ETF comparison
SPMB vs VMBS
Both US Aggregate Bond.
State Street SPDR Portfolio Mortgage Backed Bond Index ETF · Vanguard Mortgage-Backed Securities Index Fund ETF Shares
Holdings overlap
794 positions appear in both funds. Buying equal dollars of SPMB and VMBS would leave roughly 20.2% 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 1 bps cheaper than SPMB. On a $100,000 position that's about $10/yr more in fees for SPMB.
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 SPMB vs VMBS.
Top shared holdings
794 shared in total| # | Holding | In SPMB | In VMBS | Overlap |
|---|---|---|---|---|
| 1 | Government National Mortgage Association | 0.41% | 0.29% | 0.29% |
| 2 | Government National Mortgage Association | 0.42% | 0.27% | 0.27% |
| 3 | Freddie Mac | 0.42% | 0.25% | 0.25% |
| 4 | Government National Mortgage Association | 0.32% | 0.24% | 0.24% |
| 5 | Freddie Mac | 1.17% | 0.23% | 0.23% |
| 6 | Freddie Mac | 0.41% | 0.22% | 0.22% |
| 7 | Freddie Mac | 0.29% | 0.22% | 0.22% |
| 8 | Freddie Mac | 0.33% | 0.19% | 0.19% |
| 9 | Government National Mortgage Association | 0.28% | 0.19% | 0.19% |
| 10 | Freddie Mac | 0.35% | 0.18% | 0.18% |
| 11 | Government National Mortgage Association | 0.30% | 0.18% | 0.18% |
| 12 | Fannie Mae | 0.30% | 0.17% | 0.17% |
Only in SPMB
1,905 total- Fannie Mae 0.79%
- UMBS, TBA 0.63%
- Freddie Mac 0.61%
- Fannie Mae 0.49%
- Fannie Mae 0.47%
- UMBS, TBA 0.46%
- UMBS, TBA 0.45%
- Fannie Mae 0.45%
- Government National Mortgage Association 0.44%
- Freddie Mac 0.44%
Only in VMBS
4,068 total- Fannie Mae or Freddie Mac 0.33%
- Fannie Mae or Freddie Mac 0.30%
- Ginnie Mae II Pool 0.30%
- Ginnie Mae II Pool 0.28%
- Ginnie Mae II Pool 0.27%
- Fannie Mae Pool 0.27%
- Ginnie Mae II Pool 0.26%
- Fannie Mae or Freddie Mac 0.26%
- Freddie Mac Pool 0.26%
- Fannie Mae or Freddie Mac 0.25%
Related comparisons
More comparisons with SPMB
- SPMB vs SPAB · State Street SPDR Portfolio Aggregate Bond Index ETF 18.0%
- SPMB vs MBB · iShares MBS ETF 14.9%
- SPMB vs SCHZ · Schwab U.S. Aggregate Bond ETF 8.9%
- SPMB vs BND · Vanguard Total Bond Market Index Fund ETF Shares 5.9%
- SPMB vs AGG · iShares Core U.S. Aggregate Bond ETF 5.4%
- SPMB vs VCRB · Vanguard Core Bond ETF 4.9%
More comparisons with VMBS
- VMBS vs MBB · iShares MBS ETF 18.6%
- VMBS vs BND · Vanguard Total Bond Market Index Fund ETF Shares 15.6%
- VMBS vs SCHZ · Schwab U.S. Aggregate Bond ETF 11.0%
- VMBS vs SPAB · State Street SPDR Portfolio Aggregate Bond Index ETF 9.4%
- VMBS vs EAGG · iShares ESG U.S. Aggregate Bond ETF 7.7%
- VMBS vs AGG · iShares Core U.S. Aggregate Bond ETF 7.7%
Percentages are holdings overlap with the named fund.
Open SPMB 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.