MDY vs MTUM: Correlation & Overlap
How closely do SPDR S&P MidCap 400 ETF (MDY) and iShares MSCI USA Momentum Factor ETF (MTUM) trade together? Their weekly returns over three years give a correlation of 0.72, which is strong. By holdings, the two funds overlap 1.1% by weight.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are MDY and MTUM?
On 3 years of weekly data the MDY/MTUM correlation comes out at 0.72, strong. The link has loosened recently: the 1-year correlation (0.61) runs below the 3-year figure (0.72). The 5-year figure is 0.75, and annualized covariance runs at 242.8 %².
Within MDY's tracked universe of 359 assets, MTUM comes in at #48 by 3-year correlation. The trailing year gives MTUM the advantage: +18.3% versus +25.2%, a 6.9-point spread. The rolling one-year correlation moved between 0.57 and 0.89 over the past three years, a moderate range.
How is this computed?
Pearson correlation on weekly returns: ρ(A,B) = cov(rA, rB) / (σA · σB), over windows of 52, 156 and 260 weeks. Covariance is annualized (×52) and expressed in %². Full definitions on the methodology page.
MDY vs MTUM: side by side
| MDY (SPDR S&P MidCap 400 ETF) | MTUM (iShares MSCI USA Momentum Factor ETF) | |
|---|---|---|
| 1-year return | +18.3% | +25.2% |
| 5-year return | +47.5% | +76.1% |
| Volatility (ann.) | 16.5% | 20.6% |
| Beta vs S&P 500 | 0.91 | 1.25 |
| Max drawdown (3Y) | -24.0% | -21.0% |
| Dividend yield | 1.02% | 0.62% |
| Expense ratio | 0.23% | 0.15% |
| Assets under management | $26.5B | $25.3B |
| Sector / category | ETF · US Small & Mid Cap | ETF · US Style |
On the fund side, MDY sits in the Mid-Cap Blend category at State Street Investment Management, with $26.5B under management, 400 holdings, a 0.23% expense ratio, a 1.02% trailing dividend yield. MTUM is a Large Blend fund from iShares: $25.3B under management, 126 holdings, a 0.15% expense ratio, a 0.62% trailing dividend yield.
Portfolio overlap between MDY and MTUM
The two portfolios are largely distinct, with 8 holdings in common adding up to 1.1% of fund weight. Where correlation shows the co-movement, the overlap shows its source.
| Common holding | Weight in MDY | Weight in MTUM |
|---|---|---|
| FTI | 0.83% | 0.28% |
| CW | 0.63% | 0.14% |
| MTZ | 0.42% | 0.14% |
| XPO | 0.62% | 0.12% |
| ENTG | 0.60% | 0.11% |
| FN | 0.43% | 0.10% |
| UTHR | 0.60% | 0.10% |
| SN | 0.37% | 0.07% |
Largest positions held only by MDY: TWLO (0.95%), P (0.94%), ILMN (0.93%), ATI (0.80%), NVT (0.69%). Only by MTUM: MU (6.60%), AMD (5.09%), AVGO (4.25%), INTC (3.91%), XOM (3.78%).
Overlap = sum of the smaller of the two weights across common holdings, from issuer disclosures as of 2026-08-26. Top 8 common positions shown.
Year-by-year returns
| Year | MDY | MTUM |
|---|---|---|
| 2022 | -13.3% | -18.3% |
| 2023 | +16.1% | +9.1% |
| 2024 | +13.6% | +32.9% |
| 2025 | +7.2% | +22.1% |
| 2026 | +16.4% | +21.8% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Are MDY and MTUM good diversifiers for each other?
Only partially. A correlation of 0.72 means MDY and MTUM share most of their swings. Pairing them dampens volatility somewhat, but it will not protect against a common drawdown.
FAQ
What is the correlation between MDY and MTUM?
The MDY/MTUM correlation stands at 0.72 on a 3-year window (1 year: 0.61, 5 years: 0.75), computed from weekly returns as of 2026-08-27.
Is MTUM a good diversifier for MDY?
Only partially. A correlation of 0.72 means MDY and MTUM share most of their swings. Pairing them dampens volatility somewhat, but it will not protect against a common drawdown.
How much do MDY and MTUM overlap?
Per the issuers' own portfolio disclosures (2026-08-26), the overlap is 1.1% by weight over 8 common positions.
Use this data
$ curl https://www.pairbook.io/api/v1/pairs/mdy-vs-mtum.json
Markdown for the live badge, attribution link included:
[](https://www.pairbook.io/pair/mdy-vs-mtum/)
Free with attribution; caching and terms are described in the API documentation.
Related comparisons
Hubs: MDY correlations · MTUM correlations
