MDY vs VB overlap - what they share and where they differ
MDY and VB share 42.3% of their weight across 386 common positions, read from what each fund reported to the SEC.
Each week Ploutos reads the reported positions of the largest US equity ETFs and measures, pair by pair, the weight they share: for every stock both funds hold, the smaller of the two weights counts. Two funds tracking the same index land near 100%. A sector fund inside a broad index fund lands at roughly that sector's weight.
MDY and VB
42.3%
386 shared positions
MDY
State Street SPDR S&P MidCap 400SM ETF Trust
Reported positions cover 99% of the fund, 400 positions · Jun 30, 2026
Top 10: 7.7%·Holdings of MDY
VB
VANGUARD SMALL-CAP INDEX FUND
Reported positions cover 100% of the fund, 1,274 positions · Jun 30, 2026
Top 10: 4.3%·Holdings of VB
Reported positions cover MDY 99%, VB 100% of each fund. An overlap cannot exceed the smaller coverage, so a low figure can mean little overlap or thin reporting.
VB vs MDY side by side
MDYState Street SPDR S&P MidCap 400SM ETF Trust
400
stock positions reported to the SEC
3.6% of its weight is in 14 names VB does not hold
VBVANGUARD SMALL-CAP INDEX FUND
1,274
stock positions reported to the SEC
57.6% of its weight is in 888 names MDY does not hold
Where each fund's weight sits
Largest sectors for both funds
The widest gap is Healthcare: VB has 2.4 points more of it.
The figures side by side
| MDY | VB | |
|---|---|---|
| Filing date | Jun 30, 2026 | Jun 30, 2026 |
| Stock positions reported | 400 | 1,274 |
| Weight of the ten largest | 7.7% | 4.3% |
| Largest position | TWLO 0.9% | CRDO 0.6% |
| Held alone | 14 positions, 3.6% | 888 positions, 57.6% |
| Covered by stock positions | 99% | 100% |
Holdings they share
| Stock | In MDY | In VB | Counted |
|---|---|---|---|
| TWLOTWILIO INC | 0.86% | 0.38% | 0.38% |
| MKSIMKS INC | 0.82% | 0.37% | 0.37% |
| CRSCARPENTER TECHNOLOGY CORP | 0.84% | 0.35% | 0.35% |
| CWCURTISS-WRIGHT CORP | 0.77% | 0.34% | 0.34% |
| ATIATI INC | 0.74% | 0.33% | 0.33% |
| ENTGENTEGRIS INC | 0.75% | 0.33% | 0.33% |
| NVENT ELECTRIC PLC | 0.75% | 0.33% | 0.33% |
| FTITECHNIPFMC PLC | 0.73% | 0.32% | 0.32% |
| MTSIMACOM TECHNOLOGY SOLUTIONS HOLDINGS INC | 0.68% | 0.32% | 0.32% |
| MTZMASTEC INC | 0.70% | 0.32% | 0.32% |
What each holds alone
The heaviest positions one fund reports and the other does not.
Only in MDY
Only in VB
Questions people ask
Is MDY the same as VB?
42.3% of their weight sits in the same 386 holdings. MDY also reports SGI, WPC, DICKS SPORTING GOODS INC, which the other does not. VB also reports CRDO, JBL, RVMD, which the other does not.
How is the overlap between MDY and VB measured?
For every stock both funds report, the smaller of the two weights counts, and the sum is the overlap. The reported positions cover 99% of MDY and 100% of VB, so the number cannot exceed the smaller coverage.
Which holds more, VB or MDY?
MDY reports 400 stock positions and VB reports 1,274. 3.6% of MDY's weight sits in names VB does not hold, and 57.6% of VB's weight in names MDY does not hold. The ten largest positions are 7.7% of MDY and 4.3% of VB.
How do MDY and VB differ by sector?
The widest gap is Healthcare: VB has 2.4 points more of it. Sectors come from each holding's SIC code in its SEC record, summed by the weight the fund reports.
Where do the numbers come from?
From each fund's own N-PORT filing to the SEC, which lists every position and its weight. The comparison uses every equity position the fund reports; cash, futures and bonds are not counted, which is why a coverage figure sits next to every result. Holdings change between filings.
Other pairs with these funds
MDY against other funds in the table
Add a third fund in the tool·All fund pairs
Descriptive data from public SEC filings. Nothing on this page is a recommendation to buy, sell or hold any fund or stock, and holdings change between filings.