Data as of Sep 12, 2026. Both funds on the fields they both publish, from the same sources.
MBB vs VBK: how they differ
MBB and VBK hold 0% of their weight in the same names, and VBK returned more over the year.
iShares MBS ETF and Vanguard Small-Cap Growth Index Fund.
What they hold in common
By the books each fund has filed, MBB and VBK hold 0% of their money in the same securities at the same weight.
| Only in MBB | Only in VBK |
|---|---|
| Freddie Mac 1.07% | Credo Technology Group Holding Ltd 1.27% |
| Government National Mortgage Association 0.97% | REVOLUTION Medicines Inc 1.07% |
| UMBS, TBA 0.85% | Astera Labs Inc 1.05% |
| Government National Mortgage Association 0.69% | Natera Inc 1.04% |
| UMBS, TBA 0.66% | Twilio Inc 0.88% |
| Government National Mortgage Association 0.56% | Casey's General Stores Inc 0.83% |
| Government National Mortgage Association 0.55% | Carpenter Technology Corp 0.82% |
| Government National Mortgage Association 0.54% | Curtiss-Wright Corp 0.79% |
Weight overlap is an ETFIQ calculation: for every security both funds hold, the smaller of the two weights, summed. Above 50%, holding both is close to holding one of them twice. Holdings dated Jun 30, 2026 and May 31, 2026.
| MBB iShares MBS ETF | VBK Vanguard Small-Cap Growth Index Fund | |
|---|---|---|
| Where it sits | Core index fund | Core index fund |
| Issuer | iShares | Vanguard |
| What it is | Mbs | Small-Cap Growth |
| Total return, 1 year | −0.1% | +13.8% |
| S&P 500 over the same days | +17.5% | +17.5% |
| Gap to the S&P 500 | −17.6 pts | −3.7 pts |
| Expense ratio | 0.04% | 0.05% |
| Holdings | 11144 | 545 |
MBB in plain words
MBB is a bond fund tracking the Mbs. Over the year to Sep 11, 2026 it returned −0.1% with distributions reinvested, against +17.5% for the S&P 500 and +23.0% for the Nasdaq-100. The prospectus expense ratio is 0.04% a year. It sat 3.3% below its high of Feb 27, 2026 on Sep 11, 2026.
VBK in plain words
VBK is an index equity fund tracking the Small-Cap Growth. Over the year to Sep 11, 2026 it returned +13.8% with distributions reinvested, against +17.5% for the S&P 500 and +23.0% for the Nasdaq-100. The prospectus expense ratio is 0.05% a year. By its holdings filed for Jun 30, 2026, 10% of the fund by weight is stocks the S&P 500 also holds, across 545 positions, with the top ten at 9.3%. It sat 7.0% below its high of Aug 17, 2026 on Sep 11, 2026.
Questions people ask
- Which returned more over the last year, MBB or VBK?
- In the year to Sep 12, 2026, with distributions reinvested, MBB returned −0.1% and VBK returned +13.8%, so VBK returned more. One year is one year; the longer windows are in the table.
- Which is cheaper, MBB or VBK?
- MBB charges 0.04% a year and VBK charges 0.05%, so MBB is cheaper. Fees come from each fund's prospectus.
Other comparisons
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Where these figures came from
ETFIQ links to the documents behind every figure. It is not affiliated with any issuer, and a link is not an endorsement.
Cite this page. ETFIQ, MBB against VBK, data as of Sep 12, 2026. https://etfiq.com/compare/any/MBB-VBK Free to use with attribution; the underlying files are at Open data.
A comparison is not a recommendation. Standards and sources