ETF comparison
IUSB vs VMBS
Both US Aggregate Bond.
iShares Core Universal USD Bond ETF · Vanguard Mortgage-Backed Securities Index Fund ETF Shares
Holdings overlap
385 positions appear in both funds. Buying equal dollars of IUSB and VMBS would leave roughly 4.7% of each dollar exposed to the same underlying securities.
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.
Side by side
Sub-score comparison
Tracking quality isn't part of the composite — see what we don't score for why.
Cost difference
VMBS 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 VMBS.
Top shared holdings
385 shared in total| # | Holding | In IUSB | In VMBS | Overlap |
|---|---|---|---|---|
| 1 | Federal National Mortgage Association | 0.12% | 0.23% | 0.12% |
| 2 | Federal Home Loan Mortgage Corp. | 0.11% | 0.11% | 0.11% |
| 3 | Government National Mortgage Association | 0.18% | 0.10% | 0.10% |
| 4 | Government National Mortgage Association | 0.09% | 0.12% | 0.09% |
| 5 | Federal Home Loan Mortgage Corp. | 0.08% | 0.13% | 0.08% |
| 6 | Federal National Mortgage Association | 0.08% | 0.13% | 0.08% |
| 7 | Government National Mortgage Association | 0.08% | 0.12% | 0.08% |
| 8 | Government National Mortgage Association | 0.08% | 0.32% | 0.08% |
| 9 | Federal National Mortgage Association | 0.07% | 0.14% | 0.07% |
| 10 | Federal Home Loan Mortgage Corp. | 0.08% | 0.07% | 0.07% |
| 11 | Federal National Mortgage Association | 0.07% | 0.10% | 0.07% |
| 12 | Government National Mortgage Association | 0.07% | 0.14% | 0.07% |
Only in IUSB
17,659 total- Federal National Mortgage Association or Federal Home Loan Mortgage Corp. 0.41%
- United States of America 0.37%
- United States of America 0.37%
- United States of America 0.36%
- United States of America 0.35%
- United States of America 0.34%
- United States of America 0.34%
- United States of America 0.34%
- United States of America 0.33%
- United States of America 0.33%
Only in VMBS
4,727 total- Fannie Mae or Freddie Mac 0.52%
- Ginnie Mae II Pool 0.36%
- Ginnie Mae II Pool 0.31%
- Fannie Mae Pool 0.29%
- Ginnie Mae II Pool 0.29%
- Freddie Mac Pool 0.27%
- Freddie Mac Pool 0.27%
- Fannie Mae or Freddie Mac 0.25%
- Freddie Mac Pool 0.24%
- Freddie Mac Pool 0.24%
Related comparisons
More comparisons with IUSB
- IUSB vs NEAR · iShares Short Duration Bond Active ETF 4.1%
- IUSB vs TLT · iShares 20+ Year Treasury Bond ETF 4.1%
- IUSB vs BINC · iShares Flexible Income Active ETF 3.7%
- IUSB vs SPMB · State Street SPDR Portfolio Mortgage Backed Bond ETF 3.6%
- IUSB vs BOND · PIMCO Active Bond Exchange-Traded Fund 3.2%
- IUSB vs PYLD · PIMCO ETF Trust - PIMCO Multisector Bond Active Exchange-Traded Fund 1.8%
More comparisons with VMBS
- VMBS vs VCRB · Vanguard Core Bond ETF 4.6%
- VMBS vs FBND · Fidelity Total Bond ETF 4.5%
- VMBS vs CGCP · Capital Group Core Plus Income ETF 1.8%
- VMBS vs AGGY · WisdomTree Yield Enhanced U.S. Aggregate Bond Fund 1.8%
- VMBS vs JCPB · JPMorgan Core Plus Bond ETF 1.1%
- VMBS vs BOND · PIMCO Active Bond Exchange-Traded Fund 0.8%
Percentages are holdings overlap with the named fund.
Open IUSB or VMBS at a brokerage
Both funds trade commission-free at major US brokerages.
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.