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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
51.3 %

6,838 positions appear in both funds. Buying equal dollars of IUSB and SPAB would leave roughly 51.3% of each dollar exposed to the same underlying securities.

IUSB only 49.9% Shared 51.3% SPAB only 47.8%
In IUSB only
10,941 positions
Shared
6,838 positions
In SPAB only
1,490 positions

Side by side

IUSB

iShares Core Universal USD Bond ETF

iShares · US Aggregate Bond

88 composite / 100
Expense ratio
0.060%
Net assets
$42.77B
TTM yield
4.26%
Top-10 conc.
6.7%
SPAB

State Street SPDR Portfolio Aggregate Bond ETF

State Street · US Aggregate Bond

89 composite / 100
Expense ratio
0.030%
Net assets
$9.63B
TTM yield
4.08%
Top-10 conc.
9.3%

Sub-score comparison

94
Cost
97
52
Tax efficiency
52
100
Liquidity
99
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

6,838 shared in total
# Holding In IUSB In SPAB Overlap
1 United States of America 0.37% 0.36% 0.36%
2 United States of America 0.37% 0.36% 0.36%
3 United States of America 0.36% 0.37% 0.36%
4 United States of America 0.36% 0.37% 0.36%
5 United States of America 0.36% 0.39% 0.36%
6 United States of America 0.37% 0.35% 0.35%
7 United States of America 0.34% 0.37% 0.34%
8 United States of America 0.33% 0.42% 0.33%
9 United States of America 0.35% 0.33% 0.33%
10 United States of America 0.33% 0.34% 0.33%
11 United States of America 0.29% 0.29% 0.29%
12 United States of America 0.34% 0.28% 0.28%

Only in IUSB

10,941 total
  • Blackrock Liquidity Tempcash 2.88%
  • Federal National Mortgage Association 0.32%
  • Federal National Mortgage Association or Federal Home Loan Mortgage Corp. 0.22%
  • Government National Mortgage Association 0.21%
  • United States of America 0.21%
  • Federal National Mortgage Association or Federal Home Loan Mortgage Corp. 0.20%
  • Federal National Mortgage Association or Federal Home Loan Mortgage Corp. 0.19%
  • Government National Mortgage Association 0.18%
  • United States of America 0.15%
  • United States of America 0.14%

Only in SPAB

1,490 total
  • State Street Global Advisors 1.15%
  • UMBS, TBA 0.38%
  • Government National Mortgage Association 0.36%
  • Government National Mortgage Association 0.26%
  • Freddie Mac 0.22%
  • Freddie Mac 0.21%
  • Freddie Mac 0.19%
  • UMBS, TBA 0.19%
  • Government National Mortgage Association 0.18%
  • Freddie Mac 0.17%

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.