SPMD vs MDY: Holdings Overlap
SPMDState Street® SPDR® Portfolio S&P 400™ Mid Cap ETF
State Street (SPDR) · 399 holdings · $18.5B · as of 2026-08-06
MDYState Street® SPDR® S&P MIDCAP 400® ETF Trust
State Street (SPDR) · 399 holdings · $27.1B · as of 2026-08-06
How similar are SPMD and MDY?
State Street® SPDR® Portfolio S&P 400™ Mid Cap ETF (SPMD, by State Street (SPDR)) holds 399 positions; State Street® SPDR® S&P MIDCAP 400® ETF Trust (MDY, by State Street (SPDR)) holds 399. They have 399 holdings in common, and by portfolio weight the two funds are 105.1% identical. In practical terms the pair is essentially interchangeable, so holding both adds little diversification.
- Overlap by Weight
- 105.1%Sum of the smaller weight of each shared holding
- Shared Holdings
- 399SPMD holds 399 · MDY holds 399
- Weight in Shared Holdings
- SPMD 106%·MDY 105%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 SPMD
Every position in SPMD is also held by MDY, so it brings nothing the other fund doesn’t already own.
Only in MDY
Every position in MDY is also held by SPMD, so it brings nothing the other fund doesn’t already own.
Sector Breakdown
| Sector | SPMD | MDY |
|---|---|---|
| Industrials | 26.0% | 25.9% |
| Financials | 16.1% | 16.0% |
| Information Technology | 15.7% | 15.6% |
| Consumer Discretionary | 11.7% | 11.6% |
| Health Care | 10.3% | 10.3% |
| Other Sectors | 25.8% | 25.7% |
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 |
|---|---|---|---|---|---|---|---|
| SPMD | +3.1% | +18.5% | +26.0% | +14.6% | +9.1% | +11.3% | 1.19% |
| MDY | +3.1% | +18.1% | +25.6% | +14.2% | +8.8% | +10.9% | 0.99% |
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 SPMD vs MDY →
Shared Holdings(399)
The top 10 shared positions account for 7% of the overlap, led by ATI, TWLO and ILMN.
 ATIATI Inc COM | 0.84% | 0.83% | 0.83% |
|---|---|---|---|
 TWLOTwilio, Inc., Class A | 0.81% | 0.80% | 0.80% |
 ILMNIllumina Inc COM | 0.81% | 0.80% | 0.80% |
 FTITechnipFMC PLC USD1 | 0.76% | 0.76% | 0.76% |
 CRSCarpenter Technology Corporation COM | 0.76% | 0.76% | 0.76% |
 PEverpure, Inc., Class A | 0.76% | 0.75% | 0.75% |
 NVTNVent Electric PLC COM USD0.01 | 0.73% | 0.72% | 0.72% |
 CWCurtiss-Wright Corporation | 0.73% | 0.72% | 0.72% |
 FIVEFive Below Inc COM | 0.69% | 0.68% | 0.68% |
 AAAlcoa Corporation COM | 0.68% | 0.68% | 0.68% |
 BJBJ's Wholesale Club Holdings, Inc. | 0.68% | 0.67% | 0.67% |
 SNSharkninja Inc. COM SHS | 0.67% | 0.67% | 0.67% |
 SMTCSemtech Corporation COM | 0.67% | 0.67% | 0.67% |
 FHNFirst Horizon Corporation COM | 0.67% | 0.67% | 0.67% |
 DYDycom Industries, Inc. COM | 0.67% | 0.67% | 0.67% |
 EVREvercore, Inc., Class A | 0.67% | 0.66% | 0.66% |
 OKTAOkta Inc. Class A | 0.66% | 0.66% | 0.66% |
 OCOwens Corning COM | 0.65% | 0.65% | 0.65% |
 USFDUS Foods Holding Corp COM | 0.65% | 0.64% | 0.64% |
 BMRNBiomarin Pharmaceutical Inc. COM | 0.65% | 0.64% | 0.64% |
 PINSPinterest, Inc., Class A | 0.64% | 0.64% | 0.64% |
 SCIService Corporation International COM | 0.64% | 0.64% | 0.64% |
 BURLBurlington Stores Inc. COM | 0.64% | 0.64% | 0.64% |
 LFUSLittelfuse Inc. COM | 0.64% | 0.64% | 0.64% |
 MOG-AMoog, Inc., Class A | 0.64% | 0.64% | 0.64% |
Showing the top 250 of 399 shared holdings by overlap weight.
Frequently Asked Questions
How much do SPMD and MDY overlap?
SPMD and MDY overlap by 105.1% of portfolio weight. They share 399 holdings (SPMD holds 399 positions and MDY holds 399), based on each fund's latest SEC-reported holdings.
Is it redundant to own both SPMD and MDY?
The two portfolios are 105.1% identical by weight. Owning both is largely redundant: they are close to the same portfolio, so a second position mostly duplicates the first.
What are the biggest shared holdings of SPMD and MDY?
The largest positions held by both funds are ATI, TWLO, ILMN, FTI and CRS. Together the top 10 shared positions account for 7% of the total overlap.
What does SPMD own that MDY doesn't?
Nothing. Every position in SPMD is also held by MDY. In the other direction, 0 positions (0.0% of MDY) are unique to MDY.