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
0 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
0 shared in totalNo shared holdings between these funds.
Only in MDY
401 total- Okta Inc. Class A 0.97%
- U.S. Dollar 0.96%
- TechnipFMC plc 0.76%
- United Therapeutics Corporation 0.73%
- US Foods Holding Corp. 0.66%
- XPO Inc. 0.64%
- ATI Inc 0.64%
- Tenet Healthcare Corporation 0.63%
- Reliance Inc. 0.62%
- Roku Inc. Class A 0.62%
Only in SPY
504 total- NVIDIA CORP 7.78%
- APPLE INC 7.70%
- MICROSOFT CORP 5.86%
- AMAZON.COM INC 3.72%
- ALPHABET INC CL A 2.88%
- BROADCOM INC 2.33%
- ALPHABET INC CL C 2.31%
- META PLATFORMS INC CLASS A 2.17%
- TESLA INC 1.60%
- ELI LILLY + CO 1.58%
Related comparisons
More comparisons with MDY
- MDY vs SPYM · State Street SPDR Portfolio S&P 500 ETF 0.0%
- MDY vs VOO · Vanguard S&P 500 ETF 0.0%
- MDY vs VTV · Vanguard Morningstar Value ETF 0.0%
- MDY vs IVOO · Vanguard S&P Mid-Cap 400 Index Fund ETF Shares 87.1%
- MDY vs SPMD · State Street SPDR Portfolio S&P 400 Mid Cap ETF 84.4%
- MDY vs IJH · iShares Core S&P Mid-Cap ETF 84.4%
More comparisons with SPY
- SPY vs SCHY · Schwab International Dividend Equity ETF 0.0%
- SPY vs SPSM · State Street SPDR Portfolio S&P 600 Small Cap ETF 0.0%
- SPY vs VIGI · Vanguard International Dividend Appreciation Index Fund ETF Shares 0.0%
- SPY vs VIOG · Vanguard S&P Small-Cap 600 Growth Index Fund ETF Shares 0.0%
- SPY vs VIOO · Vanguard S&P Small-Cap 600 Index Fund ETF Shares 0.0%
- SPY vs VIOV · Vanguard S&P Small-Cap 600 Value Index Fund ETF Shares 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.