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IUSB vs SPAB

iShares Core Universal USD Bond ETF

IUSBANasdaq

State Street SPDR Portfolio Aggregate Bond ETF

SPABANYSE Arca

Overlap

0.0%by weight

Expense ratio

SPAB −0.03pt a year

IUSB 0.06%SPAB 0.03%

Avg volume · 30D

IUSB 2.0×the volume

IUSB 5.66MSPAB 2.89M

10Y return · a year

IUSB +0.3pt

IUSB +1.5%SPAB +1.2%

IUSB vs SPAB Performance

Oct 13, 2025 – Oct 13, 2026

−1.6%IUSB−2.0%SPAB

Oct 13, 2025 to Oct 13, 2026. IUSB −1.6%. SPAB −2.0%. Use the arrow keys to read each point.−1%0%1%2%Oct 2025Apr 2026Oct 2026
Expense ratio
IUSB 0.06%
SPAB 0.03%, better
Fund size
IUSB $48.8B
SPAB $10.3B
1Y total return
IUSB −1.6%, better
SPAB −2.0%
Yield (12M)
IUSB 4.39%, better
SPAB 4.27%
Holdings
IUSB 18241
SPAB 8724
Avg volume (30D)
IUSB 5.66M sh, better
SPAB 2.89M sh
NAV per share
IUSB $44.11
SPAB $24.38
52W range

ETF.net Grade

IUSB: Cost 91, Risk 49, Mission 100, Tradability 88, Holdings 75, Durability 94. SPAB: Cost 95, Risk 49, Mission 100, Tradability 92, Holdings 75, Durability 92.
Pillar letters and Scores for IUSB, SPAB, with each pillar’s weight
PillarIUSBSPAB
Cost30% weightA91A95Higher
Mission25% weightA100A100
Risk15% weightC49C49
Tradability15% weightA88A92Higher
Holdings10% weightA75A75
Durability5% weightA94HigherA92

Rank among US Aggregate Bond funds

Same Category. IUSB and SPAB are both graded against the same 114 US Aggregate Bond funds, so their Grades compare head to head.

US Aggregate Bond⁠

Category · 114 funds
See all 114 ›

SPAB ranks 2nd and IUSB 4th of 114 funds in the US Aggregate Bond Category.

  1. Rank 1AAGGiShares Core U.S. Aggregate Bond ETFScore 87
  2. Rank 2ASCHZSchwab U.S. Aggregate Bond ETFScore 86
  3. Rank 2ASPABState Street SPDR Portfolio Aggregate Bond ETFScore 86
  4. Rank 4ABNDVanguard Total Bond Market ETFScore 85
  5. Rank 4AIUSBiShares Core Universal USD Bond ETFScore 85
  6. Rank 6ABKAGBNY Mellon Core Bond ETFScore 83

Our read on each fund

ETF.net Research

IUSBAiShares Core Universal USD Bond ETF

SPABAState Street SPDR Portfolio Aggregate Bond ETF

In short

IUSB Most core bond funds stop at investment grade. IUSB keeps going, folding high-yield USD debt into the same wrapper across roughly 18,000 bonds, for 0.06% a year.

SPAB A 2007-vintage core bond fund priced at 0.03%: roughly 8,500 US investment-grade bonds in one ticket, at the same rock-bottom fee the household names charge for the same index.

Stated mandate

IUSB The Fund seeks to track an index of U.S.-dollar-denominated bonds spanning investment-grade and high-yield sectors.

SPAB The fund seeks to track the price and yield performance of the Bloomberg U.S. Aggregate Bond Index before fees and expenses, providing broad exposure to U.S.-dollar-denominated investment-grade bonds.

Why people hold it

  • IUSB 0.06% a year, a fraction of what the typical broad bond fund in its category charges, and iShares has run it since 2014.
  • Roughly 18,000 bonds spanning investment-grade and high-yield sectors, so one ticker covers ground a plain Agg tracker leaves on the table.ishares.com
  • Tracks its index closely, trades heavily, and sits on a multi-billion-dollar asset base. Income is paid monthly.
  • Among the strongest implementations in a crowded field of nearly 200 core bond funds.
  • SPAB 0.03% a year against a 0.36% median for its peer group, and the same ticket price as AGG, SCHZ and BBAG on the identical index.
  • Roughly 8,500 dollar-denominated investment-grade bonds in one line item, tracking the Bloomberg U.S. Aggregate Bond Index. Diversification you could not assemble bond by bond.ssga.com
  • Trades actively and has tracked its index closely, putting it among the stronger implementations in the core-bond group.
  • Running since 2007, now a multi-billion-dollar fund, and it pays monthly rather than quarterly.

Worth knowing

  • IUSB That high-yield sleeve is the trade-off: more credit risk than an investment-grade-only fund, and more movement when spreads widen.
  • BND, SPAB and SCHZ charge 0.03%, half IUSB's fee, but they stay inside investment grade.
  • Payouts land monthly, but the amount floats with the coupons underneath. Nothing about the income stream is fixed.
  • SPAB Bond prices move opposite yields. When rates rise the index falls and the fund follows it down; a 0.03% fee cannot cushion that.
  • AGG, SCHZ and BBAG hold the same declared index at the same 0.03%. Picking among them comes down to spreads and platform, not the portfolio.
  • Investment grade and US dollar only by mandate: high yield and foreign-currency debt sit outside the remit.ssga.com

Full IUSB profile⁠

Full SPAB profile⁠

IUSB vs SPAB Holdings

Overlap

0.0%by weight

Only IUSB
17,795
of 17,795
In both
0
holdings
Only SPAB
8,674
of 8,674

Holdings side by side

Top 10 holdings by combined weight
HoldingIUSBSPAB
CashBLK Liquidity Temp Cash Inst #215.21%Not held
Ssi Us Gov Money Market ClassSsi Us Gov Money Market ClassNot held3.34%
Us Treasury N/B 12/28 3.5Us Treasury N/B 12/28 3.5Not held0.67%
Treasury Note 4.63% 02/15/2035Treasury Note 4.63% 02/15/20350.50%Not held
Us Treasury N/B 05/35 4.25Us Treasury N/B 05/35 4.25Not held0.49%
Us Treasury N/B 12/30 3.625Us Treasury N/B 12/30 3.625Not held0.44%
Us Treasury N/B 11/27 3.375Us Treasury N/B 11/27 3.375Not held0.44%
Us Treasury N/B 09/33 5Us Treasury N/B 09/33 5Not held0.43%
Us Treasury N/B 03/28 3.875Us Treasury N/B 03/28 3.875Not held0.43%
Treasury Note 4.00% 11/15/2035Treasury Note 4.00% 11/15/20350.42%Not held

All 18,240 IUSB holdings⁠All 8,741 SPAB holdings⁠

Sectors

IUSBSPAB

  • TreasuryIUSB 40.6%SPAB —
  • MBS Pass-ThroughIUSB 19.5%SPAB —
  • IndustrialIUSB 18.4%SPAB —
  • Financial InstitutionsIUSB 10.0%SPAB —
  • SovereignIUSB 3.3%SPAB —
  • UtilityIUSB 2.7%SPAB —
  • AgencyIUSB 2.4%SPAB —
  • CMBSIUSB 1.2%SPAB —
  • SupranationalIUSB 1.0%SPAB —
  • Local AuthorityIUSB 0.5%SPAB —
  • ABSIUSB 0.3%SPAB —

IUSB vs SPAB Cost

Expense ratio

  • 0.06%IUSB
  • 0.03%SPAB, cheaper
  • Middle half of US Aggregate Bond funds
  • Median 0.34%

0 of 113 US Aggregate Bond funds charge less than SPAB

9 of 113 charge less than IUSB

$632less in fees with SPAB over 30 years, on $10,000 invested

$0$250$500$750$1,000$1,250$1,500Start10 years20 years30 years

Assumes $10,000 invested once and 7% growth a year before fees.

IUSB vs SPAB Dividends

Last 12 months to Oct 13, 2026
Yield (12M)
IUSB: 4.39%, better
SPAB: 4.27%
Payout (12M)
IUSB: $1.94
SPAB: $1.04
Last payment
IUSB: $0.15
SPAB: $0.09
Ex-dividend
IUSB: Oct 1, 2026
SPAB: Oct 1, 2026
Paid on
IUSB: Oct 6, 2026
SPAB: Oct 6, 2026
Frequency
IUSB: Monthly
SPAB: Monthly

Distribution history

Per share, 2023 to 2026, same scale for both

IUSBMonthly · 45 paymentsAll IUSB payments⁠
One bar per payment. 45 payments from 2023 to 2026 YTD. Feb 1, 2023 $0.12; Mar 1, 2023 $0.12; Apr 3, 2023 $0.12; May 1, 2023 $0.13; Jun 1, 2023 $0.14; Jul 3, 2023 $0.13; Aug 1, 2023 $0.14; Sep 1, 2023 $0.13; Oct 2, 2023 $0.13; Nov 1, 2023 $0.14; Dec 1, 2023 $0.14; Dec 14, 2023 $0.15; Feb 1, 2024 $0.13; Mar 1, 2024 $0.15; Apr 1, 2024 $0.15; May 1, 2024 $0.15; Jun 3, 2024 $0.15; Jul 1, 2024 $0.15; Aug 1, 2024 $0.16; Sep 3, 2024 $0.16; Oct 1, 2024 $0.15; Nov 1, 2024 $0.16; Dec 2, 2024 $0.16; Dec 18, 2024 $0.16; Feb 3, 2025 $0.15; Mar 3, 2025 $0.16; Apr 1, 2025 $0.16; May 1, 2025 $0.16; Jun 2, 2025 $0.17; Jul 1, 2025 $0.16; Aug 1, 2025 $0.17; Sep 2, 2025 $0.16; Oct 1, 2025 $0.17; Nov 3, 2025 $0.16; Dec 1, 2025 $0.16; Dec 19, 2025 $0.16; Feb 2, 2026 $0.17; Mar 2, 2026 $0.16; Apr 1, 2026 $0.16; May 1, 2026 $0.16; Jun 1, 2026 $0.15; Jul 1, 2026 $0.16; Aug 3, 2026 $0.17; Sep 1, 2026 $0.17; Oct 1, 2026 $0.15. Use the arrow keys to read each point.$0$0.1020232026YTD
SPABMonthly · 45 paymentsAll SPAB payments⁠
One bar per payment. 45 payments from 2023 to 2026 YTD. Feb 1, 2023 $0.07; Mar 1, 2023 $0.06; Apr 3, 2023 $0.07; May 1, 2023 $0.07; Jun 1, 2023 $0.07; Jul 3, 2023 $0.07; Aug 1, 2023 $0.07; Sep 1, 2023 $0.07; Oct 2, 2023 $0.07; Nov 1, 2023 $0.08; Dec 1, 2023 $0.08; Dec 18, 2023 $0.08; Feb 1, 2024 $0.08; Mar 1, 2024 $0.08; Apr 1, 2024 $0.08; May 1, 2024 $0.08; Jun 3, 2024 $0.08; Jul 1, 2024 $0.08; Aug 1, 2024 $0.08; Sep 3, 2024 $0.08; Oct 1, 2024 $0.08; Nov 1, 2024 $0.08; Dec 2, 2024 $0.08; Dec 19, 2024 $0.08; Feb 3, 2025 $0.09; Mar 3, 2025 $0.08; Apr 1, 2025 $0.08; May 1, 2025 $0.08; Jun 2, 2025 $0.09; Jul 1, 2025 $0.08; Aug 1, 2025 $0.09; Sep 2, 2025 $0.09; Oct 1, 2025 $0.08; Nov 3, 2025 $0.09; Dec 1, 2025 $0.08; Dec 18, 2025 $0.09; Feb 2, 2026 $0.08; Mar 2, 2026 $0.08; Apr 1, 2026 $0.09; May 1, 2026 $0.09; Jun 1, 2026 $0.09; Jul 1, 2026 $0.09; Aug 3, 2026 $0.09; Sep 1, 2026 $0.09; Oct 1, 2026 $0.09. Use the arrow keys to read each point.$0$0.1020232026YTD

IUSB vs SPAB Risk

Fall from peak · 5 years

  • IUSB
  • SPAB
Oct 13, 2021 to Oct 13, 2026. Worst fall: SPAB −17.4% · Oct 2022. Use the arrow keys to read each point.−15%−10%−5%0%Oct 2021Apr 2024Oct 2026

Risk facts

VolatilityStd dev, 3 years
IUSB 5.5%, betterSPAB 5.6%
Return per unit of riskSharpe ratio, 3 years
IUSB 0.01, betterSPAB −0.07
Worst fallMax drawdown, 5 years
IUSB −17.4%SPAB −17.4%=
Market sensitivityBeta, 3 years
IUSB 0.96SPAB 1.00

IUSB and SPAB in the news

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