IVOO vs MDYG: Holdings Overlap
IVOOVanguard S&P Mid-cap 400 Index Fund
Vanguard · 400 holdings · $3.9B · as of 2026-05-31
MDYGState Street® SPDR® S&P 400™ Mid Cap Growth ETF
State Street (SPDR) · 245 holdings · $2.9B · as of 2026-08-06
Holdings snapshots are 67 days apart (IVOO: 2026-05-31, MDYG: 2026-08-06). Weights and index membership change between snapshots, so the true current overlap is typically higher than shown. For funds tracking the same index, the gap can be 5–15 points.
How similar are IVOO and MDYG?
Vanguard S&P Mid-cap 400 Index Fund (IVOO, by Vanguard) holds 400 positions; State Street® SPDR® S&P 400™ Mid Cap Growth ETF (MDYG, by State Street (SPDR)) holds 245. They have 235 holdings in common, and by portfolio weight the two funds are 62.4% identical. In practical terms the pair is heavily overlapping, with largely the same stocks driving both funds.
- Overlap by Weight
- 62.4%Sum of the smaller weight of each shared holding
- Shared Holdings
- 235IVOO holds 400 · MDYG holds 245
- Weight in Shared Holdings
- IVOO 65%·MDYG 94%Share of each fund's weight in stocks both funds own
Based on each fund's latest official holdings. How is this calculated?
What makes each fund different
Only in IVOO
165 of 400 positions (35.2% of the fund) are not held by MDYG. Showing the top 30 by weight.
Sector Breakdown
| Sector | IVOO | MDYG |
|---|---|---|
| Industrials | 25.6% | 29.8% |
| Information Technology | 15.7% | 20.2% |
| Health Care | 8.7% | 15.5% |
| Financials | 14.3% | 8.0% |
| Consumer Discretionary | 11.1% | 9.0% |
| Other Sectors | 24.4% | 17.3% |
Share of each fund's portfolio weight by GICS-style sector, compiled from issuer fund data and our own classification of the holdings, not the issuers' published sector charts.
Performance
| Fund | 1M | YTD | 1Y | 3Y (ann.) | 5Y (ann.) | 10Y (ann.) | Yield |
|---|---|---|---|---|---|---|---|
| IVOO | +3.1% | +18.5% | +26.0% | +14.6% | +9.0% | +11.2% | 1.14% |
| MDYG | +3.3% | +21.6% | +28.0% | +16.0% | +8.5% | +11.3% | 0.56% |
Total returns including dividends, from adjusted daily closes as of 2026-08-07. 3Y/5Y/10Y are annualized. Yield is trailing-12-month distributions over the last close. Past performance does not predict future results.
Project the growth of $10,000 in IVOO vs MDYG →
Shared Holdings(235)
The top 10 shared positions account for 12% of the overlap, led by TWLO, FTI and CW.
 TWLOTwilio, Inc., Class A | 0.82% | 1.56% | 0.82% |
|---|---|---|---|
 FTITechnipFMC PLC USD1 | 0.79% | 1.48% | 0.79% |
 CWCurtiss-Wright Corporation | 0.79% | 1.41% | 0.79% |
 NVTNVent Electric PLC COM USD0.01 | 0.77% | 1.41% | 0.77% |
 STRLSterling Infrastructure Inc COM | 0.75% | 0.88% | 0.75% |
 XPOXPO Inc COM | 0.72% | 1.23% | 0.72% |
 PEverpure, Inc., Class A | 0.71% | 1.47% | 0.71% |
 ILMNIllumina Inc COM | 0.71% | 0.84% | 0.71% |
 UTHRUnited Therapeutics Corporation COM | 0.68% | 1.21% | 0.68% |
 ATIATI Inc COM | 0.68% | 1.63% | 0.68% |
 MTSIMACOM Technology Solutions Holdings Inc. COM | 0.67% | 1.06% | 0.67% |
 FNFabrinet COM USD0.01 | 0.67% | 1.04% | 0.67% |
 CRSCarpenter Technology Corporation COM | 0.67% | 1.48% | 0.67% |
 MTZMastec, Inc. COM | 0.66% | 0.85% | 0.66% |
 MKSIMKS Inc. COM | 0.62% | 0.74% | 0.62% |
 OKTAOkta Inc. Class A | 0.60% | 1.28% | 0.60% |
 WWDWoodward Inc. COM | 0.59% | 1.16% | 0.59% |
 BURLBurlington Stores Inc. COM | 0.57% | 0.76% | 0.57% |
 RBARB Global Inc COM | 0.56% | 0.92% | 0.56% |
 LSCCLattice Semiconductor Corporation COM | 0.57% | 0.55% | 0.55% |
 RGLDRoyal Gold, Inc. COM | 0.52% | 0.95% | 0.52% |
 RBCRBC Bearings Incorporated | 0.52% | 0.95% | 0.52% |
 TTMITTM Technologies Inc COM | 0.51% | 0.76% | 0.51% |
 BWXTBWX Technologies Inc. COM | 0.51% | 0.81% | 0.51% |
 NXTNextpower Inc. CLASS A COM | 0.66% | 0.51% | 0.51% |
Frequently Asked Questions
How much do IVOO and MDYG overlap?
IVOO and MDYG overlap by 62.4% of portfolio weight. They share 235 holdings (IVOO holds 400 positions and MDYG holds 245), based on each fund's latest SEC-reported holdings.
Is it redundant to own both IVOO and MDYG?
The two portfolios are 62.4% identical by weight. Owning both mostly doubles down on the shared core rather than diversifying: the same large positions drive both funds.
What are the biggest shared holdings of IVOO and MDYG?
The largest positions held by both funds are TWLO, FTI, CW, NVT and STRL. Together the top 10 shared positions account for 12% of the total overlap.
What does IVOO own that MDYG doesn't?
165 positions (35.2% of IVOO) are unique to IVOO, led by FLEX, AA and RS. In the other direction, 10 positions (5.9% of MDYG) are unique to MDYG.