. The Bloomberg U.S. Universal Index covers U.S. dollar bonds rated either investment grade or high yield. High-yield bonds, also called junk bonds, pay more interest because their issuers are more likely to default. The prospectus lists high-yield securities among the fund's principal risks. Even so, Treasuries and mortgage agency debt make up most of the fund. As of July 31, 2026, U.S. Treasuries were 39.5% and government-sponsored enterprises such as Fannie Mae and Freddie Mac were 15.7%. Company bonds made up 32.2%.
What is IUSB's expense ratio?
IUSB's expense ratio is 0.06% a year, with no fee waiver, according to its prospectus filed February 23, 2026. The SEC's standard example assumes $10,000 invested and a 5% annual return. On that basis, the fee comes to about $6 after one year and $77 over 10 years. That is below the 0.22% average of similar bond funds and well under Fidelity Total Bond ETF (FBND) at 0.36%. It is double the 0.03% charged by BND and AGG.