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ETF comparison

IUSB vs SPAB

Both US Aggregate Bond.

iShares Core Universal USD Bond ETF · State Street SPDR Portfolio Aggregate Bond ETF

Holdings overlap

Weighted by ISIN/CUSIP
51.5 %

6,788 positions appear in both funds. Buying equal dollars of IUSB and SPAB would leave roughly 51.5% of each dollar exposed to the same underlying securities.

IUSB unmatched 46.7% Shared 51.5% SPAB unmatched 46.7%

Unmatched is the part of a fund's weight the other fund doesn't match: names only it holds, plus any extra weight it puts in names both funds hold.

In IUSB only
11,256 positions
Shared
6,788 positions
In SPAB only
1,497 positions

Side by side

IUSB

iShares Core Universal USD Bond ETF

iShares · US Aggregate Bond

88 composite / 100
Expense ratio
0.060%
Net assets
$48.08B
TTM yield
4.34%
Top-10 conc.
3.5%
SPAB

State Street SPDR Portfolio Aggregate Bond ETF

State Street · US Aggregate Bond

89 composite / 100
Expense ratio
0.030%
Net assets
$9.90B
TTM yield
4.22%
Top-10 conc.
4.4%

Sub-score comparison

94
Cost
97
52
Tax efficiency
52
100
Liquidity
100
100
Concentration
100
—
Tracking quality
—
IUSB sub-score SPAB

Tracking quality isn't part of the composite — see what we don't score for why.

Cost difference

SPAB is 3 bps cheaper than IUSB. On a $100,000 position that's about $30/yr more in fees for IUSB.

Fee figure is the annual expense charged on $100,000. To see how the gap compounds over a multi-decade holding period, open the cost calculator pre-filled with IUSB vs SPAB.

Top shared holdings

6,788 shared in total
# Holding In IUSB In SPAB Overlap
1 United States of America 0.35% 0.37% 0.35%
2 United States of America 0.34% 0.40% 0.34%
3 United States of America 0.36% 0.34% 0.34%
4 United States of America 0.34% 0.37% 0.34%
5 United States of America 0.34% 0.40% 0.34%
6 United States of America 0.33% 0.34% 0.33%
7 United States of America 0.33% 0.36% 0.33%
8 United States of America 0.33% 0.37% 0.33%
9 United States of America 0.32% 0.33% 0.32%
10 United States of America 0.29% 0.37% 0.29%
11 United States of America 0.28% 0.43% 0.28%
12 United States of America 0.29% 0.27% 0.27%

Only in IUSB

11,256 total
  • Federal National Mortgage Association or Federal Home Loan Mortgage Corp. 0.41%
  • Federal National Mortgage Association or Federal Home Loan Mortgage Corp. 0.31%
  • Federal National Mortgage Association or Federal Home Loan Mortgage Corp. 0.30%
  • United States of America 0.26%
  • Federal National Mortgage Association 0.26%
  • Federal National Mortgage Association or Federal Home Loan Mortgage Corp. 0.26%
  • United States of America 0.24%
  • Federal National Mortgage Association or Federal Home Loan Mortgage Corp. 0.22%
  • Government National Mortgage Association 0.19%
  • Government National Mortgage Association 0.18%

Only in SPAB

1,497 total
  • Government National Mortgage Association 0.28%
  • UMBS, TBA 0.27%
  • UMBS, TBA 0.23%
  • Government National Mortgage Association 0.21%
  • Freddie Mac 0.20%
  • Freddie Mac 0.20%
  • Freddie Mac 0.20%
  • Government National Mortgage Association 0.17%
  • Freddie Mac 0.17%
  • Freddie Mac 0.17%

Related comparisons

More comparisons with IUSB

More comparisons with SPAB

Percentages are holdings overlap with the named fund.

Open IUSB or SPAB at a brokerage

Both funds trade commission-free at major US brokerages.

Open at Fidelity

Affiliate links — opening an account through these earns PlainIndex a one-time referral. Scoring is computed before any affiliate consideration; see our methodology and funding disclosure.

Holdings overlap is the sum of min(weight_a, weight_b) over positions matched on ISIN (CUSIP fallback). Methodology: see /methodology/.

Comparing two funds doesn't endorse swapping one for the other. Tax-lot history, account type, and personal goals matter — PlainIndex publishes data and methodology, not investment advice.