ETF comparison
MDY vs SPY
US Mid Cap vs US Large Cap.
State Street SPDR S&P MIDCAP 400 ETF Trust · State Street SPDR S&P 500 ETF Trust
Holdings overlap
1 positions appear in both funds. Buying equal dollars of MDY and SPY would leave roughly 0.0% 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
SPY is 14 bps cheaper than MDY. On a $100,000 position that's about $136/yr more in fees for MDY.
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 MDY vs SPY.
Top shared holdings
1 shared in total| # | Holding | In MDY | In SPY | Overlap |
|---|---|---|---|---|
| 1 | Fox Corporation Class A | 0.25% | 0.02% | 0.02% |
Only in MDY
400 total- U.S. Dollar 1.09%
- ATI Inc 0.72%
- TechnipFMC plc 0.72%
- United Therapeutics Corporation 0.72%
- Royal Gold Inc. 0.69%
- US Foods Holding Corp. 0.68%
- Tenet Healthcare Corporation 0.67%
- Roivant Sciences Ltd. 0.63%
- XPO Inc. 0.63%
- Reliance Inc. 0.62%
Only in SPY
503 total- APPLE INC 7.86%
- NVIDIA CORP 6.64%
- MICROSOFT CORP 6.21%
- AMAZON.COM INC 4.02%
- ALPHABET INC CL A 2.60%
- BROADCOM INC 2.33%
- META PLATFORMS INC CLASS A 2.17%
- ALPHABET INC CL C 2.09%
- ELI LILLY + CO 1.73%
- BERKSHIRE HATHAWAY INC CL B 1.64%
Related comparisons
More comparisons with MDY
- MDY vs QQQ · Invesco QQQ Trust 0.0%
- MDY vs IVOO · Vanguard S&P Mid-Cap 400 Index Fund ETF Shares 91.4%
- MDY vs SPMD · State Street SPDR Portfolio S&P 400 Mid Cap ETF 81.5%
- MDY vs IJH · iShares Core S&P Mid-Cap ETF 81.4%
- MDY vs IJJ · iShares S&P Mid-Cap 400 Value ETF 58.9%
- MDY vs BBMC · JPMorgan BetaBuilders U.S. Mid Cap Equity ETF 54.8%
More comparisons with SPY
- SPY vs AVUV · Avantis US Small Cap Value ETF 0.0%
- SPY vs BBSC · JPMorgan BetaBuilders U.S. Small Cap Equity ETF 0.0%
- SPY vs DEM · WisdomTree Emerging Markets High Dividend Fund 0.0%
- SPY vs DGS · WisdomTree Emerging Markets SmallCap Dividend Fund 0.0%
- SPY vs DVYE · iShares Emerging Markets Dividend ETF 0.0%
- SPY vs EEMV · iShares MSCI Emerging Markets Min Vol Factor ETF 0.0%
Percentages are holdings overlap with the named fund.
Open MDY or SPY 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.